Antibiogram and non-detection of mecA gene in Staphylococcus spp. isolated from a sewage-imparted stream within a University community

Wastewater from households containing varying amount of chemicals such as antiseptics, antibiotics, bacteria and other toxic chemicals are directly discharged into the environment. The compounds present in the wastewater could play a role in the selection of antibiotic resistance in environmental bacteria and pose a public health risk to the environment. Water samples were obtained from five (5) selected points along the stream channel fortnightly for a period of four months. Isolation of Staphylococcus spp. was carried out on mannitol salt agar using the pour plate technique. Antibiotics susceptibility testing was done using the Kirby-Bauer disc diffusion method. Detection of mecA was carried out on methicillin resistant isolates by PCR using specific primers. A total of 53 Staphylococcus spp. were obtained from the wastewater sample; Staphylococcus aureus (79.2%), S. epidermidis (17%) and S. saprophyticus (3.8%). The antibiotics susceptibility test showed that 42% of the total isolates obtained were resistant to oxacillin, tetracycline (4%), chloramphenicol (4%), sulfamethoxazole/trimethoprim (2%) and linezolid (2%). There was no resistance to vancomycin, erythromycin, clindamycin, ciprofloxacin and gentamycin. None of the twenty-two methicillin resistant isolates in this study possessed mecA gene. There is a need for adequate treatment of wastewater discharge before release into various receiving channels to prevent the increasing rate of antibiotics resistance develop in environmental bacteria.