Serotyping and phylogenetic grouping of pathogenic Escherichia coli strains isolated from milk and milk products.

Abstract

Keywords Escherichia coli represents as one of gut microflora of worm-blooded animals that distributed widely. This bacterium is attributed into 4 phylogenetic groups A, B1, B2 and D that differ from each other’s in their virulence and disease caused by them. The current study examined the serotyping of E. coli strains isolated from milk and milk products with investigation of their phylogenetic grouping. Eight strains isolated from raw milk, Kariesh cheese, feta (white) cheese, and Ice cream (two strains from each product) were examined serologically by rapid diagnostic E. coli antisera sets and the result showed the presence of three serotypes O114:K90 (two strains), O128:K67 (three strains) and O55:K59 (three strains). Their phylogenetic grouping came out triplex PCR depend on the amplification of chu A , yja A, and the DNA fragment of tsp E4.C2 . It showed that six strains belonged to the B2 group, and two strains belonged to D group based on the presence or absence of these genes.