Prevalence of the Six Major Non-O157 Serogroups of Shiga Toxin–Producing <i>Escherichia coli</i> in Food Marketed in Morocco

The six major non-O157 serogroups of Shiga toxin-producing <i>Escherichia coli</i> (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 <i>stx1</i>, <i>stx2</i>, <i>eae</i>, <i>wzx O26</i>, <i>wzx O45</i>, <i>wzx O103</i>, <i>wbdl O111</i>, <i>wzx O121</i>, and <i>ihp1 O145</i> genes. Out of 310 samples analyzed, Shiga toxin (<i>stx)</i> was detected in 55 enrichments (17.74%), <i>stx,</i> and <i>eae</i> were detected in 54/310 enrichments (17.42%), <i>stx</i>, <i>eae,</i> 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 <i>stx</i>, <i>eae,</i> 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.