This is the first ultrastructural study of an adult tapeworm providing data on the morphological aspects of the pathways of lipid excretion via the tegumental surface and excretory system in the monozoic tapeworm Caryophyllaeus brachycollis (Janiszewska, 1953) from the chub Squalius tenellus (Heckel, 1843) obtained from a lake in the Bosnia-Herzegovina Federation. Our study has shown that the release of lipid droplets onto the parasite-host interface from the tegumental cytoplasm is carried out with the participation of tegumental vesicles, which clustered and fused with each other to form electron-lucent, membrane-bound sacs around lipid droplets. The ultrastructural pattern of the excretory bladder is presented for the first time for an adult tapeworm. In C. brachycollis, the syncytial epithelial lining of both the distal and proximal bladder is a derivative of the tegumental distal cytoplasm of the posterior body surface. Variations in the structural organization of both bladder parts were observed in the kinds of luminal microtriches and in the presence of large cytoplasmic protrusions in the proximal bladder. In C. brachycollis, the lipid droplets are released into the proximal bladder lumen via 10 collecting descending excretory ducts. In adult mature monozoic caryophyllidean tapeworms, an accumulation of a large number of sarcoplasmic lipid droplets is observed and their presence in the protonephridial cyrtocytes is revealed at the posterior body end, where there are the reproductive organs and ducts.

The current treatments for leishmaniasis come with various side effects and the risk of drug resistance. Nanoliposomal quercetin - paromomycin and clindamycin - is being explored as a new therapeutic approach to replace existing treatments. In this research, nanoliposomal was created using the ultrasonic thin-layer dispersion method and evaluated for its encapsulation efficiency, size and zeta potential. The average particle size in the nanoliposome containing quercetin - paromomycin and clindamycin - was 74.8nm. The dispersibility indices were equal to 0.61. The zeta potential of the nanoliposome was 24.2mV. EC50 levels of nanoliposomal quercetin (QN), nanoliposomal quercetin-paromomycin (QPN), quercetin-paromomycin and clindamycin (QPC), nanoliposomal quercetin-clindamycin and paromomycin (QCPN), paromomycin (P) against L. major promastigotes were 70±2, 57±2, 51±9, 43±8 and 41±8 micromolar, respectively. There was no significant difference in the activity of liposomal formulations against L. major promastigotes. The topical application of all treatment groups compared to PBS and the untreated group caused significant reductions in the lesion sizes. The nanoliposomal quercetin - paromomycin and clindamycin - displayed a significant anti-leishmanial effect, showing promise as a potential candidate for treatment of cutaneous leishmaniasis.

The sambaqui (shellmounds) people are recognized as fisher-gatherers who inhabited the coastal regions of Brazil, with a subsistence on a diet composed of fish, molluscs, and plants. Paleoparasitological investigations in these open-air sites are challenged by the severe taphonomic processes affecting parasite vestige preservation. Previous palaeogenetic work reported parasite helminth infection by Ascaris sp. in an individual from Jabuticabeira II (JABII) sambaqui, located in the Santa Catarina state, Brazil (2890±55 to 1805±65years BP). To expand our knowledge about helminth infections in sambaqui people, this study applied a palaeogenomics approach in JABII. Sediments from pelvic and sacral regions of 3 JABII individuals and environmental samples underwent ancient DNA extraction and cox1 gene PCRs. High-throughput sequencing data were compared to a custom-built reference database. The JABII dataset revealed reads that are mapped against plathelminth and nematode parasites. Plathelminth observations are probably attributableto pseudo-parasitism and are associated with the animal hosts identified within the JABII faunal assemblages. Two JABII individuals exhibited Anisakis simplex, Contracaecum osculatum, and Ascaris sp. Anisakids are common parasites of marine fish, crustaceans, and mammals that infect humans by consuming fish. Most of the fish identified at the JABII site are currently documented as being infected by Anisakidae. Ascaris sp. is verified in different JABII individuals from the previous study, confirming the spread of this soil-transmitted helminthiasis. The novel data herein agree with the subsistence of the JABII fisher-gatherers, the sedentary lifestyle and the faunal surroundings in the Southern coastal region of Brazil.

Calodium hepaticum (syn. Capillaria hepatica) is a generalist nematode that infects liver parenchyma of mammals worldwide and can cause human infections. Prevalence ranges from 0% to 100% in wildlife across small geographic areas, making it an ideal parasite for understanding ecological drivers of variation given intensive land use or cover change. Here, we quantify prevalence of Calodium hepaticum and present initial surveys of synanthropic small mammals. Cross-sectional rodent trapping was conducted within and around households over 2 consecutive dry seasons in 4 villages with differing land cover. DNA was extracted from liver tissue and the 18s rRNA gene of C. hepaticum was amplified to confirm presence of C. hepaticum. Landscape structural diversity was classified by tree crown density and mean canopy height derived from 30 m LiDAR data within a 0.5 km buffer. Multivariable binomial generalized linear models were fit to C. hepaticum prevalence. Calodium hepaticum infection was common (overall 34.5%, CI 95%: 27.9-41.0) and found in rodent and shrew species inside and outside residences. We observe village-level differences in prevalence (18.2-75.0%), with higher C. hepaticum prevalence associated with lower relative proportion of native rodent species to Rattus rattus (adjusted OR = 0.55, CI 95%: 0.33-0.92). Host diversity appears to be protective against parasite prevalence. Differences in molecular and gross parasitological identification highlight challenges in diagnosis and a need for more specialized molecular tools. Further investigation is required to understand individual host and community variation in pathogen infection intensity and implications for zoonotic risk.

Pentanchids (Elasmobranchii) are among the most species-rich groups of chondrichthyans. In the North Atlantic Ocean, the Icelandic catshark [Apristurus laurussonii (Saemundsson)], white ghost catshark (Apristurus aphyodes Nakaya & Stehmann), and mouse catshark [Galeus murinus (Collett)] are commonly found in deepwater habitats. However, information on their parasite communities remains scarce. This study provides the first comprehensive characterization of the metazoan parasite communities of the 3 pentanchid species. In total, 56 specimens were collected in Icelandic waters at depths of 466-1322 m between 2023 and 2024 and examined using standardized parasitological protocols, including morphological and molecular methods. Infection patterns were assessed in relation to size, maturity, body condition and capture area of hosts. Parasite intensities in all sharks ranged from 2 to 227 individuals, comprising 15 different taxa and resulting in 27 new parasite-host records, some of which likely representing new species. Eight out of 9 commonly found parasites did not display a high degree of host-specificity, indicating similar feeding habits, niche preferences, and trophic position of these sympatric species. Nonetheless, multivariate analyses revealed significant differences in the structure and composition of their parasite assemblages, with some parasites representing indicator species and occurring more abundantly and frequently in a certain deepwater catshark species. In addition, significant small-scale geographic differences were detected. At a broader geographical scale, North Atlantic pentanchids showed higher parasite richness and diversity, and lower dominance compared to standardized data from Mediterranean counterparts. Ecological factors underlying these patterns on host-parasite dynamics in (deepwater) cat sharks are discussed.

The phytohormone auxin plays a crucial role in the development of so-called syncytia induced by cyst nematodes upon feeding on plant roots. However, it is unknown whether nematode-derived auxin contributes to plant parasitism by cyst nematodes. To do so, plant-parasitic nematodes should be able to produce and release auxin into the environment. Here, we investigated whether this is the case. Mass-spectrometry analyses show that the cyst nematode Globodera pallida is able to synthesize and release the auxin indole-3-acetic acid (IAA) and indicates that its biosynthesis can be stimulated by root diffusate. Using a collection of known auxin biosynthesis genes from well-studied pathways in bacteria and plants we revealed that in the genome of G. pallida candidate genes are present for 5 major biosynthesis pathways, which could be responsible for auxin production. RNA-seq data supported the genomic analysis and revealed the upregulation of various candidate biosynthesis genes during parasitic life stages of the nematode, suggesting a possible role in plant parasitism. However, genomic analysis within the phylum Nematoda showed that the potential auxin biosynthesis genes are wide-spread and also occur in bacterivorous, fungivorous, entomopathogenic and animal-parasitic nematodes. Therefore, our data show that G. pallida is able to synthesize and release auxin into the environment, but that potential auxin biosynthesis pathways are not unique for plant-parasitic nematodes. So, auxin biosynthesis may play a broader role in the life history of nematodes. However, a more specialized role for nematode-produced auxin in plant parasitism cannot be excluded and needs further investigation.