Occurrence of multidrug resistant shiga-toxigenic E. coli in retailed cheese in Zagazig city, Egypt

Abstract

Cheese is regarded as an essential dairy product that cover part of the human needs with vitamins and minerals. However, cheese is also implicated in many food poisonings outbreaks worldwide. This study conducted to estimate coliforms and E. coli, and to investigate the occurrence of shigatoxigenic E. coli in four cheese types mostly consumed in Zagazig city, Egypt. In addition, detection of coding genes for shiga toxins (stx1, and stx2) was further screened using PCR. Besides, antimicrobial susceptibility of the isolated E. coli was further examined. The obtained results revealed that Kariesh cheese had the highest coliforms and E. coli counts, followed by Rumy, Domiati, and Feta cheeses, respectively. The isolation rates of E. coli were 52%, 24%, 20%, and 8% in Kariesh, Rumy, Domiati and Feta cheeses, respectively. The identified E. coli serotypes were E. coli O55:H7, E. coli O86:H11, E. coli O78:H-, E. coli O111:H4, E. coli O127:H6, and E. coli O26:H11. The expression of shiga toxin-coding genes indicated that E. coli O55:H7 harbored only stx1, E. coli O111:H4, and E. coli O86:H11 harbored only stx2, E. coli O78:H-, and E. coli O26:H11 harbored both stx1, and stx2; however, E. coli O127:H6 did not express any of the tested genes. Antimicrobial sensitivity testing revealed multidrug resistance profiles, particularly among E. coli O86:H11, E. coli O78:H-, and E. coli O26:H11. Therefore, strict hygienic measures should be adopted during all manufacture steps of these kinds of cheese.