Journal of Parasitology最新文献

{"title":"COMPARATIVE PHYLOGENETIC ANALYSIS OF COI AND NAD1 GENES IN ANIMAL AND HUMAN ISOLATES OF ECHINOCOCCUS CANADENSIS (G6 GENOTYPE) IN IRAN.","authors":"Alireza Latifi, Masoud Alebouyeh, Hamid Choobineh, Bahram Nikmanesh","doi":"10.1645/25-78","DOIUrl":"https://doi.org/10.1645/25-78","url":null,"abstract":"<p><p>Cystic echinococcosis (CE), caused by members of the Echinococcus granulosus sensu lato complex, remains endemic in Iran. Genotype G6, classified within Echinococcus canadensis, is epidemiologically important because of its frequent occurrence in camels and its ability to cause human infection. This study compared the genetic diversity, haplotype composition, and phylogenetic relationships of Iranian G6 isolates using 129 publicly available mitochondrial sequences derived from 120 unique GenBank records, including 79 cytochrome c oxidase subunit 1 (COI) and 50 NADH dehydrogenase subunit 1 (NAD1) sequences. COI exhibited higher haplotype diversity (Hd = 0.518) and nucleotide diversity (π = 0.00678) than NAD1 (Hd = 0.226 and π = 0.00273, respectively), indicating greater resolution for detecting intraspecific variation. Tajima's D was significantly negative for both markers, whereas Fu's Fs was strongly negative for COI, indicating an excess of low-frequency variants and departure from the standard neutral-equilibrium model. Haplotype networks and phylogenetic trees revealed shared haplotypes and intermingled lineages among isolates from different host species, with no visually evident host-associated clustering within the mitochondrial fragments examined. These findings highlight the genetic diversity and epidemiological importance of G6 in Iran and support integrated surveillance involving camels, other susceptible intermediate hosts, and canid definitive hosts. Broader population-based studies incorporating additional geographic regions, host species, and independent genetic markers are required to clarify the population structure and transmission dynamics of G6.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 5","pages":"521-530"},"PeriodicalIF":1.2,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148955906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DEEP LEARNING PREDICTION OF ANTIMICROBIAL PEPTIDES IN PROTOZOA.","authors":"Fabiano Pinheiro da Silva, Suely Kubo Ariga, Thais Martins de Lima, João Marcelo Pereira Alves","doi":"10.1645/25-99","DOIUrl":"10.1645/25-99","url":null,"abstract":"<p><p>Antimicrobial resistance has become a major global health challenge, creating an urgent need for novel anti-infective molecules. Antimicrobial peptides (AMPs) constitute a promising alternative to conventional antibiotics because of their broad-spectrum antimicrobial activity and immunomodulatory properties. Despite the remarkable diversity of protozoa, very few protozoan AMPs have been experimentally identified. Here, we employed the deep learning algorithm AMPlify to systematically screen the proteomes of Blastocystis hominis, Trypanosoma cruzi, Leishmania major, Toxoplasma gondii, and Entamoeba histolytica for high-confidence AMP candidates. Candidate proteins with prediction probabilities greater than 0.90 were further annotated by sequence similarity searches and prioritized for experimental validation. We identified 48 candidate AMPs in B. hominis, 27 in T. cruzi, 23 in T. gondii, and 24 in E. histolytica, whereas no high-confidence candidates were detected in L. major. Predicted candidates represented diverse functional classes, including ribosomal proteins, enzymes, membrane-associated proteins, and proteins involved in nucleic acid metabolism. Three peptides were synthesized and evaluated against Escherichia coli K12. Among them, a peptide derived from the 60S ribosomal protein L3 of B. hominis inhibited bacterial growth with a minimum inhibitory concentration of 125 μM, whereas peptides derived from ribosomal protein L8 and T. cruzi trans-sialidase showed no detectable activity. These findings demonstrate the utility of deep learning for prioritizing novel AMP candidates while highlighting the importance of experimental validation. The identified candidates provide a valuable resource for future functional studies and the development of peptide-based antimicrobial therapeutics.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"514-520"},"PeriodicalIF":1.2,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13595442/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"REVIEW: CAUSES AND CONSEQUENCES OF DOING IT WITH ONESELF-SYNTHESIS AND META-ANALYSIS OF NEODERMATAN HERMAPHRODITIC MATING SYSTEMS.","authors":"Jenna M Hulke, Charles D Criscione","doi":"10.1645/25-100","DOIUrl":"10.1645/25-100","url":null,"abstract":"<p><p>Hermaphroditic mating systems profoundly influence evolution, yet in parasitic flatworms (Neodermata) they remain strikingly understudied. For decades, sweeping claims have oscillated between pervasive selfing and near-universal outcrossing, reflecting a lack of comprehensive synthesis. This review, the first in more than 40 yr, integrates nearly a century of research, from early observational studies to modern genetic analyses, to reveal a far more nuanced picture. Our meta-analysis of population-genetic data shows a sharp departure from the bimodal selfing patterns typical of plants and other hermaphroditic animals: neodermatan parasites are strongly skewed toward outcrossing. We link variation in mating systems to parasite demography and life-history traits, especially in species exhibiting mixed mating or elevated selfing. Current evidence suggests outcrossing is common, but taxonomic and life-history gaps preclude definitive conclusions. Beyond patterns and causes, we explore evolutionary consequences ranging from fitness costs such as inbreeding depression to trait evolution, including delayed selfing, sex allocation, and complex life cycles. Evidence for inbreeding depression is mixed and limited, yet emerging approaches using selfing-rate comparisons offer promising avenues for future research. Notably, demographic constraints, such as infection intensity and life-cycle architecture, often explain mixed mating without invoking selection, challenging classical models. Similarly limited in number, studies on sex allocation indicate that hermaphroditic mating systems can shape reproductive investment, with patterns consistent with local sperm competition in some taxa. By consolidating historical observations with modern genetic insights, this review provides the most comprehensive synthesis of hermaphroditic mating systems in the Neodermata to date. We highlight critical gaps in taxonomic coverage and experimental data and point to future opportunities for integrating genomic approaches with ecological and demographic frameworks. Such integration will be essential to illuminate how mating systems shape parasite evolution and to resolve long-standing questions about the persistence of mixed mating despite theoretical expectations.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"451-474"},"PeriodicalIF":1.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148764338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STRONGYLID COINFECTIONS IN SYMPATRIC CHIMPANZEES AND GORILLAS FROM THE REPUBLIC OF THE CONGO REVEALED BY FECAL METAGENOMICS.","authors":"Damien M O'Halloran","doi":"10.1645/25-102","DOIUrl":"10.1645/25-102","url":null,"abstract":"<p><p>Soil-transmitted strongylid nematodes are common intestinal parasites of African great apes, yet most surveys have relied on microscopy or targeted PCR assays that are limited in taxonomic breadth and comparability across hosts. I reanalyzed 46 publicly available shotgun fecal metagenomes from sympatric central chimpanzees (Pan troglodytes troglodytes; n = 18) and western lowland gorillas (Gorilla gorilla gorilla; n = 28) in the Goualougo Triangle, Nouabalé-Ndoki National Park, Republic of the Congo, to test whether host species structures genus-level strongylid community composition and relative read signal. Non-host reads were classified against a custom strongylid-focused database targeting 4 genera repeatedly reported from African apes: Ancylostoma, Necator, Oesophagostomum, and Trichostrongylus. All 4 focal genera were detected in every library under baseline filtering, and multi-genus detection remained robust under increasingly stringent read-count thresholds. However, host species differed strongly in community composition. Chimpanzee libraries had relatively even genus-level profiles, whereas gorilla libraries were consistently Necator-dominated. Gorillas also had substantially higher relative strongylid read abundance. The results show that shotgun metagenomic reanalysis can recover host-structured strongylid community signals from wildlife samples and can complement targeted parasitological surveys in conservation and One Health surveillance.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"443-450"},"PeriodicalIF":1.2,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148620335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SARCOCYSTIS CANADENSIS N. SP. (PROTOZOA: SARCOCYSTIDAE) FROM LIMB MUSCLES OF THE CANADA LYNX (LYNX CANADENSIS).","authors":"J P Dubey, Aditya Gupta, Carolin Humpal, Michelle Carstensen, B M Rosenthal","doi":"10.1645/26-37","DOIUrl":"10.1645/26-37","url":null,"abstract":"<p><p>Most species of endotherms and some ectotherms harbor muscle cysts (sarcocysts) of 1 or more species of apicomplexan parasites in the genus Sarcocystis. We report a novel species discovered in the muscles of a Canada lynx (Lynx canadensis). We found microscopic sarcocysts in limb muscles of 1 of 3 endangered Canada lynx from Minnesota. The sarcocyst wall was relatively thin (<2 µm) and had short, stubby protrusions with apical thickening. We characterized these further by sequencing the 18S, 28S, and ITS1 portions of nuclear ribosomal RNA genes. The sequences of each marker perfectly matched those of an undescribed species of Sarcocystis previously identified in the brains of river otters (Lontra canadensis) in Alberta, Canada. We propose Sarcocystis canadensis n. sp. for the parasite.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"436-442"},"PeriodicalIF":1.2,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148620262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SURVIVAL ON THE MARGINS: NICHE PARTITIONING AND DENSITY-DEPENDENT SPATIAL DISTRIBUTION OF EQUINE CYATHOSTOMINS.","authors":"Nichol E Ripley, Holli S Gravatte, Craig R Reinemeyer, Martin K Nielsen","doi":"10.1645/26-35","DOIUrl":"10.1645/26-35","url":null,"abstract":"<p><p>Habitat preferences of gastrointestinal nematodes are well-documented in small hosts, but equine cyathostomin diversity has largely been characterized only at farm or regional levels. While organ-level site preferences are known, within-organ spatial distributions remain unexplored. We investigated the longitudinal and radial distribution of adult cyathostomins within the large-intestinal lumen. Intact large intestines from 5 Shetland ponies were frozen post-necropsy and transected into 4-cm sections. Three micro-habitat samples (2.5 cm diameter) were collected per section. We recovered 2,444 intact worms, which were identified individually to species. Data were analyzed using generalized linear mixed models (GLMMs) and Shannon-Wiener Diversity metrics. Fourteen species were identified, dominated by Cylicocyclus nassatus and Cyathostomum catinatum. Spatial modeling revealed a highly structured community hierarchy: dominant species monopolized the central lumen of the anterior ventral colon. Consequently, less abundant species exhibited strict spatial niche partitioning. When aggregated as a guild, \"rare\" species utilized the cecum and peripheral lumen as significant spatial refugia to avoid luminal competition (P < 0.001). Furthermore, increased host infection intensity did not force spatial expansion into marginal habitats; instead, high worm burdens significantly exacerbated crowding within the anterior central lumen (P < 0.001). These findings support interspecific niche partitioning consistent with Schad's species-flock framework: dominant species occupied the central lumen of the orad ventral colon, whereas less abundant species used peripheral/paramucosal and cecal refugia. However, increased host infection intensity did not produce density-dependent spatial expansion; instead, higher worm burdens intensified crowding within the preferred central/orad ventral-colon habitat.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"426-434"},"PeriodicalIF":1.2,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148579046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PARASITIC WORMS IMPAIR NUTRIENT ASSIMILATION AND REPRODUCTIVE INVESTMENT WITHOUT ALTERING MACRONUTRIENT PREFERENCE IN FEMALE HOUSE CRICKETS.","authors":"Christina Anaya, David Benhaïm, Ben Hanelt, Matthew G Bolek, Larisa Vredevoe","doi":"10.1645/25-104","DOIUrl":"10.1645/25-104","url":null,"abstract":"<p><p>Growth and reproduction in insects are strongly influenced by dietary protein and carbohydrate intake, yet parasitism may alter how hosts acquire and allocate these resources. Hairworms (Nematomorpha) develop within arthropod hosts and consume host-derived nutrients, but the effects on host nutrition and development remain poorly understood. We tested the effects of Paragordius varius (Leidy, 1851) parasitism on diet choice, growth, and reproduction in experimentally infected female house crickets, Acheta domesticus (Linnaeus, 1758). Crickets were offered complementary high-protein and high-carbohydrate diets, and we quantified food intake, nutrient preference, and host performance metrics. Infected crickets consumed similar protein-to-carbohydrate ratios as controls but ingested 14% less total food. Control crickets exhibited higher standard growth rates (SGR), whereas SGR decreased with increasing parasite intensity in infected individuals. Infected crickets produced no eggs and had significantly reduced lipid content, ovipositor growth, and fecal output relative to controls. Nutritional indices on the basis of wet mass indicated no difference in the conversion of intake to body mass; however, indices on the basis of parasite-free dry mass revealed that control crickets converted food intake 3.7 times more efficiently than infected crickets. These results indicate that hairworm parasitism reduces host growth and reproductive output and decreases the efficiency of energy assimilation, likely due to direct or indirect resource competition with developing parasites.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"406-416"},"PeriodicalIF":1.2,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148471423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PARASITIC REINFECTION IN WILD NORTHERN BOBWHITE (COLINUS VIRGINIANUS) FOLLOWING CONSISTENT TREATMENT WITH A BIANNUALLY ADMINISTERED ANTHELMINTIC FEED.","authors":"Hannah N Suber, Ashley Kaskocsak, Jeremiah Leach, Ronald J Kendall","doi":"10.1645/25-107","DOIUrl":"10.1645/25-107","url":null,"abstract":"<p><p>Northern bobwhite (Colinus virginianus) populations have experienced sustained declines across their native range, with parasitic helminths, particularly the eyeworm (Oxyspirura petrowi) and cecal worm (Aulonocephalus pennula), emerging as contributing stressors. This study assessed the long-term efficacy of a biannually administered anthelmintic feed treatment (QuailGuard®) and characterized seasonal and annual reinfection patterns in wild bobwhite populations at 2 sites (Oklahoma and Texas) from 2023 to 2025. Fecal samples were collected from wild bobwhite from March to October and analyzed via quantitative polymerase chain reaction (qPCR) to estimate infection levels. Aulonocephalus pennula infection levels were consistently reduced following spring and fall treatments, with efficacy ranging from 61 to 92%, except for 1 unsuccessful treatment in the fall of 2024 at the Texas site. Reinfection was rapid during the summer, and overwinter reinfection was more severe in 2024-2025 than the previous year. Oxyspirura petrowi prevalence was lower overall but showed similar seasonal trends. Birds under approximately 10 wk of age were less likely to have high infection levels, and the population's age structure influenced infection dynamics in late summer. A significant co-infection association between A. pennula and O. petrowi suggests overlapping parasite incidence, which is expected given their shared intermediate hosts. Although the medicated feed demonstrated sustained effectiveness, treatment outcomes varied, likely due to climate conditions and bird behavior. These results support continued biannual treatments but emphasize the need for site-specific adjustments, such as extending pre-baiting periods, to enhance efficacy. Continued monitoring will refine treatment timing, enhance cost-effectiveness, and mitigate the impacts of helminths on bobwhite populations.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"417-425"},"PeriodicalIF":1.2,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148471372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MUSCULAR SARCOCYSTIS INFECTIONS IN HORSES IN NORTH AMERICA: ETIOLOGY, CLINICAL DISEASE, PERSONAL PERCEPTION, AND DEPOSITION OF SPECIMENS IN THE SMITHSONIAN MUSEUM.","authors":"J P Dubey, Aditya Gupta, B M Rosenthal","doi":"10.1645/26-30","DOIUrl":"10.1645/26-30","url":null,"abstract":"<p><p>Uncertainty shrouds the number and identity of the species of Sarcocystis infecting horses in the United States. Horses are intermediate hosts for Sarcocystis fayeri, for which the domestic dog is the definitive host. Clinical signs and lesions associated with S. fayeri are not defined. Granulomatous myositis, especially involving the chest and dysphagia, is one of the clinical presentations associated with S. fayeri infections. Whether S. fayeri is the sole species that forms sarcocysts in equine muscles in the United States is not clear. Little is known of the molecular diagnosis of Sarcocystis species in the muscles of horses. One of us (J.P.D.) has studied equine sarcocystosis for the past 5 decades. Here, we review the status of these aspects from a historical and personal perspective.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 4","pages":"397-405"},"PeriodicalIF":1.2,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148436936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASSOCIATION BETWEEN MACROCYCLIC LACTONE AND BENZIMIDAZOLE RESISTANCE IN THE DOG HOOKWORM ANCYLOSTOMA CANINUM.","authors":"Elise L McKean, Catherine A Jackson, Damien M O'Halloran, John M Hawdon","doi":"10.1645/25-80","DOIUrl":"10.1645/25-80","url":null,"abstract":"<p><p>Anthelmintic resistance is a growing threat to the treatment and control of parasitic nematode infections in both humans and animals. In the canine hookworm, Ancylostoma caninum, multi-anthelmintic drug-resistant (MADR) isolates have been identified, but the molecular mechanisms underlying resistance and the potential for these mechanisms to promote cross-resistance between drug classes remain unclear. In this study, we report evidence for a previously uncharacterized association between resistance to macrocyclic lactones (MLs) and benzimidazoles (BZs) in A. caninum. In a wild-type isolate with no history of drug exposure, serial passaging without treatment led to an unexpected rise in F167Y allele frequency, accompanied by increased resistance to ivermectin (ML) but not to thiabendazole (BZ). Separately, 3 rounds of combination treatment of a triple-resistant isolate with moxidectin (ML) and pyrantel (tetrahydropyrimidine) led to a substantial increase in the frequency of the β-tubulin F167Y mutant allele, despite the absence of BZ selection pressure. These findings suggest that ML resistance in A. caninum may be associated with canonical BZ resistance mutations. Furthermore, the F167Y mutation does not appear to confer any negative fitness effects; instead, the mutation correlated with increased egg output and prolonged infection. This surprising observation raises concerns about the appearance, persistence, and spread of resistance alleles in populations not exposed to drugs. These results have critical implications for resistance management strategies and highlight the urgent need for surveillance tools capable of detecting early cross-resistance in hookworm populations.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"112 3","pages":"389-396"},"PeriodicalIF":1.2,"publicationDate":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148330488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}