Liu Qin, Meli Marina L, Zhang Yi, Meili Theres, Stirn Martina, Riond Barbara, Weibel Beatrice, Hofmann-Lehmann Regina
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Center for Tropical Diseases, Shanghai 200025, China; Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland; Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
Vet Parasitol. 2016 May 15;221:24-9. doi: 10.1016/j.vetpar.2016.03.003. Epub 2016 Mar 6.
A reverse line blot (RLB) hybridization assay was adapted and applied for equine blood samples collected at the animal hospital of the University of Zurich to determine the presence of piroplasms in horses in Switzerland. A total of 100 equine blood samples were included in the study. The V4 hypervariable region of the 18S rRNA gene was amplified by polymerase chain reaction and analyzed using the RLB assay. Samples from seven horses hybridized to a Theileria/Babesia genus-specific and a Theileria genus-specific probe. Of these, two hybridized also to the Theileria equi-specific probe. The other five positive samples did not hybridize to any of the species-specific probes, suggesting the presence of unrecognized Theileria variants or genotypes. The 18S rRNA gene of the latter five samples were sequenced and found to be closely related to T. equi isolated from horses in Spain (AY534822) and China (KF559357) (≥98.4% identity). Four of the seven horses that tested positive had a documented travel history (France, Italy, and Spain) or lived abroad (Hungary). The present study adds new insight into the presence and sequence heterogeneity of T. equi in Switzerland. The results prompt that species-specific probes must be designed in regions of the gene unique to T. equi. Of note, none of the seven positive horses were suspected of having Theileria infection at the time of presentation to the clinic. Clinicians should be aware of the possibility of equine piroplasma infections outside of endemic areas and in horses without signs of piroplasmosis.
我们对反向线杂交（RLB）分析方法进行了改良，并将其应用于苏黎世大学动物医院采集的马血样本，以确定瑞士马匹中梨形虫的存在情况。本研究共纳入了100份马血样本。通过聚合酶链反应扩增18S rRNA基因的V4高变区，并使用RLB分析方法进行分析。来自7匹马的样本与泰勒虫属/巴贝斯虫属特异性探针以及泰勒虫属特异性探针发生杂交。其中，有2份样本还与马泰勒虫特异性探针发生杂交。另外5份阳性样本未与任何种特异性探针杂交，这表明存在未被识别的泰勒虫变种或基因型。对后5份样本的18S rRNA基因进行测序后发现，它们与从西班牙（AY534822）和中国（KF559357）马匹中分离出的马泰勒虫密切相关（同一性≥98.4%）。7匹检测呈阳性的马中，有4匹有明确的旅行史（法国、意大利和西班牙）或居住在国外（匈牙利）。本研究为瑞士马泰勒虫的存在情况和序列异质性提供了新的见解。结果提示，必须在马泰勒虫基因的独特区域设计种特异性探针。值得注意的是，这7匹阳性马在就诊时均未被怀疑感染泰勒虫。临床医生应意识到在非流行地区以及无梨形虫病体征的马匹中存在马梨形虫感染的可能性。
