title: Molecular characterization of Shiga-toxigenic Escherichia coli isolated from diverse sources from India by multi-locus variable number tandem repeat analysis (MLVA).
abstract: In a first study from India, a diverse collection of 140 environmental and clinical non-O157 Shiga-toxigenic Escherichia coli strains from a large geographical area in north India was typed by multi-locus variable number tandem repeat analysis (MLVA). The distribution of major virulence genes stx1, stx2 and eae was found to be 78%, 70% and 10%, respectively; 15 isolates were enterohaemorrhagic E. coli (stx1 +/stx2 + and eae +). By MLVA analysis, 44 different alleles were obtained. Dendrogram analysis revealed 104 different genotypes and 19 MLVA-type complexes divided into two main lineages, i.e. mutton and animal stool. Human isolates presented a statistically significant greater odds ratio for clustering with mutton samples compared to animal stool isolates. Five human isolates clustered with animal stool strains suggesting that some of the human infections may be from cattle, perhaps through milk, contact or the environment. Further epidemiological studies are required to explore these sources in context with occurrence of human cases.
authors.affiliation: Department of Medical Microbiology,Post Graduate Institute of Medical Education and Research,Chandigarh,India.
authors.forename: A
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Medical Microbiology,Post Graduate Institute of Medical Education and Research,Chandigarh,India.
authors.forename: N
authors.initials: N
authors.lastname: Taneja
authors.affiliation: Institute of Himalayan Bioresource and Technology,Palampur, Himachal Pradesh,India.
authors.forename: R K
authors.initials: RK
authors.lastname: Sharma
authors.affiliation: Institute of Himalayan Bioresource and Technology,Palampur, Himachal Pradesh,India.
authors.forename: H
authors.initials: H
authors.lastname: Sharma
authors.affiliation: Division of Bacteriology,National Institute of Cholera and Enteric Diseases,Beliaghata, Kolkata, West Bengal,India.
authors.forename: T
authors.initials: T
authors.lastname: Ramamurthy
authors.affiliation: Department of Medical Microbiology,Post Graduate Institute of Medical Education and Research,Chandigarh,India.
authors.forename: M
authors.initials: M
authors.lastname: Sharma
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D000483:Alleles; D000818:Animals; D015373:Bacterial Typing Techniques; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005838:Genotype; D006801:Humans; D007194:India; D008460:Meat / Q000382:microbiology; D018598:Minisatellite Repeats; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D014774:Virulence / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli