Spiroplasma, Wolbachia, Sodalis and trypanosome associations in Glossina tachinoides from Yankari game reserve, Nigeria

Background . Tsetse flies are vectors of African trypanosomiasis, a disease that affects both humans and animals. Trypanosomiasis remains a threat to lives and an impediment to socio-economic development in sub-Saharan Africa. In spite of decades of chemotherapy and vector control, the disease has not been eradicated. The parasites have developed resistance to the existing drugs, while the available vector control strategies are expensive and unsustainable. Therefore, there is a need to explore other control approaches, such as the transformation of tsetse fly endosymbionts to render the fly refractory to trypanosome infection. The aim of this study was to investigate the prevalence and association of trypanosome infection with some endosymbionts in tsetse flies from Yankari Game Reserve. Results . Tsetse flies were caught using biconical traps and identified morphologically. They were dissected and their entire gut was isolated and used for DNA extraction. Polymerase chain reaction was used to confirm the identity of the flies by amplifying the cytochrome C oxidase-1 gene and to screen for the presence of endosymbionts ( Sodalis glossinidius , Wolbachia , and Spiroplasma sp.) and trypanosomes. A single tsetse fly species was identified: Glossina tachinoides . A trypanosome infection rate of 10.70% was found and three species of trypanosomes detected ( Trypanosoma grayi , Trypanosoma congolense, and Trypanosoma vivax ), with Trypanosoma grayi being the most prevalent (9.78%). Wolbachia and Spiroplasma species were found in 2.80% and 40.8% of flies respectively, while Sodalis glossinidius was not detected. There was an association between the presence of trypanosomes and Wolbachia, while no association was found between trypanosomes and Spiroplasma . Conclusion. This study revealed that the presence of Wolbachia seems to favour trypanosome infections. Investigation on the Wolbachia genetic polymorphism in tsetse could help to better understand this association.