Pherotypes of co-colonizing pneumococci among Portuguese children.
A recent study showed that pneumococcal pherotypes often coexist in the nasopharynx and suggested that the impact of pherotype-mediated fratricide on competition is limited. We determined the impact of pherotype (or competence-stimulating peptide [CSP]) on pneumococcal nasopharyngeal co-colonization. Of 184 nasopharyngeal samples yielding two serotypes, 39.9% contained CSP1 only, 12.6% CSP2 only, and 47.5% had one strain of each pherotype. The observed proportions of concordant and discordant pherotypes (52.5% and 47.5%, respectively), were compared with the ones estimated (53.8% and 46.2%, respectively), and there were no significant differences (p=0.9, χ(2) test). Our results support the hypothesis that there is a limited role of pherotype in co-colonization.
Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
Carina
C
Valente
Hermínia
H
De Lencastre
Raquel
R
Sá-Leão
D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D000898:Antibiosis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D002648:Child; D003430:Cross-Sectional Studies; D061269:DNA Transformation Competence / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D009305:Nasopharynx / Q000187:drug effects / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D020033:Protein Isoforms / Q000235:genetics; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D020033:Protein Isoforms; C423628:competence factor, Streptococcus