Trypanosomes of the Trypanosoma theileri Group: Phylogeny and New Potential Vectors

Abstract

Trypanosomes belonging to Trypanosoma theileri group are mammalian blood parasites with keds and horse fly vectors. Our aim is to study to vector specificity of T. theileri trypanosomes. During our bloodsucking Diptera survey, we found a surprisingly high prevalence of T. theileri trypanosomes in mosquitoes (154/4051). Using PCR and gut dissections, we detected trypanosomes of T. theileri group mainly in Aedes mosquitoes, with the highest prevalence in Ae. excrucians (22%), Ae. punctor (21%), and Ae. cantans/annulipes (10%). Moreover, T. theileri group were found in keds and blackflies, which were reported as potential vectors for the first time. The vectorial capacity was confirmed by experimental infections of Ae. aegypti using our isolates from mosquitoes; sand fly Phlebotomus perniciosus supported the development of trypanosomes as well. Infection rates were high in both vectors (47–91% in mosquitoes, 65% in sandflies). Furthermore, metacyclic stages of T. theileri trypanosomes were observed in the gut of infected vectors; these putative infectious forms were found in the urine of Ae. aegypti after a second bloodmeal. On the contrary, Culex pipiens quinquefasciatus was refractory to experimental infections. According to a phylogenetic analysis of the 18S rRNA gene, our trypanosomes belong into three lineages, TthI, ThII, and a lineage referred to as here a putative lineage TthIII. The TthI lineage is transmitted by Brachycera, while TthII and ThIII include trypanosomes from Nematocera. In conclusion, we show that T. theileri trypanosomes have a wide range of potential dipteran vectors, and mosquitoes and, possibly, sandflies serve as important vectors.

Avian Louse Flies and Their Trypanosomes: New Vectors, New Lineages and Host–Parasite Associations

“…Positive PCR products were purified by ExoSAP-IT™ (Thermo Scientific, Waltham, MA, USA) and sequenced in the Core Facility of the Faculty of Science, Charles University, using the primer 1000R (5′-ATGCCTTCGCTGTAGTTCGTCT-3′) [ 32 ], resulting in an approximately 600bp-long sequences. Further sequencing of chosen strains (K51, PAS441, and PAS433) was performed with primers 1000F (5′-AGACGAACTACAGCGAAGGCAT-3′) [ 32 ] and kin577F (GCCAGCACCCGCGGT) [ 16 ]; the assembly for each of the 3 sequences was carried out in Geneious 9.1.7 and was approximately 1500bp long. Low-quality ends were trimmed from all sequences in BioEdit 7.0.4.1.…”

Molecular identification of Trypanosoma theileri complex in Eurasian moose Alces alces (L.)

“…MK156791, Ganyukova et al, 2018 ; OL855998, OL856000, Kostygov et al, 2022 ) and 99.81% similarity with haplotypes found in Simulium sp. in the Czech Republic (GenBank accession no: OM256575, OM256576, Brotánková et al, 2022 ).…”

“…The trypanosomes of European wild mammals have so far been detected using light microscopy, and their descriptions and characteristics are usually based on the morphological features visible on microscope slides. However, molecular tools and detailed phylogenetic analysis have provided a better understanding of the taxonomic relationships of Megatrypanum trypanosomes, revealing three main lineages of T. theileri (TthI, TthII and TthIII) and several genotypes ( Rodrigues et al, 2006 ; Garcia et al, 2011 , 2020 ; Brotánková et al, 2022 ). The purpose of this study was to confirm the presence of trypanosomes in moose in Poland and classify them based on a combination of molecular approaches and traditional methods.…”

Porcisia transmission by prediuresis of sand flies

“…Contaminative transmission by ingestion of infected female sand flies presumably takes place in the subgenus Sauroleishmania ( Lainson and Shaw, 1987 ) and may occur in transmission of Leishmania to dogs while in man, rather little importance is attributed to occasional contaminative transmission by crushing the fly on the skin as it bites (reviewed by ( Killick-Kendrick, 1979 ). However, the frequent occurrence of live L. major have been confirmed in the prediuretic liquid of P. duboscqi and transmission of metacyclic forms by mosquito prediuretic fluid has also been considered for mammalian T. congolense ( Mutero and Mutinga, 1993 ) and avian T. theileri ( Brotánková et al., 2022 ). Contaminative transmission is not as conditioned by the number or localization of parasites in the gut of the vector like as is the case for transmission by bite ( Sádlová and Volf, 1999 ).…”