Antimicrobial resistance and detection of mecA and blaZ genes in coagulase-negative Staphylococcus isolated from bovine mastitis

Abstract

Pesq. Vet. Bras. 32(8) The present study evaluated the pheno-and genotypical antimicrobial resistance proϐile of coagulase-negative Staphylococcus (CNS) species isolated from dairy cows milk, specially concerning to oxacillin. Of 100 CNS isolates, the S. xylosus was the prevalent species, followed by S. cohnii, S. hominis, S. capitis and S. haemolyticus. Only 6% were phenotypically susceptible to the antimicrobial agents tested in disk diffusion assay. Penicillin and ampicillin resistance rates were signiϐicantly higher than others antimicrobials. Four isolates were positive to mecA gene (4%), all represented by the S. xylosus species. The blaZ gene was detected in 16% of the isolates (16/100). It was noticed that all mecA + were also positive to this gene and the presence of both genes was correlated to phenotypic beta-lactamic resistance. We conclude that CNS species from bovine milk presented signiϐicantly distinct antimicrobial resistance proϐiles, evaluated by phenotypic and genotypic tests, which has implications for treatment and management decisions. Accepted for publication on March 10, 2012. 2 Curso de Pós-Graduação em Ciências Veterinárias, Instituto de Veterinária (IV), Universidade Federal Rural do Rio de Janeiro (UFRRJ), BR 465 Km 7, Seropédica, RJ 23890-000, Brazil.3 Laboratório de Bacteriologia Veterinária, Depto Microbiologia Veterinária, IV, UFRRJ, Seropédica, RJ. *Corresponding author: miliane@ufrrj.br percentual de resistência à penicilina e ampicilina foi signiϐicativamente maior que aos outros antimicrobianos. Quatro isolados foram positivos para o gene mecA (4%), sendo todos representados pela espécie S.xylosus. O gene blaZ foi detectado em 16% dos isolados (16/100), sendo todos mecA positivos e a presença de ambos os genes foi correlacionada com a resistência fenotípica aos beta-lactâmicos. Foi possível concluir que as espécies de ECN provenientes de leite bovino apresentaram distintos perϐis de resistência antimicrobiana, avaliados por testes fenotípicos e genotípi-cos, podendo diϐicultar a adoção de medidas de tratamento e manejo dos animais.

PCR for detection of virulence and antibiotic resistance genes of coagulase positive staphylococcus aureus from clinical mastitis in Egypt

“…The same result obtained by [37] detected a single amplicon of 173 bp of blaZ gene. Our results showed that all tested strains for mecA gene were positive for blaZ gene and this similar to [38] who noticed that all positive strains to mecA were also positive for blaZ gene and the presence of both genes was correlated to phenotypic beta-lactam resistance of S. aureus strains.…”

Characterization of Coa Gene and Antimicrobial Profiles of Staphylococcus Aureus Isolated from Bovine Clinical and Subclinical mastitis

“…Besides, bovine multidrug resistant S. aureus strains could be zoonotic pathogens (Soares et al, 2012). Given that Vancomycin and oxacillin are important antibiotics for human, isolates.Our results indicated high resistance rate for oxacillin which is responsible for methicillin resistance.…”

Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt

“…Distinguishing to species level would be critical in the event that it has effect on administration and treatment choices [23]. …”