Incidence and multidrug resistance of Escherichia coli pathotypes on fresh vegetables and salads

Diarrhea is a severe health problem and one of the leading causes of child mortality in Africa, Asia, and Latin America. Diarrhea is often caused by consuming contaminated food and improperly washed fruit and vegetables that harbor norovirus, Campylobacter , non-typhoid Salmonella , and pathogenic Escherichia coli. The research examined 334 samples of ready-made salads with lettuce, carrots, tomatoes and fresh coriander and lettuce. Genotyping involved detecting st and lt genes for enterotoxigenic E. coli (ETEC) and the uid A gene for beta-glucuronidase. ETEC was found in 51.56% of confirmed isolates, accounting for 9.9% of samples gathered in two years. Contamination rates by ETEC were 78.78% in coriander, 9.09% in lettuce, 9.09%, and 3.03% in green salads from La Vicentina and La Purísima markets, respectively. Among samples, 12.12% have both fragments ( st/lt ), 33.3% have only the lt fragment, and 54.6% have just st . In salads, the lt/st genes were detected in 9.09% (3), lt in 3.3% (1), and st was absent. In coriander, 21.21% have lt , 51.51% st , and 6.06% showed amplification for both. ETEC was found in 9.09% of the confirmed lettuce strains, with 3.03% lt gene, 3.03% st gene, and 3.03% both ( lt/st ). There are no reported data with the same ratios for Mexico City. ETEC’s presence in products consumed in markets or streets in Mexico City, coupled with lifestyle changes that have increased vegetable consumption, is a significant concern. These findings underscore the potential health implications and the urgent need for further investigation and preventive measures.