Molecular basis for identification of species/isolates of gastrointestinal nematode parasites

Gastrointestinal（GI） parasitism is the most serious constraint throughout the world in small ruminants which causes significant production loss in animals.GI parasites are major contributor to reduce productivity in terms of meat,milk and wool in animals.Control of GI parasite is done primarily by anthelmintic treatment where choice and schedule of treatment is done after identification and quantitation of individual parasite.Identification of GI parasites is done through microscopic method by identifying specific morphological characteristics of egg and larva（L3）.Since most of parasite eggs are having similar morphological characteristics, identification up to species level through microscopy is not possible in most of cases.To address this issue,molecular techniques are the viable alternative for identification of species as well as molecular level differences within a species（isolates） of parasites.Different DNA based molecular techniques viz.PCR,AFLP,RAPD,RFLP,PCR-SSCP,real time PCR,DNA microarray etc.have been used for identification and to assess the genetic diversity among parasite population.For identification of species,the characteristic sequence of genomic DNA of different species should differ to allow the delineation of species,but at the same time,no/minor variation within the species should exist.In contrast,for purpose of identifying population variants（strains/isolates）, a considerable degree of variation in the sequence should exist within a species.Various target regions,including nuclear ribosomal DNA（rDNA）,mitochondrial DNA（mtDNA） or repetitive DNA elements（microsatellite loci）,which show considerable variation in the number of repeats within individuals have been employed to achieve the identification of parasites species or strain.

Detection of canine echinococcosis by coproantigen ELISA

Objective:To study the canine echinococcosis by coproantigen ELISA method.Methods:During the present investigation experimental infection was established using evaginated worms of Echinococcus granulosus(E.granulosus).To check cross reactivity two pups were infected with Taenia hydatigena(T.hydatigena).In order to detect the presence of antigen,hyperimmune sera were raised against excretory-secretory products of adult worms E.chinococcus granulosus. Faecal sample collected either from experimentally infected pups or from other sources were heated at 70℃to detect heat stable soluble antigen.Results:Pups harbouring less than 104 worms showed negative results.Samples collected from 14 days onwards from experimentally infected animals harbouring more than 104 worms showed positive value.The maximum positive samples were detected in samples collected from in and around slaughter house and the least number of samples were detected positive maintained by dog squad.Conclusions:The affinity purified IgG exhibited promising results for detection of canine echinococcosis by indirect ELISA.