Genetic characterization of cystic pulmonary echinococcosis in Sudan as determined by mitochondrial DNA sequences

Background: Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the larval stages of the cestode Echinococcus granulosus. It is a significant public health problem with high endemicity in east and central Africa including Sudan. Worldwide, pulmonary echinococcosis cyst is a significant problem medically, socially, and economically. Until now ten genetic variants, or genotypes designated as (G1-G10), are distributed worldwide based on genetic diversity. In this study we aimed to investigate molecular diversity of Echinococcus granulosus isolates collected from human clinical samples removed surgically from lung using mitochondrial gene nad1 in Sudan. Methods: Seven human echinococcosis cysts originated from lung were collected through surgery from ElShaab Teaching Hospital in Khartoum state during 2016-2018. The fertility of cysts was detected microscopically by examination of the cysts fluid in which the protoscoleces were found. Protoscoleces were removed from each cyst and their total genomic DNAs were extracted. PCR was performed to amplify fragments of 530 base pair (bp) forNADH dehydrogenase subunit 1(NADH-1) gene. The amplified PCR products were purified and subjected to direct sequencing for subsequent construction of phylogenetic tree and network analysis. Results: The identity of the PCR products were confirmed as NADH1 nucleotide sequences using the Basic Local Alignment Search Tool (BLAST) of NCBI (National Center for Biotechnology Information, Bethesda, MD).The phylogenetic tree revealed the presence of Echinococcus canadenesis genotype 6 (G6) in all cysts (100%). Conclusions: According to the results of the previous and present observations which has been performed by PCR only and PCR followed by sequencing respectively, it can be concluded that the pul echinococcosis in Sudan are caused by genotype 6 (G6) camel strain of E. granulosus, which indicates the camel-dog cycle in the studied area.