mecA Gene Dissemination Among Staphylococcal and Non-staphylococcal Isolates Shed in Surface Waters

Aquatic ecosystems represent important vehicles for the dissemination of antibiotic resistant bacteria and antibiotic resistance genes. Of particular interest are methicillin-resistant staphylococci (MRS) harboring mecA gene that confers their resistance to beta-lactams. Therefore, in this study, water samples collected from different locations of a river impacted by surrounding facilities and domestic effluents were analyzed to learn more about the occurrence of MRS and mecA gene. Out of 290, 12 surface water isolates displayed resistance to both cefoxitin and oxacillin antibiotics. Resistant staphylococcal and non-staphylococcal isolates, identified by 16S rRNA sequencing, were found to harbor mecA gene. The phylogenetic tree of partial mecA sequences obtained from staphylococcal and non-staphylococcal isolates showed sequence similarity values of 8 %-100 %. Surface water bodies receive contaminated waters via runoff, effluents from industrial, agricultural, and municipal discharges. Therefore, surface waters are not only hot spots for mecA harboring staphylococcal isolates but also non-staphylococcal isolates and require special scientific consideration.