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 mec A gene that confers their resistance to β-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 mec A 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 mec A gene. The phylogenetic tree of partial mec A 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 mec A harboring staphylococcal isolates but also non-staphylococcal isolates and require special scientific consideration.