title: Serotype-specific invasiveness and colonization prevalence in Streptococcus pneumoniae correlate with the lag phase during in vitro growth.
abstract: Serotypes of Streptococcus pneumoniae differ in colonization prevalence and the likelihood of causing disease. In vitro growth in brain heart infusion broth with or without 5% fetal calf serum (FCS) was compared for 47 clinical isolates representing 15 pneumococcal serotypes. Serotype-specific colonization prevalence and odds ratios for the invasive potential were obtained from an international and a local epidemiological study. The duration of the lag phase increased with the invasiveness and was inversely associated with the colonization prevalence of a serotype. Supplementation with FCS shortened the lag phase preferentially in serotypes associated with invasive disease (P=0.007). Reduction of oxidative stress by addition of manganese (Mn(2+)), Tiron, mannitol or catalase did not influence the duration of the lag phase significantly. Serotype specific invasiveness and colonization prevalence of S. pneumoniae are associated with the length of the lag phase during in vitro growth. This may correlate with serotype specific selection in vivo.
authors.affiliation: Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, CH-3010 Bern, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bättig
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Hathaway
authors.forename: Sandra
authors.initials: S
authors.lastname: Hofer
authors.forename: Kathrin
authors.initials: K
authors.lastname: Mühlemann
mesh_terms: D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry; D006801:Humans; D008353:Mannitol / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000382:microbiology*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000254:growth & development* / Q000472:pathogenicity*
chemical_list: D000975:Antioxidants; D003470:Culture Media; D008353:Mannitol; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D002374:Catalase