Multidrug-resistant diarrheagenic E. coli pathotypes are associated with ready-to-eat salad and vegetables in Pakistan

Abstract

Diarrheagenic E. coli pathotypes are major foodborne pathogens causing gastrointestinal tract infections leading to hemolytic uremic syndrome and hemorrhagic colitis. Consumption of raw vegetables is encouraged due to its nutrient content and antioxidant properties, although their ingestion is linked to a series of foodborne disease outbreaks. The aim of this study was to evaluate the prevalence of Enterotoxigenic, Enteropathogenic, and Shiga toxin-producing E. coli pathotypes in raw vegetables and ready-to-eat salad for the development of better risk management. A total of 260 vegetable and salad mix (cucumber, lettuce, spinach, and carrot) samples were collected from commercial food markets in Southern districts of Khyber Pakhtunkhawa, Pakistan. About 34 % vegetable samples were contaminated with E. coli strains. 32.4 % E. coli strains from vegetable sample were identified as diarrheagenic E. coli pathotypes. Similarly, 26.7 % of salad samples were contaminated with E. coli pathotypes. 15 % [two Enterotoxigenic E. coli and one Enteropathogenic E. coli] were isolated from spinach salad samples. 25 % [three Enterotoxigenic E. coli, one Enteropathogenic E. coli and one Shiga toxin-producing E. coli] were isolated from mixed salad type A. 40 % [four Enterotoxigenic E. coli, two Enteropathogenic E. coli and two Shiga toxin-producing E. coli] were isolated from mixed salad type B. 92 % diarrheagenic E. coli pathotypes showed resistance against Tetracycline and 87 % to Ampicillin. This study showed that fresh vegetable and their products were contaminated with multidrug-resistant E. coli pathotypes.