Prevalence oF Enterobacteriaceae in raw milk and some dairy products

Abstract

Objective: This study was performed to detect and identify members of Enterobacteriaceae in raw milk, yoghurt and ice cream to assess their hygienic quality. Methods: A total number of 200 samples distributed as follows:100 raw milk, 25 small and 25 large scale plain yoghurt, and 25 small and 25 large scale ice cream samples collected from different localities at Kafr El-Sheikh Governorate and examined for Enterobacteriaceae count and identification of members. Results: Enterobacteriaceae were detected in 84% of examined raw milk samples (with mean count of 1.02x106 + 1.98x105 cfu/ml), 40% and 32% of examined small and large scale plain yoghurt samples (with mean value of 6.95x103 + 4x103 and 1.57x103 + 8.95x102 cfu/g), while detected in 64% and 20% of examined small and large scale ice cream samples (with mean count of 1.02x104 + 4.13x103 and 1.4x103 + 8.26x102 cfu/g). The most frequent members isolated were Hafnia alive (30.95%), E. coil (44.44%), and Serratia marcescens (57.14%) from positive raw milk, yoghurt, and ice cream samples, respectively. Other members of Enterobacteriaceae were isolated from positive samples at different percentages. Conclusion: Presence of members of Enterobacteriaceae is a reliable index of fecal contamination and the possibility of the presence of associated enteric pathogenic organisms. So, it is recommended to specify Enterobacteriaceae as a sanitary index of milk and dairy products in the Egyptian food acts and regulations.