Genotyping of Echinococcus granulosus isolates by sequencing of mitochondrial cytochrome C oxidase subunit 1 (cox1) gene in Aydin

Abstract

Cyst hydatid (CH) is a zoonotic infection that is characterized by the development of metacestode form of Echinococcus granulosus primarily in liver of humans and ruminants. With a worldwide distribution, the infection is still considered as an important parasitic disease that threatens the public health in Turkey as in the other developing countries. Morphological and biological features of parasite fail to discriminate isolates for typing so molecular methods should be used for this purpose. Recently, a total of eleven genotypes of E.granulosus (G1-10 and lion strain) have been identified and these genotypes are highly correlated with host specificity of the parasite. The aim of this study, was to determine the genotypes of E.granulosus isolates from human samples in Aydın. Cyst fluids from CH operated cases in Adnan Menderes University Faculty of Medicine, Training and Research Hospital were used in the present study. Samples were washed with phosphate buffered saline (PBS) and stored in 70% ethanol at -20ºC. Mitochondrial cytochrome C oxidase subunit 1 (cox1) gene was amplified partially by polymerase chain reaction (PCR). The PCR products were sequenced initially, compared to other database in Genbank and evolutionary distances were estimated with references. The genotypes of E.granulosus isolates were determined according to the closest or exact matches to the references. A total of 20 E.granulosus isolates were genotyped in the present study, most of them (15 isolates, 75%) were identified as Genotype 1 (G1), that is defined as sheep genotype and the remaining isolates were defined as pig/camel genotype G6/7 (five isolates, 25%). A possible explanation to our results may be related to the geographical position of Turkey. The identification of G6/7 in addition to sheep genotype G1 indicated that pigs and camels in this area have role in the transmission and distribution of E.granulosus to humans. There is still limited information about the molecular epidemiology of E.granulosus in Turkey. This study reveals the first data about the genotype distribution of E.granulosus in our city, therefore the findings may help to design control program for the disease with a combination of epidemiological data.