title: Detection and characterization of verotoxin-producing strains among sorbitol non-fermenting Escherichia coli.
abstract: The presence of genes for verotoxin 1 and 2 (VT1 and 2) among sorbitol non-fermenting Escherichia coli isolates from diarrhoeal cases was assessed using polymerase chain reaction assay. Of 60 (88%) positive isolates, 37 (62%) harboured VT1 and 23 (38%) both VT1 and VT2. In HeLa cell adherence assay, 48 (71%) isolates exhibited mannose-resistant adherence to HeLa cells. Multidrug resistance was observed in 56 (82%) isolates, with ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-trimethoprim and tetracycline pattern being the most common. There were 13 common and 22 single biochemical phenotypes identified. Isolates belonging to common biochemical phenotypes normally had a similar pattern of adherence and VT production, but differed greatly in their pattern of antibiotic resistance, pointing to a high rate of antibiotic-resistance transfer among these isolates.
authors.affiliation: Molecular Biology Unit, Pasteur Institute of Iran, Teheran, Islamic Republic of Iran.
authors.forename: A
authors.initials: A
authors.lastname: Jafari
authors.forename: M
authors.initials: M
authors.lastname: Katouli
authors.forename: F
authors.initials: F
authors.lastname: Shokouhi
authors.forename: S
authors.initials: S
authors.lastname: Bouzari
mesh_terms: D000362:Agar; D001422:Bacterial Adhesion / Q000235:genetics; D018929:Cell Culture Techniques / Q000379:methods; D002648:Child; D003470:Culture Media; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D005144:F Factor / Q000235:genetics; D005285:Fermentation; D006801:Humans; D007492:Iran / Q000453:epidemiology; D017720:Molecular Epidemiology; D010641:Phenotype; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D015995:Prevalence; D012703:Serotyping / Q000379:methods; D022622:Shiga Toxin 1 / Q000235:genetics*; D022641:Shiga Toxin 2 / Q000235:genetics*; D013012:Sorbitol
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D013012:Sorbitol; D000362:Agar