Prevalence of the Six Major Non-O157 Serogroups of Shiga Toxin-Producing Escherichia Coli in Food Marketed in Morocco.

Abstract

The six major non-O157 serogroups of Shiga toxin-producing Escherichia coli (STEC) are responsible for serious foodborne outbreaks worldwide. This research aimed to detect the six major non-O157 STEC in ground beef, artisanal dairy products, lettuce, spinach, turkey, and chicken sold in northern Morocco. Real-time polymerase chain reaction was utilized to identify the presence of the stx1, stx2, eae, wzx O26, wzx O45, wzx O103, wbdl O111, wzx O121, and ihp1 O145 genes. Out of 310 samples analyzed, Shiga toxin (stx) was detected in 55 enrichments (17.74%), stx, and eae were detected in 54/310 enrichments (17.42%), stx, eae, and genes of at least one of the six serogroups were detected in 34/310 enrichments (10.97%). Among the food matrices analyzed, ground beef showed the highest contamination rate with stx, eae, and O serogroups 13/70 (18.6%), followed by dairy 17/100 (17.00%), turkey 3/40 (7.5%), and chicken 1/40 (2.5%). No O serogroups were detected in lettuce and spinach. The most frequent serogroup was O26 (22/34; 64.7%), followed by O145 (12/34; 35.3%), O45 (12/34; 35.3%), O121 (8/34; 23.5%), O103 (8/34; 23.5%), and O111 (6/34; 17.6%). A set of 32 STEC strains were isolated from nine positive samples (9/34; 26.5%). A high rate of food contamination with STEC may indicate firstly a high public health risk due to this pathogen in beef and dairy products and secondly a lack of compliance with standard hygiene practices. Consequently, it emphasizes the urgent need for rigorous monitoring and intervention measures aimed at mitigating the incidence of STEC contamination.