Co-infections with multiple pathogens in natural populations of Ixodes persulcatus ticks in Mongolia

• Published in: Parasites & Vectors
• Main Authors: Ekaterina K. Lagunova, Natalia A. Liapunova, Davaakhu Tuul, Gerechuluun Otgonsuren, Davaadorj Nomin, Nyamdorj Erdenebat, Davaajav Abmed, Galina A. Danchinova, Kozue Sato, Hiroki Kawabata, Maxim A. Khasnatinov
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2022
• Subjects: Mongolia; Borrelia burgdorferi sensu lato; Borrelia miyamotoi; Tick-borne encephalitis virus; Anaplasma phagocytophilum; Ehrlichia sp; Infectious and parasitic diseases; RC109-216; taiga
• Online Access: https://doi.org/10.1186/s13071-022-05356-x; https://doaj.org/article/24ef5c71a1bf49daa278a5a94334edda

Abstract Background In Mongolia, the taiga tick Ixodes persulcatus is the major vector of tick-borne pathogens. Knowledge about co-infections of these pathogens in ticks is necessary both for understanding their persistence in nature and for diagnosing and treating tick-borne diseases. Methods The prevalence of seven tick-borne infections in 346 I. persulcatus collected from the Selenge and Bulgan provinces of Mongolia was evaluated using real-time PCR. Quantification of Borrelia spp. was performed using multiplex quantitative PCR targeting the 16S rRNA gene. Genetic analysis of Borrelia spp. in 11 ticks infected with Borrelia miyamotoi, including six ticks co-infected with Borrelia burgdorferi sensu lato (s.l.), was performed by high-throughput sequencing of the flaB gene fragment. Results Six ticks (1.7%) were infected with tick-borne encephalitis virus (TBEV); 171 (49.4%), with B. burgdorferi sensu lato; 17 (4.9%), with B. miyamotoi; 47 (13.6%), with Anaplasma phagocytophilum; and 56 (16.2%), with Ehrlichia sp. Neither Rickettsia sibirica nor R. heilongjiangensis were detected. Borrelia burgdorferi s.l. occurred as co-infection in 55 (32.2%) of all infected ticks. The other pathogens co-infected ticks in 58.8–70.2% of cases. No pairwise associations between co-infecting pathogens were observed, with the exception of a positive association between A. phagocytophilum and Ehrlichia sp. infections. The spirochete loads of B. miyamotoi were significantly higher than those of B. burgdorferi s.l. (mean: 5.2 vs 4.0 log10 genome copies/tick, respectively). Ten isolates of B. miyamotoi belonged to the Siberian lineage. Borrelia burgdorferi s.l was represented by nine isolates of B. afzelii, B. bavariensis and B. garinii. Conclusions In populations of I. persulcatus inhabiting the Selenge and Bulgan provinces of Mongolia, five vector-borne pathogens, i.e. TBEV, B. burgdorferi s.l., B. miyamotoi, A. phagocytophilum and Ehrlichia sp., persist independently from each other, with the exception of A. phagocytophilum and ...