Open AccessAntibiotic Resistance, Virulence Gene, and Molecular Profiles of Shiga Toxin-Producing Escherichia coli Isolates from Diverse Sources in Calcutta, India
Author(s) -
Asis Khan,
Sanjukta Das,
T. Ramamurthy,
A. Sikdar,
Jasmina Khanam,
Shinji Yamasaki,
Yoshifumi Takeda,
G. Balakrish Nair
Publication year - 2002
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.40.6.2009-2015.2002
Subject(s) - pulsed field gel electrophoresis , virulence , biology , microbiology and biotechnology , rapd , escherichia coli , antibiotic resistance , dna profiling , genotype , shiga like toxin , antibiotics , shiga toxin , gene , genetics , dna , genetic diversity , population , demography , sociology
Antibiotic resistance, virulence gene, and molecular profiles of Shiga toxin-producing Escherichia coli (STEC) non-O157 strains isolated from human stool samples, cow stool samples, and beef samples over a period of 2 years in Calcutta, India, were determined. Resistance to one or more antibiotics was observed in 49.2% of the STEC strains, with some of the strains exhibiting multidrug resistance. The dominant combinations of virulence genes present in the strains studied were stx(1) and stx(2) (44.5% of strains) and stx(1), stx(2), and hlyA (enterohemorrhagic E. coli hemolysin gene) (19% of strains). Only 6.4% of the STEC strains harbored eae. The diversity of STEC strains from various sources was assessed by random amplification of polymorphic DNA (RAPD). STEC strains that gave identical or nearly similar DNA fingerprints in RAPD-PCR and had similar virulence genotypes were further characterized by pulsed-field gel electrophoresis (PFGE). Identical RAPD and PFGE profiles were observed in four sets of strains, with each set comprising two strains. There was no match in the RAPD and PFGE profiles between strains of STEC isolated from cows and those isolated from humans. It appears that the clones present in bovine sources are not transmitted to humans in the Calcutta setting although these strains showed evolutionary relatedness. Maybe for this reason, STEC has still not become a major problem in India.