RESUMEN
In the framework of a mosquito-monitoring program conducted from 2014 to 2018, non-culicid dipteran bycatch was identified to species-level with a focus on Diptera of medical and veterinary importance as part of a biodiversity initiative and barcoding project ("Austrian Barcode of Life"). Two species hitherto not known from Austria, the regularly sampled synanthropic moth fly Clogmia albipunctata (Psychodidae) and a single specimen of the louse fly Ornithoica turdi (Hippoboscidae), were collected in Vienna and Lower Austria. We confirmed identification results using a barcoding approach and provide the first reference sequence for O. turdi.
Asunto(s)
Dípteros/fisiología , Psychodidae/fisiología , Animales , Austria , Biodiversidad , Código de Barras del ADN Taxonómico , Dípteros/genética , Complejo IV de Transporte de Electrones/genética , Psychodidae/genéticaRESUMEN
Avian malaria (Plasmodium spp.) and kinetoplastid (Trypanosoma spp.) parasites are common vector-borne pathogens in birds worldwide; however, knowledge about vector competence of different mosquito species is currently lacking. For a pilot project examining vector competence of mosquitoes of the Culex pipiens complex and Culex torrentium for protozoan parasites in the city of Vienna, 316 individual mosquitoes were sampled in the months June-August 2017 around the campus of the Veterinary University of Vienna. Since vector competence for avian Plasmodium can only be ascertained by finding infectious sporozoites in mosquito salivary glands, special emphasis was on examining these, or at least insect thoraxes, which contain the salivary glands. After species identification, the mosquitoes were processed in three different ways to determine the best method of visually detecting protozoan parasites in salivary glands: (1) microscopic examination of individual, fixed and Giemsa-stained salivary glands, (2) microscopic examination of stained sections of individually fixed and embedded mosquito thoraxes and (3) stained sections of individual whole insects. Material from all three groups was also subjected to PCR to detect avian haemosporidian and trypanosomatid parasite DNA. PCR was performed on all 316 collected mosquitoes, with 37 pools (n = 2-10) of 263 individuals and 53 single individuals in all together 90 PCR reactions. Avian Plasmodium was found in 18 (20%) and trypanosomatid parasites were found in 10 (11.1%) of the examined samples and pools yielded a higher proportion of positives than did individual samples. Six different species of protozoan parasites were identified, namely Plasmodium vaughani SYAT05 which was the most common, P. elongatum GRW6, P. relictum SGS1, Trypanosoma avium, T. culicavium and Crithidia dedva. Seventy-seven mosquito salivary glands were dissected and stained with Giemsa solution. Of these, one (1.3%) featured sporozoites and one (1.3%) trypanosomatid parasites. While the trypanosomes were identified as T. avium, the avian Plasmodium species were present in a mixed infection with P. vaughani SYAT05 as the dominant species. In conclusion, mosquitoes of the Culex pipiens complex are very likely vectors of different avian Plasmodium and Trypanosoma species and PCR was the most successful and reliable method for parasite detection in mosquito samples, delivering higher rates and more accurate results. The visual detection of parasite stages in the salivary glands was more difficult and only a few specimens were detected using Giemsa stain and chromogenic in situ hybridization. For further studies on vector competence of different protozoan parasites in mosquitoes, the use of PCR-based methods would be preferable.
Asunto(s)
Culex/parasitología , Malaria Aviar/transmisión , Mosquitos Vectores/parasitología , Plasmodium/aislamiento & purificación , Glándulas Salivales/parasitología , Esporozoítos/aislamiento & purificación , Trypanosoma/aislamiento & purificación , Animales , Aves/parasitología , ADN Protozoario/análisis , Malaria Aviar/parasitología , Proyectos Piloto , Plasmodium/clasificación , Plasmodium/genética , Reacción en Cadena de la Polimerasa , Trypanosoma/clasificación , Trypanosoma/genéticaRESUMEN
Avian malaria is caused by intracellular mosquito-transmitted protist parasites in the order Haemosporida, genus Plasmodium. Although Plasmodium species have been diagnosed as causing death in several threatened species in New Zealand, little is known about their ecology and epidemiology. In this study, we examined the presence, microscopic characterization and sequence homology of Plasmodium spp. isolates collected from a small number of New Zealand introduced, native and endemic bird species. We identified 14 Plasmodium spp. isolates from 90 blood or tissue samples. The host range included four species of passerines (two endemic, one native, one introduced), one species of endemic pigeon and two species of endemic kiwi. The isolates were associated into at least four distinct clusters including Plasmodium (Huffia) elongatum, a subgroup of Plasmodium elongatum, Plasmodium relictum and Plasmodium (Noyvella) spp. The infected birds presented a low level of peripheral parasitemia consistent with chronic infection (11/15 blood smears examined). In addition, we report death due to overwhelming parasitemia in a blackbird, a great spotted kiwi and a hihi. These deaths were attributed to infections with either Plasmodium spp. lineage LINN1 or P. relictum lineage GRW4. To the authors' knowledge, this is the first published report of Plasmodium spp. infection in great spotted and brown kiwi, kereru and kokako. Currently, we are only able to speculate on the origin of these 14 isolates but consideration must be made as to the impact they may have on threatened endemic species, particularly due to the examples of mortality.