Assessment of Copro-PCR for the detection and differentiation of Echinococcus granulosus infection from Taenia spp. of dog

Abstract

Echinococcosis is a re-emerging disease, especially in developing countries like India. The diagnosis of Echinococcus granulosus infection in dogs by detecting adult worms during post mortem examination or arecoline purgation is not suitable for mass screening. Therefore, in the present study copro-PCR was used for detection and differentiation of E. granulosus infection in dogs from Taenia species. A total of 250 gut contents were collected from dogs subjected for postmortem examination and screened for Taenia eggs by direct copro-microscopy. Out of 250 faecal samples, 19 (7.6%) samples were found positive for taeniid eggs. Among positive, three dogs showed single infection of E. granulosus adult worms, seven had mixed infection of E. granulosus and Taenia hydatigena whereas, the remaining nine harboured Taenia hydatigena adult parasites. Copro-PCR was conducted using two sets of E. granulosus specific primers JB 3f, JB 4.5r to amplify the mitochondrial cytochrome oxidase (CO1) gene and Eg 1f, Eg 1r to amplify mitochondrial 12S RNA gene. The JB 3f, JB 4.5r yielded a single band of 440 bp whereas, Eg 1f, Eg 1r primers amplified single band of 255 bp, which are specific to E. granulosus in ten samples in which the adult worms of E. granulosus were recovered during necropsy. However, no amplification was observed in nine faecal samples, which were positive for Taeniid eggs by copro-microscopy. Therefore, the study confirms that, Copro-PCR was found 100 per cent sensitive in the detection of E. granulosus infection and can be used to differentiate from other taeniid species of dogs. The findings of the present study revealed that canine echinococcosis is prevalent in dogs in and around Bengaluru region of Karnataka and the present study have important implications for hydatid control programmes in the area.