Freick Markus, Konrath Andrea, Enbergs Haimo, Walraph Jörg, Weber Jim, Eulenberger Karin
Veterinary Practice Zettlitz, Straße der Jugend 68, 09306, Zettlitz, Germany.
Saxon State Laboratory of Health and Veterinary Affairs, Dresden, Germany.
Folia Microbiol (Praha). 2018 Mar;63(2):253-260. doi: 10.1007/s12223-017-0553-4. Epub 2017 Sep 30.
Coxiella burnetii (C. burnetii), an intracellular zoonotic bacterium causing Q fever, occurs widely in cattle herds. After invasion of the pregnant uterus and initial localization in the placenta, active C. burnetii infections may spread to the fetus hematogenously or by the amniotic-oral route and thus may cause abortion, premature delivery, stillbirth, and weak offspring (APSW) complex. In a case-control study, we investigated precolostral blood samples of 56 stillborn calves and 30 live births from a dairy herd endemically infected with C. burnetii "C-cluster" strains and an increased stillbirth rate in primiparous cows. Within the group of the stillborn calves, four precolostral blood samples (7.1%) were tested positive for C. burnetii DNA by PCR and one serum sample (1.8%) positive for anti-C. burnetii IgG antibodies by a commercial ELISA test, respectively. Neither C. burnetii DNA nor anti-C. burnetii IgG antibodies were detected in the samples of calves being born alive. In conclusion, we demonstrated that coxiellaemia and precolostral seroconversion occurred sporadically in stillborn calves from this endemically infected herd. Due to the low detection rates, C. burnetii could not be confirmed to be the cause of the increased stillbirth rate.
伯纳特柯克斯体（C. burnetii）是一种引起Q热的胞内人畜共患病细菌，广泛存在于牛群中。侵入怀孕子宫并最初定位于胎盘后，活跃的伯纳特柯克斯体感染可能通过血液或羊膜 - 口腔途径传播至胎儿，从而可能导致流产、早产、死产和弱仔（APSW）综合征。在一项病例对照研究中，我们调查了来自一群感染“C簇”伯纳特柯克斯体菌株且初产母牛死产率升高的奶牛场的56头死产犊牛和30头活产犊牛的初乳前血液样本。在死产犊牛组中，通过PCR检测到4份初乳前血液样本（7.1%）的伯纳特柯克斯体DNA呈阳性，通过商业ELISA检测到1份血清样本（1.8%）的抗伯纳特柯克斯体IgG抗体呈阳性。在活产犊牛的样本中未检测到伯纳特柯克斯体DNA或抗伯纳特柯克斯体IgG抗体。总之，我们证明了在这个地方性感染牛群的死产犊牛中偶尔会出现柯克斯体血症和初乳前血清转化。由于检测率低，无法确认伯纳特柯克斯体是死产率升高的原因。
