Niethammer Florian Martin, Ade Julia, Hoelzle Ludwig Eduard, Schade Benjamin
Tiergesundheitsdienst Bayern e.V., Senator-Gerauer-Str. 23, 85586, Poing, Germany.
Institut für Nutztierwissenschaften, Universität Hohenheim, Garbenstr. 30, 70593, Stuttgart, Germany.
Acta Vet Scand. 2018 Nov 16;60(1):74. doi: 10.1186/s13028-018-0428-y.
The significance of hemotrophic mycoplasma in cattle remains unclear. Especially in Europe, their epidemiological parameters as well as pathophysiological influence on cows are lacking. The objectives of this study were: (1) to describe the prevalence of 'Candidatus Mycoplasma haemobos' ('C. M. haemobos') and Mycoplasma wenyonii (M. wenyonii) in Bavaria, Germany; (2) to evaluate their association with several blood parameters; (3) to explore the potential of vertical transmission in Simmental cattle; and (4) to evaluate the accuracy of acridine-orange-stained blood smears compared to real-time polymerase chain reaction (PCR) results to detect hemotrophic mycoplasma. A total of 410 ethylenediaminetetraacetic acid-blood samples from cows from 41 herds were evaluated by hematology, acridine-orange-stained blood smears, and real-time PCR. Additionally, blood samples were taken from dry cows of six dairy farms with positive test results for hemotrophic mycoplasma to investigate vertical transmission of infection.
The period prevalence of both species was 60.24% (247/410), C. M. haemobos 56.59% (232/410), M. wenyonii 8.54% (35/410) and for coinfection 4.88% (20/410). Of the relevant blood parameters, only mean cell volume (MCV), mean cell hemoglobin (MCH), and white blood cell count (WBC) showed differences between the groups of infected and non-infected individuals. There were lower values of MCV (P < 0.01) and MCH (P < 0.01) and higher values of WBC (P < 0.05) in 'C. M. haemobos'-infected cows. In contrast, co-infected individuals had only higher WBC (P < 0.05). In M. wenyonii-positive blood samples, MCH was significantly lower (P < 0.05). Vertical transmission of 'C. M. haemobos' was confirmed in two calves. The acridine-orange-method had a low sensitivity (37.39%), specificity (65.97%), positive predictive value (63.70%) and negative predictive value (39.75%) compared to PCR.
'Candidatus Mycoplasma haemobos' was more prevalent than M. wenyonii in Bavarian Simmental cattle, but infection had little impact on evaluated blood parameters. Vertical transmission of the infection was rare. Real-time PCR is the preferred diagnostic method compared to the acridine-orange-method.
血液支原体在牛群中的意义仍不明确。特别是在欧洲，缺乏关于它们的流行病学参数以及对奶牛病理生理学影响的研究。本研究的目的是：（1）描述德国巴伐利亚州“嗜血性支原体（暂定种）”（“C.M.haemobos”）和温氏支原体（M.wenyonii）的流行情况；（2）评估它们与几种血液参数的关联；（3）探讨西门塔尔牛垂直传播的可能性；（4）与实时聚合酶链反应（PCR）结果相比，评估吖啶橙染色血涂片检测血液支原体的准确性。通过血液学、吖啶橙染色血涂片和实时PCR对来自41个牛群的410份奶牛乙二胺四乙酸抗凝血样本进行了评估。此外，从6个血液支原体检测呈阳性的奶牛场的干奶期奶牛采集血样，以调查感染的垂直传播情况。
两种支原体的期间患病率为60.24%（247/410），其中“C.M.haemobos”为56.59%（232/410），温氏支原体为8.54%（35/410），混合感染率为4.88%（20/410）。在相关血液参数中，仅平均红细胞体积（MCV）、平均红细胞血红蛋白含量（MCH）和白细胞计数（WBC）在感染组和未感染组个体之间存在差异。“C.M.haemobos”感染的奶牛中MCV（P<0.01）和MCH（P<0.01）值较低，WBC值较高（P<0.05）。相比之下，混合感染个体仅WBC值较高（P<0.05）。在温氏支原体阳性血样中，MCH显著降低（P<0.05）。在两头犊牛中证实了“C.M.haemobos”的垂直传播。与PCR相比，吖啶橙法的灵敏度（37.39%）、特异性（65.97%）、阳性预测值（63.70%）和阴性预测值（39.75%）较低。
在巴伐利亚西门塔尔牛中，“嗜血性支原体（暂定种）”比温氏支原体更普遍，但感染对评估的血液参数影响较小。感染的垂直传播很少见。与吖啶橙法相比，实时PCR是首选的诊断方法。
