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Escherichia coli and other microorganisms underscore the importance of milk and similar milk products as the causative agent for several infections in humans. The present study deals with the contamination of milk in the villages of Dehradun district. Seventy four percent milk samples have been found to be contaminated with E.coli. Though pasteurization most often kills a majority of bacteria in milk, some strains produce enzymes that survive the pasteurization treatment. Heat stabile enzymes have the capability of further degrading the processed product, especially long-life milk products. The present study reveals the infection potential and resistant microbes in Dehradun city.
Milk is synthesized in specialized cells of the mammary gland and is virtually sterile when
secreted into the alveoli of the udder (Tolle, 1980). Raw milk represents an ideal growth
medium for microorganism (Haridy, 1992). Raw milk as it leaves the udder of healthy cow
gets contaminated because of its complex biochemical composition and high water activity
with the microorganisms and generally contains less than 1,000 bacterial cells per ml
(Kurweil and Busse, 1973). Microbial contamination can generally occur from three main
sources, namely: (1) within the udder; (2) exterior of the udder; and
(3) the surface of milk handling and storage equipment (Bramley and Mc Kinnon, 1990).
Escherichia coli and other microorganisms underscore the importance of milk and milk
products as vehicles of human infection. The presence of human pathogens has been
attributed to the farm level factors that reflect general hygiene, such as the degree of
cleanliness of the facilities and animal’s cleanliness of milking equipment. Inappropriateprocessing results of milk attributes to the poor quality of milk. Fifty percent of the milk
produced is consumed as fresh or boiled, one sixth as yoghurt or curd and remaining is utilized
for manufacturing of indigenous varieties of milk products (Anjum et al., 1989). E. coli is
frequently contaminating organism and reliable indicator of water, food, milk and other dairy
products (Dilielo, 1982). If environmental contamination of milk supply are very important
parameters, then farm level factors that reflect general hygiene, such as the degree of
cleanliness of the facilities and animal’s cleanliness of milking equipment, and other factors
might be important in limiting access of these agents to milk (Mc Ewes et al., 1988). |
