INCIDENCE OF MULTIDRUG RESISTANT STAPHYLOCOCCUS AUREUS AND ENTEROBACTERIACEAE FROM GROUNDNUT CAKES (KULI-KULI) AND ROASTED GROUNDNUTS OBTAINED FROM ZARIA METROPOLIS

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Department of Pharmaceutical Sciences

ABSTRACT
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for several difficult-to-treat infections in humans. Previous studies reported the identification of MRSA in food demonstrating that food can represent a source of Staphylococcus aureus which may carry the mecA gene. The aim of this study is to determine the incidence of multidrug resistant Staphylococcus aureus and Enterobacteriaceae from groundnut cakes (Kuli-Kuli) and roasted groundnut obtained from Zaria metropolis. A total of 294 samples were obtained from different batches of roasted groundnut, kuli-kuli, and swabs from the hands of the vendors. Bacteriological analysis of roasted groundnut and kuli-kuli samples were carried out by growth on specific culture media.Nutrient Agar plates were also opened around the environment where the kuli-kuli and groundnut were sold. A total of 152 bacterial isolates were recovered from the 106 samples with significant bacteria growth. Using the Microgen kits for identification, it was found that the isolates consisted mainly of Enterobacteriaceae and Staphylococci. 82% (125/152) of the isolates were Staphylococci. The Staphylococci were Staphylococcus aureus (40.6%), Staphylococcus xylosus (23.2%), Staphylococcus intermedius and Staphylococcus hyicus (8.7%), Staphylococcus chromogenes (7.2%), Staphylococcus schleiferi (5.8%), Staphylococcus haemolyticus and Staphylococcus epidermidis (2.9%). Full identification of isolates showed that the most prevalent Enterobacteriaceae were Citrobacter freundii (22.2%),Klebsiellaoxytoca (11.1%), Salmonella arizonae (7.4%), Salmonella species (7.4%), Acinetobacter lwoffi (7.4%), Proteus vulgaris (7.4%), Serratia marcescens and Acinetobacter haemolyticus (7.4%). The other Enterobacteriaceae isolatedinclude Escherichia coli inactive (3.7%), Providencia stuartii (3.7%), Proteus viii mirabilis (3.7%), Enterobacter agglomerans (3.7%), Klebsiella pneumoniae (3.7%) and Providencia alcalifaciens (3.7%). Antibiotic resistance profile of the bacteria isolates showed that most of the Enterobacteriaceae isolates were resistant to the inhibitory activities of Cefixime (96%) and Amoxicillin/Clavulanic acid (74%). Gentamicin, Imipenem and Quinolones showed high activities with 0%, 0% and 4% resistance respectively. Staphylococcus aureusisolates also showed high resistance to Cefixime (82%). High percentages, (88.9%) of Enterobacteriaceae, and (50.0%) of Staphylococcus aureus were observed to have MAR index of 0.3 and above and 78% of Enterobacteriaceae and 61% of Staphylococcus aureus were MDR, indicating that the isolates might have been pre-exposed to the antibiotics used in this study. Six (6) of the Staphylococcus aureusisolates were found to be MRSA phenotypically and molecular characterization of the isolates confirmed them to be carriers of mecAgene, while 33.3% of them carried the vanA gene but, none of the MRSA expressed the blaZ gene.