Abstract:
Domestic ruminant abortions due to infectious agents represent an important cause of
economic losses in the agricultural industry. This study aimed to optimise and apply qPCR assays for
detection of Chlamydiales in domestic ruminant abortion cases. Primers and probes for detection
of the order Chlamydiales, Chlamydia abortus, Chlamydia pecorum, Parachlamydia acanthamoeba and
Waddlia chondrophila were taken from the literature to create one singleplex and two duplex assays
and the assays were optimised. Placentitis and pneumonia are pathological lesions associated with
Chlamydiales infection. In a previous study, twenty-five clinical cases had pathological lesions
of placentitis or pneumonia. These cases were investigated further by application of the qPCR
assays in this study. Chlamydiales were detected in 16 cases. C. abortus, P. acanthamoeba and W.
chondrophila were detected in bovine; and C. pecorum and W. chondrophila in ovine and caprine cases.
Chlamydiales were detected in three previously inconclusive cases. Identification was improved from
genus to species level (C. pecorum). Four cases remained inconclusive. In conclusion, detection of
Chlamydiales and differentiation to species level was improved. This study reports the first detection
of P. acanthamoeba and W. chondrophila in abortion cases in South Africa, indicating a potentially
significant role in abortions in this country.
