Invasive agriolimacid slug Krynickillus melanocephalus was found infected by several species of malacopathogenic nematodes of the genus Pellioditis. Now, this Caucasian slug is actively spreading across Europe. Pellioditis is a genus of nematodes capable of killing molluscs, and its two species have been developed into widely used biological control agents. As malacopathogenic nematodes can pose a threat to survival of native, susceptible gastropod species, the distribution of K. melanocephalus and examination of associated parasites are needed. All Pellioditis species found in association with K. melanocephalus were of Caucasian origin. The new Pellioditis species was found to belong to a different clade within the genus than the other five Caucasian species and is the first representative of the clade Papillosa in the Caucasus.

Ulcerative colitis (UC), a chronic recurrent inflammation of the colonic mucosa, has become a global emergency. With the restricted response and significant side effects of traditional drugs, a search for alternatives is mandatory. The current study aimed to evaluate the therapeutic effects of hydatid cyst fluid (HCF) and laminated layer (HLL) derived crude extract of E. granulosus, combined with the standard medication sulfasalazine (SLZ), for treating acetic acid-induced colitis. Mice were divided into 7 groups. A colitis model using acetic acid (150 μl of 5% con.) intrarectally was induced. On the 8th day following colitis induction, the mice were sacrificed. We assessed the severity of colitis using survival rate, disease activity index, colon weight/length ratio, colon weight/bodyweight ratio, and gross and histopathological score of colon damage. Immunohistochemistry for Foxp3 T-reg expression in colonic tissues was done. The levels of inflammatory cytokines tumor necrosis factor-α and IL-10, oxidative stress marker malondialdehyde, and total antioxidant capacity in serum samples were assessed. Groups treated with a combination of SLZ+HCF and SLZ+HLL revealed a statistically significant improvement compared to the colitis group by improving disease activity index, colon weight/length ratio and colon weight/bodyweight ratio, and gross and histopathological colon damage scores. Additionally, there was a significant rise in IL-4, TAC, and Foxp3+ Treg cell expression and decreased TNF-α and MDA expression. E. granulosus-derived HCF and HLL potentiate the protective effect of SLZ by increasing anti-inflammatory and antioxidant properties against murine colitis, suggesting the potential for novel therapeutic approaches.

Zoonotic diseases caused by parasites of wildlife origin represent a global health problem. As a top mammalian predator, the brown bear (Ursus arctos) can spread various parasites, including those that are potentially hazardous to human health. However, data on brown bear parasite fauna in Europe, and especially its seasonal dynamics, are scarce. The aim of this study was to analyse brown bear gastrointestinal parasites (helminths and protozoa) and to investigate their seasonal dynamics. Brown bear scats were collected from the eastern part of Estonia during one year, from spring 2022 to spring 2023. At first, we performed genetic host identification and selected 148 scat samples for further analyses. Parasite eggs and oocysts were identified based on morphology. The results revealed that the endoparasite prevalence among brown bears of Estonia is one of the highest in Europe (FO = 75%). The most prevalent were nematodes (60%), followed by protozoa (16%), cestodes (7%), trematodes (4%), and a single finding of an acanthocephalan. Of all endoparasites, the bear nematode Baylisascaris transfuga had the highest prevalence (51%). Importantly, the prevalence of nematodes and protozoa was season-dependent: highest for nematodes in autumn and lowest in spring, whereas protozoa followed the opposite dynamics. The vast majority of identified parasite taxa were zoonotic and are thus potentially hazardous to humans. This highlights the importance of monitoring wildlife parasites as an essential part of the One Health approach.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected parasitic disease and a major global public health issue. This infection exhibits diverse clinical manifestations that, along with the high rates of asymptomatic cases and low-sensitivity diagnostic methods, contribute to the underreporting of the disease. With an estimated 600 million people infected worldwide, this disease is particularly prevalent in tropical and subtropical regions with poor sanitary conditions, which includes Brazil. Understanding the epidemiology of the disease is essential for the development of control strategies, but the lack of comprehensive data makes it difficult to identify the real impact of the infection, thus leading to underreporting and a lack of awareness of its severity on public health. Given this scenario, this literature review aimed to summarize the reported prevalence and associated factors of strongyloidiasis in Brazil. A total of 33 articles published between 2005 and 2025 were retrieved from PubMed, Science Direct, Scielo, and LiLacs databases using keywords related to strongyloidiasis in Brazil. The data collected in this review indicate that the majority of the published studies are concentrated in the Southeast region of Brazil, with the state of Minas Gerais accounting for the highest number of publications. It was also observed that the prevalence of strongyloidiasis is underestimated due to diagnostic challenges and high rates of false negatives, especially among asymptomatic patients. In addition, the scarcity of specific studies on the disease in Brazil limits the understanding of its true incidence, underscoring the need for further research.

The taxonomic status of Sphincteristomum Oshmarin, Mamaev & Parukhin, 1961 (sensu lato) and Lobatotrema Manter, 1963 is controversial due to overlap/confusion in distinctive diagnostic characteristics for each genus and morphological/allometric ambiguity among some of their representatives and/or within records of the same species. To address these in-depth, morphological descriptions, molecular characterizations, and species delimitation analyses were conducted using a combination of comparative morphology, molecular phylogeny, multivariate analyses, and host-parasite data. Following a comprehensive review, a refined restricted concept of Sphincteristomum and Lobatotrema is proposed. Representatives of Lobatotrema comprise Lobatotrema aniferum Manter, 1963 (sensu lato) and the morphologically/phylogenetically distinct Lobatotrema droneni n. sp. Representatives of Sphincteristomum (sensu stricto) include Sphincteristomum acollum Oshmarin, Mamaev & Parukhin, 1961, and Sphincteristomum nikolaevi Parukhin, 1970. The taxonomic status of Sphincteristomum mediterraneae Abid-Kachour, Mouffok & Boutiba, 2013 is problematic based on its intermediate taxonomic position between the Megaperinae Manter, 1934 and the Schistorchiinae Yamaguti, 1942. Molecular datasets are employed in an attempt to delineate and interpret more phylogenetic relationships among schistorchiines in light of differences in oral sucker nature, oral sucker shape, and oral sphincter shape. Distributions of schistorchiines in the Indo-West Pacific are discussed. Testes arrangement as a characteristic in this group and glandular components within a muscular oral sucker are presented. We comment on the close phylogenetic relationship between members of the Schistorchiinae and the Megaperinae.

Two Xiphinema species, one new and one known, were found from Bushehr province, southern Iran, and are herein described based on morphological and molecular data. These include Xiphinema pedrami sp. nov. and X. basiri, both belonging to the ‘Xiphinema non-americanum group’. The new dagger nematode is characterised by a body length of 3.54–5.00 mm, a lip region separated from the rest of body by a depression, odontostyle 128–148 μm long, 60–89 μm long odontophore, guiding ring at 107–138 μm from anterior end, female tail rounded to dorsally more convex with small bulge and four juvenile stages. Males have one pair of cloacal and three to five ventromedian single supplements. The new species belongs to morphospecies Xiphinema non-americanum group 5, characterised by having two equally developed female genital branches with uterine differentiation in the form of pseudo-Z-organ along with the rhomboid-shaped crystalloid bodies, and a short, rounded tail ending in a peg. The polytomous identification codes of the new species are A4, B2, C5a5b, D6, E56, F4(5), G23, H2, I34, J5a5b, K3, L2. Morphologically, the new species comes close to several known species (namely, X. andalusiense, X. artemisiae, X. baetica, X. hyrcaniense, X. ingens, X. macroacanthum and X. pseudocoxi) belonging to morphospecies group 5. The morphological differences of the new species and the aforementioned species are discussed. The second recovered species, Xiphinema basiri, belongs to the same group and has a pseudo-Z-organ in the shape of globular bodies close to pars dilatata uterus and short, conical, distinctly digitate tail. Integrative diagnosis was completed using molecular data obtained from partial sequences of the D2-D3 region of 28S rDNA, ITS1 rDNA, 18S rDNA, and COI mtDNA genes.

Adult trematodes of two species of the genus Plagiorchis were found in the southern Far East of Russia: one species in the intestine of a naturally infected Japanese large-footed bat (Myotis macrodactylus) and the other in a golden hamster (Mesocricetus auratus) experimentally infected with metacercariae collected from a stonefly. On the basis of morphological and molecular studies, the trematode individuals found in the bat were identified as Plagiorchis koreanus, which confirms that this species is cosmopolitan. The trematodes reared in the hamster were similar in their morphological features to the European Plagiorchis eutamiatis. However, due to the lack of nucleotide sequences for this species from the type region, the southern Far East of Russia trematodes, found in this study, were provisionally designated as Plagiorchis cf. eutamiatis. In addition, the phylogenetic reconstruction based on a mitochondrial marker revealed inconsistency of the data obtained from cercariae diagnosed as a single species, Plagiorchis elegans. Our data also indicate that the specimens available in the NCBI database referred to as Plagiorchis multiglandularis and Plagiorchis neomidis belong to the same species.

The genus Bursaphelenchus has attracted significant attention due to its economically devastating and quarantined species – notably the pine wood nematode B. xylophilus and B. cocophilus. Despite their ecological and agricultural importance, genomic data for this genus remain scarce. In this study, we sequenced and assembled the complete mitochondrial genomes of three Bursaphelenchus species (B. chengi, B. parantoniae, and B. sinensis) using high-throughput sequencing. The circular mitogenomes exhibited size variation, with B. chengi (17,670 bp), B. parantoniae (15,021 bp), and B. sinensis (18,386 bp) each containing the typical nematode mitochondrial gene complement: 12 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, and 22 transfer RNA (tRNA) genes. Phylogenetic analysis based on the concatenated amino acid sequences of the 12 PCGs revealed that these species form a sister clade to B. xylophilus and B. mucronatus. Comparative mitogenomic analysis demonstrated a conserved gene arrangement shared among Bursaphelenchus, Aphelenchoides, Caenorhabditis, Cruznema tripartitum, and Pristionchus pacificus, suggesting strong evolutionary conservatism across the families Aphelenchoididae, Neodiplogasteridae, and Rhabditidae. Our study enriched the mitochondrial genomic resources for Bursaphelenchus and advanced resolution of their intrageneric phylogenetic relationships.

The mother sporocyst is the least understood digenean life cycle stage. This study provides the first detailed description of the neuromusculature and reproductive apparatus of mother sporocysts in the hemiuroid digenean Bunocotyle progenetica, a monoxenous parasite of White Sea mud snails, using transmission electron microscopy and fluorescent staining for muscles, FMRFamide-related peptides (FaRP), and serotonin (5HT). These parthenitae lack a germinal mass and have only a few germinal elements, which explains their limited reproductive potential. Germinal cells are incorporated into the syncytial brood-cavity lining, asynchronously maturing and forming germinal balls, which develop into rediae within the cavity. Rediae are expelled through a birth canal differentiated into three regions; their expulsion involves coordinated action of circular sphincter muscles and several extrinsic muscles. Sporocysts are highly mobile, with a dense subtegumental network of circular and longitudinal muscles. Subtegumental myocyte reconstruction showed that each perikaryon is linked to several myofibrils. The nervous system, although lacking distinct ganglia, is well-differentiated, with numerous neurons and at least three types of tegumental sensilla. FaRP-immunoreactive (IR) somata surround the birth canal, forming a nerve net around its middle region and two posterior longitudinal nerves. The unusually abundant 5HT-IR neurons are distributed throughout the body, but most lie in the posterior region. 5HT-IR cells form an anterior nerve ring, from which several nerves project anteriorly and two main nerves extend posteriorly, along with additional nerves. The morphology of the studied sporocysts is discussed in the context of current knowledge on the parthenital biology and development in B. progenetica.

The present study describes a new Ditylenchoides species, isolated from Meknès, Morocco, during nematode surveys conducted to investigate the biodiversity of plant-parasitic nematodes in Mediterranean olive groves and adjacent patches of natural vegetation. Application of integrative taxonomical approaches clearly verified that it is a new species designated herein as Ditylenchoides morocciensis sp. nov., also representing the first report of the genus in Morocco. The new species is parthenogenetic, characterised by a short body 460 (373–528 μm); stylet delicate, relatively short, 8.7 (8.0–9.0) μm long with rounded basal knobs; six lines in the lateral fields; median bulb of pharynx oval, muscular and valvate; secretory-excretory pore located at the level of basal pharyngeal bulb region; vulva located at 79.9 (76.9–81.3) % of body length; relatively long post-vulval uterine sac 29.1 (20.0–39.0) μm; and a subcylindrical tail 24.4 (22.0–28.0) μm long, with a bluntly rounded tip. The results of molecular analysis of D2-D3 28S rRNA, ITS rRNA, partial 18S rRNA, and cytochrome oxidase c subunit 1 (COI) gene sequences support for the new species status and clearly separated D. morocciensis sp. nov. from all other species within Ditylenchoides. Phylogenetic analyses of ribosomal markers (D2-D3 28S rRNA and partial 18S rRNA) of this study confirms that Ditylenchoides is a monophyletic genus, clearly separated from other genera within Anguinoidea.

This study provides a comprehensive analysis of the morphology and genetics of Raillietiella gigliolii, an endoparasitic pentastomid found in amphisbaenians. The research was based on specimens deposited in the Universidade Regional do Cariri (URCA), as well as newly collected individuals from the Brazilian Caatinga. Detailed morphological descriptions were carried out, including measurements of the hooks, cephalothorax, tail, buccal cadre, and the copulatory spicule in males. In parallel, the first molecular characterisation of this species was performed, targeting the mitochondrial COI gene (barcode region). All specimens exhibited consistent morphotypes, particularly in the shape of the hooks, with no observable variation between males and females, nor between individuals parasitising different hosts (Amphisbaena alba and A. vermicularis). Molecular analyses revealed a well-supported monophyletic clade, with no detectable genetic divergence among individuals, confirming both the morphological stability and genetic delimitation of the species. These findings support the recognition of R. gigliolii as a clearly delineated species, currently restricted to amphisbaenians, which does not exhibit significant morphological variability, in contrast to other congeners.

Molecular evidence (28S DNA) has suggested that Triplotaenia undosa from macropodid marsupials is a species complex. Additional data (cox 1) presented in this study confirmed the hypothesis and a morphological examination of all available specimens identified a new species, T. macropodis sp. nov., in the grey kangaroos Macropus fuliginosus and M. giganteus as well as the tammar wallaby, Notamacropus eugenii, and the red kangaroo, Osphranter rufus. The new species differs in the ratio of the number of testes to the number of female genital complexes. Specimens of T. undosa from the swamp wallaby, Wallabia bicolor, the type host, and the common wallaroo, Osphranter robustus, are each genetically distinct, but the fixed material from O. robustus is too fragmentary to permit a detailed morphological description. An amended description and new illustrations of T. undosa from W. bicolor are provided.

A bottlenose dolphin, Tursiops sp., stranded on the coast of South Carolina, USA was found to be heavily infected in its intestine by tapeworms, which we identified molecularly. Sequencing of portions of the mitochondrial cytochrome c oxidase I (COI) and nuclear large subunit ribosomal RNA (28S rRNA) genes showed the cestodes to be Diphyllobothrium stemmacephalum, commonly known as a broad tapeworm. Infections of marine mammals by Diphyllobothrium have been previously reported in the Northwestern Atlantic Ocean, but only to genus level. Infection by tapeworms may be rare in dolphins in South Carolina, but because this species is zoonotic, its presence indicates the potential for an emerging public health concern.

Visceral larva migrans syndrome (VLM) is caused by L2 Toxocara canis. This parasitic disease is difficult to diagnose in humans, but specific antigen identification could allow for parasite detection. The aim of this study was to analyse antigens of different parasite developmental stages and observe their cross-reactions with antigens from other parasites to determine their importance in the diagnosis of VLM caused by T. canis. Sera from 14 children with cryptogenic epilepsy previously positive for T. canis were analysed via Western blot (WB) using T. canis excretion-secretion antigens (TESs) from distinct morphological parasite stages; cross-reactivity of these antigens with antigens from other parasites were evaluated. Children sera recognized antigens from L2 T. canis TES, mainly a protein of 24 kDa. Proteins in the medium- and high-molecular-weight ranges were also detected in the egg phase. In the adult phase, only 42.9% of analysed sera recognized a protein of high-molecular weight. Cross-reaction tests identified medium and high-molecular weight proteins, mainly from L2 of Ascaris lumbricoides and Gnathostoma binucleatum and adults of Ancylostoma caninum, but none of the proteins found had crossover with low-molecular weight proteins from Toxocara canis. Antigens in the larval morphological stage of T. canis TES were recognized in the highest percentage of the analysed sera; these antigens could be used to diagnose VLM.

Malacological surveys were conducted in 2021 in the Kimpese region of Central Kongo Province, west of the Democratic Republic of Congo (DRC). Snail specimens were collected following a standardised protocol, identified using morphological and molecular methods, and tested for schistosome infection using a diagnostic PCR assay. Positive snail samples were sequenced to characterise the infecting schistosome species. Partial mitochondrial cytochrome c oxidase subunit 1 (COX1) gene sequences were used in phylogenetic analyses to explore the evolutionary position of these snail species within the broader African context. At least four intermediate snail hosts were identified: Bulinus truncatus, Bulinus forskalii, Biomphalaria pfeifferi, and a Biomphalaria species belonging to the Nilotic species complex (tentatively named Biomphalaria cf sudanica), of which the species identity needs to be confirmed. A total of 37 out of 1,196 snails (3.1%) tested positive for schistosome infection, with an infection prevalence of 7.4% for B. truncatus with Schistosoma haematobium and 1.5% for Biomphalaria spp. with Schistosoma mansoni. The S. mansoni sequence retrieved from these samples formed a basal clade relative to Zambian isolates, whereas S. haematobium grouped with the most frequently characterised haplotype cluster previously identified across mainland Africa. It is important to note that no animal schistosome species were identified in this study. Both the sequences from the snail hosts and the parasites represent novel contributions from the DRC. Additionally, the findings update the current knowledge of schistosomiasis transmission in the Kimpese region by providing insight into the phylogenetic placement, species diversity, and infection status of local snail populations.

Aprocta bainae Mutafchiev & Kinsella sp. nov, collected from the orbits of a flammulated owl, Psiloscops flammeolus (Kaup) (Strigiformes: Strigidae), from Montana, USA is described based on light and scanning electron microscopies. Additionally, fragments of 18S and 12S rRNA genes of the new species are provided. Based on the molecular data of the 18S gene, A. bainae n. sp. was included in a monophyletic clade of the genus Aprocta. Aprocta ophthalmophaga Stossich, 1902 and Aprocta colaptidis Schuurmans-Stekhoven, 1950 are considered species inquirendae. Aprocta colaptidis Schuurmans-Stekhoven, 1951, a homonym of A. colaptidis Schuurmans-Stekhoven, 1950, is considered a species incertae sedis.

Understanding the stock structure of a commercial species is essential for sustainable management. Failure to do so can lead to the depletion of regional sub-populations, erosion of genetic diversity, and ecosystem services loss. Plaice, Pleuronectes platessa, is a commercially exploited species inhabiting the continental shelf around Iceland. Despite a tagging study providing support for strong spawning site and feeding ground fidelity, and otolith microstructure analysis revealing local population structure, plaice is managed as a single stock in Icelandic waters. Here, we describe and quantify the parasite fauna of plaice and assess the potential of parasites as biological tags for stock identification of plaice in Icelandic waters. A total of 82 plaice were sampled from different geographical locations (north and south) and seasons (summer and winter) in Iceland. Our sampling identified 11 parasites, five of which are new parasite records for plaice in Icelandic waters: the trematodes Zoogonoides viviparus (adults) and Rhipidocotyle sp. (metacercariae), and the nematodes Contracaecum osculatum (larvae), Dichelyne sp. (adults), and Hysterothylacium aduncum (larvae and adults). Additionally, we recovered metacercariae of the trematode genus Apatemon, which has not been recorded previously from plaice. Two parasites were identified as potential biological tags for stock identification – namely, the nematode Anisakis simplex and the trematode Z. viviparus. Our findings support a complex stock structure for plaice in Icelandic waters and the need for an integrative strategy to stock identification to provide fine spatial scale data required to inform fisheries managers.