Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis

Rato, Márcia G.; Bexiga, Ricardo; Florindo, Catarina; Cavaco, Lina; Vilela, C. L.; Sanches, Ilda Santos

doi:10.1016/j.vetmic.2012.07.043

“…In the present work, consistent with such investigations (GUÉRIN-FAUBLÉE et al, 2002;MINST et al, 2012;RATO et al, 2013), most isolates (96.6%) were susceptible to penicillin, indicating that this antibiotic is a viable option for the treatment of mastitis. In humans, penicillin is the recommended first-line treatment for S. agalactiae infections for all age groups, in addition to being administered prophylactically to pregnant women (BOLUKAOTO et al, 2015;VERANI et al, 2010).…”

Section: Discussionsupporting

confidence: 90%

“…Cefazolin and cefoperazone resistance was not detected by Rato et al (2013) in their analysis of 60 mastitis-associated S. agalactiae strains from Portugal. Similarly, in the present work, all isolates were susceptible to cefalotin and ceftiofur.…”

Section: Discussionmentioning

confidence: 94%

“…High rates of tetracycline resistance (60-90%) have been reported among both human and bovine S. agalactiae isolates (DOGAN et al, 2005;DUARTE et al, 2004;GAO et al, 2012;PINTO et al, 2013;RATO et al, 2013). In the current work, resistance to this antimicrobial was found to be approximately 35.6%.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast, all 85 strains of this bacterium recovered from Brazilian cattle in an investigation by Duarte et al (2004) were found to be resistant. In addition, Rato et al (2013) documented a resistance rate of 80.6% among 108 isolates collected from Portuguese cows. The results of the present study differ somewhat in this respect, given that only 9.3% of the tested strains were resistant to gentamicin, while 38.1% were resistant to amikacin, another aminoglycoside antibiotic.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Silva

¹

,

Castro

²

,

Gonçalves

³

et al. 2017

SCA

View full text Add to dashboard Cite

Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%), tetO in 23 (19.5%), and tetM in 24 (20.3%). The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%), tetracycline (35.6%), gentamicin (9.3%), clindamycin (20.3%), penicillin (3.4%), and amikacin (38.1%); conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health. Key words: Antimicrobial resistance genes. Bovine diseases. Bovine mastitis. GBS, MIC. ResumoStreptococcus agalactiae é um dos principais agentes causadores de mastite em bovinos e de consequentes perdas econômicas aos produtores. Poucos estudos que avaliaram a susceptibilidade a antimicrobianos e a presença de determinantes genéticos de resistência para este agente em bovinos leiteiros do Brasil. Este trabalho teve por objetivo avaliar a frequência dos genes de resistência a antimicrobianos ermA, ermB, mefA, tetO, tetM, aphA3, aad-6, bem como a susceptibilidade in vitro aos antimicrobianos amicacina, eritromicina, clindamicina, tetraciclina, gentamicina, penicilina, ceftiofur e cefalotina, e as associações entre genótipos e fenótipos de resistência em 118 isolados de S. agalactiae provenientes de casos de mastite em rebanhos bovinos brasileiros. Dentre os genes de resistência pesquisados, ermB foi encontrado em 19 isolados (16,1%), tetO em 23 (19,5%) e tetM em 24 (20,3%). Os genes ermA, mefA, apha3 e aad6 não foram detectados. Verificou-se associação entre a presença dos genes ermB, tetM e tetO e os fenótipos de resistência à eritromicina, clindamicina e tetraciclina. Foram encontrados diferentes índices de resistência aos antibióticos testados: Eritromicina (19,5%), tetraciclina (35,6%), gentamicina (9,3%), clindamicina (20,3%), penicilina (3,4%) e amicacina (38,1%). Todos os isolados foram susceptíveis ceftiofur e cefalotina. ...

show abstract

“…These are the most commonly identified tet genes among both bovine and human S. agalactiae isolates (DOGAN et al, 2005;DUARTE et al, 2005;DUTRA et al, 2014;PINTO et al, 2014), while others determinants such as tetS and tetK being observed less frequently (DUARTE et al, 2004;RATO et al, 2013). Four isolates exhibiting phenotypic tetracycline resistance harbored neither tetM nor tetO, suggesting the presence of a different tet gene, such as tetS or tetK.…”

Section: Discussionmentioning

confidence: 98%

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Silva

¹

,

Castro

²

,

Gonçalves

³

et al. 2017

SCA

5

1

0

View full text Add to dashboard Cite

Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%), tetO in 23 (19.5%), and tetM in 24 (20.3%). The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%), tetracycline (35.6%), gentamicin (9.3%), clindamycin (20.3%), penicillin (3.4%), and amikacin (38.1%); conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health. Key words: Antimicrobial resistance genes. Bovine diseases. Bovine mastitis. GBS, MIC. ResumoStreptococcus agalactiae é um dos principais agentes causadores de mastite em bovinos e de consequentes perdas econômicas aos produtores. Poucos estudos que avaliaram a susceptibilidade a antimicrobianos e a presença de determinantes genéticos de resistência para este agente em bovinos leiteiros do Brasil. Este trabalho teve por objetivo avaliar a frequência dos genes de resistência a antimicrobianos ermA, ermB, mefA, tetO, tetM, aphA3, aad-6, bem como a susceptibilidade in vitro aos antimicrobianos amicacina, eritromicina, clindamicina, tetraciclina, gentamicina, penicilina, ceftiofur e cefalotina, e as associações entre genótipos e fenótipos de resistência em 118 isolados de S. agalactiae provenientes de casos de mastite em rebanhos bovinos brasileiros. Dentre os genes de resistência pesquisados, ermB foi encontrado em 19 isolados (16,1%), tetO em 23 (19,5%) e tetM em 24 (20,3%). Os genes ermA, mefA, apha3 e aad6 não foram detectados. Verificou-se associação entre a presença dos genes ermB, tetM e tetO e os fenótipos de resistência à eritromicina, clindamicina e tetraciclina. Foram encontrados diferentes índices de resistência aos antibióticos testados: Eritromicina (19,5%), tetraciclina (35,6%), gentamicina (9,3%), clindamicina (20,3%), penicilina (3,4%) e amicacina (38,1%). Todos os isolados foram susceptíveis ceftiofur e cefalotina. ...

show abstract

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models

Alves-Barroco

¹

,

Roma‐Rodrigues

²

,

Raposo

³

et al. 2018

Self Cite

View full text Add to dashboard Cite

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability.

show abstract

Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis

Cited by 97 publications

References 29 publications

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models

Contact Info

Product

Resources

About