Title: Occurrence, quantification, and genotyping of Mycoplasma conjunctivae in wild Caprinae with and without infectious keratoconjunctivitis
Authors : Mavrot, Fabien
Vilei, Edy M.
Marreros, Nelson
Signer, Claudio
Frey, Joachim
Ryser-Degiorgis, Marie-Pierre
Published in : Journal of wildlife diseases
Volume(Issue) : 48
Issue : 3
Pages : 619
Pages to: 631
Publisher / Ed. Institution : Wildlife Disease Association
Issue Date: 2012
License (according to publishing contract) : Licence according to publishing contract
Type of review: Peer review (Publication)
Language : English
Subject (DDC) : 571: Physiology and related subjects
590: Animals (Zoology)
Abstract: Mycoplasma conjunctivae, the causative agent of infectious keratoconjunctivitis (IKC), was recently detected in asymptomatic Alpine ibex (Capra ibex ibex). This suggested that an external source of infection may not be required for an IKC outbreak in wildlife but might be initiated by healthy carriers, which contradicted previous serologic investigations in chamois. Our aims were to 1) assess the prevalence of M. conjunctivae among asymptomatic ibex and Alpine chamois (Rupicapra rupicapra rupicapra) and its frequency in IKC-affected animals, 2) determine mycoplasma loads in different disease stages, and 3) characterize the M. conjunctivae strains involved. Eye swabs from 654 asymptomatic and 204 symptomatic animals were collected in diverse Swiss regions between 2008 and 2010, and tested by TaqMan real-time PCR. Data analysis was performed considering various patterns of IKC occurrence in the respective sampling regions. Strains from 24 animals were compared by cluster analysis. Prevalence of M. conjunctivae was 5.6% (95% confidence interval [CI]: 3.7–8.1%) in asymptomatic ibex and 5.8% (CI: 3.0–9.9%) in asymptomatic chamois, with significant differences between years and regions in both species. Detection frequency in symptomatic animals was significantly higher during IKC outbreaks than in nonepidemic situations (i.e., regular but low incidence or sporadic occurrence). Mycoplasma load was significantly lower in eyes from healthy carriers and animals with mild signs than from animals with moderate and severe signs. Although some strains were found in both asymptomatic and diseased animals of the same species, others apparently differed in their pathogenic potential depending on the infected species. Overall, we found a widespread occurrence of M. conjunctivae in wild Caprinae with and without IKC signs. Our results confirm the central role of M. conjunctivae in outbreaks but suggest that other infectious agents may be involved in IKC cases in nonepidemic situations. Additionally, presence and severity of signs are related to the quantity of M. conjunctivae in the eyes rather than to the strain. We propose that individual or environmental factors influence the clinical expression of the disease and that persistence of M. conjunctivae in populations of wild Caprinae cannot be excluded.
Departement: Life Sciences and Facility Management
Organisational Unit: Institute of Natural Resource Sciences (IUNR)
Publication type: Article in scientific Journal
DOI : 10.7589/0090-3558-48.3.619
ISSN: 0090-3558
1943-3700
URI: https://digitalcollection.zhaw.ch/handle/11475/15462
Appears in Collections:Publikationen Life Sciences und Facility Management

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