| Abstrakt: |
Staphylococcus aureusis a common causative agent of bovine mastitis in dairy cows and commonly associated with foodborne disease outbreaks. The aim of this study was to evaluate the presence of enterotoxin genes, agrtyping, antimicrobial resistance, and genetic diversity of S. aureusisolated from milk of cows with mastitis in dairy farms from southern Brazil. Results showed that 7 (22.6%) of 31 S. aureusisolates were positive for enterotoxin genes. Specifically, the genes encoding for enterotoxins A (n= 4), C (n= 2), and B (n= 1) were detected. Isolates belonging to the agrgroup III (10 of 31, 32.2%) and agrgroup I (7 of 31, 22.5%) were the most common. To our knowledge, this is the first report of both agrI and III in the same S. aureusisolate from milk of cows with bovine mastitis. The antimicrobial resistance test showed that 54% of the isolates were multiresistant to antimicrobial agents. The macrorestriction analysis produced 16 different major SmaI pulsed-field gel electrophoresis patterns, with up to two subpatterns. Moreover, the presence of some S. aureusclones in a distinct area was observed.Although this study characterized a limited number of S. aureusisolates, the presence of classical enterotoxin genes and resistance to multiple antimicrobial agents reinforces the importance of this microorganism to animal and human health. In addition, similar genetic profiles have been identified in distinct geographic areas, suggesting clonal dissemination of S. aureusin dairy herds from southern Brazil. |
