Microbial communities and symbionts in the hard tick Haemaphysalis longicornis (Acari: Ixodidae) from north China

Abstract

BackgroundClose relationships between ticks and microbial communities are important for tick fitness and pathogen colonization and transmission. Haemaphysalis longicornis, distributed widely in China, can carry and transmit various pathogens and pose serious damages to public health and economics. However, little is known about the broader array of microbial communities and symbionts in H. longicornis under natural conditions. In the present study, we investigated the composition of bacterial communities associated with H. longicornis and evaluated the putative symbionts.MethodsThe eubacterial 16S rRNA gene clone libraries of H. longicornis were constructed and analyzed by restriction fragment length polymorphism (RFLP) and DNA sequencing. In addition, diagnostic PCR was performed to assess the prevalence, vertical transmission and infection sites of the symbionts in H. longicornis.ResultsVertically-transmitted symbionts, potential pathogens and allochthonous nonpathogenic bacteria were identified from the field-collected H. longicornis. Three types of symbionts (Coxiella-like, Arsenophonus-like and Rickettsia-like symbionts) were identified in a single host simultaneously. A series of analyses revealed the vertical transmission, prevalence, and infection sites of these symbionts. However, only Coxiella-like bacteria were transmitted stably in the laboratory-reared ticks. In addition, we identified a novel Coxiella-like agent with 95.31% sequence similarity to the taxon described previously.ConclusionsThe present study demonstrated that natural H. longicornis harboured a diverse array of microbial communities. Three types of symbionts were identified in a single host simultaneously. Moreover, high prevalence, vertical transmission and the infection sites supported an obligate symbiotic association between Coxiella symbiont and its host. The role of Coxiella symbiont in the host fitness and the interaction among microbial communities remained to be elucidated. Our investigation of microbial communities in the ticks revealed the complexity of ecological interactions between host and microbe and provided insight for the biological control of ticks.

Characterization of microbiota diversity of field‐collected Haemaphysalis longicornis (Acari: Ixodidae) with regard to sex and blood meals

“…In this study, we found microbial community of H . longicornis is consistent with previous findings that Proteobacteria is the most abundant phylum in tick species , with Coxiella showing the highest abundance . Researches have been suggested that female Amblyomma americanum and Rhipicephalus microplus ticks possessed higher relative abundance of Coxiella ‐like endosymbionts compared to male ticks .…”

Symbiont dynamics of the Tibetan tick Haemaphysalis tibetensis (Acari: Ixodidae)

“…The CLS-Ht mainly infects the ovaries and the Malpighian tubes, which is consistent with the previous observation of Coxiella -like symbionts in R. sanguineus and R. turanicus ticks [18]. No tissue-specific infectivity was observed for RLS-Ht, a conclusion that is similar with the Rickettsia- like symbiont distribution in H. longicornis and D. silvarum found previously [4]. The coinfection of symbionts is common in ticks.…”

Tick-Pathogen Interactions and Vector Competence: Identification of Molecular Drivers for Tick-Borne Diseases

“…It has been ascribed a possible helper role in tick molting processes (Zchori-Fein and Bourtzis, 2011, Figure 3). Rickettsia -like symbionts have also been reported to infect hard ticks from several genera (Baldridge et al, 2004; Clay et al, 2008; Liu et al, 2013). One study reported that Rickettsia -infected Dermacentor variabilis have slightly greater motility than uninfected ticks, indirectly influencing disease risk (Kagemann and Clay, 2013).…”