The European wildcat (Felis silvestris silvestris) is a rare species in Croatia, yet data on its vector-borne pathogens (VBPs) have been entirely lacking. This study provides the first molecular survey of VBPs in twelve Croatian wildcats collected between 2018 and 2025. Using broad-range PCR assays and sequencing, we found pathogen DNA in all analyzed animals (12/12). The most common pathogen was Hepatozoon felis (10/12), followed by Cytauxzoon europaeus (4/12), Mycoplasma spp. (2/12), and Hepatozoon silvestris (1/12). Dual infections were identified in 5/12 animals. Notably, phylogenetic analysis of hemotropic mycoplasmas revealed a Mycoplasma suis-like genotype, typically associated with swine, suggesting potential cross-species transmission at the sylvatic-domestic interface. The high prevalence of pathogens highlights a potential health risk for this protected population as well as to domestic cats (Felis catus) in the region. These findings fill a critical knowledge gap in the studied region and emphasize the need for integrated conservation strategies that consider the domestic-sylvatic interface in pathogen dynamics.
Theileria orientalis comprises tick‑borne protozoan parasites that can cause substantial economic losses in cattle. We previously reported an outbreak of oriental theileriosis associated with mixed T. orientalis Ikeda and Chitose infection on a closed dairy farm. However, the predominant genotype and the mechanisms underlying long-term persistence under closed-herd management remain unclear. In December 2024, conventional PCR detected T. orientalis in 41 of 147 periparturient cows; sequencing of MPSP amplicons from 18 positive samples detected Chitose in all 18 and co-detected Ikeda in four. Chitose‑specific PCR was subsequently developed from the MPSP sequences. In 528 cross-sectional samples collected from April to September 2025, Chitose-specific PCR positivity ranged from 38.00
Heat shock cognate protein 70 (HSC70), a member of the heat shock protein 70 (HSP70) family, is highly expressed in the salivary glands, midgut, and ovaries of the Haemaphysalis flava ticks, and is known to participate in vital physiological processes such as blood feeding and blood meal digestion. However, whether HSC70 is also involved in the reproductive and oviposition processes of H. flava and the underlying molecular mechanisms remains unclear. In this study, RNA interference (RNAi) was employed to knock down the expression of HSC70 in H. flava, and its effects on oviposition efficiency, the rate of egg morphological abnormality, and hatchability were examined. Additionally, full-length transcriptome sequencing technology was conducted to analyze differentially expressed genes (DEGs) and their associated signaling pathways following HSC70 knockdown. The results showed that silencing HSC70 significantly reduced female oviposition efficiency, increased the rate of egg morphological abnormality, and decreased the hatchability. Comparative transcriptomic analysis revealed that knocking down HSC70 in H. flava significantly downregulates genes involved in the metabolism of amino sugar and chitin, which may affect symbiont interactions and the integrity of the midgut peritrophic matrix (PM). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that two critical genes in the insect hormone biosynthesis pathway, Novelgene3177 (encoding juvenile hormone acid methyltransferase) and HaeL11405 (annotated as cytochrome P450), were markedly downregulated. These two genes are involved in the biosynthesis of juvenile hormone and 20-hydroxyecdysone, respectively, which regulate vitellogenesis and vitellogenin (Vg) synthesis, ultimately influencing tick reproduction and oviposition. Furthermore, HSC70 silencing alters the innate immune pathway, highlighting its role in tick immunity. These findings suggest that HSC70 may play a critical role in the reproduction and oviposition of H. flava by affecting peritrophic membrane structure, hormonal signaling, and innate immunity.
Foodborne parasitic zoonoses such as toxoplasmosis and sarcocystosis represent a public health challenge and an economic loss in the beef production chain, a sector in which Brazil lacks a specific laboratory monitoring program. This study aimed to detect Sarcocystis spp. and Toxoplasma gondii in bovine heart samples from the retail trade in the city of São Paulo, employing parasitological, histological, serological, and molecular diagnostic techniques. Parasitological research to identify tissue cysts formed by both protozoa was performed by microscopic methods. Histological research was performed on fragments of bovine heart tissue stained with hematoxylin-eosin. Nucleic acid detection was performed by Polymerase Chain Reaction (PCR), using specific primers for the cytochrome c oxidase subunit I (COX1) gene of Sarcocystis spp. and T. gondii B1 gene. Serology was performed by indirect Enzyme-linked immunosorbent assay (ELISA), using meat exudate as biological material. Our data demonstrated the presence of S. cruzi in 100
Leishmaniasis is a neglected tropical disease that remains a major public health problem in many endemic regions. Current treatments are limited by toxicity, high cost, and emerging drug resistance. Plant-derived compounds have been investigated as potential therapeutic alternatives due to their antiparasitic and immunomodulatory properties. This systematic review aimed to evaluate the therapeutic potential and immunomodulatory effects of plant-derived compounds in experimental models of leishmaniasis. A systematic search was conducted in PubMed, Scopus, and Web of Science databases for studies published between January 2014 and December 2024. The search strategy included terms related to Leishmania, medicinal plants, natural products, and experimental models. Eligible studies were in vivo experimental investigations evaluating plant extracts, fractions, or isolated compounds in animal models of leishmaniasis. Study selection followed the PRISMA 2020 guidelines. Data were extracted regarding experimental models, phytochemical composition, antiparasitic outcomes, and immunological responses. Ten studies met the inclusion criteria. Most studies were conducted in BALB/c mice infected with Leishmania donovani or Leishmania (Leishmania) amazonensis. Plant-derived treatments included crude extracts, purified fractions, and isolated compounds such as lupeol and plant-derived protease inhibitors. The evaluated treatments demonstrated significant reductions in parasite load in liver, spleen, or lesion sites. Immunological analyses consistently showed a shift toward a protective Th1-type immune response, characterized by increased production of IFN-γ, IL-12, nitric oxide (NO), and reactive oxygen species (ROS), along with decreased levels of IL-10 and TGF-β. Several studies also reported improvements in histopathological parameters and low toxicity. Plant-derived compounds demonstrate promising antiparasitic and immunomodulatory effects in experimental models of leishmaniasis. These findings support the potential of natural products as alternative or complementary therapeutic strategies for leishmaniasis. However, further standardized experimental studies and clinical investigations are necessary to validate their safety and efficacy.
Objective Sparganosis is a rare parasitic disease caused by the larvae of Spirometra mansoni, with pediatric cases being particularly uncommon and prone to misdiagnosis. This study aims to analyze the clinical features, diagnostic strategies, and treatment responses in pediatric sparganosis, and to investigate its global epidemiological trends and diagnostic and therapeutic advancements through a systematic review. Methods We conducted a retrospective analysis of 5 confirmed pediatric sparganosis cases admitted to our center between 2014 and 2023. A systematic search of the PubMed database (1980–2025) for relevant literature was performed, leading to the screening and data extraction of 135 global case reports. Descriptive statistics, correlation analysis, and trend visualization were conducted using R software (version 4.5.1). Results Among the 5 children in our center, the median age was 7 years, and all were from high-parasitic-endemicity areas in Yunnan Province, China. All cases (100
Palmyra Atoll is considered a well-conserved and relatively pristine area with high fish diversity. Since digenean trematodes represent one of the most abundant and diverse parasites of marine fish, the aim of this study was to perform taxonomic analysis of adult digeneans in fishes from the intertidal lagoon of Palmyra Atoll. Parasitological analyses were conducted on 653 individual fishes from 44 species collected from the intertidal sand flats, lagoon, and submerged reefs. Along with morphological descriptions of the adult digeneans, we report prevalence, mean intensities, host species, and tissue microhabitats. We identified 306 individual digeneans representing ten species across six families: one enenterid, Enenterum elongatum Yamaguti 1970; one gyliauchenid, Ichthyotrema vogelsangi Caballero Bravo-Hollis 1952; one lepocreadiid, Diploproctodaeum arothroni Bray Nahhas 1998; two opecoelids, Opecoelus mulloidichthydis Yamaguti 1970 and Paropecoelus parupenei Yamaguti 1970; one zoogonid, Lecithostaphylus nitens (Linton 1898) Linton 1940; and four monorchiids, Hurleytrematoides coronatus Yamaguti 1970; Sinistroporomonorchis palmyrensisn. sp.; Sinistroporomonorchis crenimugilisn. sp.; and Lasiotocus glossodontaen. sp. The composition of adult digenean species in fishes from Palmyra Atoll’s sand flats shows significant affinities with previously reported for the Eastern Indo-Pacific (EIP) marine ecoregion, specifically Hawaii and the Central Indo-Pacific (CIP), as well as the Great Barrier Reef.
Parasitic infections constitute a major cause of morbidity among people living with HIV (PLHIV), especially in resource-limited settings. This study investigated the prevalence, distribution, diagnostic awareness and treatment practices of parasitic infections among HIV-positive adults attending antiretroviral therapy (ART) clinics in three tertiary hospitals across South-West Nigeria. A cross-sectional design was used to collect socio-demographic data, clinical history, diagnostic awareness, and treatment preferences through structured questionnaires. Stool and blood samples were analysed for intestinal and blood-borne parasitic infections using standard microscopy techniques. Overall, 64 (38.3
Anopheles stephensi, a major urban malaria vector in South Asia and the Arabian Peninsula, has recently spread to several African countries, raising significant public health concerns. Understanding its genetic structure is important for tracing invasion pathways; however, population genetic studies have been limited by sparse genome-wide datasets particularly from India, its native range. Here, we sequenced five An. stephensi samples from southern India and integrated them with 33 publicly available genomic datasets from India and Ethiopia to enable a comparison across native and invasive populations. Genome-wide analysis across 38 samples, revealed higher genetic diversity and evidence of broad-scale population differentiation among Indian and Ethiopian samples. Genetic differentiation between regions was moderate (FST = 0.14). A total of 813 SNPs were fixed (FST = 1) between populations, with 586 fixed in Ethiopian samples and 227 in Indian samples. Several fixed SNPs were concentrated in genes involved in sensory perception, ion transport, development, and transcriptional regulation, highlighting candidate genomic regions associated with population-specific differentiation that warrant further investigation. Overall, the results provide evidence of genetic differentiation between native and invasive populations and highlight genomic regions that may contribute to population-specific divergence in An. stephensi.
Cystic echinococcosis (CE) is a globally distributed parasitic zoonosis caused by infection with Echinococcus granulosus. This study investigated the ferroptosis mechanism in hepatocyte injury induced by Echinococcus granulosus cyst fluid (EgCF) and its relationship with the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway using an in vitro model. We employed the Cell Counting Kit-8(CCK-8) assay, Calcein AM/PI staining, and flow cytometry to assess cell viability, reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP). Additionally, we measured lipid peroxides, malondialdehyde (MDA), glutathione (GSH), and ferrous iron (Fe²⁺) levels. Western blot analysis examined the expression of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11(SLC7A11), prostaglandin-endoperoxide synthase 2 (Ptgs2), ferritin heavy chain (FTH1), Nrf2, and heme oxygenase-1 (HO-1). Results indicated that EgCF inhibited hepatocyte proliferation and promoted hepatocyte apoptosis while inducing ferroptosis. Treatment with ferroptosis inhibitors Deferoxamine (DFO) or N-acetylcysteine (NAC) significantly attenuated EgCF-induced cytotoxicity. Nrf2 activation markedly mitigated EgCF-induced hepatocyte injury. This study elucidates the role of EgCF-induced ferroptosis and Nrf2 signaling in CE-associated liver injury, providing novel theoretical insights and new targets for disease prevention and treatment strategies.
Rainbow trout Oncorhynchus mykiss serves as second intermediate host to the eyefluke Diplostomum pseudospathaceum, which resides as the metacercarial stage in the fish lens. The parasite uses a fish-eating bird as the definitive host and a pulmonate lymnaeid snail as first intermediate host. The fish achieves the infection when penetrated by cercariae released by the snail. The internal route of the migrating parasite (termed the diplostomule stage) in the fish (from penetration of the external surface to its destination, the eye lens) has remained partly unknown. In order to elucidate the parasite migration we exposed rainbow trout to cercarial invasion, whereafter we traced the diplostomules at selected internal locations by three approaches: (1) dissection of exposed fish and recovery of live parasites, (2) quantitative realtime PCR (qPCR) and (3) histology. We here demonstrate the presence of diplostomules in the CNS (along the spinal cord, medulla oblongata, brain) before it reaches the eye probably along the optic nerve. In the eye the parasite first enters the corpus vitreum and subsequently the lens. The regulation of immune relevant genes (encoding innate and adaptive immune factors) in the central immune organs (spleen and liver) and in tissues affected (CNS and eyes) by the migrating parasites were followed by qPCR. We suggest that the route taken from skin penetration via CNS to the eye elevates the probability of the parasite to survive during migration and reach its destination (eye lens) due to the low concentration of immune effector cells and molecules in CNS.
Sciomyzidae (Diptera) larvae live as predators and/or parasitoids of snails. They have potential economic importance as biological control agents against gastropods that are vectors of parasitic diseases. In the present study, the use of Sepedon larvae in schistosomiasis control was evaluated by studying the influence of environmental parameters on snail distribution and the impact of prey duration and availability on the survival of Sepedon (P) ruficeps and Sepedon (S) nasuta larvae. The predatory capacity of the larvae was also evaluated by determining the influence of snail consumption on the longevity of the different larval stages. The study was carried out from August 2014 to July 2015 in three locations. A total of 3,448 specimens were collected, showing high diversity and abundance, with a significant difference (df = 2, c2 = 582.97; P < 0.05) among locations. The snail distribution was influenced by environmental variables (total hardness, electric conductivity, Ca2+, O2, Mg2+). The predator/prey interaction between Sciomyzidae species and snails was examined. No difference in the mean duration of immature stages and a mean predation capacity of the two flies (P = 0.50) vs. (P = 0.31) respectively for Sepedon (P) ruficeps and Sepedon (S) nasuta. The consumption varied considerably depending on the ratio of predator (larva) to prey (snail) size and the larval stage. Both these Sciomyzidae consume healthy or parasitized snails by schistosome larvae indiscriminately. They appear to be equivalent agents for biological control of freshwater snails which are intermediate hosts, involved in the transmission of human schistosomiasis or veterinary distomatosis.
Cutaneous larva migrans (CLM) is a common parasitic dermatosis in tropical regions that classically presents with intensely pruritic serpiginous tracks. Atypical manifestations, including bullous lesions, may lead to diagnostic confusion and delayed treatment. We report a case of bullous CLM in a previously healthy 34-year-old man following barefoot exposure to mud during a hike in Thailand. The lesion was initially treated with antibiotics for presumed bacterial infection without improvement. Nine days after symptom onset, multiple tense bullae with surrounding erythema developed on the right foot. Review of a prior photograph demonstrating a serpiginous track, together with the exposure history, supported the diagnosis of bullous CLM. Treatment with a single oral dose of ivermectin resulted in rapid clinical improvement without recurrence. This case report aims to increase awareness of the wide spectrum of atypical presentations of CLM and highlights the diagnostic value of prior clinical photographs, detailed exposure history, and careful re-evaluation of non-resolving symptoms in avoiding delayed diagnosis and unnecessary treatment.
Baylisascaris species parasitizing skunks have received limited attention compared to the well-characterized raccoon roundworm (B. procyonis). We present the first complete mitochondrial genome of a Baylisascaris sp. collected in Kansas, United States, from a striped skunk (Mephitis mephitis). We morphologically identified the nematode as Baylisascaris sp., extracted DNA, sequenced it on the Illumina platform, and de novo assembled the complete mitochondrial genome. The complete mitochondrial genome was 14,752 bp, consisting of 12 protein-coding genes, 2 rRNAs, and 22 tRNAs. The genome had a significant AT-skew (70.5
Ascaris lumbricoides remains one of the most prevalent soil-transmitted helminths worldwide, with ongoing transmission in endemic regions despite long-standing control programs. This study investigated the genetic diversity, population structure, and benzimidazole resistance of A. lumbricoides across three endemic regions of Thailand using mitochondrial (cox1 and nad1) and nuclear (β-tubulin) markers. Haplotype network analysis identified 13 haplotypes within the Thailand dataset, including three newly identified haplotypes, indicating measurable genetic diversity at the local scale. When analyzed in a global context incorporating reference sequences, substantially higher haplotype diversity was observed, reflecting broad genetic diversity across geographic regions. Despite this diversity, no clear geographic structuring was detected among Thai populations, suggesting ongoing gene flow and population connectivity. Phylogenetic analyses further demonstrated that all isolates clustered within a single major lineage and shared haplotypes with Ascaris suum (infecting pig), supporting genetic overlap and potential zoonotic transmission. Analysis of the β-tubulin gene revealed exclusively wild-type alleles at codons 167, 198, and 200, with no evidence of mutations associated with benzimidazole resistance. Overall, this study demonstrates measurable genetic diversity in Thailand's A. lumbricoides populations, with no evidence of clear geographic structuring. These findings provide baseline molecular data to support future surveillance of transmission dynamics and anthelmintic resistance.
Chicken coccidiosis is a ubiquitous and economically significant disease that causes substantial production losses in the poultry industry. It is caused by protozoan parasites of the genus Eimeria, which damage the intestinal epithelium, leading to diarrhoea, poor growth, and mortality. This study investigated the prevalence, risk factors, molecular diversity, and phylogenetic relationships of Eimeria infections in commercial poultry farms in Bangladesh. A total of 350 fresh fecal samples were collected from seven major poultry-producing regions and screened microscopically for oocysts. Farm-level data were obtained through structured interviews to assess associated risk factors. Samples with high oocyst loads were subjected to molecular analysis targeting the internal transcribed spacer 1 region, followed by Sanger sequencing and phylogenetic reconstruction. The overall prevalence was 85.14
Post-mortem myoliquefaction, commonly referred to as ‘jelly flesh’, is associated with infection by myxozoan parasites of the genus Kudoa, particularly Kudoa thyrsites; the effects of infections can render fish fillets unusable in food preparation. Although the parasite has been documented in Atlantic mackerel (Scomber scombrus) across parts of the Northeast Atlantic, its presence in mackerel landed in Ireland has not been previously confirmed. In this study, mackerel obtained from commercial landings were screened for signs of post-mortem myoliquefaction. Three individuals displaying characteristics of softening of the musculature were examined using light microscopy and molecular analysis. Microscopic examination revealed numerous spores consistent with Kudoa-like morphology. Sequencing of the amplified region confirmed the presence of K. thyrsites in all three samples. The sequences showed a 100
The Anthropocene is the most recent period in Earth’s history and is characterized by humankind-driven alterations to all ecosystems. Climate change, pollution, overfishing, invasive species and habitat degradation continue to reshape aquatic ecosystems, and like all living organisms in our changing world, parasites are likely to be affected at different levels. This Collection features research and review papers on some of these topics: parasites co-introduced with their fish hosts illustrate that biological invasions must be studied case-by-case, as some fish hosts lose their parasites upon translocation (enemy release), some pass them on to the invaded ecosystems (overspill) and some acquire –and sometimes amplify– native parasites (spillback), regardless of the time frame, as illustrated in studies of parasites co-introduced from 150 to 15 years ago. Biological information is a powerful tool to predict and prevent the spread of invasive/pathogenic species, and while this Collection provides baseline data for several introduced parasites, it also features practical proposals to control pathogenic/zoonotic species. Climate change and habitat alterations also exert a powerful influence on parasite populations – which likewise, must be studied individually, as some species decline and/or modify their distribution markedly (leading to hybridization and potentially speciation of previously separated taxa), while others benefit from the modified environment, are able to invade new hosts and/or become more infective or pathogenic. Parasites play different ecosystemic roles and are finely-tuned bioindicators of anthropogenic impact in freshwater ecosystems, and this Collection highlights the notion that they should be integrated in public health and conservation initiatives.
Toxoplasmosis is a globally prevalent parasitic disease with significant therapeutic limitations, especially in vulnerable populations. This scoping review assesses the efficacy of quinolones against Toxoplasma gondii in vitro and in vivo. PubMed, ScienceDirect, Web of Science, Embase, Scopus, ProQuest, and Google Scholar were searched from inception to August 2024. Original English-language studies evaluating quinolone effects on T. gondii were included. Screening and data extraction followed PRISMA 2020 guidelines. Of 5,252 initial records, 29 studies were shortlisted for final qualitative synthesis. In vitro analysis revealed a stark dichotomy: while clinical fluoroquinolones such as ciprofloxacin (IC50 = 3.44–20 µM) possessed weak-to-moderate activity, experimental scaffolds, particularly Hydroxyquinolone derivatives (e.g., Compound A, IC50 = 0.0004 μM) and endochin-like quinolones (ELQs) (e.g., ELQ-316, IC50 = 0.000007 μM) achieved sub-nanomolar potency by inhibiting the mitochondrial electron transport chain. Structural optimization was essential; for example, adamantane-conjugated ciprofloxacin (Adam-Cipro) was 31-fold more potent than the parent drug (IC50 = 0.64 µM vs. 20 µM). Combination regimens (e.g., gatifloxacin-pyrimethamine) maximized efficacy while also lowering resistance risks. Novel compounds such as ELQ-316 (0.08 mg/kg) decreased brain cyst burden by up to 88
Human activities have profoundly altered freshwater ecosystems, reshaping host-parasite dynamics with sometimes far-reaching ecological and public health consequences. Based on the examples of stream degradation and restoration, dam construction, agriculture, and urbanization, this review synthesizes how habitat alteration influences parasite communities in freshwater systems. Restoration efforts, such as those in Germany’s Emscher River, demonstrate partial recovery of parasite diversity, though persistent stressors often favour generalist taxa with simple life cycles, reflecting incomplete ecosystem recovery. Dams and reservoirs, by contrast, frequently amplify parasite transmission by creating lentic habitats that aggregate hosts and vectors, increasing risks for diseases such as schistosomiasis and malaria. Agricultural land use further complicates these dynamics: while eutrophication and irrigation can boost trematode transmission, agrochemicals and habitat fragmentation may depauperate parasite communities or disrupt complex life cycles. Additionally, urbanization-related stressors, such as pollutants and artificial light, can suppress sensitive parasites while benefiting those adapted to disturbed environments. Our review demonstrates that, under habitat alteration, freshwater parasites fulfil multiple roles: they constitute a component of the impacted biodiversity, serve as indicators of ecosystem health, and influence disease risk, with their responses governed by life cycle complexity, host specificity, and environmental resilience. These findings underscore the need for integrated management strategies that account for parasites in conservation and public health planning.
