Pathogens Detected in Questing Ixodes ricinus Ticks in a Mountainous Area in Greece

Ixodes ricinus ticks are widespread in Europe and important vectors for multiple pathogens. The purpose of the study was to collect ticks in a mountainous area in Greece and screen those of I. ricinus species for several pathogens. I. ricinus was the predominant tick species identified (398/440, 90.45%). Following pooling (1-17 ticks per pool), homogenization and extraction of genetic material of the ticks, a real time PCR was applied for the detection of a panel of tick-borne pathogens, while additional conventional PCRs combined with Sanger sequencing were applied for detection of viruses and for typing of Rickettsia and Borrelia species. At least one pathogen was detected in 60 of the 80 (75%) pools. Rickettsia spp. predominated as it was detected in 63.75% of the tick pools (51/80), followed by Borrelia spp. (35 pools, 45%); A. phagocytophilum was detected in 2 (2.5%) pools, phleboviruses in 3 (3.75%) and nairoviruses in 7 (8.75%) pools. All the Rickettsia sequences taken belonged to R. monacensis, while among Borrelia spp., B. garinii and B. valaisiana were detected. Regarding viruses, Norway phlebovirus 1, Sulina and Grotenhout nairoviruses were detected. Although a small number of ticks from only one area in Greece was tested, a variety of pathogens and recently identified viruses were detected, prompting for further studies in ticks and surveillance studies in humans.