Molecular characterisation of Chlamydia pneumoniae associated to atherosclerosis

Chlamydia pneumoniae is a respiratory pathogen associated with chronic inflammatory diseases such as asthma and atherosclerosis, and its detection in human carotid and coronary atheroma suggests some support for its involvement in atherogenesis. The main objective of our study was to evaluate the association between Chlamydia pneumoniae and atherosclerosis in Moroccan patients through a case-control approach and detected strain genotyping. A total of 137 cases and 124 controls were enrolled, nested PCR was performed for Chlamydia pneumoniae screening of the peripheral blood mononuclear cells (PBMCs) of both cases and controls as well as atheroma plaques from 37 cases, and positive samples were subjected to sequencing for genotyping and phylogenetic analysis. The results showed 54% and 18%, respectively, for positivity in cases and control PBMCs and 86.5% in atheroma plaques, the difference being significant between the two groups (P < 0.001, ORa = 8.580, CI, 95% [3.273-22.491]). Strain sequence analyses showed more than 98% similarity with human reference strains, and revealed various genotypes. This study supports the involvement of Chlamydia pneumoniae in atherosclerosis in the studied population and genotyping revealed that detected strains were identical to human strains circulating worldwide.