Tsetse flies Glossina spp. (Diptera: Glossinidae) harbor three different symbiotic microorganisms, one being an intracellular Rickettsia of the genus Wolbachia. This bacterium infects a wide range of arthropods, where it causes a variety of reproductive abnormalities, one of which is termed cytoplasmic incompatibility (CI) that, when expressed, results in embryonic death due to disruptions in fertilization events. We report here that in colonized flies, Wolbachia infections can be detected in 100% of sampled individuals, while infections vary significantly in field populations. Based on Wolbachia Surface Protein (wsp) gene sequence analysis, the infections associated with different fly species are all unique within the A group of the Wolbachia pipientis clade. In addition to being present in germ-line tissues, Wolbachia infections have been found in somatic tissues of several insects. Using a Wolbachia-specific PCR-based assay, the tissue tropism of infections in Glossina morsitans morsitans Westwood, Glossina brevipalpis Newstead and Glossina austeni Newstead were analysed. While infections in G. m. morsitans and G. brevipalpis were limited to reproductive tissues, in G. austeni, Wolbachia could be detected in various somatic tissues.

No abstract

No abstract

BackgroundBased on the recently sequenced gene coding for the Trypanosoma evansi (T. evansi) RoTat 1.2 Variable Surface Glycoprotein (VSG), a primer pair was designed targeting the DNA region lacking homology to other known VSG genes. A total of 39 different trypanosome stocks were tested using the RoTat 1.2 based Polymerase Chain Reaction (PCR).ResultsThis PCR yielded a 205 bp product in all T. evansi and in seven out of nine T. equiperdum strains tested. This product was not detected in the DNA from T. b. brucei, T. b. gambiense, T. b. rhodesiense, T. congolense, T. vivax and T. theileri parasites. The Rotat 1.2 PCR detects as few as 10 trypanosomes per reaction with purified DNA from blood samples, i.e. 50 trypanosomes/ml.ConclusionPCR amplification of the RoTat 1.2 VSG gene is a specific marker for T. evansi strains, except T. evansi type B, and is especially useful in dyskinetoplastic strains where kDNA based markers may fail to amplify. Furthermore, our data support previous suggestions that some T. evansi stocks have been previously misclassified as T. equiperdum.

Orthogonal‐field‐alternation gel electrophoresis and DNA blot hybridizations have been used to investigate the genomic relationships among trypanosome clones of subgenus Nannomonas. The results indicate that Trypanosoma (Nannomonas) congolense comprises at least two distinct groups of parasites that differ in both molecular karyotype and repetitive DNA sequences. A description of these two groups and their distinction from Trypanosoma (Nannomonas) simiae is presented.