Rickettsia bacterial diversity detected by Targeted and SRA
screens
The targeted Rickettsia screen of 1,612 individuals from 169
invertebrate species detected infections in 16 species (9.47%)
including both aquatic and terrestrial taxa (Table 1). Of these, 14
profiles clustered within the Torix group with the remaining two placed
in the Belli and Rhyzobius groups (Figure 5). Comparisons of TorixRickettsia frequency between aquatic/semiaquatic vs terrestrial
arthropods revealed evidence for a higher representation of TorixRickettsia infected species in the aquatic biome (Fisher’s Exact,P = 0.019).
During the SRA search, phyloFlash flagged 29 Rickettsia sequences
in the groups: Bellii (n=12), Torix (n=8), Transitional (n=6), Rhyzobius
(n=2), and Spotted Fever (n=1) (Figure 5). In addition, Kraken
identified nine Rickettsia -containing arthropod SRA datasets
missed by phyloFlash. Two of these were from the Torix group, in phantom
midge hosts (Diptera: Chaobaridae: Mochlonyx cinctipes andChaoborus trivitattus ), with the remaining seven placed in Belli
and Spotted Fever groups (Table S3). The search of NCBI revealed 11
deposits ascribed to host mtDNA that were in fact TorixRickettsia sequences (Table S9 and Figure S2).