The use of polymerase chain reaction (PCR) to confirm presence of selected pathogenic bacteria along milk value chain in Tanga region uri icon


  • BACKGROUND Despite the fact that foods of animal source are a minor constituent in most diets, they are responsible for incidents of food-borne illness; dairy products being implicated. Up to 90% of all dairy ? related diseases are due to pathogenic bacteria found in milk. Emergence of new milk-borne bacterial pathogens with more serious challenges such as E.coli O157:H7 has been reported. OBJECTIVES The main objective was to determine milk-borne zoonotic risks associated with milk handling and storage along the dairy value chain. Specific objectives included: 1. To assess possible sources of microbial contamination of milk from farm to consumer 2. To identify practices that lead to microbial contamination along the milk value chain 3. To enumerate total number of bacteria and coliforms present in milk 4. To assess presence of E. coli and B. abortus along the milk value chain MATERIALS AND METHODS Milk samples and questionnaires from all the actors along the dairy value chains of Handeni and Lushoto districts in Tanga region were collected. The questionnaires were analyzed using Stata/IC 11 while standard microbiological cultures and polymerase chain reaction were used to identify and confirm microbial contamination in milk. RESULTS A total of 184 (118 farmers, 4 collection centres, 16 restaurants, 35 vendors, 11 consumers) milk samples were collected and a total of 81 (65 farmers, 11 restaurants, 15 vendors). A checklist of questions for four collection centres was also filled. From the sociological data, different practices that could lead to microbial contamination of milk during milking, storage and delivery were identified. Preliminary analysis showed that only 43 % of farmers cleaned the animal shed before milking, only 71 % washed hands before milking, and, only 71 % of farmers washed the cows? teats before milking. Detailed results of the study, including laboratory results and sociological results are presented

publication date

  • 2013