title: Differential expression of key pneumococcal virulence genes in vivo.
abstract: Few studies have examined in vivo virulence gene expression in Streptococcus pneumoniae. In this study, expression of key pneumococcal virulence genes cbpA, pspA, ply, psaA, cps2A, piaA, nanA and spxB in the nasopharynx, lungs and bloodstream of mice was investigated, following intranasal challenge with the serotype 2 strain D39. Bacterial RNA was extracted, linearly amplified and assayed by real-time RT-PCR. At 72 h, cbpA mRNA was present at higher levels in the nasopharynx and lungs than in the blood. At this time-point, the mRNAs for PspA and PiaA were most abundant in the nasopharynx, whereas no significant difference in gene expression between niches was observed for ply, psaA and cps2A. Both nanA and spxB mRNAs were present in higher amounts in the nasopharynx than in the lungs or blood. These findings illustrate the dynamic nature of pneumococcal virulence gene expression in vivo.
authors.affiliation: School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia 5005, Australia.
authors.forename: Kim S
authors.initials: KS
authors.lastname: LeMessurier
authors.affiliation: School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia 5005, Australia.
authors.forename: Abiodun David
authors.initials: AD
authors.lastname: Ogunniyi
authors.affiliation: School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia 5005, Australia.
authors.forename: James C
authors.initials: JC
authors.lastname: Paton
mesh_terms: D000818:Animals; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D008168:Lung / Q000382:microbiology; D051379:Mice; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000276:immunology / Q000382:microbiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics*
chemical_list: D012333:RNA, Messenger