Detection and characterization of Wolbachia infections in laboratory and natural populations of different species of tsetse flies (genus Glossina)

Vangelis Doudoumis,Florence Wamwiri,Adly Abd-Alla,Peter Takac,Corey Brelsfoard,Stelios Dalaperas,Emre Aksoy,Serap Aksoy,George Tsiamis,Uzma Alam,Johnson Ouma,Kostas Bourtzis

doi:10.1186/1471-2180-12-s1-s3

Abstract

BackgroundWolbachia is a genus of endosymbiotic α-Proteobacteria infecting a wide range of arthropods and filarial nematodes. Wolbachia is able to induce reproductive abnormalities such as cytoplasmic incompatibility (CI), thelytokous parthenogenesis, feminization and male killing, thus affecting biology, ecology and evolution of its hosts. The bacterial group has prompted research regarding its potential for the control of agricultural and medical disease vectors, including Glossina spp., which transmits African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals.ResultsIn the present study, we employed a Wolbachia specific 16S rRNA PCR assay to investigate the presence of Wolbachia in six different laboratory stocks as well as in natural populations of nine different Glossina species originating from 10 African countries. Wolbachia was prevalent in Glossina morsitans morsitans, G. morsitans centralis and G. austeni populations. It was also detected in G. brevipalpis, and, for the first time, in G. pallidipes and G. palpalis gambiensis. On the other hand, Wolbachia was not found in G. p. palpalis, G. fuscipes fuscipes and G. tachinoides. Wolbachia infections of different laboratory and natural populations of Glossina species were characterized using 16S rRNA, the wsp (Wolbachia Surface Protein) gene and MLST (Multi Locus Sequence Typing) gene markers. This analysis led to the detection of horizontal gene transfer events, in which Wobachia genes were inserted into the tsetse flies fly nuclear genome.ConclusionsWolbachia infections were detected in both laboratory and natural populations of several different Glossina species. The characterization of these Wolbachia strains promises to lead to a deeper insight in tsetse flies-Wolbachia interactions, which is essential for the development and use of Wolbachia-based biological control methods.

Highlights

Wolbachia is a genus of endosymbiotic a-Proteobacteria infecting a wide range of arthropods and filarial nematodes
Wolbachia infections were detected in multiple species of the morsitans complex: G. m. morsitans, G. m. centralis, G. pallidipes and G. austeni, in the fusca complex in G. brevipalpis, while it was absent in the analysed species from the palpalis complex: G. p. palpalis, G. fuscipes and G. tachinoides
Despite the heterogenous infections found in field populations, Wolbachia infection was fixed in the laboratory colonies of G. m. morsitans, and G. m. centralis

Summary

Introduction

Wolbachia is a genus of endosymbiotic a-Proteobacteria infecting a wide range of arthropods and filarial nematodes. Wolbachia induce a range of reproductive abnormalities in their arthropod hosts, such as cytoplasmic incompatibility (CI), parthenogenesis, male-killing and feminization [1,6,7,8,9,10,11], while they have developed mutualistic associations with filarial. The sole vectors of pathogenic trypanosomes in tropical Africa, infect many vertebrates, causing sleeping sickness in humans and nagana in animals [23]. It is estimated by the World Health Organization (WHO) that 60 million people in Africa are at risk of contracting sleeping sickness (about 40% of the continent’s population). Should active case finding and treatment be discontinued, it would be prudent to maintain vector surveillance and control measures to prevent (re)emergence of the disease as was witnessed in the early 1990’s in various parts of the continent [26,27]

Methods

Results

Discussion

Conclusion