Skin infectome of patients with a tick bite history

Abstract

Introduction: Ticks are the most important obligate blood-feeding vectors of human pathogens. With the advance of high-throughput sequencing, more and more bacterial community and virome in tick has been reported, which seems to pose a great threat to people.

Methods: A total of 14 skin specimens collected from tick-bite patients with mild to severe symptoms were analyzed through meta-transcriptomic sequencings.

Results: Four bacteria genera were both detected in the skins and ticks, including Pseudomonas, Acinetobacter, Corynebacterium and Propionibacterium, and three tick-associated viruses, Jingmen tick virus (JMTV), Bole tick virus 4 (BLTV4) and Deer tick mononegavirales-like virus (DTMV) were identified in the skin samples. Except of known pathogens such as pathogenic rickettsia, Coxiella burnetii and JMTV, we suggest Roseomonas cervicalis and BLTV4 as potential new agents amplified in the skins and then disseminated into the blood. As early as 1 day after a tick-bite, these pathogens can transmit to skins and at most four ones can co-infect in skins.

Discussion: Advances in sequencing technologies have revealed that the diversity of tick microbiome and virome goes far beyond our previous understanding. This report not only identifies three new potential pathogens in humans but also shows that the skin barrier is vital in preventing horizontal transmissions of tick-associated bacteria or virus communities to the host. It is the first research on patients' skin infectome after a tick bite and demonstrates that more attention should be paid to the cutaneous response to prevent tick-borne illness.

Keywords: infectome; metatranscriptomic sequencing; patients; skin; ticks.

Figure 1

Bacteria and viruses identified in skin samples from 14 patients with a tick bite as determined by metatranscriptomic sequencing. (A) Percentage of bacterial read counts in the skin samples after a tick bite. (B) Comparisons of the bacterial and viral read counts of six tick-borne pathogens in skin and blood samples. (C) Viral abundance of the Jingmen tick virus by viral segments in the positive skin and blood samples.

Figure 2

Phylogenetic analyses of (potential) pathogens detected in patients in this study. (A) Roseomonas, (B) Rickettsia, (C) Jingmen tick virus, (D) Bole tick virus 4, and (E) deer tick Mononegavirales-like virus. The symbol * mean the value of bootstrap for this branch >70.