ISOLATION AND IDENTIFICATION OF BACTERIAL SPECIES ASSOCIATED WITH THE CONTAMINATION OF FERMENTED COW MILK (NONO) SOLD IN GADAU CENTRAL MARKET

ABSTRACT This study assessed the bacteriological quality and safety of raw fermented milk (nono) marketed in Gadau metropolis, Bauchi State, Nigeria. Raw milk and dairy products are nutritionally rich but highly susceptible to microbial contamination due to unhygienic handling and storage practices. Nono samples were collected from five street vendors and analyzed using standard microbiological methods, including total viable count (TVC), isolation, Gram staining, and biochemical tests (catalase, coagulase, oxidase, indole). The isolates were identified as Streptococcus (40%), Lactobacillus (30%), Lactococcus (20%), and Staphylococcus (10%). TVC ranged from (1.1 \times 10⁵\) to \(2.1 \times 10⁵\) CFU/g, indicating tolerable but marginal hygienic quality according to ICMSF (1996) standards. The prevalence of lactic acid bacteria (LAB) suggested natural fermentation due to inadequate refrigeration, while Staphylococcus contamination pointed to poor handler hygiene. The study concludes that nono sold in Gadau poses potential public health risks due to unsanitary production conditions. Recommendations include vendor training on hygiene, consumer education on boiling milk before consumption, and regulatory enforcement of microbial quality standards. Further research using molecular techniques for species-level identification and pathogen detection is advised.