Dixit A K, Yadav S C, Sharma R L
Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, India.
Vet Parasitol. 2002 Nov 11;109(3-4):233-47. doi: 10.1016/s0304-4017(02)00202-9.
Coprological confirmation of ovine fasciolosis in the field, prior to out breaks of the disease and/or strategic antifluke medication, seem to be of little consequence. Efforts are, therefore, being made to evolve a putative antigen specific to serodiagnostic test for early diagnosis during prepatency. In the present investigation, 28 kDa cysteine proteinase was used in ELI SA and Western blot to detect Fasciola gigantica antibodies and further Dipstick-ELISA was developed for field application, using known positive monospecific sera from experimentally infected sheep with 100 F. gigantica metacercariae. Isolation of 28 kDa cysteine proteinase was achieved from bubalian origin flukes. The specific antigen, recognised homologous antifluke antibodies by Western blot as early as 2nd week post-infection (wpi) with 100% sensitivity, in sera samples of sheep harbouring 38 flukes and by 10th wpi in sheep harbouring 3-8 flukes. All sheep were found positive for the infection when ELISA and/or Dipstick-ELISA was applied from 4th wpi. In pooled sera of infected sheep, these were positive during 4th wpi.
在羊肝片吸虫病爆发之前和/或进行预防性抗吸虫药物治疗之前，通过粪便学方法在现场确认羊肝片吸虫病似乎没什么意义。因此，人们正在努力研发一种在潜伏期用于早期诊断的血清学诊断试验的假定抗原。在本研究中，利用28 kDa半胱氨酸蛋白酶进行酶联免疫吸附测定（ELISA）和蛋白质印迹法来检测巨片形吸虫抗体，并进一步开发了试纸条ELISA用于现场应用，使用的是来自经100个巨片形吸虫囊蚴实验感染绵羊的已知阳性单特异性血清。从水牛源吸虫中分离出了28 kDa半胱氨酸蛋白酶。这种特异性抗原在感染后第2周（wpi）时，通过蛋白质印迹法就能识别同源抗吸虫抗体，对感染38条吸虫的绵羊血清样本的敏感性为100%，对感染3 - 8条吸虫的绵羊在第10周时就能识别。从第4周起应用ELISA和/或试纸条ELISA检测时，所有绵羊均被发现感染呈阳性。在感染绵羊的混合血清中，第4周时呈阳性。
