Prevalence of Microbiological Contaminants in Milk Samples in Kathmandu, Nepal

Contaminated milk is responsible for mild to life threatening disease in humans. This study was aimed to access the microbiological contaminants present in milk samples collected from different sites in Kathmandu. A cross-sectional study was conducted between January and July 2019. A total of 90 milk samples were collected (30 farm milk, 30 dairy milk and 30 pasteurized packaged milk) from local farms and outlets. All the collected samples were processed for bacterial and fungal growth in standard in-vitro conditions. Identification was done via colony characteristics, biochemical tests and staining property. Identified bacterial isolates were tested for antibiotic susceptibility. Out of 90 samples, 41.1% were contaminated with bacteria and 46.6% showed fungal growth. Overall prevalence of S.aureus and E.coli was 26.6% and 14.4% respectively. 25.0% of the S.aureus isolates were methicillin-resistant. In addition, the prevalence of Aspergillus spp. was 26.6% and Penicillium spp. was 20.0%.The highest mean bacterial (279.13 x10 cfu/ml) and coliform count (175.53x10 cfu/ml) was recorded in dairy milk. Also, six samples showed polymicrobal growth. In conclusion, dairy milk samples are highly contaminated than farm and pasteurized packaged milk.