Detection of Anaplasma phagocytophilum in fetal and placental tissue of bovine abortions and perinatal mortalities

BackgroundAnaplasma phagocytophilum is a tick-borne zoonotic bacterium that is the aetiologic pathogen of tick-borne fever (TBF) in ruminants. In clinical bovine cases of TBF, abortion and stillbirth may be observed. However, in this regard, the pathophysiology of TBF has not yet been completely elucidated, and no clear guidelines to diagnose A. phagocytophilum-related abortions and perinatal mortalities (APM) are available. MethodsThis exploratory study aimed to investigate the presence of A. phagocytophilum in bovine cases of APM and determine whether placental or fetal spleen tissue has the greatest sensitivity for A. phagocytophilum identification. The placenta and fetal spleen of 150 late-term bovine APM cases were analysed using real-time PCR to detect A. phagocytophilum. ResultsA total of 2.7% of sampled placentas were positive for A. phagocytophilum, while none of the fetal spleen samples was. LimitationsNo histopathology to detect associated lesions was performed. Consequently, no evidence of causality between the detection of A. phagocytophilum and APM events could be achieved. ConclusionThe detection of A. phagocytophilum suggests a potential role of this pathogen in bovine APM, and placental tissue seems to be the most suitable tissue for its identification.

Automated summary

This study investigated the presence of A. phagocytophilum in bovine cases of abortion and stillbirth, and identified placental tissue as the most suitable for its detection. Results showed that 2.7% of sampled placentas were positive for A. phagocytophilum, while fetal spleen samples were all negative.