title: Highly variable penicillin resistance determinants PBP 2x, PBP 2b, and PBP 1a in isolates of two Streptococcus pneumoniae clonal groups, Poland 23F-16 and Poland 6B-20.
abstract: Penicillin-binding proteins (PBPs) in representatives of two Streptococcus pneumoniae clonal groups that are prevalent in Poland, Poland 23F-16 and Poland 6B-20, were investigated by PBP profile analysis, antibody reactivity pattern analysis, and DNA sequence analysis of the transpeptidase (TP) domain-encoding regions of the pbp2x, pbp2b, and pbp1a genes. The isolates differed in their MICs of beta-lactam antibiotics. The majority of the 6B isolates were intermediately susceptible to penicillin (penicillin MICs, 0.12 to 0.5 microg/ml), whereas all 23F isolates were penicillin resistant (MICs, >or=2 microg/ml). The 6B isolates investigated had the same sequence type (ST), determined by multilocus sequence typing, as the Poland 6B-20 reference strain (ST315), but in the 23F group, isolates with three distinct single-locus variants (SLVs) in the ddl gene (ST173, ST272, and ST1506) were included. None of the isolates showed an identical PBP profile after labeling with Bocillin FL and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and only one pair of 6B isolates and one pair of 23F isolates (ST173 and ST272) each contained an identical combination of PBP 2x, PBP 2b, and PBP 1a TP domains. Some 23F isolates contained PBP 3 with an apparently higher electrophoretic mobility, and this feature also did not correlate with their STs. The data document a highly variable pool of PBP genes as a result of multiple gene transfer and recombination events within and between different clonal groups.
authors.affiliation: National Medicines Institute, Division of Clinical Microbiology and Infection Prevention, Chełmska 30/34, Warsaw 00-725, Poland.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Izdebski
authors.forename: Jens
authors.initials: J
authors.lastname: Rutschmann
authors.forename: Janusz
authors.initials: J
authors.lastname: Fiett
authors.forename: Ewa
authors.initials: E
authors.lastname: Sadowy
authors.forename: Marek
authors.initials: M
authors.lastname: Gniadkowski
authors.forename: Waleria
authors.initials: W
authors.lastname: Hryniewicz
authors.forename: Regine
authors.initials: R
authors.lastname: Hakenbeck
mesh_terms: D000595:Amino Acid Sequence; D019881:Aminoacyltransferases / Q000737:chemistry / Q000235:genetics*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000940:Antigenic Variation; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001896:Boron Compounds / Q000494:pharmacology; D002999:Clone Cells; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010403:Penicillin Resistance / Q000235:genetics*; D046915:Penicillin-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D010406:Penicillins / Q000494:pharmacology; D010458:Peptidyl Transferases / Q000737:chemistry / Q000235:genetics*; D011044:Poland; D017422:Sequence Analysis, DNA; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; C118961:BOCILLIN FL; D001426:Bacterial Proteins; D001896:Boron Compounds; D046915:Penicillin-Binding Proteins; D010406:Penicillins; C072223:PBP 2x protein, Streptococcus; D019881:Aminoacyltransferases; C478701:penicillin-binding protein 2b, Streptococcus; C480727:PBP1a protein, Streptococcus pneumoniae; D010458:Peptidyl Transferases