(Ilia State University, Georgia)
Molecular-genetic description and barcoding of hard ticks (Ixodidae) distributed in Georgia
Hard ticks (Ixodidae) are important vectors of infectious diseases (borreliosis, Crimean-Congo hemorrhagic fever) around the world. Because of its geographical location, Georgia is a bridge between different biogeographical and climate zones and is rich in biodiversity. Different species of hard ticks are distributed in Georgia, which have not been barcoded yet. The aim of this research was molecular-genetic characterization and barcoding of hard ticks distributed in Georgia. For this purpose, magnetic bead DNA extraction and PCR amplification protocols were selected and optimized. Samples of hard ticks were collected from different regions of Georgia (Shida Kartli, Aspindza, Akhaltsikhe); gDNA was extracted from 40 samples and COI region was PCR amplified with primers HCO/LCO and ChelF1/ChelR2. ChelF1/ChelR2 primers were chosen for further research as they showed more specificity in amplification reactions. PCR amplicons were sequenced with Sanger sequencing method and results were analyzed in Geneious Prime. All sample species were identified with high reliability (Query coverage 99.3 %). It was found that 4 out of 40 samples were Hyalomma scupense (Shida Kartli and Aspindza), 5 Dermacentor marginatus (Shida Kartli), 3 Hyalomma marginatum (Aspindza), 21 Rhipicephalus annulatus (Shida Kartli, Akhaltsikhe, and Aspindza) and 7 Rhipicephalus bursa (Shida Kartli, Akhaltsikhe, and Aspindza). All of the listed species pose a threat to humans (including Crimean-Congo hemorrhagic fever), except for the species Rhipicephalus annulatus, which mostly infects cattle. The phylogenetic tree of hard ticks was built according to the sequencing results. The sequences were uploaded and published in the International Biodiversity Database - BOLD, with indications of geographical locations. This allows further statistical analysis and comparison of species distribution across the Caucasus region and the globe.