Parachlamydiaceae, which naturally infect amoebae, form a sister taxon to the Chlamydiaceae on the basis of the Chlamydia-like cycle of replication and 80% to 90% homology of ribosomal RNA genes. Because intra-amoebal growth could increase the virulence of some intracellular bacteria, Parachlamydiaceae may be pathogenic. Arguments supporting a pathogenic role are that Chlamydia pneumoniae, a we...

The following adaptations led to improved growth of Chlamydia pneumoniae on HEp-2 cells compared to that by the standard method: monolayer preincubation with 7% polyethylene glycol (PEG), extension of incubation time to 7 days, and extension of incubation to 7 days in combination with centrifugation on days 3, 4, and 5. These adaptations resulted in approximate increases in numbers of inclusion...

A total of 189 temporal artery biopsy samples from giant cell arteritis (GCA) patients were investigated using sensitive PCR targeting Chlamydia pneumoniae. Chlamydial DNA was detected in 17 samples, 11 of which were positive for chlamydial antigens. Our data did not reveal strong evidence that C. pneumoniae plays an important role in the pathogenesis of GCA.

BACKGROUND Chlamydophila pneumoniae has been postulated as an aetiological agent in the pathophysiology of multiple sclerosis. Previous studies show conflicting results. OBJECTIVE To investigate patients with multiple sclerosis and other neurological diseases for evidence of past or present infection with C pneumoniae. METHODS 19 patients with multiple sclerosis and 29 with other neurologic...

The polymorphic membrane protein (Pmp) paralogous families of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia abortus are putative targets for Chlamydia vaccine development. To determine whether this is also the case for Pmp family members of C. psittaci, we analyzed transcription levels, protein production and localization of several Pmps of C. psittaci. Pmp expression profiles were ...

BACKGROUND Serologic diagnosis of Chlamydophila pneumoniae (Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measuremen...

The aim of the present study was to express the recombinant Chlamydophila pneumoniae (C. pneumoniae) protein, Cpn 0810, in Escherichia coli (E. coli) BL21, and investigate the effects of Cpn 0810 on inflammatory and apoptotic processes in human monocytic (THP-1) cells. An ELISA was performed to detect the levels of the proinflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL...

Since current studies indicate possible infection of human lymphocytes with Chlamydia (Chlamydophila) pneumoniae, establishment of an in vitro C. pneumoniae infection model using lymphocyte cell lines was demonstrated. Human lymphoid cell lines (Molt 4 [T-cell] and P3HR1 [B-cell]) were utilized for this purpose besides human monocyte cell line (THP-1) and human epithelial cell line (HEp-2), as ...

Members of the family Chlamydiaceae possess at least 13 genes, distributed throughout the chromosome, that are homologous with genes of known type III secretion systems (TTS). The aim of this study was to use putative TTS proteins of Chlamydophila pneumoniae, whose equivalents in other bacterial TTS function as chaperones, to identify interactions between chlamydial proteins. Using the Bacterio...

BACKGROUND Airway mucus hypersecretion is an important problem in chronic respiratory diseases including bronchial asthma. Chlamydophila pneumoniae is recently confirmed to be a pathogen in bronchial asthma, but the relationship between C. pneumoniae and mucus hypersecretion is uncertain. In this study, we examined whether C. pneumoniae induces MUC5AC mucin in airway epithelial cells. We also e...