The multidrug resistant and the emergence of methicillin-resistant staphylococci isolated from animals, food, and humans are public health concern. These microorganisms produce different toxins related to food poisoning in humans. This study aimed to characterize Staphylococcus spp. isolated from two organic milk farms in Brazil. A total of 259 milk samples were collected, from which 58 (22.4%) Staphylococcus spp. were isolated. The highest sensibility to ceftiofur and sulfamethoxazole/trimethoprim was observed in 96.6% of Staphylococcus spp., and whereas 89% were resistant to penicillin G. The mecA gene was detected in 13.8% of the isolates. SEA and SEC were the most common enterotoxins detected. PFGE revealed genetic heterogeneity from S. intermedius and S. warneri analyzed, while S. aureus presented similar profiles among isolates from the two studied herds. To the best of our knowledge, the current study describes for the first time presence of enterotoxins, mecA gene, and genetic diversity of staphylococci isolated from organic dairy farms in Brazil.

Staphylococcosis infections are common in poultry worldwide because of the causative bacteria resisting a wide range of commonly used antibiotics. The formation of biofilm is the hallmark characteristic of staph infection. Biofilms constitute reservoir of pathogens and are associated with resistance to antimicrobial agent and chronic infections. In this study 90 multidrug resistant staphylococcus strains (61 coagulase- negative staphylococcus (CNS) and 29 S. aureus) were screened by tissue culture plate method for biofilm formation and presence of mecA, icaA, and icaD genes by PCR technique. 38 (42.2%) isolates were strongly positive for biofilm production, 49 (54.4%) were moderate biofilm producers and 3 (3.4%) were weak or negative for biofilm formation. All biofilm producing strains were positive for icaA and icaD genes, and all biofilm negative strains were negative for icaA gene. Biofilm production was higher in methicillin resistant strains as compared to the methicillin sensitive strains of Staphylococcus species. From this study attention should be given in treatment of staphylococcus because Staphylococci isolated showed a high extent of biofilm production. All biofilm producing Staphylococci are positive for icaA and icaD genes, which indicates the important role of ica genes as virulence markers in staphylococcal infections.