Diversity, distribution and changes in communities of fleas on small mammals along the elevational gradient from the Pannonian Plain to the Carpathian Mountains

Trypanosome diversity in small mammals in Uganda and the spread of Trypanosoma lewisi to native species

Uganda's diverse small mammalian fauna thrives due to its rich habitat diversity, which hosts a wide range of blood parasites, including trypanosomes, particularly the subgenus Herpetosoma typical for rodent hosts. We screened a total of 711 small mammals from various habitats for trypanosomes, with 253 microscopically examined blood smears and 458 tissue samples tested by nested PCR of the 18S rRNA gene. Of 51 rodent and 12 shrew species tested, microscopic screening reaches 7% overall prevalence (with four rodent species positive out of 15 and none of the shrew species out of four), while nested PCR indicated a prevalence of 13% (17 rodent and five shrew species positive out of 49 and 10, respectively). We identified 27 genotypes representing 11 trypanosome species, of which the majority (24 genotypes/9 species) belong to the Herpetosoma subgenus. Among these, we detected 15 new genotypes and two putative new species, labeled AF24 (found in Lophuromys woosnami) and AF25 (in Graphiurus murinus). Our finding of three new genotypes of the previously detected species AF01 belonging to the subgenus Ornithotrypanum in two Grammomys species and Oenomys hypoxanthus clearly indicates the consistent occurrence of this avian trypanosome in African small mammals. Additionally, in Aethomys hindei, we detected the putative new species of the subgenus Aneza. Within the T. lewisi subclade, we detected eleven genotypes, including six new; however, only the genotype AF05b from Mus and Rattus represents the invasive T. lewisi. Our study has improved our understanding of trypanosome diversity in African small mammals. The detection of T. lewisi in native small mammals expands the range of host species and highlighting the need for a broader approach to the epidemiology of T. lewisi.

Host specificity of flea parasites of mammals from the Andean Biogeographic Region

Host specificity of fleas affects their biodiversity that plays a major role in determining the potential transmission routes by pathogens through vertebrate hosts, including humans. In the Biogeographic Andean region, numerous systematic and ecological studies have been conducted, revealing a high diversity of flea taxa of mammals and the presence of pathogenic organisms transmitted by fleas; however, the degree of preference with which each flea species associates with a mammal host remains poorly understood in this region. Herein, host specificity in mammal fleas from the Andean region was analysed. We employed the number of host species for each flea species and the index of host specificity STD *. Following the literature, 144 species and 13 subspecies of fleas (31 genera and 10 families) have been described in the Andean biogeographic region; 76 taxa are endemic to this region. To carry out the analyses of host specificity, we considered 1759 records of fleas collected from 124 species and 59 genera of wild and domestic mammals, mostly rodent species (85.9%). Our results indicate that typical Andean fleas are genus or family host specific (mostly STD * less than 3.0). More diverse mammal hosts are parasitized by more diverse flea genera and families and these hosts are phylogenetically related. Otherwise, these hosts are associated with different flea lineages, suggesting the interaction of ecological and evolutionary mechanisms (host-switching, ecological adaptations and co-evolutionary alternation). The fields of disease ecology and One Health are considering the host specificity of arthropod vectors as an important point to understand the mechanisms of emergence and re-emergence of diseases. Our results allow us to estimate the risk of diseases involving fleas in the Andean region.