First molecular identification of the tularemia agent in the ticks Ixodes trianguliceps Bir. in Russia

Abstract

The ticks Ixodes trianguliceps (140 nymph pool and 211 adults) collected from small forest mammals in the forests of the Middle Urals (Chusovskoy district of the Perm Region) were tested using real-time PCR for the presence of Francisella tularensis DNA. Using the target gene 16S rRNA, the locus size 1165-1170 bp Francisella DNA was detected in 12 adults and 4 pools of nymphs. DNA-positive samples from 17 individuals from 128 adults and in 16 of 89 nymph pools were additionally detected by amplification of a shorter locus of the same gene (221-222 bp). All 49 16S rRNA gene-positive samples of real-time Taqman PCR assays directed against the tul4 (lpnA) gene locus and ISFtu2 element were identified as F. tularensis. These data suggest the possible involvement of the ticks I. trianguliceps in the circulation of the causative agent of tularemia in the natural foci of the forest type.