Resistance patterns of non-O157 Shiga toxin-producing Escherichia coli (STEC) strains isolated from animals, food and asymptomatic human carriers in Switzerland.
OBJECTIVE
The objective of the present study was to determine the resistance patterns of non-O157 Shiga toxin-producing Escherichia coli (STEC) strains isolated from different sources in Switzerland during the period 1997-99 as an epidemiological marker.


RESULTS
The disk diffusion method was used to test 82 non-O157 STEC strains for susceptibility to 13 antibiotics. Ten strains were resistant to one and 20 strains to two and more antibiotics. The most frequent resistance types were streptomycin (14 strains), cephalothin (14 strains), sulfamethoxazole (14 strains) and tetracycline (14 strains). Three O100:H- STEC strains isolated from healthy slaughter pigs were resistant to eight antibiotics: streptomycin, sulfamethoxazole, trimethoprim, tetracycline, ampicillin, chloramphenicol, neomycin and gentamicin.


CONCLUSIONS
Periodic surveillance of the antibiotic susceptibilities would be an important measure in detecting emergence and spread of resistance.


CONCLUSIONS
Antibiotic susceptibility testing can be a useful tool for typing strains and should be used in combination with other phenotypic and genotypic methods.
Stephan
R
R
Institute for Food Safety and Hygiene, Faculty of Veterinary Medicine, University of Zurich, Zurich, Switzerland. stephanr@safety.unizh.ch
Schumacher
S
S
D000818:Animals; D002353:Carrier State / Q000382:microbiology*; D002417:Cattle; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000662:veterinary; D005516:Food Microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D022603:Shiga Toxins / Q000096:biosynthesis*; D013552:Swine; D013557:Switzerland
D022603:Shiga Toxins