The first molecular genetic identification of the tularemia pathogen in Ixodes trianguliceps Bir. ticks in Russia

Abstract

A real-time PCR (RT PCR) assay for Francisella tularensis DNA in ixodes ticks Ixodes trianguliceps (140 mature individuals and 211 nymph pools) found on small mammals from the Middle Ural forests (Chusovskoi district, Perm Region) has been performed for the first time. Francisella DNA was detected in 12 mature ticks and 4 nymph pools when the 16SrRNA gene (amplicon size 1165–1170 bp) was used as the target. Amplification of a shorter fragment of the same gene (221–222 bp) resulted in identification of additional positive samples among mature ticks (17 of 128) and nymph pools (16 of 89). All 49 RT-PCR positive samples were identified as F. tularensis DNA using primers and probes complementary to a fragment of the lpnA (tul4) gene and the ISFtu2 element. The data obtained are indicative of the possible involvement of I. trianguliceps ticks in tularemia pathogen circulation in natural foci of forest type.