RESUMEN
Trypanosomes are blood-borne parasites that can infect a variety of different vertebrates, including animals and humans. This study aims to broaden scientific knowledge about the presence and biodiversity of trypanosomes in Australian bats. Molecular and morphological analysis was performed on 86 blood samples collected from seven different species of microbats in Western Australia. Phylogenetic analysis on 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) sequences identified Trypanosoma dionisii in five different Australian native species of microbats; Chalinolobus gouldii, Chalinolobus morio, Nyctophilus geoffroyi, Nyctophilus major and Scotorepens balstoni. In addition, two novels, genetically distinct T. dionisii genotypes were detected and named T. dionisii genotype Aus 1 and T. dionisii genotype Aus 2. Genotype Aus 2 was the most prevalent and infected 20.9% (18/86) of bats in the present study, while genotype Aus 1 was less prevalent and was identified in 5.8% (5/86) of Australian bats. Morphological analysis was conducted on trypomastigotes identified in blood films, with morphological parameters consistent with trypanosome species in the subgenus Schizotrypanum. This is the first report of T. dionisii in Australia and in Australian native bats, which further contributes to the global distribution of this cosmopolitan bat trypanosome.
Asunto(s)
Quirópteros , Trypanosoma/aislamiento & purificación , Tripanosomiasis/veterinaria , Animales , Gliceraldehído-3-Fosfato Deshidrogenasas/análisis , Microcuerpos/química , Prevalencia , Proteínas Protozoarias/análisis , ARN Protozoario/análisis , ARN Ribosómico 18S/análisis , Trypanosoma/enzimología , Trypanosoma/genética , Tripanosomiasis/epidemiología , Australia Occidental/epidemiologíaRESUMEN
Australian bat lyssavirus (ABLV) is a known causative agent of neurological disease in bats, humans and horses. It has been isolated from four species of pteropid bats and a single microbat species (Saccolaimus flaviventris). To date, ABLV surveillance has primarily been passive, with active surveillance concentrating on eastern and northern Australian bat populations. As a result, there is scant regional ABLV information for large areas of the country. To better inform the local public health risks associated with human-bat interactions, this study describes the lyssavirus prevalence in microbat communities in the South West Botanical Province of Western Australia. We used targeted real-time PCR assays to detect viral RNA shedding in 839 oral swabs representing 12 species of microbats, which were sampled over two consecutive summers spanning 2016â»2018. Additionally, we tested 649 serum samples via Luminex® assay for reactivity to lyssavirus antigens. Active lyssavirus infection was not detected in any of the samples. Lyssavirus antibodies were detected in 19 individuals across six species, with a crude prevalence of 2.9% (95% CI: 1.8â»4.5%) over the two years. In addition, we present the first records of lyssavirus exposure in two Nyctophilus species, and Falsistrellus mackenziei.
RESUMEN
The purpose of this study was to localize the cholinergic amacrine cells, one of the key elements of a functional retina, in the retina of a microbat, Rhinolophus ferrumequinum. The presence and localization of choline acetyltransferase-immunoreactive (ChAT-IR) cells in the microbat retina were investigated using immunocytochemistry, confocal microscopy, and quantitative analysis. These ChAT-IR cells were present in the ganglion cell layer (GCL) and inner part of the inner nuclear layer (INL), as previously reported in various animals. However, the bat retina also contained some ChAT-IR cells in the outer part of the INL. The dendrites of these cells extended into the outer plexiform layer, and those of the cells in the inner INL extended within the outer part of the inner plexiform layer (IPL). The dendrites of the ChAT-IR cells in the GCL extended into the middle of the IPL and some fibers ramified up to the outer IPL. The average densities of ChAT-IR cells in the GCL, inner INL, and outer INL were 259±31cells/mm2, 469±48cells/mm2, and 59±8cells/mm2, respectively. The average total density of the ChAT-IR cells was 788±58cells/mm2 (mean±S.D.; n=3; 2799±182 cells/retina). We also found that the cholinergic amacrine cells in the bat retina contained calbindin, one of the calcium-binding proteins, but not calretinin or parvalbumin. As the cholinergic amacrine cells play key roles in the direction selectivity and optokinetic eye reflex in the other mammalian retinas, the present study might provide better information of the cytoarchitecture of bat retina and the basic sources for further physiological studies.
Asunto(s)
Células Amacrinas/citología , Quirópteros , Neuronas Colinérgicas/citología , Retina/citología , Células Amacrinas/metabolismo , Animales , Neuronas Colinérgicas/metabolismo , Inmunohistoquímica , Microscopía ConfocalRESUMEN
Maximum lifespan varies by two orders of magnitude across mammals. How such divergent lifespans have evolved remains an open question, with ramifications that may potentially lead to therapies for age-related diseases in humans. Several species of microbats as well as the naked mole-rat live much longer than expected given their small sizes, show reduced susceptibility to neoplasia, and largely remain healthy and reproductively capable throughout the majority of their extended lifespans. The convergent evolution of extreme longevity in these two groups allows for the opportunity to identify potentially important aging related genes that have undergone adaptive sequence convergence in these long-lived, yet small-bodied species. Here, we have tested 4,628 genes for evidence of convergence between the microbats and naked mole-rat. We find a strong signal of adaptive sequence convergence in the gene A disintegrin-like and metalloprotease with thrombospondin type 1 motifs 9 (ADAMTS9). We also provide evidence that the shared substitutions were driven by selection. Intriguingly, ADAMTS9 is a known inhibitor of the mTor pathway and has been implicated in several aging related processes.