AUTHOR=Borşan Silvia-Diana , Ionică Angela Monica , Galon Clémence , Toma-Naic Andra , Peştean Cosmin , Sándor Attila D. , Moutailler Sara , Mihalca Andrei Daniel 

TITLE=High Diversity, Prevalence, and Co-infection Rates of Tick-Borne Pathogens in Ticks and Wildlife Hosts in an Urban Area in Romania

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.645002

DOI=10.3389/fmicb.2021.645002

ISSN=1664-302X

ABSTRACT=<p>Despite the increasingly recognized eco-epidemiological importance of ticks as vectors for numerous zoonotic pathogens in urban areas, data regarding the pathogen diversity and co-infection rates in ticks and wildlife hosts in urban and peri-urban Romania are scanty. We aimed to establish the risk of human exposure to co-infected ticks in Cluj-Napoca, a major city in Romania. DNA was isolated from 151 questing ticks: <italic>Ixodes ricinus</italic> (<italic>n</italic> = 95), <italic>Haemaphysalis punctata</italic> (<italic>n</italic> = 53), <italic>Dermacentor reticulatus</italic> (<italic>n</italic> = 2), and <italic>Dermacentor marginatus</italic> (<italic>n</italic> = 1); 222 engorged ticks: <italic>I. ricinus</italic> (<italic>n</italic> = 164), <italic>I. hexagonus</italic> (<italic>n</italic> = 36), <italic>H. punctata</italic> (<italic>n</italic> = 16), <italic>H. concinna</italic> (<italic>n</italic> = 6), and 70 tissue samples collected from wildlife hosts during 2018 in five urban, and two peri-urban sites. Using a pre-designed Fluidigm real-time PCR dynamic array, all DNA samples were individually screened for the presence of 44 vector-borne pathogens. Subsequently, conventional PCRs were performed for a selection of samples to allow validation and sequencing. In total, 15 pathogens were identified to species and 6 to genus level. In questing ticks, single infections were more common than co-infections. Seven <italic>Borrelia</italic> spp. were detected in questing <italic>I. ricinus</italic>, and three in <italic>H. punctata</italic> ticks. An overall high prevalence 26.35% (95% CI: 19.46–34.22) and diversity of <italic>Borrelia burgdorferi</italic> sensu lato was seen in urban questing ticks. Other pathogens of the order Rickettsiales were present with variable prevalence. Co-infections occurred in 27.4% (95% CI: 18.72-37.48) of all infected questing ticks. In engorged ticks the overall <italic>Bo. burgdorferi</italic> sensu lato prevalence was 35.6% (95% CI: 29.29–42.27), with five species present. Pathogens of the order Rickettsiales were also frequently detected. We report for the first time in Romania the presence of <italic>Rickettsia aeschlimannii</italic> and <italic>Rickettsia felis</italic>. Overall, from the infected engorged ticks, 69.2% showcased co-infections. In <italic>Ixodes</italic> spp., dual co-infections, namely <italic>Borrelia</italic> spp. and <italic>Anaplasma phagocytophilum</italic>, and <italic>Rickettsia helvetica</italic> and <italic>A. phagocytophilum</italic> were the most prevalent. Given the outcome, we underline the need to establish proper tick-surveillance programs in cities and include co-infections in the management plan of tick-borne diseases in Romania.</p>