The Chlamlydophila abortus genome sequence reveals an array of variable proteins that contribute to interspecies variation

The obligate intracellular bacterial pathogen Chlamydophila abortus strain S26/3 (formerly the abortion Subtype of Chlamydia psittaci) is all important Cause of late gestation abortions ill ruminants and pigs. Furthermore, although relatively rare, zoonotic infection call result ill acute illness and miscarriage ill pregnant women. The complete genome sequence was determined and shows a high level of conservation in both sequence and overall gene content in comparison to other Chlamydiaceae. The 1,144,377-bp genome contains 961 predicted coding sequences, 842 of which are conserved with those of Chlamydophila caviae and Chlamydophila pneumoniae. Within this conserved Cp. abortus core genorne we have identified the major regions of variation and have focused our analysis oil these loci, several of which were found to encode highly variable protein families, such as TMH/Inc and Pmp families, which are strong candidates for the Source of diversity ill host tropism and disease causation ill this group of organisms. Significantly, Cp. abortus lacks any toxin genes, and also lacks genes involved in tryptophan metabolism and nUcleoticle salvaging (guaB is present as a psuedogene), suggesting that the genetic basis of niche adaptation of this species is distinct from those previously proposed for other chlamyclial species.