Identification of tick-borne pathogens using metagenomic analyses in H. longicornis feeding on humans in downtown Beijing

Jizhou Lv,Xueqing Han,Xiangfen Yuan,Lin Mei,Junhua Deng,Zhen F Fu,Shaoqiang Wu,Xiangmei Lin,Huiyu Wang,Yufang Kong

doi:10.1186/s44149-021-00018-4

Jizhou Lv, Xueqing Han + Show 8 more

Open Access

https://doi.org/10.1186/s44149-021-00018-4

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Abstract

On August 14th, 2018, a Beijing resident living in Xicheng District found a female H. longicornis tick attached to the skin at the front of his upper shin. On examination, the patient was afebrile and appeared well. The species of the tick was identified through morphological characteristics and phylogenetic analysis based on cytochrome C oxidase subunit I. This H. longicornis tick was screened for tick-borne pathogens such as viruses, bacteria and parasites. RNA pathogens were screened by PCR and sequencing, while DNA pathogens were screened by metagenomic analyses. It was found that the tick was positive for the DNA sequences of zoonotic and animal pathogens such as A. phagocytophilum, Ehrlichia minasensis and C. burnetii. Considering the good health condition of the patient, we hypothesized that the pathogens originated from the tick specimen itself rather than host blood meal. For the first time, our study reveals the possible risk of transmission of tick-borne pathogens to human beings through tick bit in downtown Beijing. Further research is needed to screen for tick-borne pathogens among unfed ticks collected from central Beijing.

Highlights

Ticks were the first arthropods to be recognized as vectors that can transmit pathogens to human beings and are second only to mosquitoes as vectors of infectious diseases (Dantas-Torres et al 2012)
Tick-borne pathogens, including viruses, bacteria and parasites, were screened in this tick specimen, and our results showed that this tick was positive for the Deoxyribonucleic acid (DNA) sequences of zoonotic and animal pathogens such as A. phagocytophilum, Ehrlichia minasensis and C. burnetii
Have been previously proven to be present in China (Liu et al 2020; Yu et al 1993). We certified that this tick was positive for the DNA sequences of zoonotic and animal pathogens such as A. phagocytophilum, Ehrlichia minasensis and C. burnetii by using metagenomic analyses

Summary

Introduction

Ticks were the first arthropods to be recognized as vectors that can transmit pathogens to human beings and are second only to mosquitoes as vectors of infectious diseases (Dantas-Torres et al 2012). Humans are occasional host of ticks, and these emerging tick-borne agents have become a real threat to human health in China (Socolovschi et al 2009).The northwestern part of Beijing, especially Yanqing and Huairou Districts, is dominated by the Jundu Mountains, while the western part, Mentougou and Fangshan Districts, is framed by Xishan or the Western Hills (Cheng et al 2016). There are several reports that ticks bit humans in the suburban areas of Beijing (Li et al 2002; Lu et al 2013). The cases of humans bitten by ticks reported in Beijing have all occurred in suburban areas rather than downtown areas. Downtown Beijing includes Chaoyang, Haidian, Fengtai and Shijingshan Districts, especially the Dongcheng and Xicheng Districts, which are in the center of Beijing

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