Genotyping of enterotoxigenic methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) among commensal rodents in North Sinai, Egypt.

ABSTRACT

AIM: This study aimed to identify genotype enterotoxigenic antimicrobial-resistant Staphylococcus aureus species, mainly methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) among commensal rodents. METHODS AND RESULTS: A total of 280 samples were collected from nasal and mouth swabs, heart blood, intestinal content and lung tissues of 56 commensal rodents trapped from North Sinai, Egypt. Antimicrobial susceptibility testing was performed to bacteriologically identified S. aureus isolates against 15 antimicrobial agents by disc diffusion method. Detection was conducted for identifying coagulase gene (coA), antimicrobial-resistant genes (mecA and vanA/B), enterotoxigenic and virulence determinant genes (hlg, seb, sed and see) among the MRSA and VRSA isolates. RESULTS: Staphylococcus aureus species were isolated from 24 (42.86%) out of 56 rodents. Phenotypic examination revealed that all the isolates were multidrug-resistant, whereas two isolates were multiple antibiotic resistant (MAR). Out of 33 examined isolates, 33 (100%) were resistant to oxacillin and amoxicillin, 31 (93.93%) to cefoxitin and 12 (36.36%) to vancomycin. PCR assay revealed that 24 isolates revealed (100%) positivity to coA gene, 17 (70.83%) to mecA gene and 12 (50%) to vanA/B genes. Enterotoxin genes and haemolysin genes were detected among MRSA and VRSA isolates. There was a strong positive correlation between the tested antimicrobial-resistant genes and virulence genes (p > 0.05). CONCLUSIONS: This study demonstrated the occurrence of MRSA and VRSA strains among commensal rodents in North Sinai, Egypt. The detection of enterotoxigenic and virulence genes of the isolated MRSA and VRSA strains indicated the health hazards of food contamination and zoonotic infections. SIGNIFICANCE AND IMPACTS OF THE STUDY This study emphasizes the role of commensal rodents in maintaining and disseminating multidrug-resistant MRSA and VRSA strains to the environment, animals and human beings.