Assessing the Tsetse Fly Microbiome Composition and the Potential Association of Some Bacteria Taxa with Trypanosome Establishment

Abstract

The tsetse flies, biological vectors of African trypanosomes, harbour a variety of bacteria involved in their vector competence that may help in developing novel vector control tools. This study provides an inventory of tsetse bacterial communities in Cameroon and explores their possible associations with trypanosome establishment in Glossina palpalis palpalis. High throughput sequencing of the V3-V4 hypervariable region of the bacterial 16S rRNA gene, with subsequent metagenomic, multivariate, and association analyses, were used to investigate the levels and patterns of microbial diversity in four tsetse species. Overall, 31 bacterial genera and four phyla were identified. The primary symbiont Wigglesworthia dominated almost all the samples, with an overall relative abundance of 47.29%, and seemed to be replaced by Serratia or Burkholderia in some G. tachinoides flies. Globally, significant differences were observed in the microbiome diversity and composition among tsetse species and between teneral and non-teneral flies, or between flies displaying or not displaying mature trypanosome infections. In addition, differential abundance testing showed some OTUs, or some bacteria taxa, associated with trypanosome maturation in tsetse flies. These bacteria could be further investigated for an understanding of their mechanism of action and alternatively, transformed and used to block trypanosome development in tsetse flies.

Lipid metabolism dysfunction following symbiont elimination is linked to altered Kennedy pathway homeostasis

“…This has prevented studies where aposymbiotic tsetse flies can be monocolonized with Wigglesworthia to allow for the recovery of a control phenotype. Tsetse flies do harbor only a single, consistent symbiont ( Wigglesworthia ), with other species showing very little impact on tsetse biology or found very rarely in the population, 19 , 20 , 21 suggesting that phenotypes observed are most likely from Wigglesworthia . Thus, until Wigglesworthia can be cultured (has yet to be accomplished) and monocolonized back into tsetse flies (has yet to be accomplished), the role of other factors in these phenotypes cannot be fully excluded.…”

“… 15 , 17 , 18 However, the mechanistic basis for this phenotype remains unclear. Other bacteria have been associated with tsetse flies, 19 , 20 , 21 but these are only at low levels. Sodalis is a commonly found facultative bacteria for tsetse flies but is not present in all lineages, 19 , 20 , 21 highlighting that Wigglesworthia mediates nutritional supplementation.…”

Arthropod microbiota: shaping pathogen establishment and enabling control

“…The analyses of the microbiota composition of tsetse flies from two HAT/AAT endemic areas (Kafue in Zambia and Hurungwe in Zimbabwe) in sub-Saharan Africa revealed that the bacterial diversity is relatively similar in flies of both sexes, fed on different mammal species, and infected or not infected with T. brucei (Gaithuma et al, 2020). Conversely, significant differences were observed in microbiota diversity and composition among tsetse species, between teneral and nonteneral flies, and between infected and noninfected flies collected in Campo (Camaroon) (Tsakeng et al, 2022). The primary symbiont Wigglesworthia was present in almost all samples, with a relative abundance of approximately 47%.…”

“…The primary symbiont Wigglesworthia was present in almost all samples, with a relative abundance of approximately 47%. Interestingly, Serratia or Burkholderia seems to be a substitute for Wigglesworthia in some Glossina tachinoides flies (Tsakeng et al, 2022).…”

Current Status of Metatranscriptomic and Related Studies in Hematophagous Disease-Transmitting Vectors

“…The bacterial component of the microbiome has been studied to a certain degree using culture dependent and independent approaches (Geiger et al 2011(Geiger et al , 2009Lindh and Lehane 2011), DNA metabarcoding (Aksoy et al 2014;Doudoumis et al 2017;Griffith et al 2018;Tsakeng et al 2022), and one DNA metabarcoding analysis that simultaneously gauged the bacterial component and the blood meal source (Gaithuma et al 2020). Compared to other VBDs, the number of NGS studies is very limited.…”