Monitoring clinical outcomes, pathological changes and shedding of Chlamydophila abortus following experimental challenge of periparturient ewes utilizing the natural route of infection

Jorge Gutierrez*, Erin J. Williams, James O'Donovan, Colm Brady, Aisling F. Proctor, Patricia X. Marques, Sheila Worrall, Jarlath E. Nally, M. McElroy, Hugh F. Bassett, Donal J. Sammin, Bryan K. Markey

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Enzootic abortion of ewes (EAE) caused by Chlamydophila abortus is an important disease resulting in significant lamb loss in most sheep producing countries. Ewes are considered to be naturally infected with C. abortus via the oral-nasal route and may become persistent carriers, shedding during subsequent oestrous cycles and at lambing. The aim of this study was to monitor the clinical outcomes, pathological changes and shedding of C. abortus in 18 periparturient orally infected sheep for two breeding seasons. In the first season, C. abortus was detected by real-time PCR (rt-PCR) in 13/18 conjunctival swabs at oestrus. Three out of the 15 pregnant ewes gave birth to 1 live and 1 dead lamb, and 2 of them aborted. Following parturition/abortion, C. abortus was detected in 12/15 vaginal swabs and in all the collected foetal membranes. However, only those membranes containing high copy numbers of the bacterium displayed the EAE typical lesions. In the second season, none of the 13 pregnant ewes aborted, and 5 of them gave birth to dead or weak lambs. C. abortus was not detected in conjunctival or vaginal swabs at oestrus or parturition. The bacterium was detected at low levels in 36% of the foetal membranes, but with no evidence of histopathological lesions. These results indicate that C. abortus can be detected in a large proportion of animals during the first pregnancy after oral infection. However, this proportion is reduced at the subsequent breeding season, confirming the occurrence of a chronic low level persistent infection in post-abortion/lambing ewes.

Original languageEnglish
Pages (from-to)119-126
Number of pages7
JournalVeterinary Microbiology
Volume147
Issue number1-2
DOIs
Publication statusPublished - 10 Jan 2011

Keywords / Materials (for Non-textual outputs)

  • Breeding
  • Chlamydophila abortus
  • Enzootic abortion
  • Placenta
  • Real-time PCR
  • Sheep

Fingerprint

Dive into the research topics of 'Monitoring clinical outcomes, pathological changes and shedding of Chlamydophila abortus following experimental challenge of periparturient ewes utilizing the natural route of infection'. Together they form a unique fingerprint.

Cite this