Recombination in theompAGene but Not theomcBGene ofChlamydiaContributes to Serovar-Specific Differences in Tissue Tropism, Immune Surveillance, and Persistence of the Organism

• DOI: 10.1128/jb.183.20.5997-6008.2001
• Publication Date: 2002-07-27T10:01:09Z
• Authors: Kim L. Millman; Simon Tavaré; Deborah Dean
• Keywords: Recombination, Genetic; 0303 health sciences; Genetic Linkage; Molecular Sequence Data; Chlamydia trachomatis; Chromosome Breakage; Chlamydia Infections; Chlamydophila pneumoniae; 03 medical and health sciences; Chlamydophila psittaci; Species Specificity; Genes, Bacterial; Animals; Humans; Chlamydia; Serotyping; Phylogeny; Bacterial Outer Membrane Proteins

ABSTRACTSequences of the major outer membrane protein (MOMP) gene (ompA) and the outer membrane complex B protein gene (omcB) fromChlamydia trachomatis, Chlamydia pneumoniae, andChlamydia psittaciwere analyzed for evidence of intragenic recombination and for linkage equilibrium. The Sawyer runs test, compatibility matrices, and index of association analyses provided substantial evidence that there has been a history of intragenic recombination atompAincluding one instance of interspecies recombination between theC. trachomatismouse pneumonitis strain and theC. pneumoniaehorse N16 strain. Although none of these methods detected intragenic recombination withinomcB, differences in divergence reported in earlier studies suggested that there has been intergenic recombination involvingomcB, and the analyses presented in this study are consistent with this. ForC. trachomatis, index-of-association analyses suggested a higher degree of recombination for C class than for B class strains and a higher degree of recombination in the downstream half ofompA. In concordance with these findings, many significant breakpoints were found in variable segments 3 and 4 of MOMP for the recombinant strains D/B120, G/UW-57, E/Bour, and LGV-98 identified in this study. We provide examples of how genetic diversity generated by repeated recombination in these regions may be associated with evasion of immune surveillance, serovar-specific differences in tissue tropism, and persistence.