Identification and molecular characterization of Echinococcus granulosus from domestic goat in Chittagong, Bangladesh

The tapeworm Echinococcus granulosus causes cystic echinococcosis (CE) in human and many domestic animals worldwide including Bangladesh. The parasite has significant public health importance in the country and no in-depth study has been conducted to determine this cestode in either human or animals. The aim of present study was to evaluate genotype of E. granulosus isolated from domestic goats reared in Chittagong, Bangladesh using DNA based tools. Partial gene fragment of 12S rRNA gene and Cytochrome oxidase 1 gene were accomplished by PCR followed by sequencing and phylogenetic analyses. A total of 19 hydatid cyst samples were collected from 385 goats from several local slaughterhouses located in Chittagong. The rates of fertile hydatid cysts were found as high as 57.89% while remaining cysts were found non-viable and sterile. Genomic DNA was extracted from germinal membrane and/or protoscolices for PCR assay. Sequence similarity based on BLAST search revealed variable prevalence of E. granulosus genotypes such as G1 (68.42%) and G1/G3 complex (31.58%) which is reported for the first time in the country. This result indicates common sheep strain G1 is the dominant subtype of E. granulosus in this region. The study generated six sequences of which four were aligned with G1 common sheep strain and two were aligned with G3 strain (commonly referred as Buffalo strain). Phylogenetic analysis of 12S rRNA gene and Cytochrome oxidase 1 gene also indicated that common sheep strain (G1) and Buffalo strain (G3) are circulating among domestic goats in Chittagong region of Bangladesh.