PclA, a pneumococcal collagen-like protein with selected strain distribution, contributes to adherence and invasion of host cells

• Published in: FEMS microbiology letters Vol. 285; no. 2; pp. 170 - 176
• Main Authors: Paterson, Gavin K., Nieminen, Leena, Jefferies, Johanna M.C., Mitchell, Tim J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2008; Oxford University Press
• Subjects: adherence; Adhesins, Bacterial - genetics; Adhesins, Bacterial - metabolism; Amino Acid Motifs; Animals; Bacterial Adhesion; Blood - microbiology; Cell walls; Clinical isolates; Clonal deletion; Collagen; collagen‐like protein; Deletion mutant; DNA, Bacterial - genetics; Female; Gene Deletion; Gene Expression Profiling; Gene Order; Genes; Genes, Bacterial; Genomes; Mice; Microbiology; Pneumonia; Pneumonia, Pneumococcal - microbiology; Polymerase Chain Reaction; Protein A; Proteins; Repetitive Sequences, Amino Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Bacterial - biosynthesis; RNA, Messenger - biosynthesis; Strain distribution; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - physiology; Survival Analysis; Transcription; Transcription Factors - genetics; Transcription Factors - metabolism; Virulence; Virulence Factors - genetics; Virulence Factors - metabolism; virulence; collagen-like protein; adherence
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2008.01217.x

Abstract Analysis of Streptococcus pneumoniae sequenced genomes revealed a region present only in selected strains consisting of two ORFs: a putative cell wall anchored protein and a putative transcriptional regulator. The cell wall anchored protein contains large regions of collagen-like repeats, the number of which varies between strains. We have therefore named this protein PclA for pneumococcal collagen-like protein A. The second gene, spr1404, encodes a putative transcriptional regulator. We examined the strain distribution of these two genes among a collection of clinical isolates from invasive pneumococcal disease and found them to be present in 39% of the strains examined. Strains were either positive for both genes or lacked both, with the two genes always present together in the same location of the genome. RT-PCR analysis revealed that pclA is transcribed in vitro, even in the absence of spr1404. Single deletion mutants lacking either gene were not attenuated in a mouse model of invasive pneumonia. However, the pclA mutant was defective in adherence and invasion of host cells in vitro.