title: DNA polymorphisms and variant penicillin-binding proteins as evidence that relatively penicillin-resistant pneumococci in western Canada are clonally related.
abstract: Previous studies have suggested that relatively penicillin-resistant (RPR) capsular group 9L strains in western Canada may be clonally related. To test this hypothesis, restriction fragment length polymorphisms (RFLPs) were examined using DNA probes for pspA and a newly recognized pneumococcal genetic element, IS1167. Penicillin-binding proteins (PBPs) and PBP genes from representative strains were also studied. All RPR type 9L strains demonstrated an identical RFLP when probed with IS1167, and 12 of 14 RPR strains had the same RFLP when examined with pspA. Amplification of pspA by polymerase chain reaction and restriction endonuclease digestion showed that the 9L strains had common DNA fragments not identified in any of the penicillin-susceptible strains. The 9L strains apparently have a low-affinity PBP 2B distinct from those of other capsular types. These data derived from new genetic markers and PBP analysis strongly support a clonal origin of RPR type 9L pneumococci of western Canada.
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham 35294, USA.
authors.forename: E
authors.initials: E
authors.lastname: Swiatlo
authors.forename: M J
authors.initials: MJ
authors.lastname: Crain
authors.forename: L S
authors.initials: LS
authors.lastname: McDaniel
authors.forename: A
authors.initials: A
authors.lastname: Brooks-Walter
authors.forename: T J
authors.initials: TJ
authors.lastname: Coffey
authors.forename: B G
authors.initials: BG
authors.lastname: Spratt
authors.forename: D A
authors.initials: DA
authors.lastname: Morrison
authors.forename: D E
authors.initials: DE
authors.lastname: Briles
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis*; D006360:Heat-Shock Proteins / Q000235:genetics*; D006602:Hexosyltransferases; D006801:Humans; D002267:Muramoylpentapeptide Carboxypeptidase / Q000032:analysis* / Q000235:genetics; D010403:Penicillin Resistance; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D012150:Polymorphism, Restriction Fragment Length; D013296:Streptococcus pneumoniae / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D006360:Heat-Shock Proteins; D046915:Penicillin-Binding Proteins; C069816:phage shock protein, Bacteria; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase