The Nippostrongylinae is a group of strongylid nematodes that includes species typically associated with coprophagous mammals; in the New World, it is represented by 82 species within 11 genera. Two main morphological features, the synlophe and the caudal bursa, are used to evaluate the characteristics that allow identification and classification of the organisms in the taxon. However, the analysis of these characters often requires a partial or total destruction of specimens and therefore morphological variation is studied in only a very small subset of organisms per species. To evaluate the phylogenetic signal from these characteristics, we use genetic data to reconstruct the first phylogeny for the Nippostrongylinae using nuclear and mitochondrial genes and include representatives of the most common and diverse genera. The reconstructed phylogeny features five distinct clades and allows us to identify three non-monophyletic taxa including Carolinensis, Vexillata and Hassalstrongylus. From these, Carolinensis s. l. is divided into four genera including Carolinensis, Boreostrongylus, Neoboreostrongylus n. gen. and Tepalcuanema n. gen. Stunkardionema is resurrected to include Vexillata noviberiae and Hassalstrongylus is divided into two, establishing Lovostrongylus n. gen. to include species that are closely related to Guerrerostrongylus and Trichofreitasia. Organisms in these three genera feature a caudal arrangement of type 2-2-1. Furthermore, species in Hassalstrongylus sensu stricto are more closely related to species in Malvinema and Stilestrongylus. Our results reveal the existence of an additional unnamed genus and underscore the usefulness of framing morphological characters in a comparative framework. A key for genera from the Americas is proposed.

Schistosomiasis is a parasitic disease that imposes a significant burden on society. The eggs are the primary pathogenic factor in schistosomiasis, and their accumulation in liver could lead to the formation of granulomas and liver fibrosis. However, the metabolic changes in liver resulting from schistosomiasis remain poorly understood. We established a mouse model of schistosomiasis japonica, where the eggs accumulate in the liver and form egg granulomas. We used mass spectrometry imaging to analyze the differences in metabolites among various liver regions, including the liver tissue from normal mice, the liver area outside the granulomas in schistosomiasis mice, and the granuloma region in schistosomiasis mice. There were significant differences in metabolites between different liver regions, which enriched in metabolic pathways such as the biosynthesis of unsaturated fatty acids, taurine and hypotaurine metabolism, glycerophospholipid metabolism, glycolysis/gluconeogenesis, purine metabolism, arachidonic acid metabolism, and bile secretion. In normal liver tissue, higher concentrations of oleic acid (FA (18:1)), eicosapentaenoic acid (FA (20:5)), and L-glutamine were observed. In liver regions outside the granulomas, D-glucose and pyruvic acid were elevated compared to those in normal mice. Taurine increased in the liver of schistosomiasis. Meanwhile, there were elevated uric acid and spermidine in the egg granulomas. We employed mass spectrometry imaging technology to investigate metabolic reprogramming in liver of Schistosoma japonicum-infected mice. We explored the spatial distribution of differential metabolites in liver of schistosomiasis including unsaturated fatty acids, taurine, glutamine, spermidine, and uric acid. Our research provides valuable insights for further elucidating metabolic reprogramming in schistosomiasis.

Acanthocephalans, which are in the family Polymorphidae, are a globally distributed group of endoparasites whose adults reside in the intestines of fish-eating birds, waterfowl and marine mammals. Adults of Polymorphus brevis and Pseudocorynosoma constrictum are endoparasites of fish-eating birds (Ardeids) and waterfowl (Anatidae), respectively, and are considered one of the most abundant and widely distributed species of polymorphids in freshwater systems from the Nearctic and Neotropical regions of Mexico and the USA. In the present study, sequences of cytochrome c oxidase subunit 1 (cox1) from mitochondrial DNA were generated from 67 specimens of P. brevis and 32 of Ps. constrictum from 12 localities on 6 biogeographic provinces in Mexico (the Trans-Mexican Volcanic Belt, Pacific Lowlands, Veracruzan, Californian, Sierra Madre Occidental, and Sonoran), plus the Temperate Prairies biogeographical province in the USA. The phylogeographic analyses indicated that the populations of both species lacked phylogeographic structure and exhibited high haplotype diversity, low nucleotide diversity and low Fst values among the biogeographic provinces; in combination with negative values in the neutrality test, these findings suggest that the populations of both species of acanthocephalan are undergoing expansion. The current evidence indicates that the biology of the definitive hosts, in combination with their migration patterns, could play a key role in shaping the distribution of haplotypes and the population genetic structure of the studied 2 acanthocephalan species.

Accurate species identification is essential for biodiversity research, especially in the field of parasitological systematics. In particular, the incorporation of DNA-based methods in the study of Digenea has transformed taxonomy by allowing for precise species delimitation, clarification of life cycles, and the identification of cryptic diversity. However, to prevent taxonomic misidentification, a growing concern in public sequence databases, these molecular techniques must be supplemented with high-quality morphological data. This study provides an integrative assessment (combining both morphological and molecular data) of Cotylurus brandivitellatus, based on adult specimens obtained from naturally infected mute swan (Cygnus olor) in Gdańsk Pomerania. The observed morphological characteristics are consistent with the original description of C. brandivitellatus and align with the established description of the genus Cotylurus. Phylogenetic analysis, utilizing concatenated LSU rDNA and COI mtDNA markers, confirms the distinct taxonomic status of C. brandivitellatus. It forms a sister clade with C. strigeoides, which is clearly separate from other species within the Cotylurus genus. These findings validate the existence of C. brandivitellatus and offer new insights into species delineation and evolutionary relationships within Cotylurus, highlighting the importance of integrative approaches in trematode systematics.

Molecular analyses of geographically dispersed Fasciola spp. isolates based on ribosomal, mitochondrial and nuclear molecular markers have revealed high levels of genetic diversity within liver fluke populations. To investigate the Fasciola population substructure across Pakistan 4 molecular markers were compared (fatty acid binding protein, fabp; phosphoenolpyruvate carboxykinase, pepck; random amplified polymorphic DNA, RAPD; mitochondrial NADH dehydrogenase, mt-nd1). Adult parasites (n = 595) were collected from buffalo and cattle across 4 provinces in Pakistan (Baluchistan, Gilgit Baltistan, Khyber Pakhtunkhwa, Punjab). Species classification of all 595 parasites was confirmed by the 3 gel-based markers (pepck, fabp and RAPD) as F. gigantica, except for the fabp marker which unexpectedly could not be amplified in 274 parasites (46%). Analysis of a subset of samples indicates the potential for mis-priming due to multiple genomic loci that match the fabp primer sequences resulting in negative PCR products in some cases. Sequence analysis of the mt-nd1 PCR products identified 29 haplotypes within the samples from Pakistan, the majority of which are unique to this study. None of the 29 haplotype sequences were identified in samples from Africa, highlighting the genetic diversity between geographically disparate liver fluke populations. Inconsistencies between Fasciola spp. molecular markers in this study highlights the need for multiple markers, validated on large numbers of geographically disparate parasites, to generate robust analyses of liver fluke genetic diversity. This study echoes other Fasciola spp. population studies and highlights the genetic diversity of F. gigantica populations in Pakistan that is comparable to observations of diversity throughout Asia.

Risk factors for Eimeria infections are well documented in farm and pet animals, but studies focusing on wildlife species are less common. This research aimed to investigate the impact of selected demographic and environmental factors on the prevalence of Eimeria in the European hare (Lepus europaeus). Additionally, we analysed whether Eimeria infection affected the behaviour of hares by examining the relationship between infection status and the likelihood of a hare being killed by a vehicle at a hotspot for road mortality. Between 11 February 2022 and 24 June 2024, we collected 22 hare carcasses that had been killed in traffic along an 83.9 km monitoring route in central Bohemia, Czech Republic, to evaluate Eimeria prevalence in relation to factors such as age, hare density, distance to the nearest water source and rainfall over the previous 3 months. Contrary to our expectations, we found a higher prevalence of Eimeria in adult hares compared to juveniles. We propose that this outcome may be due to the high mortality rates among leverets and juvenile hares, which removes susceptible individuals from the population early on. The effects of the other factors examined were not significant. In conclusion, our study revealed that Eimeria infection did not contribute to the clustering of hare–vehicle collisions. We emphasize the importance of studying risk factors in wildlife species across different ecological contexts. Our findings challenge the general assumption that age negatively influences Eimeria prevalence.

Rosacea is a chronic inflammatory skin disease affecting approximately 5.4% of the world population. Among its pathogenic factors is infestation by Demodex spp. Standardized skin surface biopsy (SSSB) and direct microscopic examination (DME) are widely used methods to measure Demodex spp density (Dd); however, there is no agreement on the method of choice, nor the prevalence of infestation in rosacea patients. This study compared both techniques in rosacea patients. A prospective study was conducted with 61 patients diagnosed with rosacea by dermatologists from two dermatology centres. Dd was evaluated using SSSB and DME in each patient. Results, median sampling time and reported pain were analyzed using appropriate statistical methods. The median Dd was significantly higher with SSSB (11 mites/cm2) compared to DME (1 mites/cm2; P < 0.001). Infestation (>5 mites/cm2) was detected in 64% of patients with SSSB and in 28% with DME (P < 0.001). The median sampling time was longer for SSSB (60 s) than for DME (30 s; P < 0.001). Both methods were associated with mild pain, slightly lower with DME (P = 0.033). SSSB proved more effective than DME for detecting Demodex spp. in rosacea, identifying a greater total number of mites and a higher percentage of infestation. Up to 64% of rosacea patients showed infestation with Demodex spp. using the SSSB technique. The results reinforce the use of SSSB as the standard technique for diagnosing Demodex spp. infestation in rosacea patients.

Hookworms are common parasites of Eurasian badgers (Meles meles), typically identified as Uncinaria criniformis. The taxonomic distinction from Uncinaria stenocephala, a species found in dogs and foxes, has long been debated. In this study, we molecularly characterized U. criniformis from a Eurasian badger in Romania using genome skimming. We assembled the complete mitochondrial genome and internal transcribed spacer (ITS) rDNA region from 2 adult hookworms morphologically consistent with U. criniformis. Phylogenetic analysis of 12 mitochondrial protein-coding genes demonstrated strongly supported clade of U. criniformis with Ancylostoma spp. ITS rDNA and cox1 sequence comparisons revealed only 92.4–92.8% and 88.0–88.5% identity, respectively, between U. criniformis and U. stenocephala, confirming their molecular distinctiveness. In contrast, our sequences showed >99% identity to sequences from Arthrostoma leucurus, a hookworm recently described from the Asian badger (Meles leucurus), suggesting conspecificity. These findings support the validity of U. criniformis as a distinct species parasitizing M. meles, and we propose A. leucurus as a junior synonym of U. criniformis. Our results highlight the polyphyly of the genus Uncinaria and point to the need for broader mitogenomic sampling of hookworms. The molecular markers generated here provide a reference for future parasitological surveys and wildlife disease studies.

Chemotaxis is the phenomenon of sensing external concentration gradients by cells and the cellular movement towards or away from the cells. While there have been intensive studies on prokaryotes, little research has been conducted on the chemotaxis in flagellated eukaryotes, such as Giardia lamblia (G. lamblia) and Trichomonas vaginalis (T. vaginalis). The current study uses a 2-chamber assay to discuss the motility of G. lamblia and T. vaginalis towards simple sugars. The cells were observed moving towards the sugars in a concentration and time-dependent manner. Furthermore, the cell movements were independent of change in osmolarity. Experiments compared the motility of the parasites grown in TYI-S-33 medium and TYI-S-33 medium without glucose (starvation media). It was noted that the starved cells showed a better chemotactic response towards the carbohydrates than the non-starved cells.

Toxoplasma gondii is a protozoan parasite that causes infection in birds and mammals (terrestrial and marine), both domestic and wild. The state of Tabasco has favourable climatic and ecological conditions for the replication and dissemination of this parasite. Therefore, the aim of this study was to isolate and genotype T. gondii from free-range chickens in this region of México by PCR-RFLP of 15 genetic markers. A total of 12 chickens were obtained from 7 municipalities. Serological survey by the modified agglutination test (MAT) of chicken serum samples revealed that 9 out of the 12 chickens (75%) tested had antibodies against T. gondii (titres ≥ 1:10). Toxoplasma gondii DNA was detected by PCR in tissues from 8 out of the 12 chickens. Twelve viable strains of T. gondii were isolated from the heart and brain samples of eight chickens by bioassay in mice. Genetic characterization of tachyzoite-derived DNA was performed using 10 multilocus RFLP-PCR genotyping markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and five virulence-related markers (CS3, ROP5, ROP16, ROP17 and ROP18). A total of 6 ToxoDB PCR-RFLP genotypes were identified, including #8 (also known as Type BrIII), #28, #38, and 3 new genotypes designated as #344, #345 and #346. Combination of ROP18/ROP5 alleles were 1/3, 3/3 and 4/3. ToxoDB #344 and #345 genotypes also had a new allele at the ROP5 locus. These results suggest high genetic diversity of T. gondii in southeastern México.