title: Ceftazidime-resistant Enterobacteriaceae isolates from three Polish hospitals: identification of three novel TEM- and SHV-5-type extended-spectrum beta-lactamases.
abstract: Twelve ceftazidime-resistant isolates of the family Enterobacteriaceae (11 Klebsiella pneumoniae isolates and 1 Escherichia coli isolate) were collected in 1995 from three Polish hospitals located in different cities. All were identified as producers of extended-spectrum beta-lactamases (ESBLs). Detailed analysis of their beta-lactamase contents revealed that six of them expressed SHV-5-like ESBLs. The remaining six were found to produce three different TEM enzymes, each characterized by a pI value of 6.0 and specified by new combinations of amino acid substitutions. The amino acid substitutions compared to the TEM-1 beta-lactamase sequence were Gly238Ser, Glu240Lys, and Thr265Met for TEM-47; Leu21Phe, Gly238Ser, Glu240Lys, and Thr265Met for TEM-48; and Leu21Phe, Gly238Ser, Glu240Lys, Thr265Met, and Ser268Gly for TEM-49. The new TEM beta-lactamases, TEM-47, TEM-48, and TEM-49, belong to a subfamily of TEM-2-related enzymes. Genes coding for TEM-47 and TEM-49 could have originated from the TEM-48-encoding sequence by various single genetic events. The new TEM derivatives probably document the already advanced microevolution of ESBLs ongoing in Polish hospitals, in a majority of which no monitoring of ESBL producers was performed before 1996.
authors.affiliation: Sera & Vaccines Central Research Laboratory, Warsaw, Poland. marekg@ibbrain.ibb.waw.pl
authors.forename: M
authors.initials: M
authors.lastname: Gniadkowski
authors.forename: I
authors.initials: I
authors.lastname: Schneider
authors.forename: R
authors.initials: R
authors.lastname: Jungwirth
authors.forename: W
authors.initials: W
authors.lastname: Hryniewicz
authors.forename: A
authors.initials: A
authors.lastname: Bauernfeind
mesh_terms: D001426:Bacterial Proteins / Q000187:drug effects / Q000235:genetics*; D002442:Ceftazidime / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000187:drug effects / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002511:Cephalosporins; D002442:Ceftazidime; D001618:beta-Lactamases