Molecular biology of chlamydiae.

Abstract

Chlamydiae are obligate, intracellular bacteria which cause disease in many species of mammals and birds. There are three species of chlamydiae, Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia psittaci. Chlamydiae which cause disease in humans are listed in Table 2.1. C. trachomatis is a common human mucosal pathogen which causes three forms of disease; trachoma, genital infection and lymphogranuloma venereum (LGV).The only non-human strain is the murine pathogen, mouse pneumonitis agent. C. trachomatis is divided into 15 serovars, A, B, Ba, C, D, E, F, G, H, I, J, K, L1, L2 and L3. These serovars are grouped into two sub-species; the B complex which comprises serovars B, Ba, D, E, F, G, L1 and L2, and the C complex which comprises serovars A, C, H, I, J, K and L3. C. pneumoniae includes the human pathogens IOL 207 and TWAR. The first isolates came from the eyes of children with trachoma in Iran and Taiwan; more recent isolates have been obtained from patients with respiratory infection. Many people have serum antibodies to C. pneumoniae, indicating that infection iscommon. Most strains of C. psittaci are pathogens of non-primate mammals and birds; only a few of these strains are human pathogens.