title: Survey and molecular genetics of SHV beta-lactamases in Enterobacteriaceae in Switzerland: two novel enzymes, SHV-11 and SHV-12.
abstract: Sixty isolates of Enterobacteriaceae resistant to beta-lactam antibiotics were collected over a period of 2 years in Switzerland and screened by hybridization for the carriage of SHV genes. Thirty-four positive strains were found, and their SHV genes were amplified and sequenced. SHV extended-spectrum beta-lactamases (ESBLs) were found: 13 strains contained SHV-2a, 12 harbored SHV-2, and SHV-5 was found twice. Four strains were shown to contain SHV-1. In addition, we report two new SHV variants, termed SHV-11 (non-ESBL) and SHV-12 (ESBL). In spite of the carriage of SHV ESBLs, many strains showed only low resistance to one or more third-generation cephalosporins. In addition, 26 did not transfer the blaSHV gene in mating experiments.
authors.affiliation: Department of Medical Microbiology, University of Zürich, Switzerland.
authors.forename: M T
authors.initials: MT
authors.lastname: Nüesch-Inderbinen
authors.forename: F H
authors.initials: FH
authors.lastname: Kayser
authors.forename: H
authors.initials: H
authors.lastname: Hächler
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008967:Molecular Biology; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D013557:Switzerland; D001618:beta-Lactamases / Q000145:classification / Q000235:genetics*; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; C107197:beta-lactamase SHV-11; C107198:beta-lactamase SHV-12; D001618:beta-Lactamases