Isolation and identification of coliform bacteria from spicy yogurt milk and plain butter milk sold in different markets of Dhaka city

Abstract

Spicy yogurt milk and plain butter milk are two of the most popular drinks in the south Asian region, especially in Bangladesh and India. These two drinks are widely consumed by people of this region as beverages in all seasons as it is a good source of nutrients in an affordable price. In Bangladesh, these drinks are so connected with our culture that in occasion like weddings these two drinks are served. For healthy diet plans, these two drinks can be a good option. However, because of hygiene and making procedure these drinks can become so unhealthy that it can be harmful for human health. The study was conducted to find out the quality of spicy yogurt drink and plain butter milk sold in the market of Dhaka city. In this study, total 31 (16 spicy yogurt milk and 15 plain butter milk) samples were collected from different markets and food shops of Dhaka city to check their microbial quality. The microbial quality was evaluated by quantifying total viable count, total coliform and fecal coliform count. During the study, it was found that out of all the 31 different samples of spicy yogurt drink and plain butter milk 1 spicy yogurt milk and 2 plain butter milk showed presence of Pseudomonas spp. Escherichia coli was found in other 2 plain butter milk and spicy yogurt milk samples. Another 2 spicy yogurt milk samples showed the presence of Staphylococcus spp. Klebsiella spp. was found in 2 spicy yogurt milk and 1 plain butter milk samples. One of the samples of spicy yogurt milk showed the presence of Staphylococcus aureus which is skin disease causing bacteria and can be found on affected person‘s skin. Some of the other organisms such as Salmonella spp. and Listeria spp. was found in 1 sample and Shigella spp. was found in other 3 samples. After the identification antibiotic susceptibility test was done to find out if any resistance strain is present. During the susceptibility test it the presence of multi-drag resistance microorganisms such as Escherichiacoli and Pseudomonas spp. were confirmed. Although from this study it can be said that, the microbial quality of the samples were not good for human health because of presence of different disease causing microbes at a very high level. The main purpose of this study was to create awareness among the consumers about the quality of the drink that they are taking and towards the seller who are providing low quality products to the society. The government should take some preventive steps and introduce some strict rules towards the manufactures and sellers so that they maintain proper hygiene. It is very important to maintain proper hygienic conditions for personal health benefit. Keywords: Spicy yogurt milk, plain utter milk, coliform, fecal coliform, multi-drag resistance.