Objective-To examine whether reactive arthritis (ReA) known to occur after a urogenital infection with Chlamydia trachomatis can also follow an infection with Chlamydia pneumoniae, a recently described species of Chlamydiae that is a common cause of respiratory tract infections. Methods-Specific antibodies (microimmunofluorescence test) and lymphocyte proliferation to C trachomatis and C pneumoniae in paired samples of peripheral blood and synovial fluid were investigated in 70 patients with either reactive arthritis (ReA) or undifferentiated oligoarthritis (UOA). Results-Five patients with acute ReA after an infection with C pneumoniae are reported. Three had a symptomatic preceding upper respiratory tract infection and two had no such symptoms.In all patients a C pneumoniae-specific lymphocyte proliferation in synovial fluid and a high specific antibody titre suggesting an acute infection was found. Conclusion-C pneumoniae needs to be considered a new important cause of reactive arthritis.

No abstract

A modification of the microimmunofluorescence test to provide a practicable routine serodiagnostic test for detecting and characterising chlamydial infection is described which uses four antigen pools, one of which corresponds with each of the four main clinical and epidemiological types of chlamydial infection. The three subgroup A Chlamydia (Chlamydia trachomatis) pools are: pool 1, hyperendemic trachoma TRIC agent serotypes A, B, and C; pool 2, paratrachoma TRIC agent serotypes D, E, F, G, H, I, and K; pool 3, lymphogranuloma venereum (LGV) agent serotypes L1, L2, and L3. Pool 4 contained four representative isolates of subgroup B Chlamydia (Chlamydia psittaci). For routine purposes sera need be screened only against these four representative antigen pools. This will detect antibody and indicate which clinical and epidemiological type of chlamydial infection is implicated, thereby clearly distinguishing those infections that are due to C. psittaci. The pattern of the cross-reactions may indicate the individual serotype involved, and further titration requiring a maximum of four individual antigens is sufficient to determine the serotype. The slight loss in sensitivity (twofold) is more than compensated for by the reduction in cost and the tenfold increase in the total number of sera which can be examined.

~_ _ _ _Chlumydiupneumoniae IOL-207 genomic DNA was hybridized with a 1.5 kb labelled DNA probe containing the 3' region of the coding sequence for the major outer membrane protein (MOMP) of C. trachomatis Serovar L1. An 8.5 kb BgAI fragment containing the complete MOMP gene was cloned into ilEMBL3. Two hybridizing EcoRI fragments were sub-cloned into the LZAP I1 cloning vector and the resulting plasmids were used as templates for sequencing both strands of the C.pneumoniae MQMP gene. Computer taxonomic studies using the nucleotide and inferred amino acid sequence of the MOMP of C. pneumoniae IOL-207 and all known chlamydial MOMP sequences supported the designation of C. pneumoniae as a new species, but electron microscope studies suggested that the presence of pear-shaped elementary bodies (EBs) may not be a reliable taxonomic criterion.

SUMMARY Recent isolation studies have shown Chlamydia trachomatis to be an important aetiological agent in acute salpingitis in women. The present serological study indicates that C. trachomatis is the probable aetiological agent in two-thirds of 143 women with pelvic inflammatory disease (PID). In general, high levels of chlamydial antibody were found in sera and fluids aspirated from the pouch of Douglas and such antibody titres were shown to correlate with the severity of clinically graded tubal inflammation.