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

• Published in: Frontiers in microbiology Vol. 12; p. 645002
• Main Authors: Borşan, Silvia-Diana, Ionică, Angela Monica, Galon, Clémence, Toma-Naic, Andra, Peştean, Cosmin, Sándor, Attila D, Moutailler, Sara, Mihalca, Andrei Daniel
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media 09-03-2021; Frontiers Media S.A
• Subjects: co-infections; hard ticks; Life Sciences; Microbiology; Microbiology and Parasitology; tick-borne pathogens; urban; wildlife hosts; wildlife hosts; hard ticks; urban; co-infections; tick-borne pathogens
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.645002

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:
(
= 95),
(
= 53),
(
= 2), and
(
= 1); 222 engorged ticks:
(
= 164),
(
= 36),
(
= 16),
(
= 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
spp. were detected in questing
, and three in
ticks. An overall high prevalence 26.35% (95% CI: 19.46-34.22) and diversity of
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
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
and
. Overall, from the infected engorged ticks, 69.2% showcased co-infections. In
spp., dual co-infections, namely
spp. and
, and
and
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.