Glossina spp. gut bacterial flora and their putative role in fly-hosted trypanosome development

Abstract

Human African trypanosomiasis (HAT) is caused by trypanosomes transmitted to humans by the tsetse fly, in which they accomplish their development into their infective metacyclic form. The crucial step in parasite survival occurs when it invades the fly midgut. Insect digestive enzymes and immune defenses may be involved in the modulation of the fly's vector competence, together with bacteria that could be present in the fly's midgut. In fact, in addition to the three bacterial symbionts that have previously been characterized, tsetse flies may harbor additional bacterial inhabitants. This review focuses on the diversity of the bacterial flora in Glossina, with regards to the fly species and their geographical distribution. The rationale was (i) that these newly identified bacteria, associated with tsetse flies, may contribute to vector competence as was shown in other insects and (ii) that differences may exist according to fly species and geographic area. A more complete knowledge of the bacterial microbiota of the tsetse fly and the role these bacteria play in tsetse biology may lead to novel ways of investigation in view of developing alternative anti-vector strategies for fighting human—and possibly animal—trypanosomiasis.

Tsetse fly microbiota: form and function

“…However, several environmentally acquired bacterial commensals were recently found in the guts of wild tsetse (Geiger et al, 2013). Bacteria belonging to 3 phyla (23 species), the Firmicutes , Proteobacteria and Actinobacteria , were characterized from east African G. fuscipes (Lindh and Lehane, 2011).…”

Comparison of the Bacterial Gut Microbiome of North American Triatoma spp. With and Without Trypanosoma cruzi

“…The bacterial microbiome living in the gastrointestinal tract or other organs of a host has increasingly been investigated as a potential target for intervention in efforts to limit disease transmission by a variety of arthropod vectors (Cirimotich et al, 2011;Crotti et al, 2012;Geiger et al, 2013;Hegde et al, 2015;Taracena et al, 2015;Vieira et al, 2015;Buarque et al, 2016). To date, few studies have examined the gut microbiome of triatomine vectors, and even fewer have looked at Triatoma spp.…”

Ontogeny, species identity and environment dominate microbiome dynamics in wild populations of kissing bugs (Triatominae)

“…Furthermore, the gut bacteria of hematophagous vectors interact with parasites (like T. cruzi) occupying the same niche [2,23,24]. The microbiome can potentially impede parasite transmission through direct (competition for resources) and indirect (promoting immune response) interactions [25][26][27][28][29][30][31]. The most comprehensive background on hematophagous microbiomes has been derived from mosquitos, ticks, and tsetse flies (reviewed in [32]), whereas triatomine-bacteria associations remain neglected.…”