Shayan Parviz, Rahbari Sadegh
Pathobiology Group of Faculty of Vetrinary Medicine, University of Tehran, Tehran, Iran.
Parasitol Res. 2005 Oct;97(4):281-6. doi: 10.1007/s00436-005-1434-3. Epub 2005 Jul 9.
The tick-borne diseases of livestock constitute a complex of several diseases with different etiological agents. Theileriosis and babesiosis belong to this complex and are severe and often fatal protozoan tick-borne diseases of ruminants worldwide. This results in high economical losses yearly in Iran. The most common diagnostic method for the identification of piroplasms in Iran is Giemsa staining of blood smear, which is unspecific, accompanied by some technical problems and, in some cases, impossible, due to the carriers. In contrast, immunostaining is more specific and can only be performed with suitably prepared blood smears, but cannot be used also for the carriers. The most specific method for the differential diagnosis of piroplasms is the method of polymerase chain reaction. We extracted DNA from different sources of blood samples, including from already stained blood smears. The extracted DNA was subsequently amplified using specific primers derived from Theileria heat shock protein hsp70, Theileria lestoquardi ms1-2 gene, Babesia rhoptry protein gene and piroplasms hyper variable region V4 of 18S rRNA gene. The results show that it is possible to detect piroplasms in already stained blood smears as well enabling a simpler method to be developed for the collection of the samples. Furthermore, it is possible to analyse the already stained and registered blood smears from the patients with unclear differential diagnosis, e.g. in the carriers. In addition, the results revealed that using a primer designed from the hyper variable region V4 of 18S rRNA, it is possible to detect and differentiate simultaneously the genera Theileria and Babesia in DNA samples isolated from already stained blood smears.
家畜的蜱传疾病是由几种具有不同病原体的疾病组成的复合体。泰勒虫病和巴贝斯虫病属于该复合体，是全球范围内反刍动物严重且往往致命的原生动物蜱传疾病。这在伊朗每年造成高额经济损失。伊朗鉴定梨形虫最常用的诊断方法是血液涂片吉姆萨染色，该方法不具特异性，伴有一些技术问题，而且在某些情况下，由于带菌者的存在而无法进行。相比之下，免疫染色更具特异性，且只能用适当制备的血液涂片进行，但也不能用于带菌者。梨形虫鉴别诊断最特异的方法是聚合酶链反应法。我们从不同来源的血液样本中提取DNA，包括已染色的血液涂片。随后使用源自泰勒虫热休克蛋白hsp70、莱氏泰勒虫ms1 - 2基因、巴贝斯虫棒状体蛋白基因和18S rRNA基因的梨形虫高变区V4的特异性引物对提取的DNA进行扩增。结果表明，有可能在已染色的血液涂片中检测到梨形虫，还能开发出一种更简便的样本采集方法。此外，对于鉴别诊断不明确的患者，如带菌者，有可能对已染色并登记的血液涂片进行分析。此外，结果还显示，使用从18S rRNA高变区V4设计的引物，有可能在从已染色血液涂片分离的DNA样本中同时检测和区分泰勒虫属和巴贝斯虫属。
