Occurrence of Shiga toxin-producing Escherichia coli O157 in selected dairy and meat products marketed in the city of Rabat, Morocco

Samples of meat and dairy products taken from the city of Rabat, Morocco, were examined for the presence of Escherichia coli O157 by the selective enrichment procedure followed by plating on cefixime-tellurite-sorbitol MacConkey agar and a latex agglutination test. The ability of isolates to produce Shiga toxins (ST1 or ST2) was also tested by an agglutination test using sensitized latex. Dairy samples (n = 44) included different products commonly consumed in the country. Meat samples (n = 36) were taken from traditional butchers because these products are generally marketed in this way. Random samples were taken from each product during the period of January through May. Of the 80 samples tested, 8 (10%) harbored E. coli O157. Four dairy and four meat samples were contaminated (9.1 and 11.1%, respectively). Of 10 E. coli O157 isolates from contaminated samples demonstrating true antigen-antibody agglutination, 5 (50%) produced either ST2 alone or ST2 plus STI. Four of the five strains (80%) were meat isolates and produced ST2 with or without STI, and the fifth was a dairy isolate producing ST2.