title: Prevalence of SHV-12 among clinical isolates of Klebsiella pneumoniae producing extended-spectrum beta-lactamases and identification of a novel AmpC enzyme (CMY-8) in Southern Taiwan.
abstract: Twenty (8.5%) of 234 nonrepetitive clinical isolates of Klebsiella pneumoniae from southern Taiwan were found to produce extended-spectrum beta-lactamases (ESBLs): 10 strains produced SHV-12, 4 produced SHV-5, 2 produced a non-TEM non-SHV ESBL with a pI of 8.3, 3 produced a novel AmpC beta-lactamase designated CMY-8 with a pI of 8.25, and 1 produced SHV-12 and an unidentified AmpC enzyme with a pI of 8.2. The CMY-8 enzyme confers a resistance phenotype similar to CMY-1 and MOX-1, and sequence comparisons showed high homologies (>95%) of nucleotide and amino acid sequences among these three enzymes. Plasmid and pulse-field gel electrophoresis analyses revealed that all isolates harboring an SHV-derived ESBL were genetically unrelated, indicating that dissemination of resistance plasmids is responsible for the spread of SHV ESBLs among K. pneumoniae in this area. All three isolates carrying CMY-8 had identical genotypic patterns, suggesting the presence of an epidemic strain.
authors.affiliation: Department of Pathology, National Cheng Kung University Medical Center, Tainan, Taiwan.
authors.forename: J J
authors.initials: JJ
authors.lastname: Yan
authors.forename: S M
authors.initials: SM
authors.lastname: Wu
authors.forename: S H
authors.initials: SH
authors.lastname: Tsai
authors.forename: J J
authors.initials: JJ
authors.lastname: Wu
authors.forename: I J
authors.initials: IJ
authors.lastname: Su
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D015995:Prevalence; D013624:Taiwan / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C107198:beta-lactamase SHV-12; C048795:AmpC beta-lactamases; D001618:beta-Lactamases