Prevalence and characteristics of verotoxin-producing Escherichia coli (VTEC) in stool samples from asymptomatic human carriers working in the meat processing industry in Switzerland.
A total of 5590 stool samples from healthy employees in the meat industry were screened by PCR for verotoxin-producing Escherichia coli (VTEC). The PCR product of VT-encoding genes was detected in 3. 5% of the samples. Phenotypic and genotypic traits of 47 VTEC strains isolated from asymptomatic carriers were characterized. A variety of serotypes was found; one strain belonged to the serotype O157:H7. The majority of the isolates proved to be VT2-positive. Fifty-seven percent of the verotoxin-producing strains harboured the genes for one or several additional virulence associated factors, including intimin (eae, 8.5%), the 60 MDa plasmid (42.5%), enterohaemolysin (EHEC-hlyA, 38.3%), the heat-stable enterotoxin (astA, 6.4%), a serin protease (espP, 6.4%), colicin production (col D157, 12.8%) and a secretion system II (etpD, 10.6%). None of the strains was positive for a specific enzyme with catalase-peroxidase activity (katP).
Stephan
R
R
Institute of Food Safety and Hygiene, Faculty of Veterinary Medicine, University of Zurich, Switzerland.
Ragettli
S
S
Untermann
F
F
D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification* / Q000302:isolation & purification* / Q000378:metabolism / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D019453:Escherichia coli O157 / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity; D005243:Feces / Q000382:microbiology*; D005511:Food Handling; D006801:Humans; D008462:Meat-Packing Industry; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012703:Serotyping; D022622:Shiga Toxin 1; D013557:Switzerland / Q000453:epidemiology; D014774:Virulence / Q000235:genetics
D001427:Bacterial Toxins; D022622:Shiga Toxin 1