Abstract
Background: Blood-feeding arthropods support a diverse array of symbiotic microbes, some of which facilitate host growth and development whereas others are detrimental to vector-borne pathogens. We found a common core constituency among the microbiota of 16 different arthropod blood-sucking disease vectors, including Bacillaceae, Rickettsiaceae, Anaplasmataceae, Sphingomonadaceae, Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Staphylococcaceae. By comparing 21 genomes of common bacterial symbionts in blood-feeding vectors versus non-blooding insects, we found that certain enteric bacteria benefit their hosts by upregulating numerous genes coding for essential nutrients. Bacteria of blood-sucking vectors expressed significantly more genes (p < 0.001) coding for these essential nutrients than those of non-blooding insects. Moreover, compared to endosymbionts, the genomes of enteric bacteria also contained significantly more genes (p < 0.001) that code for the synthesis of essential amino acids and proteins that detoxify reactive oxygen species. In contrast, microbes in non-blood-feeding insects expressed few gene families coding for these nutrient categories. We also discuss specific midgut bacteria essential for the normal development of pathogens (e.g., Leishmania) versus others that were detrimental (e.g., bacterial toxins in mosquitoes lethal to Plasmodium spp.).
Highlights
Blood-feeding arthropods are the vectors of many of the most serious infectious diseases that have plagued humanity throughout history
When analyzed by two-way ANOVA (Prism, www.Graphpad.com, accessed on 9 May 2021), the results showed that there was no significant difference among the genomes for the enteric bacteria (F 8, 80) 1.88, p > 0.08, but there was a highly significant difference between rows (F 10, 80) 9.66, p < 0.001)
Increases in the densities of Francisella sp., present in the tick ovaries, in response to this same stimulus suggest that B vitamins and other nutrients provided by these bacteria may explain how they benefit the tick host
Summary
Blood-feeding arthropods are the vectors of many of the most serious infectious diseases that have plagued humanity throughout history. In-depth analysis of changes in relative abundance of diverse microbiota during development, blood feeding and reproduction has enhanced our understanding of the contributions of these microbes to vector health (fitness) and even pathogen survival and transmission to vertebrate hosts. These vector insects and acarines acquire a portion of their microbiota from their vertebrate hosts [12] or from the external environment, but all share the same food source (blood) and often share similar host body conditions (e.g., temperature). The results of our studies are supported by data tables, sequence alignments and phylogenetic trees, described in detail of this article
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
