Use of multiplex PCR assay for detection of diarrheagenic Escherichia coli in street vended food items

Pathogenic forms of Escherichia coli are commonly known to cause a variety of diarrheal diseases in hosts. Present study was designed to identify such pathogenic E. coli isolates from 7 different groups of street vended foods including cream, egg, non fried dry food and fried dry food, salad, cooked and non cooked items. Among 400 samples studied, almost all were found to be contaminated with an array of bacteria ranging between 3.24×10 2 -6.5×10 9 cfu/g. Results of multiplex polymerase chain reaction (PCR) assay revealed that out of 130 isolates of E. coli screened from all categories of food items, 52 (13%) were found to be enterotoxigenic E. coli, 32 (8%) were the Shiga toxin producing E. coli isolates, 14 (3.5%) were enteropathogenic and 6 (1.5%) were found to be enteroinvasive isolates. Results of plasmid profiling of the isolates was further in agreement to the presence of different pathogenic E. coli strains.