Chromosome-scale Echinococcus granulosus (genotype G1) genome reveals the Eg95 gene family and conservation of the EG95-vaccine molecule.

Cystic echinococcosis is a socioeconomically important parasitic disease caused by the larval stage of the canid tapeworm Echinococcus granulosus, afflicting millions of humans and animals worldwide. The development of a vaccine (called EG95) has been the most notable translational advance in the fight against this disease in animals. However, almost nothing is known about the genomic organisation/location of the family of genes encoding EG95 and related molecules, the extent of their conservation or their functions. The lack of a complete reference genome for E. granulosus genotype G1 has been a major obstacle to addressing these areas. Here, we assembled a chromosomal-scale genome for this genotype by scaffolding to a high quality genome for the congener E. multilocularis, localised Eg95 gene family members in this genome, and evaluated the conservation of the EG95 vaccine molecule. These results have marked implications for future explorations of aspects such as developmentally-regulated gene transcription/expression (using replicate samples) for all E. granulosus stages; structural and functional roles of non-coding genome regions; molecular 'cross-talk' between oncosphere and the immune system; and defining the precise function(s) of EG95. Applied aspects should include developing improved tools for the diagnosis and chemotherapy of cystic echinococcosis of humans.

Evidence of Crimean-Congo Haemorrhagic Fever Virus Occurrence in Ixodidae Ticks of Armenia.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) causes serious health problems in humans. Though ticks of the genera Hyalomma play a significant role in the CCHF virus transmission it was also found in 31 other tick species. METHODS: Totally, 1412 ticks from 8 remote sites in Armenia during 2016 were sampled, pooled (3-5 ticks per pool) and tested for the presence of CCHFV antigen using ELISA test. RESULTS: From 359 tick pools, 132 were CCHF virus antigen-positive. From 6 tick species, four species (Rhipicephalus sanguineus, R. annulatus, R. bursa, Hyalomma marginatum) were positive for the virus antigen and R. sanguineus was the most prevalent (37.9%). Dermacentor marginatus and Ixodes ricinus revealed no positive pools, but both revealed delectable but very low virus antigen titers. The highest infection rate (50%) was observed in R. sanguineus, whereas H. marginatus rate of infection was 1 out of 17 pools. CONCLUSION: For the first time in the last four decades CCHF virus antigen was detected in Ixodid ticks of Armenia. This finding substantiates the role of R. sanguineus in the disease epidemiology; however, the role of H. marginatum in the CCHF virus circulation in the country could not be excluded.

Fasciola spp. in Armenia: Genetic diversity in a global context.

Fasciolosis, a food- and waterborne infection caused by the trematodes Fasciola hepatica and F. gigantica, is recognized by WHO as a neglected zoonotic disease. Whereas F. hepatica is distributed worldwide in cooler climates, F. gigantica occurs mainly in the tropics of Africa and Asia. The southern Caucasus, with Armenia, is one of the most northern regions where both species occur and may produce hybrids. In this study, livestock in central Armenia was surveyed for fasciolosis, the causative species were determined and the genetic diversity of both species was estimated. Total prevalence in sheep (1794), cattle (324) and goats (9) was 21.2%, 15.7% and 44.4%, respectively. After morphological identification and sequencing of a mitochondrial (nad1) and a nuclear marker gene (28S rRNA), 62 collected specimens were allocated to F. hepatica (n = 55) and F. gigantica (n = 7). Intraspecific diversity was evaluated for the complete nad1 gene, resulting in 29 haplotypes of F. hepatica and six haplotypes of F. gigantica. Diversity was higher among F. gigantica than F. hepatica in the Armenian sample set, a difference that was confirmed analyzing available sequences for both species worldwide. Maximum genetic distance between haplotypes in global networks was 49 nucleotide steps for F. gigantica compared to 15 for F. hepatica. In the available sample sets, F. hepatica showed higher diversity in western Asia and the Middle East compared to Europe and eastern Asia, while for F. gigantica loosely structured clusters comprising mainly western/southern Asian and African haplotypes could be identified. A distinct clade comprising haplotypes from Zambia was basal in the phylogenetic tree. Biogeographical implications of these data are discussed.