Analysis of Tsetse Fly (Diptera: Glossinidae) blood meals using mitochondrial cytochrome genes for vertebrate host identification

Abstract

Information on the vertebrate hosts of blood feeding vectors forms a useful decision-making tool in the planning of tsetse fly control and eradication operations. The objective of this study was to investigate the utility of mitochondrial Cytochrome c oxidase I and Cytochrome b gene sequences in the identification of tsetse fly blood meals in order to provide a basis for more rational control of trypanosomosis in East Africa. Blood fed Glossina swynnertoni were sampled from the Serengeti (Tanzania) and G. pallidipes were from Nguruman and Busia in Kenya. Tsetse blood meal analysis was carried out by amplification and sequencing, to score polymorphisms in the partial COI and Cytb genes with diagnostic value. Sequences obtained were used to query the BOLD and GenBank databases, and the percent identities used to identify hosts. Hosts identified from blood fed G. swynnertoni collected in Serengeti ecosystem, included twenty five buffaloes, nine had fed on giraffes, three on warthogs and other three had fed on elephants and one on spotted hyena. In Nguruman, the analyzed G. pallidipes were found to have obtained their blood meals from different hosts which included six elephants, five warthogs, a buffalo and a baboon. Only cattle blood was detected in flies caught in Busia in western Kenya. Regarding the hosts identified in the different sampling sites, insecticides on cattle will form an integral part of a control strategy for trypanosomosis in Busia, while different approaches, for example traps and targets are needed for Serengeti and Nguruman ecosystems, where wildlife abound and are the major component of the tsetse fly food source. These results demonstrate the feasibility of the COI and Cytb gene sequences for the identification of the vertebrate hosts of tsetse fly species.