Isolation and characteristics of sorbitol-fermenting Escherichia coli O157 strains from cattle.
Cattle can be a reservoir of sorbitol-fermenting Escherichia coli O157 (SF E. coli O157) and a source of human diseases. In this study, six strains of SF E. coli O157 were isolated and characterized from cattle using an immunomagnetic separation procedure. PCR analysis of the SF E. coli O157 virulence markers showed that all six isolates tested positive for sfpA, rfbE and eaeA, and negative for terA, ureA, katP and espP. Two of the isolates contained the stx genes. Four isolates tested positive for enterohemorrhagic E. coli hlyA (EhlyA) by PCR but were nonhemolytic on the blood agar. Five isolates tested positive for the cdtA gene. The possession of these virulence factors was an indication of their pathogenic potential. The random amplified polymorphic DNA patterns, which were generated by the arbitrarily primed PCR of the SF E. coli O157 isolates from the cattle, were significantly different from those of the non-sorbitol-fermenting E. coli O157 (NSF E. coli O157) strains originating from cattle or humans. GelCompar analysis showed that the SF E. coli O157 isolates had only a 57% genetic similarity with the NSF E. coli strains. The minimal inhibitory concentration assay showed that imipenem inhibited the growth of the six isolates at a concentration of <4 microg/ml.
Lee
John Hwa
JH
College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea. johnhlee@chonbuk.ac.kr
Choi
Su-Jeong
SJ
D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000235:genetics; D002238:Carbohydrate Epimerases / Q000235:genetics; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D005285:Fermentation; D006460:Hemolysin Proteins / Q000235:genetics; D006461:Hemolysis; D015378:Imipenem / Q000494:pharmacology; D018189:Immunomagnetic Separation; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D012697:Serine Endopeptidases / Q000235:genetics; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D013012:Sorbitol / Q000378:metabolism*; D000637:Transaminases / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D037521:Virulence Factors; C067044:cytolethal distending toxin; C073819:eaeA protein, E coli; D013012:Sorbitol; D015378:Imipenem; D000637:Transaminases; C107189:EspP protein, E coli; D012697:Serine Endopeptidases; D002238:Carbohydrate Epimerases; C061272:perosamine synthetase