title: Penicillin-binding protein 1A, 2B, and 2X alterations in Canadian isolates of penicillin-resistant Streptococcus pneumoniae.
abstract: Alterations within the penicillin-binding domain of penicillin-binding protein (PBP) genes pbp1a, pbp2b, and pbp2x were determined for 15 Canadian isolates of Streptococcus pneumoniae. All penicillin-nonsusceptible S. pneumoniae isolates showed a variety of PBP 2X substitutions and contained a Thr445-Ala change after the PBP 2B SSN motif. Only isolates for which penicillin MICs were > or =0.5 micro g/ml had PBP 1A alterations near the STMK and SRN motifs. Sequence analysis revealed identical PBP 1A, PBP 2B, and PBP 2X substitution patterns among all isolates for which penicillin MICs were > or =1 micro g/ml.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Canada. knichol@hsc.mb.ca
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Nichol
authors.forename: George G
authors.initials: GG
authors.lastname: Zhanel
authors.forename: Daryl J
authors.initials: DJ
authors.lastname: Hoban
mesh_terms: D019943:Amino Acid Substitution; D019881:Aminoacyltransferases; D001426:Bacterial Proteins; D002170:Canada; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D006602:Hexosyltransferases; D006801:Humans; D008826:Microbial Sensitivity Tests; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics*; D010403:Penicillin Resistance; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000494:pharmacology; D010458:Peptidyl Transferases; D011008:Pneumococcal Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D019881:Aminoacyltransferases; C478701:penicillin-binding protein 2b, Streptococcus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase