Leverikten: en gammel kending i fremgang

Liver flukes are very successful group of parasites that can infect many different hosts including humans. They can be found in different forms and sizes, and found almost all of the world. In Denmark, two species are found. The well-known "common liver fluke" has existed in Denmark since the Vikings, but is increasing again recently. Not so known is "the lancet fluke", which is also fascinating as it can make the ants behave like zombies

Short-term temporal variation of coastal marine eDNA

Temporal variation in eDNA signals is increasingly explored for understanding community ecology in aquatic habitats. Seasonal changes have been addressed using eDNA sampling, but very little is known regarding short-term temporal variation that spans hours to days. To address this, we filtered marine water samples from a single coastal site in Denmark every hour for 32 h. We used metabarcoding to target both fish and broader eukaryote diversity and evaluated temporal changes in this marine community. Results revealed variation in fish species richness (15–27) and eukaryote class richness (35–64) across the 32 h of sampling, and we further evaluated sampling efforts needed to reach different levels of diversity saturation. Relative read frequency data for both fish and eukaryotes indicated a clear diel change in community composition, with different communities detected during daylight versus dark hours. The abundance signals in our data reflected biological variation rather than stochastic variation, since replicates taken at the same hour were more similar to each other than those taken at different hours. Our compositional results indicated a dynamic community, rather than a static pool of eDNA—even across a few hours. The fish data showed a daily pattern of relative species abundances, and the uncoupling of fish and broader eukaryote data suggest that variation in eDNA profiles across a single day can provide valuable information reflecting diel changes, at least for highly mobile organism groups. However, our results also point to several pitfalls in current eDNA experimental design, in which samples are taken over large areas without relative time-consistency or short-term replication. Our findings shed new light on short-term variation in coastal eDNA and have wide implications for experimental study design and for incorporating temporality into project conceptualization for future aquatic biodiversity monitoring.publishedVersio

Potential hybridization of Fasciola hepatica and F. gigantica in Africa

SUPPLEMENTARY MATERIALS : TABLE S1: Summary of African studies reporting on the presence of Fasciola species recovered from various definitive hosts. TABLE S2: The distribution and occurrence of Fasciola species in Africa based on studies conducted from 1980–2022. TABLE S3: Summary of African studies reporting on the occurrence of Fasciola species in their snail intermediate hosts. TABLE S4: Summary of studies reporting on the occurrence of intermediate hosts of Fasciola spp. in Africa. References [140–317] are cited in the supplementary materials.The occurrence of Fasciola gigantica and F. hepatica in Africa is well documented; however, unlike in Asia, there is a paucity of information on the existence of hybrids or parthenogenetic species on the continent. Nonetheless, these hybrid species may have beneficial characteristics, such as increased host range and pathogenicity. This study provides evidence of the potential existence of Fasciola hybrids in Africa. A literature search of articles published between 1980 and 2022 was conducted in PubMed, Google Scholar, and Science Direct using a combination of search terms and Boolean operators. Fasciola species were documented in 26 African countries with F. hepatica being restricted to 12 countries, whilst F. gigantica occurred in 24 countries, identified based on morphological features of adult Fasciola specimens or eggs and molecular techniques. The cooccurrence of both species was reported in 11 countries. However, the occurrence of potential Fasciola hybrids was only confirmed in Egypt and Chad but is suspected in South Africa and Zimbabwe. These were identified based on liver fluke morphometrics, assessment of the sperms in the seminal vesicle, and molecular techniques. The occurrence of intermediate host snails Galba truncatula and Radix natalensis was reported in Ethiopia, Egypt, South Africa, Tanzania, and Uganda, where F. hepatica and F. gigantica co-occurrences were reported. The invasive Pseudosuccinea columella snails naturally infected with F. gigantica were documented in South Africa and Egypt. In Zimbabwe, P. columella was infected with a presumed parthenogenetic Fasciola. This suggests that the invasive species might also be contributing to the overlapping distributions of the two Fasciola species since it can transmit both species. Notwithstanding the limited studies in Africa, the potential existence of Fasciola hybrids in Africa is real and might mimic scenarios in Asia, where parthenogenetic Fasciola exist in most Asian countries. In South Africa, aspermic F. hepatica and Fasciola sp. have been reported already, and Fasciola hybrids have been reported? in Chad and Egypt. Thus, the authors recommend future surveys using molecular markers recommended to identify Fasciola spp. and their snail intermediate hosts to demarcate areas of overlapping distribution where Fasciola hybrids and/or parthenogenetic Fasciola may occur. Further studies should also be conducted to determine the presence and role of P. columella in the transmission of Fasciola spp. in these geographical overlaps to help prevent parasite spillbacks.The European Union’s Horizon 2020 research and innovation program, the National Research Foundation (NRF) of South Africa, the Knud Højgaards Foundation for its support to The Research Platform for Disease Ecology, Health and Climate.https://www.mdpi.com/journal/pathogensam2023Veterinary Tropical Disease