Evidence for a Clonal Origin of Relative Penicillin Resistance among Type 9L Pneumococci in Northwestern Canada

Academic Article


  • 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 (PO). Protein types P23 differed from PO by a single epitope on pneumococcal surface protein A. These results suggest that the Canadian P23 and PO capsular group 9 isolates are likely subclones of a primordial 9L RPR strain. © 1992, The University of Chicago. All rights reserved.
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    Author List

  • Douglas Waltman W; Talkington DF; Lipinski AE; Crain MJ; Dixon JMS; Briles DE
  • Start Page

  • 671
  • End Page

  • 675
  • Volume

  • 165
  • Issue

  • 4