Phenotypic and molecular detection of methicillin resistant Staphylococcus aureus (MRSA) Isolated form Clarias gariepinus (Burchel, 1822) and Oreochromis niloticus (Linneaus, 1758) IN Maiduguri

Abstract

The phenotypic and molecular detection of methicillin resistant Staphylococcus aureus (MRSA) were carried out on fish and humans. A total of Nine hundred (900) swab samples were aseptically collected 350 each from Alau Lake and from commercial fish farms and one hundred (100) each from fish farmers and fishermen. For the phenotypic detection, the samples were inoculated on mannitol salt agar for Staphylococcus aureus isolation followed by oxacillin screening agar base (ORSAB) medium for MRSA isolation respectively. Genotype detection was carried out through the detection of Nuc gene for S. aureus and macA gene for (MRSA) using Real-Time Polymerase chain Reaction (RT-PCR). The study also determined the prevalence and molecular detection of MRSA in C. gariepinus, O. niloticus. Fish Farmers and Fishermen in Maiduguri and its environs. The result presents 218 (31.14%), 97 (50.78%), 14 (14.43%) and 10 (10.30%) positive for S. aureus, MRSA, nuc gene and mecA gene respectively. The swap samples from Oreochromis niloticus and Clarias gariepinus examined presents Clarias gariepinus to have higher S. aureus prevalence in both phenotypic and genotypic detection method. The samples from fish farmers and fishermen present 111 (55.50%), 50 (25.00%), 6 (3.00%) and 3 (1.50%) positive values for Staphylococcus aureus, MRSA; Nuc genes and MacA genes respectively. The phenotypic prevalence of MRSA was 97 (13.85%) and 50 (25.00%) for fish and fishermen respectively while the genotypic prevalence of MRSA was 14 (2.00%) and 3 (1.50%) for fish and fishermen. S. aureus isolates from fish subjected to antibiotic susceptibility testing shows all to be (100%) resistant to Vancomycin, Oxacillin, Ceftriaxone, Cephazolin and Cefoxitin, 23 (23.71%) to Clindamycin and 9.28% to Trimethoprim-sulfemethozole. All the isolates from fish were susceptible to Gentamicin and Ciprofloxacin. On the contrary all isolates from fish farmers display 100% resistance to Vancomycin, Oxacillin, Cefoxitin and Ceftrizone, but were susceptible to Gentamicin and Ciprofloxacin. Based on the findings of this study, it can be concluded that S. aureus and MRSA are present in fish from the wild, cultured, fish farmers and fishermen; Ciprofloxacin and Gentamicin are therefore recommended as drugs of choice for the treatment of Staphylococcus aureus and MRSA infection in fish in the study area.