The PCR detection and phylogenetic characterization of Babesia microti in questing ticks in Mongolia

Abstract

Babesia microti is a tick-transmitted zoonotic hemoprotozoan parasite. In the present study, we investigated B. microti infection in questing ticks in Mongolia. A total of 219 questing ticks were collected from three different Mongolian provinces (Bayan-Olgii, Khovsgol, and Selenge). Of these, 63 from Selenge were identified as Ixodes persulcatus, while the remaining 156 (from all three provinces) were identified as Dermacentor nuttalli. When the tick DNA samples were screened using a B. microti-specific nested PCR, 19 (30.2%) of the 63 I. persulcatus ticks were found to be B. microti-positive. The parasite was not detected in D. nuttalli. Subsequently, the 18S rRNA, cox1, and tufA sequences of B. microti were amplified, sequenced, and subjected to phylogenetic analyses. Sequencing analyses showed that the Mongolian 18S rRNA, cox1, and tufA sequences were 99.6-100%, 96.7-97.2%, and 94.7-95.3% homologous, respectively, with B. microti R1 strain US-type sequences from humans. In the phylogenetic analyses, the Mongolian cox1 and tufA sequences were found to be separate lineages, which formed sister-clades to the R1 strain sequences, while all of the Mongolian B. microti 18S rRNA sequences were clustered within US-type clade containing several other sequences of human origin. In conclusion, in addition to reporting the presence of B. microti for the first time in questing ticks in Mongolia, the present study found that Mongolian I. persulcatus ticks were infected with US-type B. microti. These findings warrant large-scale studies to detect and characterize B. microti in ticks, small mammals, and humans. Such studies should provide us with a better understanding of zoonotic Babesia epidemiology in Mongolia.

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

“…Previous entomological surveys focusing on ticks in Mongolia have reported a countrywide distribution of D. nuttalli , while H. asiaticum and I. persulcatus have clearly defined ecological niches on opposite sides of Mongolia [ 23 ], thus influencing the geographical distribution of species-specific tick-borne diseases. Living in close proximity to coniferous regions in the northern aimags of Mongolia likely remains a significant risk factor for exposure to diseases transmitted by I. persulcatus hard ticks [ 7 , 11 , 12 , 19 , 20 , 24 – 26 ]. Rickettsia raoultii detection among D. nuttalli ticks were observed in all five sampling districts, suggesting a wider distribution of disease, even extending into China as indicated by other reports [ 21 , 27 ].…”

Eurasian golden jackal as host of canine vector-borne protists

“…To confirm the determination of piroplasmids and to obtain further phylogenetic characterization, two modified nested PCR protocols amplifying fragments of cytochrome c oxidase subunit 1 ( cox 1 ) gene were performed [21, 22]. Table 1 provides details on the primers used, PCR conditions and obtained fragments for all PCRs.…”

Characterization, optimization, and validation of environmental DNA (eDNA) markers to detect an endangered aquatic mammal

“…In both the positive and negative control sites, we collected and filtered water samples immediately on site and transported the filter papers (stored in 95 % ethanol) on ice until samples could be frozen in the laboratory (within 24 h). As target-species DNA concentrations in natural environments are typically very low, we used a reamplification PCR protocol for all amplifications (Tuvshintulga et al 2015), using the diluted (1:10 with sterilized ddH 2 O) amplicons as DNA template for a second round of PCR amplification. These final PCR products were visualized using electrophoresis on 2 % agarose gel stained with 4S Red Plus Nucleic Acid Stain.…”