International journal for parasitology最新文献

{"title":"Do specialist and generalist parasites differ in their prevalence and intensity of infection? A test of the niche breadth and trade-off hypotheses","authors":"Sonia Cebrián-Camisón ,&nbsp;Josué Martínez-de la Puente ,&nbsp;María José Ruiz-López ,&nbsp;Jordi Figuerola","doi":"10.1016/j.ijpara.2024.11.009","DOIUrl":"10.1016/j.ijpara.2024.11.009","url":null,"abstract":"<div><div>Studying host specificity is crucial to understanding the ability of parasites to spread to new hosts and trigger disease emergence events. The relationship between host specificity and parasite prevalence and infection intensity, has typically been studied in the context of two opposing hypotheses. According to the trade-off hypothesis generalist parasites, which can infect a broad range of hosts, will reach a lower prevalence and infection intensity than more specialist parasites due to the higher costs to adapt to multiple host immune systems. In contrast, the niche breadth hypothesis proposes that generalists’ ability to infect more host species makes them more efficient in colonising host communities and thus they are found at higher prevalences and infection intensities. This study aims to test these hypotheses using the widespread avian malaria parasites of the genera <em>Plasmodium</em> and the related malaria-like parasite <em>Haemoproteus.</em> Overall, 1188 wild house sparrows from 17 localities in southwestern Spain were screened for parasite presence and intensity of infection. For each lineage found infecting house sparrows, we estimated host specificity as i) the number of different bird taxa infected by that lineage according to the MalAvi database and ii) an index that accounts for the phylogenetic relatedness between the host species. Parasite infections were recorded in 419 house sparrows, and eight <em>Plasmodium</em> and three <em>Haemoproteus</em> lineages were identified. Prevalence was positively associated with the number of host species. Lineages found in more localities showed both higher prevalence and host range. Overall, these results support the niche breadth hypothesis in relation to blood parasites infecting house sparrows.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 2","pages":"Pages 129-136"},"PeriodicalIF":3.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142785562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into extracellular vesicle biogenesis and secretion of the tapeworm Hymenolepis diminuta: host interaction and cultivation dynamics","authors":"Hynek Mazanec ,&nbsp;Javier Sotillo ,&nbsp;Peter Koník ,&nbsp;Nikol Bušková ,&nbsp;Jiří Kyslík ,&nbsp;Zdenko Gardian ,&nbsp;Tomáš Bílý ,&nbsp;Kateřina Jirků ,&nbsp;Roman Kuchta","doi":"10.1016/j.ijpara.2024.11.005","DOIUrl":"10.1016/j.ijpara.2024.11.005","url":null,"abstract":"<div><div>Extracellular vesicles (EVs) from parasites have been identified as potent modulators of host-parasite interactions. However, their biogenesis and secretory activity are still poorly understood. Here we present a comprehensive examination of the secretory dynamics of two distinct EV fractions isolated from the adult tapeworm <em>Hymenolepis diminuta</em>. Additionally, we perform a detailed analysis of changes in proteomic content and morphology during EV secretion, utilising electron tomography to shed light on a previously described novel mechanism of EV biogenesis via bead-like protrusion. Our findings reveal a significant decrease in EV secretion between 24 and 48 h of <em>in vitro</em> cultivation when external host stimuli are no longer present. Finally, this study addresses, for the first known time, the potential bias in EV analysis resulting from extended <em>in vitro</em> cultivation of model parasites.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 2","pages":"Pages 69-77"},"PeriodicalIF":3.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142785568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitogenomic analysis of the position of the Azygiidae and constituent genera, with a new species of Azygia","authors":"Danimar López-Hernández ,&nbsp;Florian B. Reyda ,&nbsp;Wenxiang Li ,&nbsp;Hudson A. Pinto ,&nbsp;Sean A. Locke","doi":"10.1016/j.ijpara.2024.11.002","DOIUrl":"10.1016/j.ijpara.2024.11.002","url":null,"abstract":"<div><div>The Azygiidae Looss, 1899 is a family of digeneans with a Holarctic distribution in which members of some genera mature in marine elasmobranchs while others occur only in freshwater teleosts. Some have questioned whether the marine genus <em>Otodistomum</em> Stafford, 1904 indeed belongs to the same family as the freshwater azygiid genera, namely <em>Azygia</em> Looss, 1899, <em>Proterometra</em> Horsfall, 1933, and <em>Leuceruthrus</em> Marshall and Gilbert, 1905. We present phylogenetic analyses based on mitochondrial genomes, rDNA operons, and partial cytochrome <em>c</em> oxidase I (<em>Cox1</em>) sequences from North American and Asian species that support the monophyly of Azygiidae, and placement of Azygioidea in the suborder Hemiurata, in contrast to recently published mitochondrial genome phylogenies. All phylogenies indicate that <em>Azygia</em> includes <em>Leuceruthrus</em>, which we therefore propose to be a junior synonym, together with suppression of the Leuceruthrinae. The status of <em>Proterometra</em> was equivocal, with support in some but not all analyses of 28S, but not in other markers. We describe a new species of <em>Azygia</em> from northeastern North America. Our results confirm the morphological variability of adults in <em>Azygia</em>, with worm size positively correlated with host size in <em>Azygia angusticauda</em>. Phylogenies suggest a marine origin for the Azygiidae, and a Palearctic origin for freshwater azygiids, with a single trans-Atlantic radiation to the Nearctic.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 2","pages":"Pages 103-115"},"PeriodicalIF":3.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142619801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro culture of the parasitic stage larvae of hematophagous parasitic nematode Haemonchus contortus","authors":"Lu Liu ,&nbsp;Zongshan Zhang ,&nbsp;Fuqiang Liu ,&nbsp;Hui Liu ,&nbsp;Lisha Ye ,&nbsp;Feng Liu ,&nbsp;Nishith Gupta ,&nbsp;Chunqun Wang ,&nbsp;Min Hu","doi":"10.1016/j.ijpara.2025.01.007","DOIUrl":"10.1016/j.ijpara.2025.01.007","url":null,"abstract":"<div><div>Current research on common parasitic nematodes is limited because their infective stages cannot be propagated in vitro. Here, we report a culture system for developing L4s of <em>Haemonchus contortus</em>, a blood-feeding nematode of ruminants. Our results demonstrated that a proportionate mixture of NCTC-109 to Luria-Bertini (1:2) media promoted the formation of early L4s and then into late L4s upon inclusion of 12.5% (v/v) defibrinated blood, albeit with a decline in survival. Adding antioxidants (0.3 mg/mL of L-glutathione or 200 nmol of vitamin C) improved survival of L4s, with approximately 90% developing to late L4s by 22 days. These L4s showed parallel morphological features (such as digestive and reproduction systems) compared with in vivo L4s at day 7 (following challenge infection), although with delayed development. Our work optimized the in vitro culture system for L4s while providing an important platform for in-depth molecular research on <em>Haemonchus</em> and other related parasitic nematodes.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 5","pages":"Pages 263-271"},"PeriodicalIF":3.7,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7617482/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143028432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trichinella spiralis extracellular vesicles induce anti-inflammatory and regulatory immune responses in vitro","authors":"Sofija Glamočlija ,&nbsp;Ljiljana Sabljić ,&nbsp;Sergej Tomić ,&nbsp;Jelena Đokić ,&nbsp;Nataša Radulović ,&nbsp;Alisa Gruden-Movsesijan ,&nbsp;Maja Kosanović","doi":"10.1016/j.ijpara.2025.01.008","DOIUrl":"10.1016/j.ijpara.2025.01.008","url":null,"abstract":"<div><div>The helminth <em>Trichinella spiralis</em>, through its excretory-secretory (ES L1) products, induces immune regulatory mechanisms that modulate the host’s immune response not only to itself, but also to bystander antigens, foreign or self in origin, which can result in the alleviation of inflammatory diseases. Under the influence of ES L1, dendritic cells (DCs) acquire a tolerogenic phenotype and the capacity to induce Th2 and regulatory responses. Since ES L1 products represent a complex mixture of proteins and extracellular vesicles (<em>Ts</em>EVs) the aim of this study was to investigate the impact of <em>Ts</em>EVs, isolated from ES L1 products, on phenotypic and functional characteristics of DCs and to elucidate whether <em>Ts</em>EVs could reproduce the immunomodulatory effects of the complete ES L1 product. Monocyte-derived DCs treated with <em>Ts</em>EVs acquired semi-matured phenotypes, characterized by low expression of human leukocyte antigen – DR isotype (HLA-DR), cluster of differentiation (CD) 86 (CD86), and CD40, moderate expression of CD83 and C–C chemokine receptor type 7 (CCR7), and increased expression of tolerogenic markers indoleamine 2,3‐dioxygenase 1 (IDO-1) and immunoglobulin-like transcript 3 (ILT3), together with the unchanged production of IL-12 and IL-23, and elevated production of IL-10 and transforming growth factor (TGF)-β, compared with controls. Gene expression analysis of <em>Ts</em>EV-treated DCs revealed elevated levels of mTOR, Ahr, NF-κB2, RelB, SOCS1 and SOCS3, which participate in signaling pathways involved in DC maturation and the subsequent regulation of release of both anti-inflammatory and pro-inflammatory cytokines. <em>Ts</em>EVs promoted the capacity of DCs to drive polarization of Th2 and anti-inflammatory responses, and impaired their capacity to induce Th1/Th17 polarization. Moreover, <em>Ts</em>EV-treated DCs possessed a high capacity to induce conventional FoxP3 + regulatory T cells, as well as unconventional T regulatory (Tr1) cells. Tolerogenic properties of <em>Ts</em>EV-treated DCs were retained even after challenge with a pro-inflammatory stimulus. These findings highlight the potential of <em>Ts</em>EVs to induce immune tolerance, suggesting their potential use as therapeutics for the treatment of inflammatory disorders.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 6","pages":"Pages 299-315"},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143023342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extensive transcriptional differentiation and specialization of a single-host parasite aligns with niche turnover generated by its host’s metamorphosis","authors":"James G. DuBose,&nbsp;Jacobus C. de Roode","doi":"10.1016/j.ijpara.2025.01.006","DOIUrl":"10.1016/j.ijpara.2025.01.006","url":null,"abstract":"<div><div>Foundational theory on life cycle evolution suggests that given genetic independence, the phenotypes presented by different life stages will diverge more when they occupy more distinct niches. When divergence between stages is significant and punctual, we typically consider the life cycle complex. In parasites, the delineation between simple and complex life cycles is usually made between those that utilize single and multiple host species. However, many parasites can experience significant niche shifts in a single host. To explore the potential for a host’s metamorphosis to shape divergence between stages across its parasite’s life cycle, we quantified the transcriptional differentiation and specialization that the protozoan parasite <em>Ophryocystis elektroscirrha</em> exhibits across the metamorphosis of its host, the monarch butterfly. We found evidence that <em>O. elektroscirrha</em> differentiates in concordance with the ecological turnover imposed by monarch transitions to different stages, and that patterns of transcriptional decoupling across <em>O. elektroscirrha</em> exceeded even those of its host. However, due to its greater gene content, the monarch butterfly exhibited greater total transcriptional turnover than its parasite. These findings suggest that a deeper understanding of life cycle evolution for both free-living and parasitic lifestyles may be facilitated by more nuanced and continuous descriptions of life cycle complexity.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 6","pages":"Pages 273-279"},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143023333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome assembly variation and its implications for gene discovery in nematodes","authors":"Grace M. Mariene ,&nbsp;James D. Wasmuth","doi":"10.1016/j.ijpara.2025.01.004","DOIUrl":"10.1016/j.ijpara.2025.01.004","url":null,"abstract":"<div><div>Genome assemblers are a critical component of genome science, but the choice of assembly software and protocols can be daunting. Here, we investigate genome assembly variation and its implications for gene discovery across three nematode species—<em>Caenorhabditis bovis</em>, <em>Haemonchus contortus</em>, and <em>Heligmosomoides bakeri</em>—highlighting the critical interplay between assembly choice and downstream genomic analysis. Selecting commonly used genome assemblers, we generated multiple assemblies for each species, analyzing their structure, completeness, and effect on gene family analysis. Our findings demonstrate that assembly variations can significantly affect gene family composition, with notable differences in gene families important in anthelmintic discovery and immunomodulation. Despite broadly similar performance using various assembly metrics, comparisons of assemblies with a single species revealed underlying structural rearrangements and inconsistencies in gene content, which would affect downstream analyses. This emphasizes the need for continuous refinement of genome assemblies and their annotations.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 5","pages":"Pages 239-252"},"PeriodicalIF":3.7,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143004909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular detection of trypanosomatids among cave-dwelling bats from Colombia","authors":"J. Manuel Matiz-González ,&nbsp;Carlos Ramiro Silva‐Ramos ,&nbsp;María T. Herrera-Sepúlveda ,&nbsp;Luz Helena Patiño ,&nbsp;Juan David Ramírez ,&nbsp;Jose Mateus ,&nbsp;Paula X. Pavia ,&nbsp;C. Miguel Pinto ,&nbsp;Jairo Pérez-Torres ,&nbsp;Claudia Cuervo","doi":"10.1016/j.ijpara.2025.01.005","DOIUrl":"10.1016/j.ijpara.2025.01.005","url":null,"abstract":"<div><div>Bats play crucial roles in various ecosystems including caves. Although the presence of trypanosomatid species in bats has been documented in Colombia, their diversity in cave-dwelling bats remains unclear. This study aimed to characterize the frequency and diversity of protists from the family Trypanosomatidae circulating in bats from the Macaregua cave ecosystem in Santander, Colombia. A total of 112 specimens from the three permanently residing bat species were examined for trypanosomatid presence through the amplification and sequencing of a region of the 18S rRNA gene in blood samples. We report an overall trypanosomatid detection rate of 42.9% (<em>n</em> = 48), involving the three evaluated bat species: <em>Carollia perspicillata</em> (19/43, 44.2%), <em>Natalus tumidirostris</em> (17/39, 43.6%), and <em>Mormoops megalophylla</em> (12/30, 40.0%). The trypanosomatids were classified by amplicon sequencing and phylogenetic analysis as <em>Trypanosoma</em> spp. (33/112, 29.5%), <em>Leishmania</em> spp. (8/112, 7.1%), and <em>Crithidia</em> spp. (9/112, 8%). In addition, two individuals simultaneously carried more than one genus: <em>Trypanosoma</em> and <em>Leishmania</em> (MT087, <em>C. perspicillata</em>), and <em>Trypanosoma</em> and <em>Crithidia</em> (MT120, <em>M. megalophylla</em>). Some of the samples positive for trypanosomatids were characterized at the species level using the same method with the Cytochrome <em>B</em> gene, identifying <em>Trypanosoma cruzi cruzi</em> (TcI-III and TcBat), <em>Trypanosoma cruzi marinkellei</em>, and <em>Leishmania braziliensis</em> in the evaluated bats. We describe the presence of pathogenic trypanosomatids (<em>T. cruzi cruzi</em>, <em>T. cruzi marinkellei</em>, and <em>L. braziliensis</em>)<em>,</em> as well as monoxenous trypanosomatids such as <em>Crithidia</em> spp. as the Trypanosomatidae protists carried by bats in cave ecosystems from Colombia. The discussion on how bats become infected by these parasites and their potential role in wild transmission cycles is provided below.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 5","pages":"Pages 253-261"},"PeriodicalIF":3.7,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143004917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic diversity and population structure of Oncomelania hupensis in Sichuan Province, China: implications for schistosomiasis control","authors":"Jingye Shang ,&nbsp;Liang Xu ,&nbsp;Bo Zhong ,&nbsp;Zisong Wu ,&nbsp;Lin Chen ,&nbsp;Xianhong Meng ,&nbsp;Jiajia Wan ,&nbsp;Yu Zhang ,&nbsp;Chen Pu ,&nbsp;Peijun Qian ,&nbsp;Shizhu Li ,&nbsp;Yang Liu","doi":"10.1016/j.ijpara.2025.01.003","DOIUrl":"10.1016/j.ijpara.2025.01.003","url":null,"abstract":"<div><div>Schistosomiasis, caused by the infection with <em>Schistosoma japonicum</em>, remains a significant public health concern in China. As the sole intermediate host of <em>S. japonicum</em>, the breeding and spread of <em>Oncomelania hupensis</em> contribute significantly to the potential risk of disease occurrence and transmission. Exploring the population genetics of the snail vector is conducive to better understanding its distribution and dispersal patterns, and provides more data for future snail surveillance and control from a molecular perspective. The genetic diversity and population structure of <em>O. hupensis</em> in Sichuan Province were evaluated based on sequencing of mitochondrial cytochrome <em>c</em> oxidase subunit 1. A total of 215 snail isolates were collected from 30 counties, identifying 80 haplotypes with high nucleotide diversity (0.05871 ± 0.00160) and haplotype diversity (0.979 ± 0.003). Phylogenetic analysis and haplotype network construction identified five distinct clades. Notably, clade 1 was confined within the Panxi region, while clade 5 exhibited a widespread distribution across the studied areas, distinct from the other four clades, but showing a close genetic relationship to individuals from Yunnan. Spatial differentiation was revealed by significant pairwise genetic distance values detected in 313 out of 435 population pairs, ranging from 0.07632 to 1.00000. Analysis of molecular variance (AMOVA) showed that the majority of variance occurred among populations, but significant differences were also observed among landscape groups. AMOVA also provided support for clade separation by exhibiting significant genetic differences among the clades, which explained 78.23% of the overall variation. Geographical distance and precipitation were found to display a significant correlation with the genetic differentiation pattern of <em>O. hupensis</em> in both Mantel and partial Mantel tests. Temporal stability was observed over sampling intervals of 7 years, particularly among snail populations inhabiting the Panxi area, despite prolonged molluscicide treatment. This study provides updated insights into the genetic diversity and population structure of <em>O. hupensis</em> in Sichuan Province, which contribute to a better understanding of the challenges faced in snail control. In light of the findings, the integration of molecular insights into snail monitoring and control, and the reinforcement of collaborative efforts in neighboring regions, in addition to long-distance monitoring, are suggested.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 5","pages":"Pages 225-238"},"PeriodicalIF":3.7,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143004905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic diversity and intercontinental dispersal of temperate and subarctic populations of Dibothriocephalus dendriticus (Cestoda; Diphyllobothriidea), a causative agent of dibothriocephalosis","authors":"Ivica Králová-Hromadová ,&nbsp;Eva Čisovská Bazsalovicsová ,&nbsp;Alžbeta Radačovská ,&nbsp;Katarína Šoltys ,&nbsp;Ľudmila Juhásová ,&nbsp;Gabriel Minárik ,&nbsp;Roman Kuchta ,&nbsp;Karl Skírnisson ,&nbsp;Egil Karlsbakk ,&nbsp;Jan Štefka","doi":"10.1016/j.ijpara.2025.01.002","DOIUrl":"10.1016/j.ijpara.2025.01.002","url":null,"abstract":"<div><div>The diphyllobothriid tapeworm <em>Dibothriocephalus dendriticus,</em> one of the causative agents of the fish-borne zoonosis dibothriocephalosis, is mainly distributed in the Arctic/subarctic and temperate zones of the Northern Hemisphere (Europe, North America, and Asia), but also in the southern cone region of South America (Patagonia). The genetic structure and gene flow among 589 individuals of <em>D. dendriticus</em>, representing 20 populations, were studied using the mitochondrial <em>cox</em>1 gene as the first choice marker and 10 polymorphic nuclear microsatellite loci as a dominant molecular tool. The haplotype network of 30 <em>cox</em>1 haplotypes and Principal Coordinate Analysis/Structure analysis based on microsatellite data revealed close genetic relationships among populations within continents, namely northern and northwestern Europe (Norway, Finland, and UK/Scotland), North America (USA/Alaska, USA/Oregon, and Greenland), and South America (Argentina and Chile). The population from Iceland, located on the Mid-Atlantic Ridge between North America and Europe, was related to both Europe and North America. The mixed Nearctic and Palaearctic origin of <em>D. dendriticus</em> in Iceland was confirmed by a coalescent-based analysis of the microsatellite loci (in Migrate software). The most likely scenarios suggested that the Icelandic population is a genetic admixture of tapeworms from northwestern Europe and USA/Alaska. These findings corresponded with the distribution and migratory routes of piscivorous birds of the family Laridae, the main definitive hosts of <em>D. dendriticus</em>. The origin of an apparently non-native population of <em>D. dendriticus</em> in Patagonia was investigated in detail. The two most plausible hypotheses based on Migrate analysis represented different scenarios. One of them points to a European origin of the Patagonian population, the other to a North American origin. Future research with more extensive and a geographically broader sampling set is recommended to trace dispersal routes of <em>D. dendriticus</em> in Patagonia.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 6","pages":"Pages 281-298"},"PeriodicalIF":3.7,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142970609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}