Isolation and Identification of Methicillin Resistant Staphylococcus Aureus (MRSA) from Traditionally Fermented Milk “Nono” and Yoghurt in Kaduna Metropolis, Nigeria

Abstract

This study was to determine the presence of Staphylococcus aureus including the methicillin resistant strains in yoghurt and nono using bacteriological and molecular techniques. Out of 280 samples of yoghurt (140) and nono(140) collected from Kaduna, the overall prevalence of Staphylococcal species were 34(12.14%) . Twenty-nine (85.29%) were methicillin resistant by the Kirby-Baeur disk diffusion method. The 34 staphylococcal isolates were further subjected to Microbact 12S identification system and 9(3.21%) were confirmed as Staphylococcus aureus. All 9(100%) were identified as MRSA using the Kirby-Baeur disk diffusion. The overall prevalence of MRSA was (3.21%). The occurrence of Staphylococcus was higher in nono 24(17.14%) than in Yoghurt 10(7.14%) while prevalence of MRSA was 8 (5.71%) and 1(0.71%) in nono and yoghurt respectively. There was no statistical significant difference between the occurrence of these organisms and the locations (P˃0.05). All the isolates were resistant to more than one antibiotic but none resistant to all. The isolates showed over 90% resistance to beta lactams such as penicillin, methicillin and oxacillin. The least resistance was to cefixime 13 (38.23%) and 3(33.33%) by both  staphylococcal species and MRSA respectively. Resistance by the isolates was by a mec A independent mechanism. Six (66.67%) out of the 9 MRSA were positive for the penicillin – binding protein out of which 5(83.33%) were from nono and 1(16.67%) from yoghurt while 7(76.5%) were positive for betalactamase production out of which 6(85.71%) were from nono and 1(14.29%) from yoghurt. The findings of this study, suggest that nono and yoghurt maybe vehicles for diseases caused by MRSA. Food safety should be advocated by relevant agencies and hygiene among the producers and sellers should be encouraged and enforced.

Keywords: MRSA, Nono, Staphylococci, Resistance