Chlamydophila abortus

Chlamydophila abortus is an intracellular Gram negative bacterial pathogen that is endemic throughout the world. C. abortus is the most common cause of infectious abortion in small ruminants (sheep and goats) in the UK, where it accounts for around 50% of all diagnosed abortions. It also causes abortion in cattle and pigs, and represents a significant zoonotic risk to pregnant women. The diseases caused by both pathogens result in enormous economic costs to their respective livestock industries.

Data Downloads

Chlamydophila abortus is a member of the Chlamydiaceae, a phylogenetically distinct Gram negative bacterial family, encompassing two genera (Chlamydia and Chlamydophila), which are subdivided into three (Chlamydia muridarum, Chlamydia suis, and Chlamydia trachomatis) and six (Chlamydophila pneumoniae, Chlamydophila abortus, Chlamydophila caviae, Chlamydophila felis, Chlamydophila pecorum and Chlamydophila psittaci) defined species, respectively (Everett et al. 1999). Chlamydiaceae undergo a unique biphasic developmental cycle switching from an infectious, but metabolically inactive, form called the elementary body (EB) to the non-infectious, metabolically active cell type known as the reticulate body (RB). The infectious process is initiated by the attachment of EBs to susceptible host cells, particularly mucosal epithelial cells. Upon entry the EB differentiates into the metabolically active form, RB, which multiplies by binary fission within specialised intracellular vacuoles called inclusions. These inclusions evade fusion with lysosomes, thus avoiding the host endocytic pathway, but instead intercept the exocytic pathway, appearing as secretory vacuoles to the host cell (Hackstadt et al. 1997). RBs transform back into EBs 2-3 days after infection (depending on species) and are then released by lysis or exocytosis to complete the infectious process. EBs can be spread by aerosols, through ingestion and by direct physical contact.


David Longbottom Moredun Research Institute, Pentlands Science Park, Penicuik, Midlothian EH26 0PZ, UK.

Published Genome Data

We have determined the complete genome sequence of a low passage strain of Cp. abortus (S26/3) and have a continued interest in the genome diversity of this species. This performed in collaboration with Dr. David Longbottom of the Moredun Research Institute and was funded by The Scottish Office (SEERAD).

The annotated genome sequence is avialable in the EMBL/GenBank databases with the accession number CR848038.

Shotgun and assembly data from this project are available from our FTP site.



  • The Chlamydophila abortus genome sequence reveals an array of variable proteins that contribute to interspecies variation.

    Thomson NR, Yeats C, Bell K, Holden MT, Bentley SD, Livingstone M, Cerdeño-Tárraga AM, Harris B, Doggett J, Ormond D, Mungall K, Clarke K, Feltwell T, Hance Z, Sanders M, Quail MA, Price C, Barrell BG, Parkhill J and Longbottom D

    Genome research 2005;15;5;629-40

Data Use Statement

This sequencing centre plans on publishing the completed and annotated sequences in a peer-reviewed journal as soon as possible. Permission of the principal investigator should be obtained before publishing analyses of the sequence/open reading frames/genes on a chromosome or genome scale. See our data sharing policy.

Sequencing enquiries

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