title: Evaluation of pathogenic Escherichia coli occurrence in vegetable samples from district bazaars in Istanbul using real-time PCR.
abstract: In this study, a total of 180 vegetable samples collected from several district bazaars of Istanbul were investigated for the occurrence of Escherichia coli using a culture-based method. The isolates were subjected to real-time PCR detection of Shiga-toxin-producing E. coli (STEC) using primers specific for the Shiga toxin (stx1 and stx2) and intimin (eae) virulence genes. The prevalences of E. coli in the samples were 93·3% in spinach, 93·3% in lettuce, 86·6% in parsley, 43·3% in carrot, 33·3% in cucumber and 13·3% in tomato. Of 180 samples, 13 contained STEC (six parsley, three carrots, three lettuces and one cucumber of 30 samples of each). Among 13 STEC-positive isolates, presence of stx1, stx2 and eae was detected in only one sample, stx2 and eae in two samples, and stx2 in ten samples. Serotype O157 was found in parsley, lettuce and carrot; O26 in lettuce, parsley, cucumber and carrot; and O111 and O113 in parsley only. In conclusion, STEC was present in vegetable samples marketed in several district bazaars in Istanbul; this might represent a route of transmission of pathogenic STEC to humans and be harmful to public health.
  
  
  CONCLUSIONS
  We assessed the occurrence of virulent Escherichia (E.) coli and Shiga-toxin-producing E. coli (STEC) virulent populations in the vegetable samples collected from several district bazaars in Istanbul, Turkey. The results indicated that the vegetables from the bazaars had poor microbial quality and represented a potential health risk to customers.
authors.affiliation: Food Engineering Department of Istanbul Aydın University, Sefaköy-Istanbul, Turkey.
authors.forename: H
authors.initials: H
authors.lastname: Ozpınar
authors.forename: B
authors.initials: B
authors.lastname: Turan
authors.forename: I H
authors.initials: IH
authors.lastname: Tekiner
authors.forename: G
authors.initials: G
authors.lastname: Tezmen
authors.forename: I
authors.initials: I
authors.lastname: Gökçe
authors.forename: O
authors.initials: O
authors.lastname: Akıneden
mesh_terms: D017931:DNA Primers / Q000235:genetics; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics; D005516:Food Microbiology; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D022621:Shiga Toxin / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014421:Turkey; D014675:Vegetables / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D017931:DNA Primers; D029968:Escherichia coli Proteins; D037521:Virulence Factors; D022621:Shiga Toxin
keywords: Shiga-toxin-producing Escherichia coli; public health; real-time PCR; serotypes; vegetable