International journal for parasitology最新文献

{"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}

{"title":"A footworm in the door: revising Onchocerca phylogeny with previously unknown cryptic species in wild North American ungulates","authors":"Matthew R. Kulpa ,&nbsp;Emilie Lefoulon ,&nbsp;Kimberlee B. Beckmen ,&nbsp;Samantha E. Allen ,&nbsp;Jennifer Malmberg ,&nbsp;John A. Crouse ,&nbsp;Daniel P. Thompson ,&nbsp;Bridgett M. Benedict ,&nbsp;Dayna A. Goldsmith ,&nbsp;Sara McCarthy ,&nbsp;Lee C. Jones ,&nbsp;Michael J. Yabsley ,&nbsp;James M. Crum ,&nbsp;Susan J. Kutz ,&nbsp;Guilherme G. Verocai","doi":"10.1016/j.ijpara.2024.10.006","DOIUrl":"10.1016/j.ijpara.2024.10.006","url":null,"abstract":"<div><div><em>Onchocerca</em> is an important genus of vector-borne filarial nematodes that infect both humans and animals worldwide. Many <em>Onchocerca</em> spp., most of medical and veterinary health relevance, are the focus of a variety of diagnostic and molecular research. However, despite the importance of these parasites, there is growing evidence of previously unexplored genetic diversity of these nematodes, particularly among wild ungulate hosts in North America. These understudied parasites prevent us from comprehending the evolutionary history of the genus <em>Onchocerca</em>, monitoring potential One Health threats, and improving our filarioid diagnostic capabilities. In order to fill these knowledge gaps, we identified five uncharacterized <em>Onchocerca</em> lineages and compared them with other well-known filarioid species using single and concatenated gene regions (i.e., <em>nd5</em>, <em>cox1</em>, 12S, 18S, 28S, <em>hsp70</em>, <em>MyoHC</em>, <em>rbp1</em>). Phylogenetic analyses revealed that the novel <em>Onchocerca</em> lineages of wild North American ungulates segregate into two clades. One clade comprised <em>Onchocerca</em> lineages II, IV, and V and other species found mainly in domestic animals and humans, and the second comprised <em>Onchocerca</em> lineages I and III and other species from a variety of hosts including cervids, bovids, and equids. The formation of two clearly separate clades supports the idea of at least two independent expansion events of ancestral <em>Onchocerca</em> spp. into the North American continent via the Bering land bridge. Cophylogenetic analysis shows evidence of ancestral <em>Onchocerca</em> spp. of Bovidae host-switching to wild Cervidae and giving rise to the novel <em>Onchocerca</em> spp. Lastly, pairwise analysis confirms informative molecular markers of diagnostic relevance in both mitochondrial and nuclear gene regions of filarioid nematodes. The overall information provides greater context to the genus <em>Onchocerca</em> and emphasizes the need to discover, characterize, and monitor neglected parasites, especially those of wildlife origin.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 59-68"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142619798","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":"The microRNAome of Strongylus vulgaris larvae and their excretory/secretory products with identification of parasite-derived microRNAs in horse arterial tissue","authors":"Katrine Toft ,&nbsp;Marie Louise Honoré ,&nbsp;Nichol E. Ripley ,&nbsp;Martin K. Nielsen ,&nbsp;Bastian Fromm ,&nbsp;Maibritt Mardahl ,&nbsp;Lise N. Nielsen ,&nbsp;Peter Nejsum ,&nbsp;Stig Milan Thamsborg ,&nbsp;Susanna Cirera ,&nbsp;Tina Holberg Pihl","doi":"10.1016/j.ijpara.2024.10.005","DOIUrl":"10.1016/j.ijpara.2024.10.005","url":null,"abstract":"<div><div>The equine bloodworm, <em>Strongylus vulgaris</em>, is a highly pathogenic parasite causing potentially fatal vascular and intestinal damage. Parasites express and release microRNAs (miRNAs) for internal regulation and to modulate host immunity. The complete set of miRNAs expressed by <em>S. vulgaris</em> (the <em>S. vulgaris</em> miRNAome) remains unannotated and the aim of this study was to annotate the miRNAome of L4 and L5 stages of <em>S. vulgaris,</em> and to examine differences in miRNA abundance between larval stages and sexes. Furthermore, we aimed to determine if miRNAs were detectable in excretory/secretory products (ESPs) from larvae and in arterial tissue from their predilection site, the cranial mesenteric artery (CMA). Larvae were collected from naturally infected foals, and categorized by sex and stage. A subset of larvae was snap-frozen, while those remaining were incubated and the (ESPs) collected. Arterial tissue samples were collected from the CMA. Small RNA sequencing, followed by a custom bioinformatic pipeline, was used for annotation. We identified 142 <em>S. vulgaris</em> miRNAs in larvae and 136 in ESPs. Significant differences in miRNA abundance were observed between larvae and ESPs, and between L5 females (L5Fs) and L5 males (L5Ms), L4s and L5Fs, and L4s and L5Ms. No differences were found between L4s and L5s overall. In ESPs, several miRNAs were differentially abundant across all groups. Validation through quantitative real-time PCR (qPCR) detected selected miRNAs and their differential abundance in larvae and ESPs. One parasite-derived miRNA was detected in some of the horse arterial tissue samples but at very low levels. This study provided the first annotation of the <em>S. vulgaris</em> miRNAome. Most of the annotated larval miRNAs were also detectable in ESPs, and differences in miRNA abundance between sexes were found for larvae, and between sexes and stages for ESPs. Parasite-derived miRNAs were, however, not consistently detectable in the surrounding host arterial tissue.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 45-58"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604442","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":"Different life strategies of closely related louse species in sympatry: specialist and “generalist“ lineages of Polyplax serrata","authors":"Jana Martinů ,&nbsp;Jan Štefka ,&nbsp;Kateřina Vránková ,&nbsp;Václav Hypša","doi":"10.1016/j.ijpara.2024.10.003","DOIUrl":"10.1016/j.ijpara.2024.10.003","url":null,"abstract":"<div><div>The origin and significance of host specificity are intriguing questions in parasitology. In the case of single-host versus multiple-host parasites, this topic integrates with the concept of the specialist/generalist trade-off. We use the model of sucking lice <em>Polyplax serrata</em> and rodent hosts <em>Apodemus</em>, to address these concepts. <em>Polyplax serrata</em> was shown to form a complex genetic structure, with a strictly specific S lineage living on <em>Apodemus flavicollis</em>, and a less specific N lineage on <em>A. flavicollis</em> and <em>Apodemus sylvaticus</em>. Moreover, the S lineage formed two mitochondrial clades with geographically exclusive distributions and a narrow hybrid zone, providing an opportunity to test the hypothesis that hybrids suffer a decrease in fitness. We sampled 451 individual lice from two host species at 103 localities. We used prevalences and intensities as proxies of fitness, which the parasites realize on their host. The S lineage, strictly specific to <em>Apodemus flavicollis</em>, reached significantly higher prevalences and intensities on its host compared with the N lineage. Conversely, the N lineage occurred with high prevalence and intensity on <em>A. sylvaticus</em> but tended to use also <em>A. flavicollis</em> when the louse populations became too dense. We discuss possible mechanisms behind this difference (particularly interspecific competition as a typical phenomenon in the specialist/generalist systems). We conclude that a parasite’s “choice”, not accessibility of the host or interspecific competition, is the main factor affecting the louse prevalences. We suggest that historical differences in geographic distribution of both lice and mice may provide a possible explanation for the observed life strategy differences. In contrast to the convincing picture in S and N lineage prevalences, we did not detect an expected drop in fitness in hybrids. We consider instability of the hybrid zone, or decline in abundance of the respective hosts, as possible explanations for this result.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 27-34"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142464482","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":"Acanthamoeba castellanii trophozoites need oxygen for normal functioning and lipids are their preferred substrate, offering new possibilities for treatment","authors":"Maarten J. Sarink ,&nbsp;Anna Z. Mykytyn ,&nbsp;Aïsha Jedidi ,&nbsp;Martin Houweling ,&nbsp;Jos F. Brouwers ,&nbsp;George Ruijter ,&nbsp;Annelies Verbon ,&nbsp;Jaap J. van Hellemond ,&nbsp;Aloysius G.M. Tielens","doi":"10.1016/j.ijpara.2024.10.004","DOIUrl":"10.1016/j.ijpara.2024.10.004","url":null,"abstract":"<div><div><em>Acanthamoebae,</em> pathogenic free-living amoebae, can cause Granulomatous Amoebic Encephalitis (GAE) and keratitis, and for both types of infection, no adequate treatment options are available. As the metabolism of pathogens is an attractive treatment target, we set out to examine the energy metabolism of <em>Acanthamoeba castellanii</em> and studied the aerobic and anaerobic capacities of the trophozoites. Under anaerobic conditions, or in the presence of inhibitors of the electron-transport chain, <em>A. castellanii</em> trophozoites became rounded, moved sluggishly and stopped multiplying. This demonstrates that oxygen and the respiratory chain are essential for movement and replication. Furthermore, the simultaneous activities of both terminal oxidases, cytochrome <em>c</em> oxidase and the plant-like alternative oxidase, are essential for normal functioning and replication. The inhibition of normal function caused by the inactivity of the respiratory chain was reversible. Once respiration was made possible again, the rounded, rather inactive amoebae formed acanthopodia within 4 h and resumed moving, feeding and multiplying. Experiments with radiolabelled nutrients revealed a preference for lipids over glucose and amino acids as food. Subsequent experiments showed that adding lipids to a standard culture medium of trophozoites strongly increased the growth rate. <em>Acanthamoeba castellanii</em> trophozoites have a strictly aerobic energy metabolism and β-oxidation of fatty acids, the Krebs cycle, and an aerobic electron-transport chain coupled to the ATP synthase, producing most of the used ATP. The preference for lipids can be exploited, as we show that three known inhibitors of lipid oxidation strongly inhibited the growth of <em>A. castellanii</em>. In particular, thioridazine and perhexiline showed potent effects in low micromolar concentrations. Therefore, this study revealed a new drug target with possibly new options to treat <em>Acanthamoeba</em> infections.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 35-44"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568484","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":"Northward migration past the nearctic biogeographical divide; neotropical Gyrodactylus spp. infecting Astyanax have crossed the Trans-Mexican Volcanic Belt","authors":"Daniel Augusto Pozos-Carré ,&nbsp;Carlos Daniel Pinacho-Pinacho ,&nbsp;Miguel Calixto-Rojas ,&nbsp;Juan Manuel Caspeta-Mandujano ,&nbsp;Juan Pablo Ramírez-Herrejón ,&nbsp;Adriana García-Vásquez ,&nbsp;Juan José Barrios-Gutiérrez ,&nbsp;Ismael Guzmán-Valdivieso ,&nbsp;Miguel Rubio-Godoy","doi":"10.1016/j.ijpara.2024.10.001","DOIUrl":"10.1016/j.ijpara.2024.10.001","url":null,"abstract":"<div><div>The neotropical fish genus <em>Astyanax</em> (Characidae) and its associated helminths migrated northward from South America following the Great American Biotic Interchange (GABI): ca. 150 <em>Astyanax</em> spp. are found throughout South and Central America, up to the Mexico-USA border. Most characids are distributed south of the Trans-Mexican Volcanic Belt (TMVB), which bisects the country and represents a major transition zone between the neotropical and nearctic realms. Here, we characterize parasites of the monogenean genus <em>Gyrodactylus</em> infecting <em>Astyanax</em> spp. in Mexico: <em>Astyanax aeneus</em> south of the TMBV, <em>Astyanax mexicanus</em> north of it<em>.</em> Based on morphological, phylogenetic (internal transcribed spacer (ITS) and cytochrome oxidase subunit II (<em>cox 2</em>)) and statistical analyses of morphometric data, we confirmed the validity of <em>Gyrodactylus pakan</em> and <em>Gyrodactylus teken</em>, and erected two new species, <em>Gyrodactylus aphaa</em> n. sp. and <em>Gyrodactylus ricardoi</em> n. sp. These four gyrodactylids are part of a complex of morphologically cryptic species, which are phylogenetically closely related to each other, and sister species to <em>Gyrodactylus carolinae</em> and <em>Gyrodactylus heteracanthus</em>, parasites of characins in Brazil. Four gyrodactylid lineages (<em>G. pakan</em>, <em>G. ricardoi</em> n. sp., <em>G. teken</em>, <em>Gyrodactylus</em> sp. A) are distributed north of the TMVB; <em>G. pakan</em> is also widely distributed south of the TMVB, together with <em>G. aphaa</em> n. sp. Based on the ITS phylogeny, Brazilian parasites form a sister clade to all Mexican gyrodactylids, whose derived clades are distributed in progressively more northerly latitudes in Mexico – the three most-derived species north of the TMVB. This would suggest that gyrodactylid species diverged gradually, presumably as their characid fish hosts colonized and adapted to new environments north of the TMVB.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 1-14"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406394","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":"Unravelling the patterns of exo-erythrocytic development of Haemoproteus parasites (Haemoproteidae, Haemosporida), with a case of abortive tissue stages in a naturally infected bird","authors":"Mélanie Tchoumbou,&nbsp;Tatjana Iezhova,&nbsp;Carolina Hernández-Lara,&nbsp;Mélanie Duc,&nbsp;Gediminas Valkiūnas","doi":"10.1016/j.ijpara.2024.10.002","DOIUrl":"10.1016/j.ijpara.2024.10.002","url":null,"abstract":"<div><div><em>Haemoproteus</em> species (Haemosporida, Haemoproteidae) are cosmopolitan blood parasites that affect bird fitness and health. Recent discoveries based on the application of molecular markers showed that exo-erythrocytic or tissue stages of haemoproteids damage various internal organs including the brain. However, the patterns of exo-erythrocytic development remain unclear for most of the described species. This study aimed to understand the exo-erythrocytic development of <em>Haemoproteus</em> parasites in naturally infected Thrush nightingales <em>Luscinia luscinia</em> (Muscicapidae). Infections were confirmed in eight bird individuals by microscopic examination and PCR-based methods. Organs were examined using histology and in situ hybridization, which applied genus-specific and lineage-specific oligonucleotide probes targeting the 18S rRNA of the parasites. Exo-erythrocytic meronts of <em>Haemoproteus attenuatus</em> (lineage hROBIN1) were found and described for the first known time in this avian host. Most meronts were seen in the lungs, with a few also present in the liver, heart, and pectoral muscle. The available data suggest that this parasite produces only meronts, and not megalomeronts. However, numerous megalomeronts at different stages of development were observed in the gizzard and the heart of one individual. Based on the morphology, location in organs, and diagnostics using the lineage-specific probes, the megalomeronts were attributed to <em>Haemoproteus majoris</em> (lineage hWW2). Two cases of empty capsular-like walls of megalomeronts were seen in the gizzard, indicating that the megalomeronts had already ruptured and degenerated. The extensive microscopic examination did not reveal gametocytes of <em>H. majoris</em>, obviously indicating an abortive development. Abortive haemosporidian infections were often speculated to occur in wildlife but have not been documented in naturally infected birds. This study recognised patterns in the exo-erythrocytic development of <em>H. attenuatus,</em> and is to our knowledge the first documentation of abortive <em>Haemoproteus</em> infection in a naturally infected bird during exo-erythrocytic development.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 1","pages":"Pages 15-26"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406395","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}