Rep-PCR of Staphylococcus aureus strains isolated from bovine mastitis in Argentina

Abstract

The aim of this study was to assess by rep-PCR the genetic relationship of 52 S. aureus strains isolated from mammary infections collected in four herds located in the central dairy region of Argentina. Results were compared with the in vitro activity of antimicrobial drugs frequently used for treating bovine mastitis. Twelve different antimicrobials patterns were observed. Forty eight percent of the strains were susceptible to all antimicrobials tested. rep-PCR typing could successfully differentiate S. aureus strains of bovine origin. At a first level of similarity (50%), it could be defined 5 clusters namely I to V. Most of the strains (75%) were grouped in cluster I. The results may suggest that genotypes were similar in the different herds. Agreement between antibiotic patterns and rep-profiles was not observed for most isolates. The present report describes the genotypes responsible for the mastitis cases in the central dairy region of Argentina. A better knowledge of infective strains distribution in dairy herds might help in formulating strategies to control of infection. Furthermore, antimicrobial susceptibility of S. aureus should be used as guide to select effective drugs to therapy in intramammary infections.