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Understanding the health and production impacts of endemic Chlamydia pecorum infections in lambs


Walker, E and Jelocnik, M and Bommana, S and Timms, P and Carver, S and Polkinghorne, A, Understanding the health and production impacts of endemic Chlamydia pecorum infections in lambs, Veterinary Microbiology, 217 pp. 90-96. ISSN 0378-1135 (2018) [Refereed Article]

Copyright Statement

2018 Published by Elsevier B.V.

DOI: doi:10.1016/j.vetmic.2018.03.009


Lamydia pecorum is a globally recognised livestock pathogen that is capable of causing severe and economically significant diseases such as arthritis in sheep and cattle. Relatively little information is available on the clinical progression of disease and the long-term effects of asymptomatic and symptomatic chlamydiosis in sheep. Recent studies in calves indicate that endemic C. pecorum infections may reduce growth rates. To investigate the clinical health parameters and production impacts of endemic C. pecorum infection in an Australian commercial lamb flock, we performed bimonthly sampling and clinical health assessments on 105 Border Leicester lambs from two to ten months of age. Chlamydial status was investigated via serology and species-specific quantitative PCR. Throughout the study period, conjunctivitis remained a persistent clinical feature while signs of arthritis (e.g. palpable synovial joint effusions) resolved in a subset of lambs while persisting in others. Clinical disease and C. pecorum infection were highest at six months of age (weaning). As previously reported, peak seroconversion tends to occur two months after the onset of clinical symptoms (6 months of age), with lambs clearing chlamydial infection by 10 months of age, despite ongoing disease still being present at this time. Notably, the presence of chlamydial infection did not affect lamb mass or growth rates throughout the study. At necropsy, C. pecorum was not detected within the joints of lambs with chronic arthritis. Molecular analysis of the strains in this flock suggest that the infecting strains circulating in this flock are clonal C. pecorum pathotypes, denoted ST 23, commonly associated with conjunctivitis and polyarthritis in Australian sheep. This study provides a platform for further research in the epidemiology and disease transmission dynamics of C. pecorum infections in sheep.

Item Details

Item Type:Refereed Article
Keywords:epidemiology,Chlamydia pecorum, ovine, arthritis, conjunctivitis, CFT, qPCR
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Veterinary sciences
Research Field:Veterinary parasitology
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Control of pests, diseases and exotic species in terrestrial environments
UTAS Author:Carver, S (Associate Professor Scott Carver)
ID Code:149592
Year Published:2018
Funding Support:Australian Research Council (LP140100315)
Web of Science® Times Cited:10
Deposited By:Zoology
Deposited On:2022-04-05
Last Modified:2022-05-03

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