Fischer P, Yocha J, Rubaale T, Garms R
Department of Helminthology and Entomology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
J Parasitol. 1997 Dec;83(6):1030-4.
In order to identify Onchocerca volvulus larvae from vectors, DNA of filaria larvae from dissected blackflies was isolated, and a 150-bp long tandemly repeated DNA sequence (0-150), which occurs in many Onchocerca species, was amplified using polymerase chain reaction (PCR). Subsequently, the PCR product was blotted onto a nylon membrane and hybridized with DNA probes specific for O. volvulus or Onchocerca ochengi. Filaria larvae from 395 infected Simulium neavei were examined and 259 samples produced detectable PCR products. Among these samples, 239 (92%) reacted with an O. volvulus-specific oligonucleotide. A sample of 69 PCR products was tested using an O. ochengi DNA probe, but all failed to hybridize. Filaria larvae from 64 infected Simulium damnosum, presumably of the cytotypes "Nyamagasani" and "Nkusi" were studied and 0-150 was amplified from 38 samples. From these samples, 35 (92%) hybridized specifically with an O. volvulus probe but none with the O. ochengi-specific DNA sequence. Nonamplified samples were obtained mainly from blackflies that contained only 1 or 2 filaria larvae, and therefore, an insufficient DNA extraction was assumed. It can be concluded that few, if any, filaria species of animal origin were transmitted by S. neavei and S. damnosum s.l. in Kabarole and Kasese districts in Uganda.
为了从媒介中鉴定盘尾丝虫幼虫，对解剖后的蚋体内丝虫幼虫的DNA进行分离，并使用聚合酶链反应（PCR）扩增一种存在于许多盘尾丝虫物种中的150 bp长串联重复DNA序列（0 - 150）。随后，将PCR产物印迹到尼龙膜上，并用盘尾丝虫或奥氏盘尾丝虫特异性DNA探针进行杂交。对395只感染了内氏蚋的丝虫幼虫进行了检测，259个样本产生了可检测到的PCR产物。在这些样本中，239个（92%）与盘尾丝虫特异性寡核苷酸发生反应。使用奥氏盘尾丝虫DNA探针检测了69个PCR产物样本，但所有样本均未杂交。对64只感染了推测为“Nyamagasani”和“Nkusi”细胞型的恶蚋的丝虫幼虫进行了研究，从38个样本中扩增出了0 - 150序列。在这些样本中，35个（92%）与盘尾丝虫探针特异性杂交，但没有一个与奥氏盘尾丝虫特异性DNA序列杂交。未扩增的样本主要来自仅含有1或2条丝虫幼虫的蚋，因此推测DNA提取不足。可以得出结论，在乌干达卡巴罗莱区和卡塞塞区，内氏蚋和恶蚋复合体传播的动物源性丝虫种类极少，即便有也非常少。
