Parachlamydia

While there is a great deal of information available on chlamydial organisms affecting ruminants, in particular Chlamydophila abortus that causes EAE and Chlamydophila pecorum that has been linked with a variety of diseases in sheep and cattle, much less is known about an emerging group of Chlamydia-like organisms affecting cattle.

Although it is some 25 years since the first identification of a Chlamydia-like organism in a case of infectious cattle abortion, it is only in the last few years that it has become clear that there are many other related organisms, such as Parachlamydia, associated with cattle abortions. Such organisms may in part be responsible for the underdiagnosis (65% of submitted cases) of infectious abortions in cattle.

Recently, work conducted at Moredun identified the presence of Chlamydia-like organisms in 27% of samples obtained from infectious cattle abortions in Scotland, indicating the endemic presence of these organisms in the UK. Analysis of these samples showed that the majority are closely related to Parachlamydia. Most recently, undiagnosed samples from cases of bovine abortion on a Scottish farm were sent by SAC to Moredun for further investigations. This analysis again revealed the presence of Chlamydia-like organisms closely related to Parachlamydia. Moredun now aims to continue investigations into these emerging pathogens in UK cattle and to determine the link with disease.