Rhipicephalus sanguineus s.l. ticks (Acari: Ixodidae) harbor non-divergent bacterial microbiomes in Arizona

TL;DR

This study found that Rhipicephalus sanguineus ticks in Arizona have similar bacterial communities regardless of genetic lineage or other factors.

Contribution

The use of a blocking primer to exclude Coxiella allowed a clearer view of non-endosymbiont bacterial communities in ticks.

Findings

Bacterial genera were common across R. sanguineus ticks in Arizona.

No significant differences in microbiomes were found based on lineage, sex, or location.

Non-pathogenic bacteria showed consistent patterns despite genetic variation in ticks.

Abstract

Rhipicephalus sanguineus (Latreille) is a species complex of ticks that are important vectors of many diseases to humans and other animals. In Arizona, the ranges of the 2 primary genetic variants—the temperate and the tropical lineages—overlap. The temperate and tropical lineages of R. sanguineus s.l. have divergent strains of the obligate Coxiella-like endosymbiont; however, it is unknown whether the microbiomes of the temperate and tropical lineages are otherwise different. There is growing evidence that non-pathogenic bacteria may be important components of vector-borne disease dynamics, even at low abundance. This research utilized a blocking primer to prevent sequencing of Coxiella to enable a closer examination of bacterial community structure of R. sanguineus s.l. ticks in Arizona. There were many commonalities among bacterial genera found within R. sanguineus s.l. ticks across the state, but no clear distinctions in bacterial community composition based on lineage, sex, female engorgement level, or collection location.

Keywords: acarology, insect–symbiont interaction, microbiology, medical entomology

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