Microbiological analysis of raw milk, pasteurized milk and yogurt samples collected from different areas of Dhaka city, Bangladesh

Abstract

A total of 300 different milk and yogurt samples were collected from Dhaka city and analyzed for total viable bacterial count (TVBC), total coliform count (TCC) and presence of several pathogens such as Escherichia coli, Salmonella spp., Shigella spp., Vibrio spp. and Listeria monocytogenes. Raw milk samples collected from Moghbazar area showed highest TVBC (4.2 × 10⁶ cfu/ml) and samples from Mohammadpur area showed lowest count (3.5 × 10³ cfu/ml). All the pasteurized milk samples showed TVBC of 1.9 × 10² to 2.8 × 10³ cfu/ml, and TCC only in one sample Yogurt samples (open) collected from vendor showed TVBC of 9.1 × 10³ to 8.2 × 10⁷ cfu/ml, and TCC only in sample collected from Dhanmondi, Dhaka. The packed yogurt samples showed TVBC of 2.2 × 10² to 6.1 × 10³ cfu/ml, and TCC only in one sample. All the milk and yogurt samples were found contaminated with E. coli and Shigella-like species. Listeria monocytogenes was not detected in any of the samples studied.

Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 31-36, 2015