title: Evidence for a clonal origin of relative penicillin resistance among type 9L pneumococci in northwestern Canada.
abstract: The relationships among capsular type, protein type, and penicillin resistance for capsular group 9 Streptococcus pneumoniae collected in northwestern Canada between 1974 and 1987 were examined. The group 9 relatively penicillin-resistant (RPR) isolates were of the rare 9L capsular type. Of 47 penicillin-susceptible (PS) group 9 isolates that were typed for capsule, only 1 was 9L. Among 29 PS group 9 isolates that were protein typed, 9 protein types were observed. Of the 70 RPR isolates, 51 were protein type P23, 1 was P19, and 18 could not be typed (P0). Protein types P23 differed from P0 by a single epitope on pneumococcal surface protein A. These results suggest that the Canadian P23 and P0 capsular group 9 isolates are likely subclones of a primordial 9L RPR strain.
authors.affiliation: Department of Microbiology, University of Alabama, Birmingham 35294.
authors.forename: W D
authors.initials: WD
authors.lastname: Waltman
authors.forename: D F
authors.initials: DF
authors.lastname: Talkington
authors.forename: A E
authors.initials: AE
authors.lastname: Lipinski
authors.forename: M J
authors.initials: MJ
authors.lastname: Crain
authors.forename: J M
authors.initials: JM
authors.lastname: Dixon
authors.forename: D E
authors.initials: DE
authors.lastname: Briles
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D016667:Bacterial Capsules / Q000032:analysis*; D001426:Bacterial Proteins / Q000032:analysis; D006801:Humans; D010403:Penicillin Resistance / Q000235:genetics*; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins