Epidemiology and Molecular Characterization of Staphylococcus aureus Enterotoxins A and B Isolated from Clarias gariepinus from Wild and Pond in the FCT Abuja, Nigeria

Abstract

Staphylococcus aureus is an important foodborne pathogen associated with food poisoning and other multiple infections in human being. Its presence in fish is of public health concern. Clarias gariepinus organs collected from the pond/wild include serious issue due to the fact that they were collected from organs from the pond/wild organs namely intestine, Staphylococcus aureus is not a normal flora of fish. The risk of zoonotic transmission to humans highlights the need to evaluate Staphylococcus aureus enterotoxin A and B from African catfish ( Clarias gariepinus ) in Federal Capital Territory, Abuja. Four hundred samples of Clarias gariepinus organs were collected with two hundred (200) samples each from the ponds/wild and 66 samples from both Gwagwalada and Abuja Municipal Area council and 68 from Bwari respectively and examined for the presences of Staphylococcus aureus from the intestines, gills and skin using standard procedures on Baird Parker (BPA) agar plates supplemented with egg yolk emulsion and tellurite solution. Isolates were further identified using conventional biochemical tests: Gram’s staining, catalase, production of coagulase, Dnase, Oxidase test, hemolytic zone on 5% sheep blood agar and fermentation of mannose, mannitol, xlylose, maltose, trehalose, lactose, fructose, sucrose and glucose. Isolates were further characterized using Microgen TM STAPH-12S KIT. Antimicrobial sensitivity test was carried out by disc diffusion method on Mueller Hinton agar and was interpreted in line with the Clinical and Laboratory Standard Institute. An overall isolation rate of from the ponds was 5.0% while from the wild was 6.0% recorded for Staphylococcus aureus . Antibiogram of Staphylococcus aureus isolates revealed high sensitivity to some of the antibiotics, doxycycline 10 (71.4%), gentamycin 9 (64.2%), clindamycin 7 (50.0%) and ampicillin 6 (42.8%). Similarly, Staphylococcus aureus isolates also showed resistance to vancomycin 11 (78.5%), oxacillin, oxtetracycline and trimethoprim-sulfamethoxazole 10 (71.4%) while erythromycin, tetracycline and streptomycin showed 7 (50.0%) respectively. Staphylococcus aureus isolates indicated a high percentage of isolates having MARI characteristics of 0.92%. A total 2/6 (33.3%) of the samples were found positive for the presence SEA and 1/6 (16.7%) for SEB. It was concluded that the study confirmed the presence of enterotoxins in African catfish which is a major concern to public health. Preventive and control measures are necessary to tackle this serious food safety concern.