Characterization and antimicrobial resistance of Moraxella ovis
isolates from clinical cases of contagious ovine keratoconjunctivitis
in Mexico
Caracterización y resistencia antimicrobiana de aislamientos de Moraxella ovis de casos clínicos de
queratoconjuntivitis contagiosa ovina en México
Caracterização e resistência antimicrobiana de Moraxella ovis isolados de casos clínicos de
ceratoconjuntivite contagiosa ovina no México
Giovany Ortiz-Arana1 ; Martín Talavera-Rojas1 ; Edgardo Soriano-Vargas1 ; Erika-Gabriela Palomares-Reséndiz2 ;
Edgar Enríquez-Gómez1 ; Celene Salgado-Miranda1 ; Jorge Acosta-Dibarrat1* .
1Centro de Investigación y Estudios Avanzados en Salud Animal. Facultad de Medicina Veterinaria y Zootecnia. Universidad Autónoma del Estado
de México, México.
2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias Centro Nacional de Investigación Disciplinaria Salud Animal e Inocuidad
Ciudad de México, México.
To cite this article:
Ortiz-Arana G, Talavera-Rojas M, Soriano-Vargas E, Palomares-Reséndiz EG, Enríquez-Gómez E, Salgado-Miranda C, Acosta-
Dibarrat J. Characterization and antimicrobial resistance of Moraxella ovis isolates from clinical cases of contagious ovine
keratoconjunctivitis in Mexico. Rev Colomb Cienc Pecu 2024; 37(1):14–26. https://doi.org/10.17533/udea.rccp.v37n1a4
Abstract
Background: Contagious ovine keratoconjunctivitis (OKC) causes blindness in sheep and goats and it is associated with
a set of bacterial genera of which some species show antimicrobial resistance. Objective: To identify phenotypic-genotypic
relationship of antimicrobial resistance from Moraxella spp. isolates obtained from clinical cases of contagious ovine
keratoconjunctivitis (OKC) in Mexico. Methods: A total of 209 samples were obtained from clinical cases of OKC in sheep
and 60 Moraxella ovis isolates were identified by bacteriological techniques and amplification of 16s rRNA and rtxA genes by
PCR. All isolates were evaluated in terms of antimicrobial resistance by the disk diffusion susceptibility test and amplification
of resistance genes by PCR. Results: We found 14 Moraxella ovis isolates with antimicrobial resistance (AMR) and five
multiresistant (MDR). The sul1, sul2, tetB, qnrA, qnrB, BlaTEM genes of antimicrobial resistance were amplified, while gene
floR was not amplified. Conclusion: This is the first isolation report of Moraxella ovis from ocular lesions in sheep in the
State of Mexico, with six antimicrobial resistance genes identified. Results suggest that Moraxella ovis plays an important
role in the course of the disease and provides a panorama for molecular epidemiological surveillance and bacterial resistance.
Received: March 22, 2023. Accepted: May 1, 2023
*Corresponding author. Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia,
Universidad Autónoma del Estado de México. Phone. +52 (722) 2925548. E-mail: jpacosta00@hotmail.com
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, which permits unrestricted reuse,
distribution, and reproduction in any medium, provided the original work is properly cited.
eISSN: 2256-2958 Rev Colomb Cienc Pecu 2023; 37(1, Jan-Mar):14–26
https://doi.org/10.17533/udea.rccp.v37n1a4
© 2024 Universidad de Antioquia. Publicado por Universidad de Antioquia, Colombia.
isolates from clinical cases of contagious ovine keratoconjunctivitis
in Mexico
Caracterización y resistencia antimicrobiana de aislamientos de Moraxella ovis de casos clínicos de
queratoconjuntivitis contagiosa ovina en México
Caracterização e resistência antimicrobiana de Moraxella ovis isolados de casos clínicos de
ceratoconjuntivite contagiosa ovina no México
Giovany Ortiz-Arana1 ; Martín Talavera-Rojas1 ; Edgardo Soriano-Vargas1 ; Erika-Gabriela Palomares-Reséndiz2 ;
Edgar Enríquez-Gómez1 ; Celene Salgado-Miranda1 ; Jorge Acosta-Dibarrat1* .
1Centro de Investigación y Estudios Avanzados en Salud Animal. Facultad de Medicina Veterinaria y Zootecnia. Universidad Autónoma del Estado
de México, México.
2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias Centro Nacional de Investigación Disciplinaria Salud Animal e Inocuidad
Ciudad de México, México.
To cite this article:
Ortiz-Arana G, Talavera-Rojas M, Soriano-Vargas E, Palomares-Reséndiz EG, Enríquez-Gómez E, Salgado-Miranda C, Acosta-
Dibarrat J. Characterization and antimicrobial resistance of Moraxella ovis isolates from clinical cases of contagious ovine
keratoconjunctivitis in Mexico. Rev Colomb Cienc Pecu 2024; 37(1):14–26. https://doi.org/10.17533/udea.rccp.v37n1a4
Abstract
Background: Contagious ovine keratoconjunctivitis (OKC) causes blindness in sheep and goats and it is associated with
a set of bacterial genera of which some species show antimicrobial resistance. Objective: To identify phenotypic-genotypic
relationship of antimicrobial resistance from Moraxella spp. isolates obtained from clinical cases of contagious ovine
keratoconjunctivitis (OKC) in Mexico. Methods: A total of 209 samples were obtained from clinical cases of OKC in sheep
and 60 Moraxella ovis isolates were identified by bacteriological techniques and amplification of 16s rRNA and rtxA genes by
PCR. All isolates were evaluated in terms of antimicrobial resistance by the disk diffusion susceptibility test and amplification
of resistance genes by PCR. Results: We found 14 Moraxella ovis isolates with antimicrobial resistance (AMR) and five
multiresistant (MDR). The sul1, sul2, tetB, qnrA, qnrB, BlaTEM genes of antimicrobial resistance were amplified, while gene
floR was not amplified. Conclusion: This is the first isolation report of Moraxella ovis from ocular lesions in sheep in the
State of Mexico, with six antimicrobial resistance genes identified. Results suggest that Moraxella ovis plays an important
role in the course of the disease and provides a panorama for molecular epidemiological surveillance and bacterial resistance.
Received: March 22, 2023. Accepted: May 1, 2023
*Corresponding author. Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia,
Universidad Autónoma del Estado de México. Phone. +52 (722) 2925548. E-mail: jpacosta00@hotmail.com
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, which permits unrestricted reuse,
distribution, and reproduction in any medium, provided the original work is properly cited.
eISSN: 2256-2958 Rev Colomb Cienc Pecu 2023; 37(1, Jan-Mar):14–26
https://doi.org/10.17533/udea.rccp.v37n1a4
© 2024 Universidad de Antioquia. Publicado por Universidad de Antioquia, Colombia.
15Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Keywords: antimicrobial resistance; contagious ovine keratoconjunctivitis; epidemiological surveillance; goat;
Moraxella spp.; multiresistance; resistance genes; sheep.
Resumen
Antecedentes: La queratoconjuntivitis contagiosa ovina (OKC) causa ceguera temporal o permanente en ovinos y caprinos
y está asociada a un conjunto de géneros bacterianos, algunos de los cuales muestran resistencia antimicrobiana. Objetivo:
Identificar la relación fenotípica-genotípica de la resistencia antimicrobiana de aislamientos Moraxella ovis obtenidos de
casos clínicos de queratoconjuntivitis contagiosa ovina (OKC) en México. Métodos: Se obtuvieron un total de 209 muestras
de casos clínicos de OKC en ovinos y se identificaron 60 aislamientos de Moraxella ovis por técnicas bacteriológicas y
amplificación de genes 16s rRNA y rtxA por PCR. En todos los aislamientos se evaluó resistencia antimicrobiana mediante
prueba de susceptibilidad de difusión en disco y amplificación de genes de resistencia por PCR. Resultados: Se encontraron
14 aislamientos de Moraxella ovis con resistencia antimicrobiana (AMR) y cinco multirresistentes (MDR). Los genes de
resistencia antimicrobiana sul1, sul2, tetB, qnrA, qnrB, BlaTEM fueron amplificados, mientras que el gen floR no fue amplificado.
Conclusión: Este es el primer reporte de aislamiento de M. ovis en lesiones oculares en ovinos en el Estado de México, con seis
genes de resistencia antimicrobiana identificados. Nuestros resultados sugieren que Moraxella ovis juega un papel importante
en el curso de la enfermedad y brinda un panorama para su vigilancia epidemiológica molecular y resistencia bacteriana.
Palabras clave: cabra; genes de resistencia; Moraxella spp.; multirresistencia; oveja; queratoconjuntivitis contagiosa
ovina; resistencia antimicrobiana; vigilancia epidemiológica.
Resumo
Antecedentes: A ceratoconjuntivite contagiosa ovina (OKC) é uma doença infeccioso contagioso que causa cegueira
temporária ou permanente em ovinos e caprinos, esta doença está associada a um conjunto de gêneros bacterianos dos quais
alguns deles relataram resistência antimicrobiana. Objetivo: O objetivo deste estudo foi identificar a relação fenotípica-
genotípica da resistência antimicrobiana de Moraxella spp. isolados obtidos de casos clínicos de ceratoconjuntivite contagiosa
ovina (OKC) no estado do México. Métodos: Um total de 209 amostras foram obtidas de casos clínicos de OKC em ovinos.e
obtidos e 60 isolados de Moraxella ovis foram identificados por técnicas bacteriológicas e amplificação dos genes 16s rRNA e
rtxA por PCR. Todos os isolados foram avaliados quanto à resistência antimicrobiana pelo método de teste de suscetibilidade
à difusão em disco e pela amplificação de genes de resistência por PCR respectivamente. Resultados: Determinamos 14
isolados de Moraxella ovis com resistência antimicrobiana (AMR) e cinco multirresistentes (MDR) e amplificou os genes de
resistência antimicrobiana sul1, sul2, tetB, qnrA, qnrB, BlaTEM e não amplificou o gene floR. Conclusão: É o primeiro relato de
isolamento de Moraxella. ovis em lesões oculares em ovinos no Estado do México e a identificação de seis genes de resistência
antimicrobiana. Sugere-se que Moraxella ovis. desempenha um papel importante no curso da doença e fornece um panorama
de interesse em vigilância epidemiológica molecular e resistência bacteriana.
Palavras-chave: cabra; genes de resistência; Moraxella spp.; multirresistência; ovelha; ceratoconjuntivite contagiosa
ovina; resistência antimicrobiana; vigilância epidemiológica.
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Keywords: antimicrobial resistance; contagious ovine keratoconjunctivitis; epidemiological surveillance; goat;
Moraxella spp.; multiresistance; resistance genes; sheep.
Resumen
Antecedentes: La queratoconjuntivitis contagiosa ovina (OKC) causa ceguera temporal o permanente en ovinos y caprinos
y está asociada a un conjunto de géneros bacterianos, algunos de los cuales muestran resistencia antimicrobiana. Objetivo:
Identificar la relación fenotípica-genotípica de la resistencia antimicrobiana de aislamientos Moraxella ovis obtenidos de
casos clínicos de queratoconjuntivitis contagiosa ovina (OKC) en México. Métodos: Se obtuvieron un total de 209 muestras
de casos clínicos de OKC en ovinos y se identificaron 60 aislamientos de Moraxella ovis por técnicas bacteriológicas y
amplificación de genes 16s rRNA y rtxA por PCR. En todos los aislamientos se evaluó resistencia antimicrobiana mediante
prueba de susceptibilidad de difusión en disco y amplificación de genes de resistencia por PCR. Resultados: Se encontraron
14 aislamientos de Moraxella ovis con resistencia antimicrobiana (AMR) y cinco multirresistentes (MDR). Los genes de
resistencia antimicrobiana sul1, sul2, tetB, qnrA, qnrB, BlaTEM fueron amplificados, mientras que el gen floR no fue amplificado.
Conclusión: Este es el primer reporte de aislamiento de M. ovis en lesiones oculares en ovinos en el Estado de México, con seis
genes de resistencia antimicrobiana identificados. Nuestros resultados sugieren que Moraxella ovis juega un papel importante
en el curso de la enfermedad y brinda un panorama para su vigilancia epidemiológica molecular y resistencia bacteriana.
Palabras clave: cabra; genes de resistencia; Moraxella spp.; multirresistencia; oveja; queratoconjuntivitis contagiosa
ovina; resistencia antimicrobiana; vigilancia epidemiológica.
Resumo
Antecedentes: A ceratoconjuntivite contagiosa ovina (OKC) é uma doença infeccioso contagioso que causa cegueira
temporária ou permanente em ovinos e caprinos, esta doença está associada a um conjunto de gêneros bacterianos dos quais
alguns deles relataram resistência antimicrobiana. Objetivo: O objetivo deste estudo foi identificar a relação fenotípica-
genotípica da resistência antimicrobiana de Moraxella spp. isolados obtidos de casos clínicos de ceratoconjuntivite contagiosa
ovina (OKC) no estado do México. Métodos: Um total de 209 amostras foram obtidas de casos clínicos de OKC em ovinos.e
obtidos e 60 isolados de Moraxella ovis foram identificados por técnicas bacteriológicas e amplificação dos genes 16s rRNA e
rtxA por PCR. Todos os isolados foram avaliados quanto à resistência antimicrobiana pelo método de teste de suscetibilidade
à difusão em disco e pela amplificação de genes de resistência por PCR respectivamente. Resultados: Determinamos 14
isolados de Moraxella ovis com resistência antimicrobiana (AMR) e cinco multirresistentes (MDR) e amplificou os genes de
resistência antimicrobiana sul1, sul2, tetB, qnrA, qnrB, BlaTEM e não amplificou o gene floR. Conclusão: É o primeiro relato de
isolamento de Moraxella. ovis em lesões oculares em ovinos no Estado do México e a identificação de seis genes de resistência
antimicrobiana. Sugere-se que Moraxella ovis. desempenha um papel importante no curso da doença e fornece um panorama
de interesse em vigilância epidemiológica molecular e resistência bacteriana.
Palavras-chave: cabra; genes de resistência; Moraxella spp.; multirresistência; ovelha; ceratoconjuntivite contagiosa
ovina; resistência antimicrobiana; vigilância epidemiológica.
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2616
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Introduction
Contagious ovine keratoconjunctivitis (OKC)
is a disease that causes temporary or permanent
blindness in sheep and goats. Its clinical signs
range from conjunctivitis to corneal ulcers.
Several bacterial pathogens have been isolated
from OKC, such as Moraxella, Mycoplasma,
and Chlamydia (Akerstedt and Hofshagen, 2004;
Gupta et al., 2014; Jelocnik et al., 2019). However,
three species of the genus Moraxella have been
associated with infectious keratoconjunctivitis
in large and small ruminants, such as Mor. ovis
(Dagnall, 1994a), Mor. bovis (Karthik et al.,
2017) and Mor. bovoculi (Farias et al., 2015). The
differential biochemical tests of Moraxella species
are phenylalaninedeaminase and gelatinase tests,
although they may be inconsistent. Molecular tests
are based on the amplification of 16s-23S rRNA
genes ISR (Shen et al., 2011; O’Connor et al.,
2012; Sosa and Zunino, 2013) and the rxtA gene
that encodes cytotoxin A (Farias et al., 2015).
Keratoconjunctivitis treatment is based
on systemic or local antimicrobials such as
tetracyclines, sulfonamides, chloramphenicol, and
tulathromycin (Alexander, 2010; Maboni et al.,
2015), although several Moraxella species have
shown resistance to those antimicrobials (Catry
et al., 2007; Loy and Brodersen, 2014; Maboni et
al., 2015). Antimicrobial resistance is associated
with the presence of genes within the bacterial
genome such as tet and otr that confer resistance
to tetracyclines (Martí et al., 2006; Mosquito
et al., 2011) sul and dfr that confer resistance to
sulfonamides and trimethoprim (Kerrn et al.,
2002; Ho et al., 2009), cat, cmlA, and floR that
confer resistance to phenicols (Schwarz et al.,
2004; Chiu et al., 2006), mph and msr that confer
resistance to macrolides and lincosamides (Lüthje
and Schwarz, 2006), BlaTEM, BlaRob and BlaCARB
that confer resistance to betalactamases (Bush
and Jacoby, 2010; Dallenne et al., 2010) and qnr,
gyr, and par that confer resistance to quinolones
(Cattoir et al., 2007; Jacoby et al., 2008). Genes
such as tetH, sul2, floR, blaRob-1, srt, (3´)-Ic, mph
and msr, have been described in the genome within
a pathogenicity island in Mor. bovoculi (Dickey
et al., 2016) although no other studies have been
reported. Hence, the aim of the present study was to
isolate Moraxella spp. from ocular lesions in sheep
in the State of Mexico (Mexico) and phenotypic-
genotypic characterization of the antimicrobial
resistance to understand the pathogenesis of these
microorganisms in the disease.
Materials and Methods
The experimental protocol was approved by the
Review Commission of the Internal Committee
for the Care of Laboratory Animals - Teaching,
Research, Service and Production of Facultad de
Medicina Veterinaria y Zootecnia, Universidad
Autónoma (State of Mexico, Mexico) (CICUAL-
DISP FMVZ).
Bacteriological sampling and isolation
Sample size was calculated considering
the clinical cases of OKC through the finite
population sampling formula (Jaramillo, 2009).
A pilot sampling was used for estimating the
p indicator, obtaining a prevalence of 0.23
(107/454), and estimating 209 samples. Samples
(n=209) were collected from a total of 845
clinically healthy sheep with ocular lesions (e.g.
ulcers, blindness) suggestive of OKC by general
physical examination and ophthalmological tests
in 15 farms from six municipalities of the State
of Mexico between February and June 2017.
Specimens were obtained by conjunctival swabs
in the lesion area without touching the palpebral
edge. The samples were placed in Stuart transport
medium (STM, Cat. 1058-A, Dibico. Cuautitlán
Izcalli, Mexico), maintained in refrigeration at
4 °C, and processed before 24 h (Akerstedt and
Hofshagen, 2004).
Regarding sample isolation, inoculations were
performed on 5% ovine blood agar plates (ABS,
BLL, Cat BD211037. Becton-Dickinson. CDMX,
Mexico) and incubated in aerobic conditions at 37
°C for 24-48 h. Colony growth criteria and classical
biochemical tests described in the literature were
used for identification of Moraxella species
involved in keratoconjunctivitis (Angelos et al.,
2007; Angelos and Ball, 2007; Shen et al., 2011).
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Introduction
Contagious ovine keratoconjunctivitis (OKC)
is a disease that causes temporary or permanent
blindness in sheep and goats. Its clinical signs
range from conjunctivitis to corneal ulcers.
Several bacterial pathogens have been isolated
from OKC, such as Moraxella, Mycoplasma,
and Chlamydia (Akerstedt and Hofshagen, 2004;
Gupta et al., 2014; Jelocnik et al., 2019). However,
three species of the genus Moraxella have been
associated with infectious keratoconjunctivitis
in large and small ruminants, such as Mor. ovis
(Dagnall, 1994a), Mor. bovis (Karthik et al.,
2017) and Mor. bovoculi (Farias et al., 2015). The
differential biochemical tests of Moraxella species
are phenylalaninedeaminase and gelatinase tests,
although they may be inconsistent. Molecular tests
are based on the amplification of 16s-23S rRNA
genes ISR (Shen et al., 2011; O’Connor et al.,
2012; Sosa and Zunino, 2013) and the rxtA gene
that encodes cytotoxin A (Farias et al., 2015).
Keratoconjunctivitis treatment is based
on systemic or local antimicrobials such as
tetracyclines, sulfonamides, chloramphenicol, and
tulathromycin (Alexander, 2010; Maboni et al.,
2015), although several Moraxella species have
shown resistance to those antimicrobials (Catry
et al., 2007; Loy and Brodersen, 2014; Maboni et
al., 2015). Antimicrobial resistance is associated
with the presence of genes within the bacterial
genome such as tet and otr that confer resistance
to tetracyclines (Martí et al., 2006; Mosquito
et al., 2011) sul and dfr that confer resistance to
sulfonamides and trimethoprim (Kerrn et al.,
2002; Ho et al., 2009), cat, cmlA, and floR that
confer resistance to phenicols (Schwarz et al.,
2004; Chiu et al., 2006), mph and msr that confer
resistance to macrolides and lincosamides (Lüthje
and Schwarz, 2006), BlaTEM, BlaRob and BlaCARB
that confer resistance to betalactamases (Bush
and Jacoby, 2010; Dallenne et al., 2010) and qnr,
gyr, and par that confer resistance to quinolones
(Cattoir et al., 2007; Jacoby et al., 2008). Genes
such as tetH, sul2, floR, blaRob-1, srt, (3´)-Ic, mph
and msr, have been described in the genome within
a pathogenicity island in Mor. bovoculi (Dickey
et al., 2016) although no other studies have been
reported. Hence, the aim of the present study was to
isolate Moraxella spp. from ocular lesions in sheep
in the State of Mexico (Mexico) and phenotypic-
genotypic characterization of the antimicrobial
resistance to understand the pathogenesis of these
microorganisms in the disease.
Materials and Methods
The experimental protocol was approved by the
Review Commission of the Internal Committee
for the Care of Laboratory Animals - Teaching,
Research, Service and Production of Facultad de
Medicina Veterinaria y Zootecnia, Universidad
Autónoma (State of Mexico, Mexico) (CICUAL-
DISP FMVZ).
Bacteriological sampling and isolation
Sample size was calculated considering
the clinical cases of OKC through the finite
population sampling formula (Jaramillo, 2009).
A pilot sampling was used for estimating the
p indicator, obtaining a prevalence of 0.23
(107/454), and estimating 209 samples. Samples
(n=209) were collected from a total of 845
clinically healthy sheep with ocular lesions (e.g.
ulcers, blindness) suggestive of OKC by general
physical examination and ophthalmological tests
in 15 farms from six municipalities of the State
of Mexico between February and June 2017.
Specimens were obtained by conjunctival swabs
in the lesion area without touching the palpebral
edge. The samples were placed in Stuart transport
medium (STM, Cat. 1058-A, Dibico. Cuautitlán
Izcalli, Mexico), maintained in refrigeration at
4 °C, and processed before 24 h (Akerstedt and
Hofshagen, 2004).
Regarding sample isolation, inoculations were
performed on 5% ovine blood agar plates (ABS,
BLL, Cat BD211037. Becton-Dickinson. CDMX,
Mexico) and incubated in aerobic conditions at 37
°C for 24-48 h. Colony growth criteria and classical
biochemical tests described in the literature were
used for identification of Moraxella species
involved in keratoconjunctivitis (Angelos et al.,
2007; Angelos and Ball, 2007; Shen et al., 2011).
17Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance ofMoraxella ovis in ovine keratoconjunctivitis
Genotypic identification through the 16s rRNA
and rtxA genes of Moraxella spp.
For DNA extraction, a heated colony was
used in a total volume of 100 μl of sterile distilled
water heated to 95 ºC for 10 min followed
by centrifugation of the cell suspension for 5
min at 9279 G (Eppendorf® Microcentrifuge
5415, Merck KGaA, Darmstadt, Germany) and
subsequent DNA collection (Dallenne et al., 2010).
Genes 16s rRNA and rtxA were amplified by
a multiplex PCR with a final reaction volume of
25 μl for each one containing: 12.5 μl Master Mix
(Gotaq Green Master mix, Cat M7122. Promega
Corporation, WI, USA), 1 μl of each primer
(Ovi16S1 F/Ovis1849 R, Bviv16S1 F/Bovi1541 R
and Bovo1915 R) for the 16s rRNA gene and for the
rtxA gene (MbxA F/MbxA R, MbvA F and MovA
R), 4 μl of bacterial DNA and 7.5 μl nucleases free
water (Nuclease-Free Water Cat. P1195. Promega
Corporation, WI, USA). The DNA sequences and
PCR product sizes are described in Table 1.
The PCR protocol regarding 16s rRNA gene was
as follows: initial denaturation for 5 min at 95 °C
followed by 35 cycles: denaturation for 40 s at 95
ºC, alignment for 40 s at 55 ºC, extension for 1 min
at 72 ºC; and a final extension for 7 min at 72 °C.
For gene rtxA 35: cycles denaturation for 50 s at 95
°C, alignment for 50 s at 65 ºC, extension for 1 min
at 72 ºC, and a final extension for 4 min at 72 °C
carried out in a ThermoCycler (MultiGeneTM
Mini, TC 020-24, Labnet International Inc.
CA, USA). All the amplification products were
identified through horizontal electrophoresis in 1%
agarose gels stained with 0.5 μg/mL of ethidium
bromide and visualized with a UV transilluminator
(Mini-Bis 16mm, DNr Bio-Imaging Systems.
Neve Yamin Israel; Shen et al., 2011; Farias et
al., 2015). A Staphylococcus aureus ATCC 25923
strain was used as negative control.
Antimicrobial susceptibility tests
Susceptibility tests were carried out using the
disk diffusion method on Mueller Hinton agar
(AMH, BD Bioxon. Becton-Dickinson. CDMX,
Mexico) supplemented to 5% with ovine blood
defibrinated according to the guidelines of the
Institute of Clinical and Laboratory standards
(CLSI, 2016). The bacterial solution turbidity
suspended Mueller-Hinton was adjusted
(MH, BBL TM. Becton-Dickinson. CDMX,
Mexico) at a scale of 0.5 Mc Farland equivalent
to a concentration of 1-2 x108 CFU/mL, the
following antimicrobials were used; ampicillin
(10 μg), carbencillin (100 μg), cephalothin (30
μg), cefotaxime (30 μg), ciprofloxacin (5 μg),
chloramphenicol (30 μg), nitrofurantoin (30 μg)
netilmicin (30 μg), gentamicin (10 μg), amikacin
(30 μg), sulfamethoxazole/trimethoprim (25 μg),
norfloxacin (10 μg), tetracycline (30 μg) and
nalidixic acid (30 μg) (BBL ™ Sensi-Disc™.
Table 1. Primer designing for Moraxella spp. identification using PCR.
Gene Species Primers Sequences 5’- 3’ Frag-ment size Reference
rtxA
Mor. bovis MbxAF GCA AAA CTG GCA ATG ACG A 943 bp Farias
et al.
(2015)
MbxAR GTG CCA TTG ACC CAA CTA GC
Mor.
bovoculi MbvAF AAT GCT GGT GCT GGT AAC GA 990 bp
Mor. ovis MovAR TGG TTG CAG GGT ATT GGA GC
16s rRNA
Mor. ovis Ovi16S1F GAA CGA TGA GTA TCC AGC TTG CT 1849 bp
Shen et al.
(2011)
Ovis1849R CTC TTT ACT TTG GTT AAT TAT TTT GTT GGA
Mor.
bovoculi
Bovo1915R TGT ATT GGG TAC AAT CAC CAT GG
1859 bp
Bviv16S1F GAA CGA TGA CTA TCT AGC TTG CTA GAT
ATG
Mor. bovis Bovi1541R AGC TAT AGA CCC AAT TTA ACT TAC GCT
ACT 1541 bp
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance ofMoraxella ovis in ovine keratoconjunctivitis
Genotypic identification through the 16s rRNA
and rtxA genes of Moraxella spp.
For DNA extraction, a heated colony was
used in a total volume of 100 μl of sterile distilled
water heated to 95 ºC for 10 min followed
by centrifugation of the cell suspension for 5
min at 9279 G (Eppendorf® Microcentrifuge
5415, Merck KGaA, Darmstadt, Germany) and
subsequent DNA collection (Dallenne et al., 2010).
Genes 16s rRNA and rtxA were amplified by
a multiplex PCR with a final reaction volume of
25 μl for each one containing: 12.5 μl Master Mix
(Gotaq Green Master mix, Cat M7122. Promega
Corporation, WI, USA), 1 μl of each primer
(Ovi16S1 F/Ovis1849 R, Bviv16S1 F/Bovi1541 R
and Bovo1915 R) for the 16s rRNA gene and for the
rtxA gene (MbxA F/MbxA R, MbvA F and MovA
R), 4 μl of bacterial DNA and 7.5 μl nucleases free
water (Nuclease-Free Water Cat. P1195. Promega
Corporation, WI, USA). The DNA sequences and
PCR product sizes are described in Table 1.
The PCR protocol regarding 16s rRNA gene was
as follows: initial denaturation for 5 min at 95 °C
followed by 35 cycles: denaturation for 40 s at 95
ºC, alignment for 40 s at 55 ºC, extension for 1 min
at 72 ºC; and a final extension for 7 min at 72 °C.
For gene rtxA 35: cycles denaturation for 50 s at 95
°C, alignment for 50 s at 65 ºC, extension for 1 min
at 72 ºC, and a final extension for 4 min at 72 °C
carried out in a ThermoCycler (MultiGeneTM
Mini, TC 020-24, Labnet International Inc.
CA, USA). All the amplification products were
identified through horizontal electrophoresis in 1%
agarose gels stained with 0.5 μg/mL of ethidium
bromide and visualized with a UV transilluminator
(Mini-Bis 16mm, DNr Bio-Imaging Systems.
Neve Yamin Israel; Shen et al., 2011; Farias et
al., 2015). A Staphylococcus aureus ATCC 25923
strain was used as negative control.
Antimicrobial susceptibility tests
Susceptibility tests were carried out using the
disk diffusion method on Mueller Hinton agar
(AMH, BD Bioxon. Becton-Dickinson. CDMX,
Mexico) supplemented to 5% with ovine blood
defibrinated according to the guidelines of the
Institute of Clinical and Laboratory standards
(CLSI, 2016). The bacterial solution turbidity
suspended Mueller-Hinton was adjusted
(MH, BBL TM. Becton-Dickinson. CDMX,
Mexico) at a scale of 0.5 Mc Farland equivalent
to a concentration of 1-2 x108 CFU/mL, the
following antimicrobials were used; ampicillin
(10 μg), carbencillin (100 μg), cephalothin (30
μg), cefotaxime (30 μg), ciprofloxacin (5 μg),
chloramphenicol (30 μg), nitrofurantoin (30 μg)
netilmicin (30 μg), gentamicin (10 μg), amikacin
(30 μg), sulfamethoxazole/trimethoprim (25 μg),
norfloxacin (10 μg), tetracycline (30 μg) and
nalidixic acid (30 μg) (BBL ™ Sensi-Disc™.
Table 1. Primer designing for Moraxella spp. identification using PCR.
Gene Species Primers Sequences 5’- 3’ Frag-ment size Reference
rtxA
Mor. bovis MbxAF GCA AAA CTG GCA ATG ACG A 943 bp Farias
et al.
(2015)
MbxAR GTG CCA TTG ACC CAA CTA GC
Mor.
bovoculi MbvAF AAT GCT GGT GCT GGT AAC GA 990 bp
Mor. ovis MovAR TGG TTG CAG GGT ATT GGA GC
16s rRNA
Mor. ovis Ovi16S1F GAA CGA TGA GTA TCC AGC TTG CT 1849 bp
Shen et al.
(2011)
Ovis1849R CTC TTT ACT TTG GTT AAT TAT TTT GTT GGA
Mor.
bovoculi
Bovo1915R TGT ATT GGG TAC AAT CAC CAT GG
1859 bp
Bviv16S1F GAA CGA TGA CTA TCT AGC TTG CTA GAT
ATG
Mor. bovis Bovi1541R AGC TAT AGA CCC AAT TTA ACT TAC GCT
ACT 1541 bp
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2618
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Becton-Dickinson. CDMX, Mexico). The plates
were incubated at 37 °C for 18-24 h. Regarding
interpretation of the results, the following profiles
were established: sensitive (S), intermediate (I),
and resistant (R). An Escherichia coli ATCC 25922
strain was used as control. As no standardized
criteria for the interpretation of sensitivity exist for
Moraxella spp., breakpoints established for Gram-
negative pathogens related with cattle respiratory
disease were used (Maboni et al., 2015) (e.g.
critical breakpoints against respiratory pathogens
of Pasteurella multocida, Moraxella catarrhalis,
Mannheimia haemolytica, Pseudomona
aeruginosa and Haemophilus somnus) (CLSI,
2013; 2016).
Antimicrobial resistance genes
Polymerase chain reaction (PCR) was used
to identify antimicrobial resistance genes. Seven
primers were used. Sequences and amplification
products sizes are described in Table 2. Detection
of genes sul1 and sul2 (sulfonamides), BlaTEM
(β-Lactams), tetB (tetracyclines), floR (florfenicol/
chloramphenicol), as well as a multiplex PCR for
qnrAand qnrB genes (quinolones) followed the same
reaction conditions previously published (Kerrn
et al., 2002; Chiu et al., 2006; Martí et al., 2006;
Cattoir et al., 2007; Dallenne et al., 2010). Positive
controls used were as follows: Escherichia coli
ATCC 25922 and other E. coli isolates from sewage
characterized as phenotypically resistant to AM
(ampicillin), CB (carbencillin), CF (cephalothin),
CL (chloramphenicol), NA (nalidixic acid), TE
(tetracycline), NET (netilmicin), NF nitrofurantoin,
CPF (ciprofloxacin) and genotypically possessing
qnrA+, qnrB+ and BlaTEM+ genes (Talavera-
González et al., 2021).
Results
A total of 209/861 examined sheep (24.27%
prevalence) in six municipalities of the State of
Mexico showed lesions compatible with OKC.
With respect to the total number of the studied
samples (209), we identified 60 isolates of
Moraxella spp. by biochemical tests. Through
the 16s rRNA gene, 54 strains of Mor. ovis were
correctly identified from the 60 isolates (90%).
The 1541 and 1959 pb amplicons corresponding to
Mor. bovis and Mor. bovoculi not amplified by any
isolate, respectively. For the rtxA gene, 57 strains
of Mor. ovis were identified of the 60 isolates
(95%) (Table 3) and no isolates amplified a band
of 943 pb corresponding to Mor. bovis.
Table 2. Antimicrobial resistance used for the identification of Moraxella spp.
Resistance Primers Sequences 5´-3´ Fragment size Reference
Sulfonamides
sul1 F CGG CGT GGG CTA CCT GAA CG 433 bp Kerrn et al.
(2002)sul1 R GCC GAT CGC GTG AAG TTC CG
sul2 F GCG CTC AAG GCA GAT GGC ATT 293 bp Kerrn et al.
(2002)sul2 R GCG TTT GAT ACC GGC ACC CGT
Tetracyclines tet B F TTG GTT AGG GGC AAG TTT TG 650 bp Martí et al.
(2006)tet B R GTA ATG GGC CAA TAA CAC CG
Quinolones
qnrA F AGA GGA TTT CTC ACG CCA GG 580 bp Cattoir et al.
(2007)qnrA R TGC CAG GCA CAG ATC TTG AC
qnrB F GGM ATH GAA ATT CGC CAC TG 264 pb Cattoir et al.
(2007)qnrB R TTT GCY GYY CGC CAG TCG AA
β-lactamases
MultiTSO-T BlaTEM
F CAT TTC CGT GTC GCC CTT ATT C
800 bp Dallenne
et al. (2010)MultiTSO-T BlaTEM
R CGT TCA TCC ATA GTT GCC TGA C
Florfenicol/
Chloramphenicol
floR F CTT TGG CTA TAC TGG CGA TG 266 bp Chiu et al.
(2006)floR R GAT CAT TAC AAG CGC GAC AG
Y=T o C; R=A or G, S=G or C, D=A or G or T, H=A or C or T; M=A o C.
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Becton-Dickinson. CDMX, Mexico). The plates
were incubated at 37 °C for 18-24 h. Regarding
interpretation of the results, the following profiles
were established: sensitive (S), intermediate (I),
and resistant (R). An Escherichia coli ATCC 25922
strain was used as control. As no standardized
criteria for the interpretation of sensitivity exist for
Moraxella spp., breakpoints established for Gram-
negative pathogens related with cattle respiratory
disease were used (Maboni et al., 2015) (e.g.
critical breakpoints against respiratory pathogens
of Pasteurella multocida, Moraxella catarrhalis,
Mannheimia haemolytica, Pseudomona
aeruginosa and Haemophilus somnus) (CLSI,
2013; 2016).
Antimicrobial resistance genes
Polymerase chain reaction (PCR) was used
to identify antimicrobial resistance genes. Seven
primers were used. Sequences and amplification
products sizes are described in Table 2. Detection
of genes sul1 and sul2 (sulfonamides), BlaTEM
(β-Lactams), tetB (tetracyclines), floR (florfenicol/
chloramphenicol), as well as a multiplex PCR for
qnrAand qnrB genes (quinolones) followed the same
reaction conditions previously published (Kerrn
et al., 2002; Chiu et al., 2006; Martí et al., 2006;
Cattoir et al., 2007; Dallenne et al., 2010). Positive
controls used were as follows: Escherichia coli
ATCC 25922 and other E. coli isolates from sewage
characterized as phenotypically resistant to AM
(ampicillin), CB (carbencillin), CF (cephalothin),
CL (chloramphenicol), NA (nalidixic acid), TE
(tetracycline), NET (netilmicin), NF nitrofurantoin,
CPF (ciprofloxacin) and genotypically possessing
qnrA+, qnrB+ and BlaTEM+ genes (Talavera-
González et al., 2021).
Results
A total of 209/861 examined sheep (24.27%
prevalence) in six municipalities of the State of
Mexico showed lesions compatible with OKC.
With respect to the total number of the studied
samples (209), we identified 60 isolates of
Moraxella spp. by biochemical tests. Through
the 16s rRNA gene, 54 strains of Mor. ovis were
correctly identified from the 60 isolates (90%).
The 1541 and 1959 pb amplicons corresponding to
Mor. bovis and Mor. bovoculi not amplified by any
isolate, respectively. For the rtxA gene, 57 strains
of Mor. ovis were identified of the 60 isolates
(95%) (Table 3) and no isolates amplified a band
of 943 pb corresponding to Mor. bovis.
Table 2. Antimicrobial resistance used for the identification of Moraxella spp.
Resistance Primers Sequences 5´-3´ Fragment size Reference
Sulfonamides
sul1 F CGG CGT GGG CTA CCT GAA CG 433 bp Kerrn et al.
(2002)sul1 R GCC GAT CGC GTG AAG TTC CG
sul2 F GCG CTC AAG GCA GAT GGC ATT 293 bp Kerrn et al.
(2002)sul2 R GCG TTT GAT ACC GGC ACC CGT
Tetracyclines tet B F TTG GTT AGG GGC AAG TTT TG 650 bp Martí et al.
(2006)tet B R GTA ATG GGC CAA TAA CAC CG
Quinolones
qnrA F AGA GGA TTT CTC ACG CCA GG 580 bp Cattoir et al.
(2007)qnrA R TGC CAG GCA CAG ATC TTG AC
qnrB F GGM ATH GAA ATT CGC CAC TG 264 pb Cattoir et al.
(2007)qnrB R TTT GCY GYY CGC CAG TCG AA
β-lactamases
MultiTSO-T BlaTEM
F CAT TTC CGT GTC GCC CTT ATT C
800 bp Dallenne
et al. (2010)MultiTSO-T BlaTEM
R CGT TCA TCC ATA GTT GCC TGA C
Florfenicol/
Chloramphenicol
floR F CTT TGG CTA TAC TGG CGA TG 266 bp Chiu et al.
(2006)floR R GAT CAT TAC AAG CGC GAC AG
Y=T o C; R=A or G, S=G or C, D=A or G or T, H=A or C or T; M=A o C.
19Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Antimicrobial susceptibility tests
The 60 isolates of Mor. ovis were sensitive
to gentamicin and norfloxacin 100% (60/60).
Antimicrobial resistance of 18.3% (11/60) to
nalidixic acid was observed, 11.6% (7/60) to
nitrofurantoin, 10.0% (6/60) to ampicillin,
6.6% (4/60) to chloramphenicol, 3.3% (2/60) to
cephalothin, 3.3% (2/60) to tetracycline, and 1.6%
(1/60) to cefotaxime, netilmicin, amikacin and
sulfamethoxazole/trimetropim (Table 4).
Table 3. Moraxella spp. isolates obtained from clinical ovine keratoconjunctivitis cases in sheep in the State of Mexico.
UPP Municipality Animals Ocular injures* Samples Bacteriology Molecular
C KC K U Isolates 16S rRNA RtxA
1949 pb 990 pb
Mor. ovis Mor. ovis Mor. ovis
51 14 2 - 67 29 26 26
4 Toluca 189 48 7 1 - 56 5 3 5
3 Xonacatlán 117 23 - - - 23 4 4 4
3 Lerma 80 20 10 1 - 31 10 10 10
1 Capulhuac 43 15 - - - 15 4 4 4
1 Calimaya 150 8 8 - 1 17 8 7 8
15 Total 861 16 39 4 1 209* 60 54 57
Prevalence 24.27% 28.70% 90% 95%
*Ocular lesions correspond to the number of animals sampled. UPP: Number of Production Units; C: Conjunctivitis; KC:
Keratoconjunctivitis; K: Keratitis; U: Corneal ulcers.
Table 4. Susceptibility test of Moraxella spp. causing ovine keratoconjunctivitis.
Antimicrobial Mor. ovis (n= 60) (#) prevalence Zone diameter
Resistance Intermediate Susceptible Interpretive criteria
(nearest whole mm)
NA 11(18.3) 8(13.3) 41(68.3) ≤22-≥28
NF 7(11.6) 1(1.6) 52(86.6) ≤14-≥17
AM 6(10.0) 7(11.6) 47(78.3) ≤13-≥27
CL 4(6.6) 2(3.3) 54(90.0) ≤25-≥29
CF 2(3.3) 3(5.0) 55(91.6) ≤16-≥20
TE 2(3.3) 1(1.6) 57(95.0) ≤24-≥29
CFX 1(1.6) 1(1.6) 58(96.6) ≤10-≥13
SXT 1(1.6) 6(10) 53(88.3) ≥26
NET 1(1.6) - 59(98.3) ≤12-15
AK 1(1.6) - 59(98.3) ≤14-17
CP . 2(3.3) 58(96.6) ≥21
CB - 2(3.3) 58(96.6) ≤18-≥25
GE - - 60(100) ≤12-≥15
NOF - - 60(100) ≤12-≥17
#: Isolates; (#): Percentage. AM: Ampicillin; CB: Carbenicillin; CF: Cephalothin; CFX: Cefotaxime; CP: Ciprofloxacin; CL:
Chloramphenicol; NF: Nitrofurantoin; NET: Netilmicin; GE: Gentamicin; AK: Amikacin; STX: Sulfamethoxazole/trimethoprim;
NOF: Norfloxacin; TE: Tetracycline; NA: Nalidixic acid (CLSI 2013; 2016).
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Antimicrobial susceptibility tests
The 60 isolates of Mor. ovis were sensitive
to gentamicin and norfloxacin 100% (60/60).
Antimicrobial resistance of 18.3% (11/60) to
nalidixic acid was observed, 11.6% (7/60) to
nitrofurantoin, 10.0% (6/60) to ampicillin,
6.6% (4/60) to chloramphenicol, 3.3% (2/60) to
cephalothin, 3.3% (2/60) to tetracycline, and 1.6%
(1/60) to cefotaxime, netilmicin, amikacin and
sulfamethoxazole/trimetropim (Table 4).
Table 3. Moraxella spp. isolates obtained from clinical ovine keratoconjunctivitis cases in sheep in the State of Mexico.
UPP Municipality Animals Ocular injures* Samples Bacteriology Molecular
C KC K U Isolates 16S rRNA RtxA
1949 pb 990 pb
Mor. ovis Mor. ovis Mor. ovis
51 14 2 - 67 29 26 26
4 Toluca 189 48 7 1 - 56 5 3 5
3 Xonacatlán 117 23 - - - 23 4 4 4
3 Lerma 80 20 10 1 - 31 10 10 10
1 Capulhuac 43 15 - - - 15 4 4 4
1 Calimaya 150 8 8 - 1 17 8 7 8
15 Total 861 16 39 4 1 209* 60 54 57
Prevalence 24.27% 28.70% 90% 95%
*Ocular lesions correspond to the number of animals sampled. UPP: Number of Production Units; C: Conjunctivitis; KC:
Keratoconjunctivitis; K: Keratitis; U: Corneal ulcers.
Table 4. Susceptibility test of Moraxella spp. causing ovine keratoconjunctivitis.
Antimicrobial Mor. ovis (n= 60) (#) prevalence Zone diameter
Resistance Intermediate Susceptible Interpretive criteria
(nearest whole mm)
NA 11(18.3) 8(13.3) 41(68.3) ≤22-≥28
NF 7(11.6) 1(1.6) 52(86.6) ≤14-≥17
AM 6(10.0) 7(11.6) 47(78.3) ≤13-≥27
CL 4(6.6) 2(3.3) 54(90.0) ≤25-≥29
CF 2(3.3) 3(5.0) 55(91.6) ≤16-≥20
TE 2(3.3) 1(1.6) 57(95.0) ≤24-≥29
CFX 1(1.6) 1(1.6) 58(96.6) ≤10-≥13
SXT 1(1.6) 6(10) 53(88.3) ≥26
NET 1(1.6) - 59(98.3) ≤12-15
AK 1(1.6) - 59(98.3) ≤14-17
CP . 2(3.3) 58(96.6) ≥21
CB - 2(3.3) 58(96.6) ≤18-≥25
GE - - 60(100) ≤12-≥15
NOF - - 60(100) ≤12-≥17
#: Isolates; (#): Percentage. AM: Ampicillin; CB: Carbenicillin; CF: Cephalothin; CFX: Cefotaxime; CP: Ciprofloxacin; CL:
Chloramphenicol; NF: Nitrofurantoin; NET: Netilmicin; GE: Gentamicin; AK: Amikacin; STX: Sulfamethoxazole/trimethoprim;
NOF: Norfloxacin; TE: Tetracycline; NA: Nalidixic acid (CLSI 2013; 2016).
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2620
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
A total of 68.33% (41/60) isolates showed
sensitivity to all the antimicrobials used, and
31.66% (19/60) were resistant to one or more
antimicrobials. Furthermore, 23.33% (14/60)
isolates were resistant to one or two antimicrobials
and 8.33% (5/60) were multi-resistant strains
(Table 4).
Phenotypic and genotypic profiles
Mor. ovis presented 36.66% (22/60) and
33.33% (20/60) amplification of sul1 and sul2
gene, respectively. Isolates of Mor. ovis 46.66%
(28/60) amplified gene BlaTEM. The gene that
confers resistance to tetracyclines, 8.33% (5/60)
of Mor. ovis isolates amplified a 650 pb band
corresponding to tetB. Mor. ovis isolates (23/60)
38.33% amplified qnrA gene and (22/60) 36.66%
qnrB gene (Table 5).
Discussion
An OKC prevalence of 24.27% (209/861)
was obtained. This was lower than reported in
the United Kingdom (Dagnall, 1994a; 1994b)
72.38% (97/134). Severity of eye lesions was
observed, which could be related to the period
taken from the samples to the raising systems and
predisposing factors. An increase in OKC cases
was reported in Norway during the autumn and
winter seasons due to animal management: in
summer sheep graze without human intervention,
while they are confined in barns during the winter
(Akerstedt and Hofshagen, 2004). In Mexico,
sheep breeding systems vary from intensive,
semi-intensive to extensive, mixed, and grazing.
In the present study, sampling was carried out in
the spring-winter period, which is characterized
by the presence of flies, dust, direct sunlight as
well as other factors involved in the evolution of
the disease (Egwu et al., 1989). Dagnall (1994b)
reported a prevalence of 28.86% (28/97) for Mor.
ovis from ovine isolates. Similarly, Akerstedt
and Hofshagen, (2004) obtained a prevalence of
28.23% (24/85) in sheep herds with the disease.
Similar data were obtained in this work: 27.75%
(58/209) of Mor. ovis isolates from sheep with
OKC.
The first isolation of Mor. bovoculi was
reported in the United States (Angelos et al., 2007)
and later in countries such as Uruguay (Sosa and
Zunino, 2013), Argentina, Norway, and Brazil
(Libardoni et al., 2012; Farias et al., 2015). The
first report of Mor. bovoculi in sheep was made
by Farias et al. (2015) in Brazil. Karthik et al.
(2017) were the first researchers who identified
Mor. bovis from ocular injuries in sheep in India.
In our study it was not possible to isolate Mor.
bovis and Mor. bovoculi from ocular injuries in
sheep.
Shen et al. (2011) amplified the 16s rRNA
gene in 89.5% (51/57) of the isolates, identifying
Mor. bovoculi (44/51) and Mor. bovis (7/51). In
this study 90.0% (54/60) of the isolates were
amplified and correctly identified as Mor. ovis.
Table 5. Phenotypic and genotypic profile of antimicrobial resistance in Moraxella.
Phenotypical
resistance
Resistance
genes
Mor. Ovis
(n= 60)
Total Prevalence of re-sistance
genes (%)
Resistance Intermediate Susceptible
AM BlaTEM 5(6) 6(7) 17(48) 28(60) 46.66
NA qnrA 8(11) 1(8) 14(41) 23(60) 38.33
qnrB 8(11) 2(8) 12(41) 22(60) 36.66
STX sul1 1(1) 1(1) 20(58) 22(60) 36.66
sul2 1(1) 1(1) 18(58) 20(60) 33.33
TE tetB 1(2) 0(1) 4(57) 5(60) 8.33
CL floR 0(4) 0(2) 0(54) 0(60) 0.00
#: Gene amplification; #: All isolates. AM: Ampicillin; TE: Tetracycline; CL: Chloramphenicol; STX: Sulfamethoxazole/
trimethoprim; NA: Nalidixic acid.
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
A total of 68.33% (41/60) isolates showed
sensitivity to all the antimicrobials used, and
31.66% (19/60) were resistant to one or more
antimicrobials. Furthermore, 23.33% (14/60)
isolates were resistant to one or two antimicrobials
and 8.33% (5/60) were multi-resistant strains
(Table 4).
Phenotypic and genotypic profiles
Mor. ovis presented 36.66% (22/60) and
33.33% (20/60) amplification of sul1 and sul2
gene, respectively. Isolates of Mor. ovis 46.66%
(28/60) amplified gene BlaTEM. The gene that
confers resistance to tetracyclines, 8.33% (5/60)
of Mor. ovis isolates amplified a 650 pb band
corresponding to tetB. Mor. ovis isolates (23/60)
38.33% amplified qnrA gene and (22/60) 36.66%
qnrB gene (Table 5).
Discussion
An OKC prevalence of 24.27% (209/861)
was obtained. This was lower than reported in
the United Kingdom (Dagnall, 1994a; 1994b)
72.38% (97/134). Severity of eye lesions was
observed, which could be related to the period
taken from the samples to the raising systems and
predisposing factors. An increase in OKC cases
was reported in Norway during the autumn and
winter seasons due to animal management: in
summer sheep graze without human intervention,
while they are confined in barns during the winter
(Akerstedt and Hofshagen, 2004). In Mexico,
sheep breeding systems vary from intensive,
semi-intensive to extensive, mixed, and grazing.
In the present study, sampling was carried out in
the spring-winter period, which is characterized
by the presence of flies, dust, direct sunlight as
well as other factors involved in the evolution of
the disease (Egwu et al., 1989). Dagnall (1994b)
reported a prevalence of 28.86% (28/97) for Mor.
ovis from ovine isolates. Similarly, Akerstedt
and Hofshagen, (2004) obtained a prevalence of
28.23% (24/85) in sheep herds with the disease.
Similar data were obtained in this work: 27.75%
(58/209) of Mor. ovis isolates from sheep with
OKC.
The first isolation of Mor. bovoculi was
reported in the United States (Angelos et al., 2007)
and later in countries such as Uruguay (Sosa and
Zunino, 2013), Argentina, Norway, and Brazil
(Libardoni et al., 2012; Farias et al., 2015). The
first report of Mor. bovoculi in sheep was made
by Farias et al. (2015) in Brazil. Karthik et al.
(2017) were the first researchers who identified
Mor. bovis from ocular injuries in sheep in India.
In our study it was not possible to isolate Mor.
bovis and Mor. bovoculi from ocular injuries in
sheep.
Shen et al. (2011) amplified the 16s rRNA
gene in 89.5% (51/57) of the isolates, identifying
Mor. bovoculi (44/51) and Mor. bovis (7/51). In
this study 90.0% (54/60) of the isolates were
amplified and correctly identified as Mor. ovis.
Table 5. Phenotypic and genotypic profile of antimicrobial resistance in Moraxella.
Phenotypical
resistance
Resistance
genes
Mor. Ovis
(n= 60)
Total Prevalence of re-sistance
genes (%)
Resistance Intermediate Susceptible
AM BlaTEM 5(6) 6(7) 17(48) 28(60) 46.66
NA qnrA 8(11) 1(8) 14(41) 23(60) 38.33
qnrB 8(11) 2(8) 12(41) 22(60) 36.66
STX sul1 1(1) 1(1) 20(58) 22(60) 36.66
sul2 1(1) 1(1) 18(58) 20(60) 33.33
TE tetB 1(2) 0(1) 4(57) 5(60) 8.33
CL floR 0(4) 0(2) 0(54) 0(60) 0.00
#: Gene amplification; #: All isolates. AM: Ampicillin; TE: Tetracycline; CL: Chloramphenicol; STX: Sulfamethoxazole/
trimethoprim; NA: Nalidixic acid.
21Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Farias et al. (2015) amplified the gene rtxA in
100% (33/33) of isolates from bovine and ovine
with keratoconjunctivitis, identifying Mor. bovis
(15/33), Mor. bovoculi (11/33) and Mor. ovis
(7/33). In the present study, we amplified the rtxA
gene 95% (57/60) of all isolates identifying Mor.
ovis. Regarding the six Mor. ovis isolates that
did not amplify the 16s rRNA and the three Mor.
ovis isolates that did not show amplification for
rtxA gene, they possibly could be related to the
variations in the reading frame of the sequences
by deletions or absence of repeated sequence
regions surrounding the RTX operon which
has been reported in non-hemolytic Mor. bovis
strains (Angelos et al., 2003). In recent studies,
Dickey et al. (2018) detected a recombination in
the nucleotide sequences within the non-coding
regions in the rRNA and RTX genes in strains of
Mor. bovoculi.
The first study of antimicrobial sensitivity
in vitro Mor. ovis strains performed by Elad
et al. (1988) reported resistance to penicillin,
ampicillin, streptomycin and neomycin. Another
study, conducted by Catry et al. (2007), reported
strains resistant to erythromycin. The most recent
work by Maboni et al. (2015) showed strains
resistant to oxytetracycline and penicillin. All
the mentioned researchers described Mor. ovis
strains sensitive to gentamicin, chloramphenicol,
florfenicol, and sulfonamides. In the present
study we reported strains of Mor. ovis susceptible
to gentamicin, as well as resistant strains to
ampicillin, chloramphenicol, tetracycline, and
sulfamethoxazole/trimethoprim.
Oxytetracycline is usually the first choice of
treatment for keratoconjunctivitis (Alexander,
2010); however, Moraxella spp. showed
resistance over time to this antimicrobial
(Maboni et al., 2015). Likewise, florfenicol
was reported as an effective therapeutic option
in keratoconjunctivitis (Gokce et al., 2002;
Angelos et al., 2011). The use of antimicrobials
is essential for controlling OKC by Mor. ovis to
avoid exacerbation of lesions associated with
other bacterial infections (Dagnall, 1994b).
To the best of our knowledge, this is the first
study to amplify the antimicrobial resistance
genes sul1, sul2, tetB, qnrA qnrB y BlaTEM in
Mor. ovis. A study associated with antimicrobial
resistance determinants (ARD) in Mor. bovoculi
was performed by Dickey et al. (2016); they
described 10 ARD located on a genomic island
greater than 27 kb in the sequences of Mor.
bovoculi and Mb58069 isolates that were resistant
to florfenicol, oxytetracycline, sulfonamides, and
showed intermediate resistance to macrolides.
A similar study, conducted by Roberts et al.
(1991), described tetracycline-resistant strains of
Mor. catarrhalis that carry the tetB gene on its
chromosome. The tetB gene has the widest range
of Gram-negative bacteria, such as E. coli (Medina
et al., 2011; Mirzaagha et al., 2011), Acinetobacter
baumannii (Martí et al., 2006), Actinobacillus
actinomycetemcomitans (Roe et al., 1995),
Haemophilus influenzae (Robert and Smith, 1980),
and Treponema denticolaum (Roberts, 1996).
Bacteria carry resistance genes sul1, sul2, sul3,
and BlaTEM such as E. coli (Kerrn et al., 2002;
Infante et al., 2005; Ho et al., 2009; Medina et
al., 2011; Gnida et al., 2014; Memariani et al.,
2015), Klebsiella pneumoniae, Pseudomona
aeruginosa (Peymani et al., 2017), Proteus
mirabilis (Feizabadi et al., 2010; Gong et al.,
2018), Salmonella spp. (Maka et al., 2015),
Stenotrophomonas maltophilia (Hu et al., 2011).
Bacteria carriers of genes qnrA and qnrB are
K. pneumoniae (Rodríguez-Martínez et al.,
2003), E coli (Wang et al., 2003; Jiang et al.,
2008; Aguilar-Montes de Oca et al., 2015), P.
aeruginosa, Enterobacter cloacae (Wu et al.,
2007), Actinobacter baumanii (Touati et al.,
2008), Salmonella enterica (Murray et al., 2008),
Enterobacter aerogenes, Citrobacter freundii
(Park et al., 2007), Kluyvera (Kraychete et al.,
2016), among others.
Mor. ovis was identified in the present study
by using 16s rRNA and RtxA genes with PCR,
confirming PCR as the most sensitive test
for diagnosing bacterial agents involved in
keratoconjunctivitis. It will be possible to establish
new criteria for choosing antimicrobials based
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Farias et al. (2015) amplified the gene rtxA in
100% (33/33) of isolates from bovine and ovine
with keratoconjunctivitis, identifying Mor. bovis
(15/33), Mor. bovoculi (11/33) and Mor. ovis
(7/33). In the present study, we amplified the rtxA
gene 95% (57/60) of all isolates identifying Mor.
ovis. Regarding the six Mor. ovis isolates that
did not amplify the 16s rRNA and the three Mor.
ovis isolates that did not show amplification for
rtxA gene, they possibly could be related to the
variations in the reading frame of the sequences
by deletions or absence of repeated sequence
regions surrounding the RTX operon which
has been reported in non-hemolytic Mor. bovis
strains (Angelos et al., 2003). In recent studies,
Dickey et al. (2018) detected a recombination in
the nucleotide sequences within the non-coding
regions in the rRNA and RTX genes in strains of
Mor. bovoculi.
The first study of antimicrobial sensitivity
in vitro Mor. ovis strains performed by Elad
et al. (1988) reported resistance to penicillin,
ampicillin, streptomycin and neomycin. Another
study, conducted by Catry et al. (2007), reported
strains resistant to erythromycin. The most recent
work by Maboni et al. (2015) showed strains
resistant to oxytetracycline and penicillin. All
the mentioned researchers described Mor. ovis
strains sensitive to gentamicin, chloramphenicol,
florfenicol, and sulfonamides. In the present
study we reported strains of Mor. ovis susceptible
to gentamicin, as well as resistant strains to
ampicillin, chloramphenicol, tetracycline, and
sulfamethoxazole/trimethoprim.
Oxytetracycline is usually the first choice of
treatment for keratoconjunctivitis (Alexander,
2010); however, Moraxella spp. showed
resistance over time to this antimicrobial
(Maboni et al., 2015). Likewise, florfenicol
was reported as an effective therapeutic option
in keratoconjunctivitis (Gokce et al., 2002;
Angelos et al., 2011). The use of antimicrobials
is essential for controlling OKC by Mor. ovis to
avoid exacerbation of lesions associated with
other bacterial infections (Dagnall, 1994b).
To the best of our knowledge, this is the first
study to amplify the antimicrobial resistance
genes sul1, sul2, tetB, qnrA qnrB y BlaTEM in
Mor. ovis. A study associated with antimicrobial
resistance determinants (ARD) in Mor. bovoculi
was performed by Dickey et al. (2016); they
described 10 ARD located on a genomic island
greater than 27 kb in the sequences of Mor.
bovoculi and Mb58069 isolates that were resistant
to florfenicol, oxytetracycline, sulfonamides, and
showed intermediate resistance to macrolides.
A similar study, conducted by Roberts et al.
(1991), described tetracycline-resistant strains of
Mor. catarrhalis that carry the tetB gene on its
chromosome. The tetB gene has the widest range
of Gram-negative bacteria, such as E. coli (Medina
et al., 2011; Mirzaagha et al., 2011), Acinetobacter
baumannii (Martí et al., 2006), Actinobacillus
actinomycetemcomitans (Roe et al., 1995),
Haemophilus influenzae (Robert and Smith, 1980),
and Treponema denticolaum (Roberts, 1996).
Bacteria carry resistance genes sul1, sul2, sul3,
and BlaTEM such as E. coli (Kerrn et al., 2002;
Infante et al., 2005; Ho et al., 2009; Medina et
al., 2011; Gnida et al., 2014; Memariani et al.,
2015), Klebsiella pneumoniae, Pseudomona
aeruginosa (Peymani et al., 2017), Proteus
mirabilis (Feizabadi et al., 2010; Gong et al.,
2018), Salmonella spp. (Maka et al., 2015),
Stenotrophomonas maltophilia (Hu et al., 2011).
Bacteria carriers of genes qnrA and qnrB are
K. pneumoniae (Rodríguez-Martínez et al.,
2003), E coli (Wang et al., 2003; Jiang et al.,
2008; Aguilar-Montes de Oca et al., 2015), P.
aeruginosa, Enterobacter cloacae (Wu et al.,
2007), Actinobacter baumanii (Touati et al.,
2008), Salmonella enterica (Murray et al., 2008),
Enterobacter aerogenes, Citrobacter freundii
(Park et al., 2007), Kluyvera (Kraychete et al.,
2016), among others.
Mor. ovis was identified in the present study
by using 16s rRNA and RtxA genes with PCR,
confirming PCR as the most sensitive test
for diagnosing bacterial agents involved in
keratoconjunctivitis. It will be possible to establish
new criteria for choosing antimicrobials based
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2622
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
on the phenotypic and genotypic characteristics
of antimicrobial resistance, which will also
allow for molecular epidemiology surveillance
of antimicrobial resistance genes in bacterial
populations of Moraxella spp.
Declarations
Acknowledgment
To the sheep producers of the State of Mexico
for allowing us to take the samples at their farms.
Funding
This work was funded by Universidad
Autónoma del Estado de Mexico through
the projects "Caracterización, fenotípica,
genotípica y resistencia antimicrobiana de
Moraxella spp., obtenidas de casos clínicos de
queratoconjuntivitis ovina” (key: 4629/2019SF)
and “Caracterización genotípica de Mycoplasma
spp., Chlamydia spp. y Moraxella spp. presentes
en casos clínicos de Oueratoconjuntivitis
Ovina y su relación con el cuadro clínico de la
enfermedad” (key: 6177/2020CIB). The first
author received a scholarship from CONACYT
Mexico to carry out his doctoral studies.
Conflicts of interest
The authors declare they have no conflicts
of interest regarding the work presented in this
report.
Author contributions
Acosta-Dibarrat J, Talavera Rojas M, Soriano
Vargas E, and Ortiz Arana G designed the
experiment. Acosta-Dibarrat J and Ortiz Arana
G administered the project. Ortiz Arana G,
Palomares-Resendiz EG, Salgado-Miranda C,
and Enriquez-Gomez E worked on the aspects
involved in the methodology. Ortiz Arana
G and Acosta Dibarrat J wrote and prepared
the manuscript. All authors provided critical
feedback during writing and editing.
Use of artificial intelligence (AI)
No AI or AI-assisted technologies were used
during the preparation of this work.
References
Aguilar-Montes de Oca S, Talavera-Rojas M,
Soriano-Vargas E, Barba-León J, Vazquez-
Navarrete J. Determination of extended spectrum β
-lactamases/AmpC β-lactamases and plasmid-
mediated quinolone resistance in Escherichia coli
isolates obtained from bovine carcasses in Mexico.
Trop Anim Health Prod 2015; 47:975–981.
https://doi.org/10.1007/s11250-015-0818-3
Akerstedt J, Hofshagen M. Bacteriological
investigation of infectious keratoconjunctivitis in
Norwegian sheep. Acta Vet Scand 2004; 45:19–26.
https://doi.org/10.1186/1751-0147-45-19
Alexander D. Infectious bovine kerato-
conjunctivitis: A review of cases in clinical
practice. Vet Clin North Am - Food Anim Pract
2010; 26(3):487–503. https://doi.org/10.1016/j.
cvfa.2010.09.006
Angelos JA, Ball LM. Differentiation of Moraxella
bovoculi sp. nov. from other coccoid Moraxellae
by the use of polymerase chain reaction and
restriction endonuclease analysis of amplified
DNA. J Vet Diagn Invest 2007; 19(5):532–534.
https://doi.org/10.1177/104063870701900511
Angelos JA, Ball LM, Byrne BA. Minimum
inhibitory concentrations of selected antimicrobial
agents for Moraxella bovoculi associated
with infectious bovine keratoconjunctivitis.
J Vet Diagn Invest 2011; 23(3):552–555.
https://doi.org/10.1177/1040638711404154
Angelos JA, Hess JF, George LW. An RTX
operon in hemolytic Moraxella bovis is absent
from nonhemolytic strains. Vet Microbiol 2003;
92(4):363–377. https://doi.org/10.1016/S0378-
1135(02)00410-8
Angelos JA, Spinks PO, Ball LM, George LW.
Moraxella bovoculi sp. nov., isolated from calves
with infectious bovine keratoconjunctivitis. Int
J Syst Evol Microbiol 2007; 57(4): 789–795.
https://doi.org/10.1099/ijs.0.64333-0
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
on the phenotypic and genotypic characteristics
of antimicrobial resistance, which will also
allow for molecular epidemiology surveillance
of antimicrobial resistance genes in bacterial
populations of Moraxella spp.
Declarations
Acknowledgment
To the sheep producers of the State of Mexico
for allowing us to take the samples at their farms.
Funding
This work was funded by Universidad
Autónoma del Estado de Mexico through
the projects "Caracterización, fenotípica,
genotípica y resistencia antimicrobiana de
Moraxella spp., obtenidas de casos clínicos de
queratoconjuntivitis ovina” (key: 4629/2019SF)
and “Caracterización genotípica de Mycoplasma
spp., Chlamydia spp. y Moraxella spp. presentes
en casos clínicos de Oueratoconjuntivitis
Ovina y su relación con el cuadro clínico de la
enfermedad” (key: 6177/2020CIB). The first
author received a scholarship from CONACYT
Mexico to carry out his doctoral studies.
Conflicts of interest
The authors declare they have no conflicts
of interest regarding the work presented in this
report.
Author contributions
Acosta-Dibarrat J, Talavera Rojas M, Soriano
Vargas E, and Ortiz Arana G designed the
experiment. Acosta-Dibarrat J and Ortiz Arana
G administered the project. Ortiz Arana G,
Palomares-Resendiz EG, Salgado-Miranda C,
and Enriquez-Gomez E worked on the aspects
involved in the methodology. Ortiz Arana
G and Acosta Dibarrat J wrote and prepared
the manuscript. All authors provided critical
feedback during writing and editing.
Use of artificial intelligence (AI)
No AI or AI-assisted technologies were used
during the preparation of this work.
References
Aguilar-Montes de Oca S, Talavera-Rojas M,
Soriano-Vargas E, Barba-León J, Vazquez-
Navarrete J. Determination of extended spectrum β
-lactamases/AmpC β-lactamases and plasmid-
mediated quinolone resistance in Escherichia coli
isolates obtained from bovine carcasses in Mexico.
Trop Anim Health Prod 2015; 47:975–981.
https://doi.org/10.1007/s11250-015-0818-3
Akerstedt J, Hofshagen M. Bacteriological
investigation of infectious keratoconjunctivitis in
Norwegian sheep. Acta Vet Scand 2004; 45:19–26.
https://doi.org/10.1186/1751-0147-45-19
Alexander D. Infectious bovine kerato-
conjunctivitis: A review of cases in clinical
practice. Vet Clin North Am - Food Anim Pract
2010; 26(3):487–503. https://doi.org/10.1016/j.
cvfa.2010.09.006
Angelos JA, Ball LM. Differentiation of Moraxella
bovoculi sp. nov. from other coccoid Moraxellae
by the use of polymerase chain reaction and
restriction endonuclease analysis of amplified
DNA. J Vet Diagn Invest 2007; 19(5):532–534.
https://doi.org/10.1177/104063870701900511
Angelos JA, Ball LM, Byrne BA. Minimum
inhibitory concentrations of selected antimicrobial
agents for Moraxella bovoculi associated
with infectious bovine keratoconjunctivitis.
J Vet Diagn Invest 2011; 23(3):552–555.
https://doi.org/10.1177/1040638711404154
Angelos JA, Hess JF, George LW. An RTX
operon in hemolytic Moraxella bovis is absent
from nonhemolytic strains. Vet Microbiol 2003;
92(4):363–377. https://doi.org/10.1016/S0378-
1135(02)00410-8
Angelos JA, Spinks PO, Ball LM, George LW.
Moraxella bovoculi sp. nov., isolated from calves
with infectious bovine keratoconjunctivitis. Int
J Syst Evol Microbiol 2007; 57(4): 789–795.
https://doi.org/10.1099/ijs.0.64333-0
23Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Bush K, Jacoby GA. Updated functional
classification of β-Lactamases. Antimicrob
Agents Chemother 2010; 54(3):969–976.
https://doi.org/10.1128/AAC.01009-09
Catry B, Boyen F, Baele M, Dewulf J, de Kruif
A, Vaneechoutte M, Haesebrouck F, Decostere
A. Recovery of Moraxella ovis from the
bovine respiratory tract and differentiation of
Moraxella species by tDNA-intergenic spacer
PCR. Vet Microbiol 2007; 120(3–4):375–380.
https://doi.org/10.1016/j.vetmic.2006.10.037
Cattoir V, Poirel L, Rotimi V, Soussy CJ,
Nordmann P. Multiplex PCR for detection of
plasmid-mediated quinolone resistance qnr genes
in ESBL-producing enterobacterial isolates. J
Antimicrob Chemother 2007; 60(2):394–397.
https://doi.org/10.1093/jac/dkm204
Chiu CH, Su LH, Chu CH, Wang MH, Yeh CM,
Weill FX, Chu C. Detection of multidrug-resistant
Salmonella enterica serovar typhimurium phage
types DT102, DT104, and U302 by multiplex
PCR. J Clin Microbiol 2006; 44(7):2354-2358.
https://doi.org/10.1128/JCM.00171-06
Clinical and Laboratory Standards Institute (CLSI).
Antimicrobial disk and dilution susceptibility tests
for bacteria isolated from animals. Approved
Standard - 4 edition. CLSI document VET01-A4.
2013. Wayne, PA.1-72.
Clinical and Laboratory Standard Institute (CLSI).
Methods for antimicrobial dilution and disk
susceptibility testing of infrequently isolated or
fastidious bacteria; Approved Guideline- 3 Edition.
CLSI document M45. 2016. Wayne, PA. 1-90.
Dagnall GJR. An investigation of
colonization of the conjunctival sac of
sheep by bacteria and mycoplasmas.
Epidemiol Infect 1994a; 112(3):561–567.
https://doi.org/10.1017/S0950268800051268
Dagnall GJR. The role of Branhamella ovis,
Mycoplasma conjunctivae and Chlamydia
psittaci in conjunctivitis of sheep. Br Vet J
1994b; 150(1):65–71. https://doi.org/10.1016/
S0007-1935(05)80097-1
Dallenne C, da Costa A, Decré D, Favier C,
Arlet G. Development of a set of multiplex
PCR assays for the detection of genes encoding
important β-lactamases in Enterobacteriaceae. J
Antimicrob Chemother 2010; 65(3):490–495.
https://doi.org/10.1093/jac/dkp498
Dickey AM, Loy JD, Bono JL, Smith TPL, Apley
MD, Lubbers BV, Dedonder KD, Capik SF,
Larsn RL, White BJ, Blom J, Chitko-McKown
CG, Clawson ML. Large genomic differences
between Moraxella bovoculi isolates acquired
from the eyes of cattle with infectious bovine
keratoconjunctivitis versus the deep nasopharynx
of asymptomatic cattle. Vet Res 2016; 47:31(2016).
https://doi.org/10.1186/s13567-016-0316-2
Dickey AM, Schuller G, Loy JD, Clawson
ML. Whole genome sequencing of Moraxella
bovoculi reveals high genetic diversity and
evidence for interspecies recombination at
multiple loci. PLoS One 2018; 13(12):e0209113.
https://doi.org/10.1371/journal.pone.0209113
Elad D, Yeruham I, Bernstein M. Moraxella ovis
in cases of infectious bovine keratoconjunctivitis
(IBK) in Israel J Vet Med Ser B 1988; 35(1–10):
431–434. https://doi.org/10.1111/j.1439-0450.1988.
tb00516.x
Egwu GO, Faull WB, Bradbury JM, Clarkson
MJ. Ovine infectious keratoconjunctivitis: a
microbiological study of clinically unaffected and
affected sheep´s eyes with special reference to
Mycocoplasma conjunctivae. Vet Rec 1989; 125
(10):253–256. https://doi.org/10.1136/vr.125.10.253
Farias LDA, Maboni G, Matter LB, Scherer CFC,
Libardoni F, de Vargas AC. Phylogenetic analysis
and genetic diversity of 3’ region of rtxA gene
from geographically diverse strains of Moraxella
bovis, Moraxella bovoculi and Moraxella
ovis. Vet Microbiol 2015; 178(3–4):283–287.
https://doi.org/10.1016/j.vetmic.2015.05.025
Feizabadi MM, Delfani S, Raji N, Manjooni A,
Aligholi M, Shahcheraghi F, Parvin M, Yadegarinia
D. Distribution of blaTEM, blaSHV, blaCTX-M
genes amoung clinical isolates of Klebsiella
pneumoniae at Labbafinejad Hospital,Tehran,Iran.
Microb Drug Resist 2010; 16(1):49–53.
https://doi.org/10.1089/mdr.2009.0096
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Bush K, Jacoby GA. Updated functional
classification of β-Lactamases. Antimicrob
Agents Chemother 2010; 54(3):969–976.
https://doi.org/10.1128/AAC.01009-09
Catry B, Boyen F, Baele M, Dewulf J, de Kruif
A, Vaneechoutte M, Haesebrouck F, Decostere
A. Recovery of Moraxella ovis from the
bovine respiratory tract and differentiation of
Moraxella species by tDNA-intergenic spacer
PCR. Vet Microbiol 2007; 120(3–4):375–380.
https://doi.org/10.1016/j.vetmic.2006.10.037
Cattoir V, Poirel L, Rotimi V, Soussy CJ,
Nordmann P. Multiplex PCR for detection of
plasmid-mediated quinolone resistance qnr genes
in ESBL-producing enterobacterial isolates. J
Antimicrob Chemother 2007; 60(2):394–397.
https://doi.org/10.1093/jac/dkm204
Chiu CH, Su LH, Chu CH, Wang MH, Yeh CM,
Weill FX, Chu C. Detection of multidrug-resistant
Salmonella enterica serovar typhimurium phage
types DT102, DT104, and U302 by multiplex
PCR. J Clin Microbiol 2006; 44(7):2354-2358.
https://doi.org/10.1128/JCM.00171-06
Clinical and Laboratory Standards Institute (CLSI).
Antimicrobial disk and dilution susceptibility tests
for bacteria isolated from animals. Approved
Standard - 4 edition. CLSI document VET01-A4.
2013. Wayne, PA.1-72.
Clinical and Laboratory Standard Institute (CLSI).
Methods for antimicrobial dilution and disk
susceptibility testing of infrequently isolated or
fastidious bacteria; Approved Guideline- 3 Edition.
CLSI document M45. 2016. Wayne, PA. 1-90.
Dagnall GJR. An investigation of
colonization of the conjunctival sac of
sheep by bacteria and mycoplasmas.
Epidemiol Infect 1994a; 112(3):561–567.
https://doi.org/10.1017/S0950268800051268
Dagnall GJR. The role of Branhamella ovis,
Mycoplasma conjunctivae and Chlamydia
psittaci in conjunctivitis of sheep. Br Vet J
1994b; 150(1):65–71. https://doi.org/10.1016/
S0007-1935(05)80097-1
Dallenne C, da Costa A, Decré D, Favier C,
Arlet G. Development of a set of multiplex
PCR assays for the detection of genes encoding
important β-lactamases in Enterobacteriaceae. J
Antimicrob Chemother 2010; 65(3):490–495.
https://doi.org/10.1093/jac/dkp498
Dickey AM, Loy JD, Bono JL, Smith TPL, Apley
MD, Lubbers BV, Dedonder KD, Capik SF,
Larsn RL, White BJ, Blom J, Chitko-McKown
CG, Clawson ML. Large genomic differences
between Moraxella bovoculi isolates acquired
from the eyes of cattle with infectious bovine
keratoconjunctivitis versus the deep nasopharynx
of asymptomatic cattle. Vet Res 2016; 47:31(2016).
https://doi.org/10.1186/s13567-016-0316-2
Dickey AM, Schuller G, Loy JD, Clawson
ML. Whole genome sequencing of Moraxella
bovoculi reveals high genetic diversity and
evidence for interspecies recombination at
multiple loci. PLoS One 2018; 13(12):e0209113.
https://doi.org/10.1371/journal.pone.0209113
Elad D, Yeruham I, Bernstein M. Moraxella ovis
in cases of infectious bovine keratoconjunctivitis
(IBK) in Israel J Vet Med Ser B 1988; 35(1–10):
431–434. https://doi.org/10.1111/j.1439-0450.1988.
tb00516.x
Egwu GO, Faull WB, Bradbury JM, Clarkson
MJ. Ovine infectious keratoconjunctivitis: a
microbiological study of clinically unaffected and
affected sheep´s eyes with special reference to
Mycocoplasma conjunctivae. Vet Rec 1989; 125
(10):253–256. https://doi.org/10.1136/vr.125.10.253
Farias LDA, Maboni G, Matter LB, Scherer CFC,
Libardoni F, de Vargas AC. Phylogenetic analysis
and genetic diversity of 3’ region of rtxA gene
from geographically diverse strains of Moraxella
bovis, Moraxella bovoculi and Moraxella
ovis. Vet Microbiol 2015; 178(3–4):283–287.
https://doi.org/10.1016/j.vetmic.2015.05.025
Feizabadi MM, Delfani S, Raji N, Manjooni A,
Aligholi M, Shahcheraghi F, Parvin M, Yadegarinia
D. Distribution of blaTEM, blaSHV, blaCTX-M
genes amoung clinical isolates of Klebsiella
pneumoniae at Labbafinejad Hospital,Tehran,Iran.
Microb Drug Resist 2010; 16(1):49–53.
https://doi.org/10.1089/mdr.2009.0096
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2624
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Gnida A, Kunda K, Ziembińska A, Łuczkiewicz
A, Felis E, Surmacz-Górska J. Detection of
sulfonamide resistance genes via in situ PCR-
FISH. Polish J Microbiol 2014; 63(2):167–173.
http://www.pjmonline.org/wp-content/uploads/
archive/vol6322014167.pdf
Gokce HI, Citil M, Genc O, Erdogan HM,
Gunes V, Kankavi O. A comparision of the
efficacy of florfenicol and oxitetracycline in
treatment of naturally ocurring infectious bovine
keratoconjuntivitis. Ir Vet J 2002; 55(11):573–576.
Gong J, Zhuang L, Zhang D, Zhang P, Dou X,
Wang C. Establishment of a multiplex loop-
mediated isothermal amplification method for
rapid detection of sulfonamide (sul1, sul2, sul3) in
clinical Enterobacteriaceae isolates from poultry.
Foodborne Pathog Dis 2018; 15(7):413–419.
https://doi.org/10.1089/fpd.2017.2410
Gupta S, Chahota R, Bhardwaj B, Malik P, Verma
S, Sharma M. Identification of Chlamydiae and
Mycoplasma species in ruminants with ocular
infections. Lett Appl Microbiol 2014; 60(2):
135–139. https://doi.org/10.1111/lam.12362
Ho PL, Wong RC, Chow KH, Que TL.
Distribution of integron-associated trimethoprim-
sulfamethoxazole resistance determinants among
Escherichia coli from humans and food-producing
animals. Lett Appl Microbiol 2009; 49(5):627–634.
https://doi.org/10.1111/j.1472-765X.2009.02717.x
Hu L, Chang X, Ye, Y, Wang Z, Shao Y, Shi
W, Li X, Li J. Stenotrophomonas maltophilia
resistance to trimethoprim/sulfamethoxazole
mediated by acquisition of sul and dfrA genes
in a plasmid-mediated class 1 integron. Int
J Antimicrob Agents 2011; 37(3):230–234.
https://doi.org/10.1016/j.ijantimicag.2010.10.025
Infante B, Grape M, Larsson M, Kristiansson
C, Pallecchi L, Rossolini GM, Kronvall G.
Acquired sulphonamide resistance genes in
faecal Escherichia coli from healthy children
in Bolivia and Peru. Int J Antimicrob Agents
2005; 25(4):308–312. https://doi.org/10.1016/j.
ijantimicag.2004.12.004
Jacoby G, Cattoir V, Hooper D, Martínez-
Martínez L, Nordmann P, Pascual A, Poirel L,
Wang M. Qnr gene nomenclature. Antimicrob
Agents Chemother 2008; 52(7):2297–2299.
https://doi.org/10.1128/AAC.00147-08
Jaramillo CJ. Epidemiologia Veterinaria. 1 ed
(Mexico) Manual Moderno 2009.
Jelocnik M, Laurence M, Murdoch FR,
Polkinghorne A. Detection of Chlamydiaceae
in ocular swabs from Australian pre-export
feedlot sheep. Aust Vet J 2019(10); 97: 1–3.
https://doi.org/10.1111/avj.12857
Jiang Y, Zhou Z, Qian Y, Wei Z, Yu Y, Hu S,
Li L. Plasmid-mediated quinolone resistance
determinants qnr and aac(60)- Ib-cr in extended-
spectrum β-lactamase-producing Escherichia
coli and Klebsiella pneumoniae in China. J
Antimicrob Chemother 2008; 61(5): 1003 –1006.
https://doi.org/10.1093/jac/dkn063
Karthik K, Manimaran K, Mahaprabhu R, Shoba
K. Isolation of Moraxella sp. from cases of
keratoconjunctivitis in an organized sheep farm
of India. Open J Vet Med 2017; 7(10);138–143.
https://doi.org/10.4236/ojvm.2017.710014
Kerrn MB, Klemmensen T, Frimodt-Møller N,
Espersen F. Susceptibility of Danish Escherichia
coli strains isolated from urinary tract infections
and bacteraemia, and distribution of sul
genes conferring sulphonamide resistance. J
Antimicrob Chemother 2002; 50(4): 513–516.
https://doi.org/10.1093/jac/dkf164
Kraychete GB, Botelho LAB, Campana EH,
Picão RC, Bonelli RR. Updated multiplex
PCR for detection of all six plasmid-
mediated qnr gene families. Antimicrob
Agents Chemother 2016; 60(12): 7524–7526.
https://doi.org/10.1128/AAC.01447-16
Libardoni F, Scherer CFC, Farias L, Vielmo A,
Balzan C, Vargas AC. Moraxella bovoculi em
casos de ceratoconjuntivite infecciosa bovina
no Rio Grande do Sul. Pesqui Vet Bras 2012;
32(8):743–746. https://doi.org/10.1590/S0100-
736X2012000800011
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Gnida A, Kunda K, Ziembińska A, Łuczkiewicz
A, Felis E, Surmacz-Górska J. Detection of
sulfonamide resistance genes via in situ PCR-
FISH. Polish J Microbiol 2014; 63(2):167–173.
http://www.pjmonline.org/wp-content/uploads/
archive/vol6322014167.pdf
Gokce HI, Citil M, Genc O, Erdogan HM,
Gunes V, Kankavi O. A comparision of the
efficacy of florfenicol and oxitetracycline in
treatment of naturally ocurring infectious bovine
keratoconjuntivitis. Ir Vet J 2002; 55(11):573–576.
Gong J, Zhuang L, Zhang D, Zhang P, Dou X,
Wang C. Establishment of a multiplex loop-
mediated isothermal amplification method for
rapid detection of sulfonamide (sul1, sul2, sul3) in
clinical Enterobacteriaceae isolates from poultry.
Foodborne Pathog Dis 2018; 15(7):413–419.
https://doi.org/10.1089/fpd.2017.2410
Gupta S, Chahota R, Bhardwaj B, Malik P, Verma
S, Sharma M. Identification of Chlamydiae and
Mycoplasma species in ruminants with ocular
infections. Lett Appl Microbiol 2014; 60(2):
135–139. https://doi.org/10.1111/lam.12362
Ho PL, Wong RC, Chow KH, Que TL.
Distribution of integron-associated trimethoprim-
sulfamethoxazole resistance determinants among
Escherichia coli from humans and food-producing
animals. Lett Appl Microbiol 2009; 49(5):627–634.
https://doi.org/10.1111/j.1472-765X.2009.02717.x
Hu L, Chang X, Ye, Y, Wang Z, Shao Y, Shi
W, Li X, Li J. Stenotrophomonas maltophilia
resistance to trimethoprim/sulfamethoxazole
mediated by acquisition of sul and dfrA genes
in a plasmid-mediated class 1 integron. Int
J Antimicrob Agents 2011; 37(3):230–234.
https://doi.org/10.1016/j.ijantimicag.2010.10.025
Infante B, Grape M, Larsson M, Kristiansson
C, Pallecchi L, Rossolini GM, Kronvall G.
Acquired sulphonamide resistance genes in
faecal Escherichia coli from healthy children
in Bolivia and Peru. Int J Antimicrob Agents
2005; 25(4):308–312. https://doi.org/10.1016/j.
ijantimicag.2004.12.004
Jacoby G, Cattoir V, Hooper D, Martínez-
Martínez L, Nordmann P, Pascual A, Poirel L,
Wang M. Qnr gene nomenclature. Antimicrob
Agents Chemother 2008; 52(7):2297–2299.
https://doi.org/10.1128/AAC.00147-08
Jaramillo CJ. Epidemiologia Veterinaria. 1 ed
(Mexico) Manual Moderno 2009.
Jelocnik M, Laurence M, Murdoch FR,
Polkinghorne A. Detection of Chlamydiaceae
in ocular swabs from Australian pre-export
feedlot sheep. Aust Vet J 2019(10); 97: 1–3.
https://doi.org/10.1111/avj.12857
Jiang Y, Zhou Z, Qian Y, Wei Z, Yu Y, Hu S,
Li L. Plasmid-mediated quinolone resistance
determinants qnr and aac(60)- Ib-cr in extended-
spectrum β-lactamase-producing Escherichia
coli and Klebsiella pneumoniae in China. J
Antimicrob Chemother 2008; 61(5): 1003 –1006.
https://doi.org/10.1093/jac/dkn063
Karthik K, Manimaran K, Mahaprabhu R, Shoba
K. Isolation of Moraxella sp. from cases of
keratoconjunctivitis in an organized sheep farm
of India. Open J Vet Med 2017; 7(10);138–143.
https://doi.org/10.4236/ojvm.2017.710014
Kerrn MB, Klemmensen T, Frimodt-Møller N,
Espersen F. Susceptibility of Danish Escherichia
coli strains isolated from urinary tract infections
and bacteraemia, and distribution of sul
genes conferring sulphonamide resistance. J
Antimicrob Chemother 2002; 50(4): 513–516.
https://doi.org/10.1093/jac/dkf164
Kraychete GB, Botelho LAB, Campana EH,
Picão RC, Bonelli RR. Updated multiplex
PCR for detection of all six plasmid-
mediated qnr gene families. Antimicrob
Agents Chemother 2016; 60(12): 7524–7526.
https://doi.org/10.1128/AAC.01447-16
Libardoni F, Scherer CFC, Farias L, Vielmo A,
Balzan C, Vargas AC. Moraxella bovoculi em
casos de ceratoconjuntivite infecciosa bovina
no Rio Grande do Sul. Pesqui Vet Bras 2012;
32(8):743–746. https://doi.org/10.1590/S0100-
736X2012000800011
25Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-26
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Loy JD, Brodersen BW. Moraxella spp. isolated
from field outbreaks of infectious bovine
keratoconjunctivitis: a retrospective study of
case submissions from 2010 to 2013. J Vet
Diagnostic Investig 2014; 26(6):761–768.
https://doi.org/10.1177/1040638714551403
Lüthje P, Schwarz S. Antimicrobial resistance of
coagulase-negative staphylococci from bovine
subclinical mastitis with particular reference to
macrolide–lincosamide resistance phenotypes
and genotypes. J Antimicrob Chemother 2006;
57(5):966–969. https://doi.org/10.1093/jac/dkl061
Maboni G, Gressler LT, Espindola JP, Schwab
M, Tasca C, Potter L, de Vargas AC. Differences
in the antimicrobial susceptibility profiles of
Moraxella bovis, M. bovoculi and M. ovis.
Brazilian J Microbiol 2015; 46:545–549.
https://doi.org/10.1590/S1517-838246220140058
Maka L, Mackiw E, Scienzynska H, Modezelewska
M, Popowska M. Resistance to sulfonamides
and dissemination of sul genes among
Salmonella spp. isolated from food in Poland.
Foodborne Pathog Dis 2015; 12(5):383–389.
https://doi.org/10.1089/fpd.2014.1825
Martí S, Fernández-Cuenca, F, Pascual Á, Ribera
A, Rodríguez-Baño J, Bou G, Cisneros, JM,
Pachón J, Martínez-Martínez L, Vila J. Prevalencia
de los genes tetA y tetB como mecanismo
de resistencia a tetraciclina y minociclina en
aislamientos clínicos de Acinetobacter baumannii.
Enferm. Infecc Microbiol Clin 2006; 24(2):77–80.
https://doi.org/10.1157/13085012
Medina A, Horcajo P, Jurado S, de la Fuente
R, Ruiz-Santana-Quinteira JA, Dominguez-
Bernal G, Orden JA. Phenotypic and genotypic
characterization of antimicrobial resistance
in enterohemorrhagic Escherichia coli and
atypical enteropathogenic E. coli strains from
ruminants. J Vet Diagn Invest 2011; 23(1):91–95.
https://doi.org/10.1177/104063871102300114
Memariani M, Najar-peerayeh S, Salehi TZ,
Khalil S. Occurrence of SHV, TEM and CTX-M
β-Lactamase genes among enteropathogenic
Escherichia coli strains isolated from children
with diarrhea. Jundishapur J Microbiol
2015; 8(4):e15620. https://doi.org/10.5812/
jjm.8(4)2015.15620
Mirzaagha P, Louie M, Sharma R, Yanke LJ, Topp E,
McAllister TA. Distribution and characterization of
ampicillin- and tetracycline-resistant Escherichia
coli from feedlot cattle fed subtherapeutic
antimicrobials. BMC Microbiol 2011; 11:78(2011).
https://doi.org/10.1186/1471-2180-11-78
Mosquito S, Ruiz J, Bauer JL, Ochoa TJ.
Molecular mechanisms of antibiotic resistance
in, associated diarrhea Rev Peru. Med.
Exp. Salud Publica 2011; 28(4):648–656.
https://doi.org/10.17843/rpmesp.2011.284.430
Murray A, Mather H, Coia JE, Brown DJ. Plasmid-
mediated quinolone resistance in nalidixic-acid-
susceptible strains of Salmonella enterica isolated
in Scotland. J Antimicrob Chemother 2008;
62(5):1153–1155. https://doi.org/10.1093/jac/dkn340
O’Connor AM, Shen HG, Wang C, Opriessnig
T. Descriptive epidemiology of Moraxella
bovis, Moraxella bovoculi and Moraxella
ovis in beef calves with naturally occurring
infectious bovine keratoconjunctivitis (Pinkeye).
Vet Microbiol 2012; 155(2–4):374–380.
https://doi.org/10.1016/j.vetmic.2011.09.011
Park Y, Yu JK, Lee S, Oh E, Woo G. Prevalence
and diversity of qnr alleles in AmpC-
producing Enterobacter cloacae, Enterobacter
aerogenes, Citrobacter freundii and Serratia
marcescens: a multicentre study from Korea. J
Antimicrob Chemother 2007; 60(4):868–871.
https://doi.org/10.1093/jac/dkm266
Peymani A, Naserpour-Farivar T, Zare E,
Azarhoosh KH. Distribution of blaTEM, bla SHV,
and bla CTX-M genes among ESBL-producing
P. aeruginosa isolated from Qazvin and Tehran
hospitals, Iran. J Prev Med Hyg 2017;58(2):
55–160. https://www.ncbi.nlm.nih.gov/pmc/articles/
PMC5584084/pdf/2421-4248-58-E155.pdf
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Loy JD, Brodersen BW. Moraxella spp. isolated
from field outbreaks of infectious bovine
keratoconjunctivitis: a retrospective study of
case submissions from 2010 to 2013. J Vet
Diagnostic Investig 2014; 26(6):761–768.
https://doi.org/10.1177/1040638714551403
Lüthje P, Schwarz S. Antimicrobial resistance of
coagulase-negative staphylococci from bovine
subclinical mastitis with particular reference to
macrolide–lincosamide resistance phenotypes
and genotypes. J Antimicrob Chemother 2006;
57(5):966–969. https://doi.org/10.1093/jac/dkl061
Maboni G, Gressler LT, Espindola JP, Schwab
M, Tasca C, Potter L, de Vargas AC. Differences
in the antimicrobial susceptibility profiles of
Moraxella bovis, M. bovoculi and M. ovis.
Brazilian J Microbiol 2015; 46:545–549.
https://doi.org/10.1590/S1517-838246220140058
Maka L, Mackiw E, Scienzynska H, Modezelewska
M, Popowska M. Resistance to sulfonamides
and dissemination of sul genes among
Salmonella spp. isolated from food in Poland.
Foodborne Pathog Dis 2015; 12(5):383–389.
https://doi.org/10.1089/fpd.2014.1825
Martí S, Fernández-Cuenca, F, Pascual Á, Ribera
A, Rodríguez-Baño J, Bou G, Cisneros, JM,
Pachón J, Martínez-Martínez L, Vila J. Prevalencia
de los genes tetA y tetB como mecanismo
de resistencia a tetraciclina y minociclina en
aislamientos clínicos de Acinetobacter baumannii.
Enferm. Infecc Microbiol Clin 2006; 24(2):77–80.
https://doi.org/10.1157/13085012
Medina A, Horcajo P, Jurado S, de la Fuente
R, Ruiz-Santana-Quinteira JA, Dominguez-
Bernal G, Orden JA. Phenotypic and genotypic
characterization of antimicrobial resistance
in enterohemorrhagic Escherichia coli and
atypical enteropathogenic E. coli strains from
ruminants. J Vet Diagn Invest 2011; 23(1):91–95.
https://doi.org/10.1177/104063871102300114
Memariani M, Najar-peerayeh S, Salehi TZ,
Khalil S. Occurrence of SHV, TEM and CTX-M
β-Lactamase genes among enteropathogenic
Escherichia coli strains isolated from children
with diarrhea. Jundishapur J Microbiol
2015; 8(4):e15620. https://doi.org/10.5812/
jjm.8(4)2015.15620
Mirzaagha P, Louie M, Sharma R, Yanke LJ, Topp E,
McAllister TA. Distribution and characterization of
ampicillin- and tetracycline-resistant Escherichia
coli from feedlot cattle fed subtherapeutic
antimicrobials. BMC Microbiol 2011; 11:78(2011).
https://doi.org/10.1186/1471-2180-11-78
Mosquito S, Ruiz J, Bauer JL, Ochoa TJ.
Molecular mechanisms of antibiotic resistance
in, associated diarrhea Rev Peru. Med.
Exp. Salud Publica 2011; 28(4):648–656.
https://doi.org/10.17843/rpmesp.2011.284.430
Murray A, Mather H, Coia JE, Brown DJ. Plasmid-
mediated quinolone resistance in nalidixic-acid-
susceptible strains of Salmonella enterica isolated
in Scotland. J Antimicrob Chemother 2008;
62(5):1153–1155. https://doi.org/10.1093/jac/dkn340
O’Connor AM, Shen HG, Wang C, Opriessnig
T. Descriptive epidemiology of Moraxella
bovis, Moraxella bovoculi and Moraxella
ovis in beef calves with naturally occurring
infectious bovine keratoconjunctivitis (Pinkeye).
Vet Microbiol 2012; 155(2–4):374–380.
https://doi.org/10.1016/j.vetmic.2011.09.011
Park Y, Yu JK, Lee S, Oh E, Woo G. Prevalence
and diversity of qnr alleles in AmpC-
producing Enterobacter cloacae, Enterobacter
aerogenes, Citrobacter freundii and Serratia
marcescens: a multicentre study from Korea. J
Antimicrob Chemother 2007; 60(4):868–871.
https://doi.org/10.1093/jac/dkm266
Peymani A, Naserpour-Farivar T, Zare E,
Azarhoosh KH. Distribution of blaTEM, bla SHV,
and bla CTX-M genes among ESBL-producing
P. aeruginosa isolated from Qazvin and Tehran
hospitals, Iran. J Prev Med Hyg 2017;58(2):
55–160. https://www.ncbi.nlm.nih.gov/pmc/articles/
PMC5584084/pdf/2421-4248-58-E155.pdf
Rev Colomb Cienc Pecu 2024; 37(1, Jan-Mar):14-2626
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Roberts MC, Smith AL. Molecular Charac-
terization of “Plasmid-Free” Antibiotic resistant
Haemophilus influenzae. J Bacteriol 1980; 144
(1):476–479. https://doi.org/10.1128/jb.144.1.476-
479.1980
Roberts MC, Pang Y, Spencer RC, Winstanley TG,
Brown BA, Wallace RJ. Tetracycline resistance
in Moraxella (Branhamella) catarrhalis:
Demonstration of two clonal outbreaks by using
pulsed-field gel electrophoresis. Antimicrob
Agents Chemother 1991; 35(11):2453–2455.
https://doi.org/10.1128/AAC.35.11.2453
Roberts MC, Chung WO, Roe DE. Characterization
of tetracycline and erythromycin resistance
determinants in Treponema denticola. Antimicrob
Agents Chemother 1996; 40(7):1690–1694.
https://doi.org/10.1128/AAC.40.7.1690
Rodríguez-Martínez JM, Pascua A, García I,
Martínez-Martínez L. Detection of the plasmid-
mediated quinolone resistance determinant
qnr among clinical isolates of Klebsiella
pneumoniae producing AmpC-type β-lactamase.
J Antimicrob Chemother 2003; 52:703–706.
https://doi.org/10.1093/jac/dkg388
Roe DE, Braham PH, Weinberg A, Roberts MC.
Characterization of tetracycline resistance in
Actinobacillus actinomycetemcomitans. Oral
Microbiol Immunol 1995; 10(4):227–232.
https://doi.org/10.1111/j.1399-302X.1995.tb00147.x
Schwarz S, Kehrenberg C, Doublet B,
Cloeckaert A. Molecular basis of bacterial
resistance to chloramphenicol and florfenicol.
FEMS Microbiol Rev 2004(5); 28:519–542.
https://doi.org/10.1016/j.femsre.2004.04.001
Shen HG, Gould S, Kinyon J, Opriessnig T,
O’Connor AM. Development and evaluation
of a multiplex real-time PCR assay for the
detection and differentiation of Moraxella
bovis, Moraxella bovoculi and Moraxella ovis
in pure culture isolates and lacrimal swabs
collected from conventionally raised cattle.
J Appl Microbiol 2011; 111(5):1037–1043.
https://doi.org/10.1111/j.1365-2672.2011.05123.x
Sosa V, Zunino P. Diversity of Moraxella
spp. strains recovered from infectious bovine
keratoconjunctivitis cases in Uruguay. J
Infect Dev Ctries 2013; 7(11):819–824.
https://doi.org/10.3855/jidc.3458
Talavera-González JM, Acosta-Dibarrat J, Reyes-
Rodríguez NE; Salgado-Miranda C, Talavera-
Rojas M. Prevalence of the qnrB, qnrA and blaTEM
genes in temperate bacteriophages of Escherichia
coli isolated from wastewater and sewer water
from slaughterhouses in the State of Mexico.
Rev Mex Cienc Pecu 2021; 12(1):298–305.
https://doi.org/10.22319/rmcp.v12i1.5378
Touati A, Brasme L, Benallaoua S, Gharout A,
Madoux J, De Champs C. First report of qnrB-
producing Enterobacter cloacae and qnrA-
producing Acinetobacter baumannii recovered
from Algerian hospitals. Diagn Microbiol Infect
Dis 2008; 60(3):287–290. https://doi.org/10.1016/j.
diagmicrobio.2007.10.002
Wang M, Tran J, Jacoby G. Plasmid-mediated
quinolone resistance in clinical isolates of
Escherichia coli from Shanghai, China. Antimicrob
Agents Chemother 2003; 47(7):2242–2248.
https://doi.org/10.1128/AAC.47.7.2242-2248.2003
Wu J, Ko W, Tsai S, Yan J. Prevalence of plasmid-
mediated quinolone resistance determinants
QnrA, QnrB, and QnrS among clinical isolates
of Enterobacter cloacae in a Taiwanese Hospital.
Antimicrob Agents Chemother 2007; 51(4):
1223–1227. https://doi.org/10.1128/AAC.01195-06
https://doi.org/10.17533/udea.rccp.v37n1a4Antimicrobial resistance of Moraxella ovis in ovine keratoconjunctivitis
Roberts MC, Smith AL. Molecular Charac-
terization of “Plasmid-Free” Antibiotic resistant
Haemophilus influenzae. J Bacteriol 1980; 144
(1):476–479. https://doi.org/10.1128/jb.144.1.476-
479.1980
Roberts MC, Pang Y, Spencer RC, Winstanley TG,
Brown BA, Wallace RJ. Tetracycline resistance
in Moraxella (Branhamella) catarrhalis:
Demonstration of two clonal outbreaks by using
pulsed-field gel electrophoresis. Antimicrob
Agents Chemother 1991; 35(11):2453–2455.
https://doi.org/10.1128/AAC.35.11.2453
Roberts MC, Chung WO, Roe DE. Characterization
of tetracycline and erythromycin resistance
determinants in Treponema denticola. Antimicrob
Agents Chemother 1996; 40(7):1690–1694.
https://doi.org/10.1128/AAC.40.7.1690
Rodríguez-Martínez JM, Pascua A, García I,
Martínez-Martínez L. Detection of the plasmid-
mediated quinolone resistance determinant
qnr among clinical isolates of Klebsiella
pneumoniae producing AmpC-type β-lactamase.
J Antimicrob Chemother 2003; 52:703–706.
https://doi.org/10.1093/jac/dkg388
Roe DE, Braham PH, Weinberg A, Roberts MC.
Characterization of tetracycline resistance in
Actinobacillus actinomycetemcomitans. Oral
Microbiol Immunol 1995; 10(4):227–232.
https://doi.org/10.1111/j.1399-302X.1995.tb00147.x
Schwarz S, Kehrenberg C, Doublet B,
Cloeckaert A. Molecular basis of bacterial
resistance to chloramphenicol and florfenicol.
FEMS Microbiol Rev 2004(5); 28:519–542.
https://doi.org/10.1016/j.femsre.2004.04.001
Shen HG, Gould S, Kinyon J, Opriessnig T,
O’Connor AM. Development and evaluation
of a multiplex real-time PCR assay for the
detection and differentiation of Moraxella
bovis, Moraxella bovoculi and Moraxella ovis
in pure culture isolates and lacrimal swabs
collected from conventionally raised cattle.
J Appl Microbiol 2011; 111(5):1037–1043.
https://doi.org/10.1111/j.1365-2672.2011.05123.x
Sosa V, Zunino P. Diversity of Moraxella
spp. strains recovered from infectious bovine
keratoconjunctivitis cases in Uruguay. J
Infect Dev Ctries 2013; 7(11):819–824.
https://doi.org/10.3855/jidc.3458
Talavera-González JM, Acosta-Dibarrat J, Reyes-
Rodríguez NE; Salgado-Miranda C, Talavera-
Rojas M. Prevalence of the qnrB, qnrA and blaTEM
genes in temperate bacteriophages of Escherichia
coli isolated from wastewater and sewer water
from slaughterhouses in the State of Mexico.
Rev Mex Cienc Pecu 2021; 12(1):298–305.
https://doi.org/10.22319/rmcp.v12i1.5378
Touati A, Brasme L, Benallaoua S, Gharout A,
Madoux J, De Champs C. First report of qnrB-
producing Enterobacter cloacae and qnrA-
producing Acinetobacter baumannii recovered
from Algerian hospitals. Diagn Microbiol Infect
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diagmicrobio.2007.10.002
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