Epidemiological Investigation, Serotypes and Distribution of Verocytotoxigenic Escherichia coli (VTEC) in Raw Milk and Milk Products in Uyo, Nigeria

Abstract

Food borne diseases are of great concern globally especially in the developing countries where poor sanitation is applied during collection and processing of milk from animals. The epidemiological investigation, serotypes and distribution of verocytotoxin (VTI and VT2)- producing Escherichia coli in raw milk and milk products were determined using structured questionnaire, Cefixime tellurite-sorbitol MacConkey agar, agglutination kits and VTEC-RPLA Toxin detection Kit. Out of 27 milkers, 7.4 % had primary education, 22.2 % washed the milk utensils with cold water and soap, 11.1 % washed their hands before milking, while 7.4 % milkers washed the udder of the animals before milking. All the yoghurts had the product names; 85.7 % had NAFDAC numbers; 80.0% had Batch Numbers, while 71.4 % had Manufacturer s’ Addresses. The unpasteurized milk samples had E. coli 0157 and non 0157 E. coli counts (CFU.ml^-1) ranging from 4.0 x 10² to 1.7 x 10³ and 6.0 x 102 to 2.0 x 10³ , respectively, while E. coli 0157 and non 0157 E. coli counts of milk products were between 1.0 x 10² and 1.0 x 10³ CFU.ml-1. E. coli 0157 had the highest percentage occurrence (38.3%), while ^{E. coli} 0145 had the lowest percentage occurrence (2.1%). More than 38.3% of the E. coli serotypes produced VT2, while ≥ 12.8% were VT1 producers. The occurrence of VTEC in the unpasteurized milk shows that the milkers should be enlightened on the necessary sanitary practices to adopt during milking and also post-pasteurization contamination of milk products should be avoided.

Key Words: Verotoxigenic, Escherichia coli, Milk, Yoghurt, Nono, Serotypes.