Molecular characterization of human lung and liver cystic echinococcosis isolates in Van Province, Turkey

Abstract

Cystic echinococcosis (CE) is a zoonotic infection and could lead to significant public health problems. The genetic diversity of CE includes five species: E. granulosus sensu stricto (s.s.) (G1–G3), Echinococcus equinus (G4), Echinococcus ortleppi (G5), Echinococcus canadensis genotypic cluster (G6, G7, G8 and G10, with the doubtful G9) and the Echinococcus felidis (lion strain). The species are important in epidemiology, pathology, control, prevention measures and vaccine/drug designs. The aim of the present study was to determine the E. granulosus genotypes in humans in the Van province in east of Turkey. In total, 102 echinococcal cysts were collected from operated patients. Genomic analyses were conducted with PCR-RFLP of the rDNA internal transcribed spacer 1 (ITS1) fragment and partial PCR sequencing of the cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA gene region. In total, DNAs of 96 isolates could be extracted, unfortunately six extractions failed. The PCR-RFLP analysis findings were identical in all isolates. Two bands were observed at approximately 300 bp and 600 bp. All profiles corresponded to the G1-G3 strain. Also, 446 bp amplified gene regions were observed for cox1. Out of 20 samples, alignment of 16 sequences exhibited a total identification (100%) of granulosus sensu stricto (G1/G3). Of 16 samples, 8 were obtained in the lung and 12 were obtained in the liver; 8 belonged to male and 12 belonged to female patients. Other four samples exhibited one nucleotide substitution at different positions. Four samples had one nucleotide substitution at different positions. We detected single nucleotide variations in TRH1, TRH67, TRH85 and TRH89 isolates at the positions C240T; G330T; G211A and T157C, respectively. In conclusion, the present study was the first comprehensive molecular investigation on genetic characterization of human CE isolates in Van region. The findings demonstrated that E. granulosus s.s. was the dominant species, which indicated that the sheep-dog cycle was the source in human infections. And, probably, it would be possible to describe these mutations as “Turkey” or “lung” variants. In addition to contributing molecular epidemiological data, the present results should be considered when designing and implementing E. granulosus control programs.