Isolation, molecular characterization and antibiotic resistance of Shiga Toxin-Producing Escherichia coli (STEC) from buffalo in India.
In total, 363 Escherichia coli were isolated from 165 faecal samples of healthy buffaloes in West Bengal, India. Twenty-four of these isolates (6·61%) were found to carry at least one gene characteristic for Shiga toxin-producing Escherichia coli (STEC). These STEC strains belonged to 13 different O-serogroups. The stx1 gene was present in 23 (95·8%) of total STEC isolates, whereas 20 (83·3%) STEC isolates carried the gene stx2. Twelve strains of E. coli (50% of total STEC isolates) possessed enterohaemolysin (ehxA) gene in combination with others. Fourteen (58·33%) isolates found to possess saa gene. However, no E. coli was detected harbouring gene for intimin protein (eaeA). Of 23 stx1 -positive isolates, seven (30·43%) were positive for genes of the stx1C subtype. Of the 20 isolates with the stx2 gene, 25% (5/20) possessed stx2C and 10% (2/20) possessed stx2d gene. The phylogenetic analysis after RAPD of STEC strains revealed six major clusters. The isolated STEC strains were resistant most frequently to erythromycin (95·83%), cephalothin (62·5%), amikacin (54·17%), kanamycin (45·83%) and gentamicin (41·67%) group of antibiotics. No ESBL-producing (blaCTXM , blaTEM , blaSHV ) or quinolone resistance gene (qnrA) was detected in the STEC isolates.
Department of Veterinary Microbiology, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India.
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Mahanti
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Samanta
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Bandopaddhay
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Joardar
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Dutta
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Batabyal
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D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002020:Buffaloes / Q000382:microbiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics; D007194:India; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D012703:Serotyping; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D037521:Virulence Factors / Q000235:genetics
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D037521:Virulence Factors; C066219:enterohemolysin