Journal Article

Distribution and molecular characteristics of rickettsiae found in ticks across Central Mongolia

Jiang, Rui-Ruo, Lkhagvatseren, Sukhbaatar, Baigalmaa, Bekhochir, Gray, Gregory C., Anderson, Benjamin D., Boldbaatar, Bazartseren, von Fricken, Michael E., Wang, Ya-Wei, Jiang, Jia-Fu, Nymadawa, Pagbajab

2017

Overview

Background Little is known regarding tick-borne diseases in Mongolia, despite having 26% of the population still living nomadic pastoral lifestyles. A total of 1497 adult unfed ticks: 261 Ixodes persulcatus , 795 Dermacentor nuttalli , and 441 Hyalomma asiaticum , were collected from three ecologically distinct regions in Central Mongolia. Tick pools ( n  = 299) containing ~5 ticks each, were tested for Rickettsia and Tick-borne encephalitis virus (TBEV) using nested polymerase chain reaction, reverse transcription-PCR, and quantitative real-time RT-PCR. Results Assays yielded pooled prevalence of 92.5% (49/53) and 1.9% (1/53) for pooled I. persulcatus testing positive for “ Candidatus Rickettsia tarasevichiae” and TBEV, respectively, while Rickettsia raoultii was found in 72.8% (115/158) of pooled D. nuttalli samples. When calculating a maximum likelihood estimation, an estimated 46.6% (95% CI: 35.2–63.6%) of I. persulcatus ticks in the pooled sample were infected with “ Candidatus R. tarasevichiae”. Conclusions Both “ Candidatus R. tarasevichiae” and R. raoultii are recognized as emerging tick-borne pathogens, with this being one of the first reports of “ Candidatus R. tarasevichiae” in Mongolia. Given that “ Candidatus R. tarasevichiae” shares the same vector ( I. persulcatus ) as TBEV, and infections may present with similar symptoms, Mongolian physicians treating suspected cases of TBEV should include “ Candidatus R. tarasevichiae” infection in their differential diagnosis and consider prescribing antimicrobial therapy.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V
• Subject: adults / Animals / Biomedical and Life Sciences / Biomedicine / Dermacentor / Distribution / drug therapy / Encephalitis Viruses, Tick-Borne - genetics / Encephalitis Viruses, Tick-Borne - isolation & purification / Entomology / Genetic aspects / Genotypes / Hard ticks / Hyalomma asiaticum / Identification and classification / Infectious Diseases / Ixodes persulcatus / Ixodidae - classification / Ixodidae - microbiology / Ixodidae - virology / Mongolia / Parasitology / pastoralism / Polymerase Chain Reaction / Real-Time Polymerase Chain Reaction / Reverse Transcriptase Polymerase Chain Reaction / Rickettsia / Rickettsiaceae - classification / Rickettsiaceae - genetics / Rickettsiaceae - isolation & purification / Rickettsiae / Short Report / statistical analysis / Tick-borne encephalitis virus / ticks / Tropical Medicine / Veterinary Medicine/Veterinary Science / Virology / Virus-vector relationships