Neglected zoonotic agents in cattle abortion: tackling the difficult to grow bacteria

BMC Veterinary Research

Kristel Kegler¹  Horst Posthaus¹  Sebastien Aeby²  Gilbert Greub²  Sara Vidal³  Vincent Perreten³  Sabrina Rodriguez-Campos³  Nicole Borel⁴  Mark P. Dagleish⁵ 

[1] Institute of Animal Pathology, Vetsuisse Faculty, University of Bern;Institute of Microbiology, University Hospital Center and University of Lausanne;Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern;Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich;Moredun Research Institute, Pentlands Science Park;

关键词: Coxiella burnetii;    Chlamydiales;    Leptospira spp.;    Bovine abortion;    Zoonosis;   

DOI  :  10.1186/s12917-017-1294-y

来源: DOAJ

【 摘 要 】

Abstract Background Coxiella burnetii, Chlamydia abortus and Leptospira spp. are difficult to grow bacteria that play a role in bovine abortion, but their diagnosis is hampered by their obligate intracellular lifestyle (C. burnetii, C. abortus) or their lability (Leptospira spp.). Their importance is based on the contagious spread in food-producing animals, but also as zoonotic agents. In Switzerland, first-line routine bacteriological diagnostics in cattle abortions is regulated by national law and includes only basic screening by staining for C. burnetii due to the high costs associated with extended spectrum analysis. The aim of this study was to assess the true occurrence of these zoonotic pathogens in 249 cases of bovine abortion in Switzerland by serology (ELISA for anti-C. burnetii and C. abortus antibodies and microscopic agglutination test for anti-Leptospira spp. antibodies), molecular methods (real-time PCR and sequencing of PCR products of Chlamydiales-positive cases), Stamp’s modification of the Ziehl-Neelsen (mod-ZN) stain and, upon availability of material, by histology and immunohistochemistry (IHC). Results After seroanalysis the prevalence was 15.9% for C. burnetii, 38.5% for C. abortus and 21.4% for Leptospira spp. By real-time PCR 12.1% and 16.9% of the cases were positive for C. burnetii and Chlamydiales, respectively, but only 2.4% were positive for C. burnetii or Chlamydiales by mod-ZN stain. Sequencing of PCR products of Chlamydiales-positive cases revealed C. abortus in 10% of cases and the presence of a mix of Chlamydiales-related bacteria in 5.2% of cases. Pathogenic Leptospira spp. were detected in 5.6% of cases. Inflammatory lesions were present histologically in all available samples which were real-time PCR-positive for Chlamydiales and Leptospira spp. One of 12 real-time PCR-positive cases for C. burnetii was devoid of histological lesions. None of the pathogens could be detected by IHC. Conclusion Molecular detection by real-time PCR complemented by histopathological analysis is recommended to improve definitive diagnosis of bovine abortion cases and determine a more accurate prevalence of these zoonotic pathogens.

【 授权许可】

Unknown