Differential Distribution of Pathogens from Raw Milk and Place of Shigella by Mode of Milking Distribution Différentielle Des Germes Pathogènes Du Lait Cru et Place de Shigella Selon Le Mode de Traite

Milk is a biologic food that has clear nutritional benefits. Because of its composition, milk is a living environment composed of a diverse flora. Among the latter, we encounter pathogens that were dangerous to human health. Milk represents an important vector of germs in humans. Milk contamination by pathogenic bacteria such as Staphylococcus aureus , Escherichia coli , Streptococcus , Shigella … is now a major concern of product chains in raw milk, because of their roles in food poisoning. In most cases, contamination of milk by these organisms occurs during milking by bacteria on the skin of the teats themselves soiled bedding contaminated by their droppings, the milking equipment or by water used for watering cows, either for operations hygiene at milking. In our study, selected pathogens were identified and counted from samples of raw milk from two types of milking and samples were collected from three different grocery stores. Varying proportions were recorded in relation to the mode of milking, E. coli occupies first place in hand milking (98.7%), followed by Streptococcus in 95%, Staphylococcus (79.3%) and Shigella with 16.5%, but these proportions diminish considerably when the milking is automatic or when the milk is collected from grocers. But in the automatic milking Shigella occupies the first place (80.7%) followed by Staphylococcus (19.9%), in contrast E. coli is almost absent and Streptococcus are present in small proportion (3.6%). The distribution of Staphylococcus and Streptococcus is homogeneous whatever the mode of milking but it is heterogeneous for E. coli and Shigella . Comparative analysis of milk from milking manually and automatically collected milk from 3 grocery stores shows that the Streptococcus which takes second place after E. coli in hand milking seems most representative and homogeneous. This differential distribution of germs is probably related to the environment of milking and its microbial ecological quality and probably the frequency and the relative volume of water used in each course operational. Further studies are needed to see the reasons for this unconventional redistribution to finding effective ways of prevention.