Use of Ion Torrent PGM in Sequencing Metagenome of Tick Rhipicephalus sanguineus

Microbiome assessments based on amplification and sequencing of their 16S rRNA genes or targeted surveys of specific agents have greatly augmented our understanding of the distribution and identity of bacteria found in ticks. The most prevalent tick bacteria include approximately 10 species, such as Coxiella-like (CLE), Francisella-like (FLE) endosymbionts, and spotted fever group Rickettsia (SFG). However, genomes of only a few of the many tick bacterial agents that are not cultivable have been characterized by very deep next generation sequencing (Illumina HiSeq). As an alternative approach, we have assessed use of the Ion Torrent Personal Genome Machine (IT-PGM) for direct sequencing and assembly of these agent genomes. We conclude that the IT-PGM is a relatively inexpensive sequencing platform for initial partial genomic characterization of some of the abundant bacterial agents found in hard ticks.