title: Molecular cloning and nucleotide sequence of a new plasmid-coded Klebsiella pneumoniae beta-lactamase gene (SHV-2a) responsible for high-level cefotaxime resistance.
abstract: Patient specimen isolates of Klebsiella pneumoniae exhibiting an MIC of greater than 128 mg/l for cefotaxime were shown to produce a beta-lactamase with a pI of 7.6, which is encoded on a 66 kb conjugative plasmid. A 3.5 kb Bam HI fragment of this plasmid was cloned into pLG339 and totally sequenced. The nucleotide sequence of the beta-lactamase gene presented 99% homology to those of SHV-2 and SHV-3, the deduced amino acid sequence differed from both enzymes in one and two positions, respectively, leading to the denomination SHV-2a for the new enzyme. Since the kinetic data of SHV-2a and SHV-2 are similar, too, quantitative effects mediated by distinctly different promotor regions are thought to be responsible for the elevated MIC for cefotaxime induced by SHV-2a.
authors.affiliation: Institute of Medical Microbiology, Technical University (RWTH), Aachen.
authors.forename: A
authors.initials: A
authors.lastname: Podbielski
authors.forename: J
authors.initials: J
authors.lastname: Schönling
authors.forename: B
authors.initials: B
authors.lastname: Melzer
authors.forename: K
authors.initials: K
authors.lastname: Warnatz
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002439:Cefotaxime / Q000494:pharmacology*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry; D004352:Drug Resistance, Microbial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005822:Genetic Vectors; D006801:Humans; D007525:Isoelectric Focusing; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D011815:R Factors; D015183:Restriction Mapping; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D001618:beta-Lactamases; D002439:Cefotaxime