Apr 7, 2014 - (e.g., Indole, Methyl red, Voges-Proskauer and Citrate utilization ..... Sabat G, Rose P, Hickey WJ, Harkin JM: Selective and sensitive method for.
Dehkordi et al. BMC Research Notes 2014, 7:217 http://www.biomedcentral.com/1756-0500/7/217
RESEARCH ARTICLE
Open Access
Virulence factors, serogroups and antimicrobial resistance properties of Escherichia coli strains in fermented dairy products Farhad Safarpoor Dehkordi*, Farshad Yazdani, Jalal Mozafari and Yousef Valizadeh
Abstract Background: From a clinical perspective, it is essential to know the microbial safety of fermented dairy products. Doogh and kashk are fermented dairies. These products are used by millions of people but their microbial qualities are unknown. Shiga toxin producing Escherichia coli (STEC) is one of the most commonly detected pathogens in the cases of food poisoning and food-borne illnesses. The present investigation was carried out in order to study the molecular characterization and antimicrobial resistance properties of STEC strains isolated from fermented dairy products. Methods: Six hundred fermented dairy samples were collected and immediately transferred to the laboratory. All samples were cultured immediately and those that were E. coli-positive were analyzed for the presence of O157 , O26, O103, O111, O145, O45, O91, O113, O121 and O128 STEC serogroups, tetA, tetB, blaSHV, CITM, cmlA, cat1, aadA1, dfrA1, qnr, aac (3)-IV, sul1 and ereA antibiotic resistance genes and stx1, stx2, eaeA, ehly, cnf1, cnf2, iutA, cdtB, papA, traT, sfaS and fyuA virulence factors using PCR. Antimicrobial susceptibility testing was performed also using disk diffusion methodology with Mueller–Hinton agar. Results: Fifty out of 600 (8.33%) dairy samples harbored E. coli. In addition, yoghurt was the most commonly contaminated dairy. O157 (26%) and O26 (12%) were the most commonly detected serogroups. A significant difference was found between the frequency of Attaching and Effacing E. coli and Enterohaemorrhagic E. coli (P
