PREVALENCE AND DISTRIBUTION OF MICROBIAL CONTAMINATION IN RAW MILK AND PROCESSED DAIRY PRODUCTS IN JOS METROPOLIS

Abstract

The study investigates the microbial contamination of dairy products collected from four locations within Jos Metropolis; (Tina Junction, Farin Gada, Terminus, and Katako) within Jos Metropolis. A total of 200 dairy samples, including raw milk, Nono (fermented milk): Cheese, and Yoghurt, were aseptically collected and analyzed using standard microbiological methods. The results revealed a significant variation in bacterial prevalence across locations and product types. Bacillus spp. was the most frequently isolated bacterium; it was detected in 144 samples (72.0%): with the highest prevalence in raw milk (94.0%) and nono (92.0%). Mycobacterium bovis (M. bovis) was detected exclusively in raw milk (6.0%): indicating a potential risk of zoonotic transmission through unpasteurized dairy. Processed dairy products had a higher occurrence of yeast cells (13.2%): Micrococcus (2.8%): and Staphylococcus (10.4%): suggesting contamination may have occurred during processing and or storage. Among the sampling locations, Farin Gada and Katako had the highest microbial prevalence of 92.0% and 82.0%, respectively, while Tina Junction and Terminus recorded lower contamination levels (60.0% each). Raw milk had prevalence of 34.7% compared to processed dairy products (94.0%). It was concluded that, raw milk poses a significant risk of microbial contamination, while processed dairy products are susceptible to post-processing contamination. Given the high prevalence of Bacillus spp. (72.0%) and the presence of M. bovis in raw milk, all raw dairy products are recommended to undergo pasteurization or other heat treatments before consumption to eliminate harmful pathogens.