International journal for parasitology最新文献

{"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}

{"title":"Effects of Nosema ceranae and Lotmaria passim infections on honey bee foraging behaviour and physiology","authors":"Courtney I. MacInnis ,&nbsp;Lien T. Luong ,&nbsp;Stephen F. Pernal","doi":"10.1016/j.ijpara.2024.12.003","DOIUrl":"10.1016/j.ijpara.2024.12.003","url":null,"abstract":"<div><div><em>Nosema ceranae</em> and <em>Lotmaria passim</em> are two commonly encountered digestive tract parasites of the adult honey bee (<em>Apis mellifera</em> L.). Although these parasites are associated with colony losses, little is known about how they affect individual bee physiology and behaviour at the colony level. Using locally obtained isolates, we investigated the effects of both single and mixed infections of <em>L. passim</em> and <em>N. ceranae</em> on honey bee vitellogenin (<em>Vg</em>) expression and foraging behaviour. At the first instance of foraging, bees inoculated with either parasite had significantly lower <em>Vg</em> expression than uninoculated bees, with bees from the mixed infection treatment having the lowest <em>Vg</em> expression. Bees from the mixed infection treatment also had significantly higher densities of <em>N. ceranae</em> spores and numerically greater densities of <em>L. passim</em> cells per bee compared with bees inoculated with either parasite alone. In addition, bees from the mixed infection treatment had a significantly younger average foraging age compared with uninoculated bees from the same cohort. Although we did not find any effect of treatment on foraging effort, we discovered that bees inoculated with <em>L. passim</em> alone, or together with <em>N. ceranae</em>, had higher returning rates of foragers than control bees or bees inoculated with <em>N. ceranae</em> alone. Our findings indicate that both parasites can alter individual bee physiology, leading to individual changes in behaviour that could alter colony foraging dynamics. These have the potential to result in smaller, less productive colonies, decreased colony survivorship and reduced income for beekeepers.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"55 5","pages":"Pages 213-223"},"PeriodicalIF":3.7,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142907094","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":"Parasite β-diversity along a stream: effect of distance and environment","authors":"Verónica Taglioretti,&nbsp;María Alejandra Rossin,&nbsp;Eugenia Levy,&nbsp;Juan Tomás Timi","doi":"10.1016/j.ijpara.2024.09.002","DOIUrl":"10.1016/j.ijpara.2024.09.002","url":null,"abstract":"<div><div>Parasites can provide suitable models for studying β-diversity due to their strict dependence on both the environment and the biology and distribution of their hosts, aiding in the interpretation of any patterns that hosts can display. With the aim of quantifying the relative importance of host features, environmental factors and spatial distances as drivers of fish parasite β-diversity along a unidirectional gradient, the structure of fish parasite assemblages was analysed using generalised dissimilarity models (GDMs). A total of 150 poeciliid fish were examined for larval trematodes, recording host features and physical parameters of each sampling site along the stream. Differences among digenean communities increased when Strahler order changed along the stream, associated with increasing species richness and abundance downstream. Environmental gradient, spatial distance and host features were identified as significant determining factors of species turnover, with conductivity being the most important, followed by spatial distance. In the present study, environmental variables were spatially structured along the stream, their effects as structurers of parasite β-diversity being higher than the pure environmental or the pure distance effect. Such predominance prevents us from establishing at what point on the continuum from niche to neutrality these communities are located. Results from the present research contribute to improving our knowledge of the factors that shape parasite community changes, and underline the importance of considering the pure and shared effects of spatial, environmental and host feature factors in order to determine the real contribution of each one as a determinant of parasite β- diversity.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 14","pages":"Pages 755-765"},"PeriodicalIF":3.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346129","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":"What shapes a microbiome? Differences in bacterial communities associated with helminth-amphipod interactions","authors":"Célia Koellsch,&nbsp;Robert Poulin,&nbsp;Priscila M. Salloum","doi":"10.1016/j.ijpara.2024.08.005","DOIUrl":"10.1016/j.ijpara.2024.08.005","url":null,"abstract":"<div><div>The fast technological advances of molecular tools have enabled us to uncover a new dimension hidden within parasites and their hosts: their microbiomes. Increasingly, parasitologists characterise host microbiome changes in the face of parasitic infections, revealing the potential of these microscopic fast-evolving entities to influence host-parasite interactions. However, most of the changes in host microbiomes seem to depend on the host and parasite species in question. Furthermore, we should understand the relative role of parasitic infections as microbiome modulators when compared with other microbiome-impacting factors (e.g., host size, age, sex). Here, we characterised the microbiome of a single intermediate host species infected by two parasites belonging to different phyla: the acanthocephalan <em>Plagiorhynchus allisonae</em> and a dilepidid cestode, both infecting <em>Transorchestia serrulata</em> amphipods collected simultaneously from the same locality. We used the v4 hypervariable region of the 16S rRNA prokaryotic gene to identify the hemolymph bacterial community of uninfected, acanthocephalan-infected, and cestode-infected amphipods, as well as the bacteria in the amphipods’ immediate environment and in the parasites infecting them. Our results show that parasitic infections were more strongly associated with differences in host bacterial community richness than amphipod size, presence of amphipod eggs in female amphipods, and even parasite load. Amphipods infected by acanthocephalans had the most divergent bacterial community, with a marked decrease in alpha diversity compared with cestode-infected and uninfected hosts. In accordance with the species-specific nature of microbiome changes in parasitic infections, we found unique microbial taxa associating with hosts infected by each parasite species, as well as taxa only shared between a parasite species and their infected hosts. However, there were some bacterial taxa detected in all parasitised amphipods (regardless of the parasite species), but not in uninfected amphipods or the environment. We propose that shared bacteria associated with all hosts parasitised by distantly related helminths may be important either in helping host defences or parasites’ success, and could thus interact with host-parasite evolution.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 14","pages":"Pages 733-742"},"PeriodicalIF":3.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107086","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 characterisation of Australasian Ixodiphagus (Hymenoptera; Encyrtidae; Encyrtinae) reveals unexpected diversity and a potential novel host switch","authors":"Madalene M. Giannotta ,&nbsp;Ina Smith ,&nbsp;Michelle Michie ,&nbsp;Kim Blasdell ,&nbsp;Mike Dunn ,&nbsp;James Nicholls ,&nbsp;Allen C.G. Heath ,&nbsp;Juanita Rodriguez ,&nbsp;Alexander W. Gofton","doi":"10.1016/j.ijpara.2024.09.001","DOIUrl":"10.1016/j.ijpara.2024.09.001","url":null,"abstract":"<div><div>Ticks are important medical and veterinary parasites that represent a substantial health threat to humans, companion animals, and livestock. <em>Ixodiphagus</em> wasps (Hymenoptera; Encyrtidae) are known endoparasitoids of ixodid (hard) and argasid (soft) ticks, with potential utility as natural biocontrol agents. Two species, <em>Ixodiphagus brunneus</em> and <em>Ixodiphagus mysorensis,</em> are previously recorded from Australia, however, the genus lacks formal revisionary work in Australia, and the validity and host ranges of these species remain uncertain. This work aimed to investigate the diversity of <em>Ixodiphagus</em> in Australasia and provide a molecular data resource for future work on these understudied endoparasitoids. We extracted DNA from archival <em>Ixodiphagus</em> specimens from Australian and New Zealand insect collections and performed high-throughput sequencing which resulted in complete or mostly complete mitochondrial genome sequences from 11 specimens, including <em>I. brunneus, Ixodiphagus taiaroaensis</em>, and a novel <em>Ixodiphagus</em> sp. reared from <em>Rhipicephalus linnaei</em> from Townsville, Australia. In addition, approximately 70% of the genome of the <em>Wolbachia</em> endosymbiont of <em>I. brunneus</em> was recovered<em>.</em> Finally, we screened 178 recently collected pooled tick samples from southern New South Wales, Australia, for <em>Ixodiphagus</em> spp. using 28S rRNA and cytochrome <em>c</em> oxidase subunit 1(<em>COI</em>) gene PCR, and recovered 14 positive samples. Phylogenetic analysis of Australasian <em>Ixodiphagus</em> spp. based on 28S rRNA and complete mitochondrial genome sequences determined that members of the Australasian fauna are distinct from <em>Ixodiphagus hookeri</em> (the only other <em>Ixodiphagus</em> species for which genetic data exists), and that at least two distinct species are present in Australia; <em>I. brunneus</em> identified from <em>Ixodes holocyclus</em> and <em>Haemaphysalis bancrofti</em> ticks, and an uncharacterised <em>Ixodiphagus</em> sp. found in <em>Rhipicephalus linnaei</em> ticks from northern Queensland. Furthermore, there was substantial genetic diversity at the 28S rRNA loci among <em>I. brunneus</em> samples, which may represent normal genetic variability or a secondary cryptic species. The molecular data generated here represents the first known for the genus <em>Ixodiphagus</em> in Australasia, doubling that of the world fauna, and provides the first known complete mitochondrial genomes for these important tick parasitoids.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 14","pages":"Pages 743-753"},"PeriodicalIF":3.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142286308","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":"Evidence for a constitutive cost of host resistance on body fat growth in ewe lambs from lines selected for resistance or susceptibility to experimental infections with Haemonchus contortus","authors":"Frédéric Douhard ,&nbsp;Xavier Matthey ,&nbsp;Didier Marcon ,&nbsp;Camille Coffre-Thomain ,&nbsp;Lucie Estivalet ,&nbsp;Delphine Serreau ,&nbsp;Fabrice Guégnard ,&nbsp;Guillaume Sallé ,&nbsp;Papa Moussa Drame ,&nbsp;Frédéric Elleboudt ,&nbsp;François Lecompte ,&nbsp;Hans Adriaensen","doi":"10.1016/j.ijpara.2024.09.004","DOIUrl":"10.1016/j.ijpara.2024.09.004","url":null,"abstract":"<div><div>Although benefits of selection for host resistance to gastro-intestinal nematodes have long been recognized, its costs on production traits remain unclear. A main difficulty when studying those costs is to disentangle genetic effects due to selection from plastic responses induced by infection. Putative costs of host resistance have been extensively investigated in growing sheep. However, while most of those studies have relied on live weight to assess body growth, more comprehensive assessments accounting for body composition are advocated to detect trade-offs. In this study we used 90 female lambs from lines divergently selected on resistance to <em>Haemonchus contortus</em> that we experimentally infected (<em>n</em> = 60) or not (<em>n</em> = 30) under controlled conditions. As those conditions were defined to enable uninfected lambs to fully express their growth potential, we sought to precisely identify the effects of selection for host resistance on health traits and on growth traits. We assessed muscular and fat growth based on repeated measurements with dorsal ultrasonography for all lambs on farm, and with whole-body computed tomography (CT) scans for a subgroup of 18 infected lambs. Lambs achieved a high growth rate, including infected ones despite their high worm burden (confirmed at necropsy in the subgroup). As expected, lambs from the resistant (R) line were less infected than those from the susceptible (S) line. However, the clear pathogenic effects observed on muscular growth and voluntary feed intake were similar between lines. In contrast, a line difference in body fat was supported both by dorsal and volumetric CT measurements. Specifically, lower fat in the R line compared with the S line was observed equally in infected and uninfected groups, thus providing evidence for a constitutive cost of host resistance. Although this cost is not necessarily disadvantageous in nutrient-rich environments exposing animals to excess fat deposition, its consequences in nutrient-scarce environments may be important to promote sustainable breeding strategies for host resistance.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 14","pages":"Pages 767-777"},"PeriodicalIF":3.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346128","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 invasive acanthocephalan parasite Pachysentis canicola is associated with a declining endemic island fox population on San Miguel Island","authors":"O. Alejandro Aleuy ,&nbsp;Leslie W. Woods ,&nbsp;Benjamin J. Padilla ,&nbsp;Dennis Richardson ,&nbsp;Juliann T. Schamel ,&nbsp;Stacy Baker ,&nbsp;Martín García-Varela ,&nbsp;Charlotte Hammond ,&nbsp;Sarah P. Lawson ,&nbsp;Jasmine N. Childress ,&nbsp;Jason Rohr ,&nbsp;Kevin D. Lafferty","doi":"10.1016/j.ijpara.2024.09.003","DOIUrl":"10.1016/j.ijpara.2024.09.003","url":null,"abstract":"<div><div>In the late 1990s, the San Miguel Island fox (<em>Urocyon littoralis littoralis</em>) faced near-extinction. Fourteen of the 15 remaining foxes were placed into an island-based captive breeding program used to repopulate the island. Although the fox population in San Miguel reached pre-decline numbers by 2010, a second decline started around 2014, coincidental with a newly observed acanthocephalan parasite. To identify this introduced acanthocephalan species and determine the pathologic consequences of its infection on the health of foxes, we used an extensive record of island fox necropsies and associated parasite collections. In addition, we used detailed fox capture-recapture data to investigate population health and demographic trends of foxes before and after parasite emergence. We identify the parasite as <em>Pachysentis canicola,</em> a common acanthocephalan in mainland foxes in North America. The parasite was detected in 69% of the necropsied foxes from San Miguel Island and was not found in any of the other five Channel Island fox subspecies. Health impacts attributed to the acanthocephalan parasite, including erosive and ulcerative enteritis, transmural necrosis, and inflammation, were described in 47% of the foxes infected with the acanthocephalan. Despite infection with various other helminth parasite species, body condition remained good and the mortality rate low in San Miguel Island foxes until the arrival of the acanthocephalan. Body condition improved after 2018, perhaps due to increases in rainfall following a drought, but remained 27% lower than the pre-acanthocephalan period, which suggests that environmental conditions and parasitism jointly drive fox population dynamics.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 14","pages":"Pages 723-732"},"PeriodicalIF":3.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346130","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":"Genomic and metagenomic analyses of the domestic mite Tyrophagus putrescentiae identify it as a widespread environmental contaminant and a host of a basal, mite-specific Wolbachia lineage (supergroup Q)","authors":"Pavel B. Klimov ,&nbsp;Jan Hubert ,&nbsp;Tomas Erban ,&nbsp;M. Alejandra Perotti ,&nbsp;Henk R. Braig ,&nbsp;Alex Flynt ,&nbsp;Qixin He ,&nbsp;Yubao Cui","doi":"10.1016/j.ijpara.2024.07.001","DOIUrl":"10.1016/j.ijpara.2024.07.001","url":null,"abstract":"<div><div><em>Tyrophagus putrescentiae</em> (mould mite) is a global, microscopic trophic generalist that commonly occurs in various human-created habitats, causing allergies and damaging stored food. Its ubiquity and extraordinary ability to penetrate research samples or cultures through air currents or by active walking through tights spaces (such as treads of screw caps) may lead to sample contamination and introduction of its DNA to research materials in the laboratory. This prompts a thorough investigation into potential sequence contamination in public genomic databases. The trophic success of <em>T. putrescentiae</em> is primarily attributed to the symbiotic bacteria housed in specialized internal mite structures, facilitating adaptation to varied nutritional niches. However, recent work suggests that horizontal transfer of bacterial/fungal genes related to nutritional functionality may also contribute to the mite’s trophic versatility. This aspect requires independent confirmation. Additionally, <em>T. putrescentiae</em> harbors an uncharacterized and genetically divergent bacterium, <em>Wolbachia</em>, displaying blocking and microbiome-modifying effects. The phylogenomic position and supergroup assignment of this bacterium are unknown. Here, we sequenced and assembled the <em>T. putrescentiae</em> genome, analyzed its microbiome, and performed detailed phylogenomic analyses of the mite-specific <em>Wolbachia</em>. We show that <em>T. putrescentiae</em> DNA is a substantial source of contamination of research samples. Its DNA may inadvertently be co-extracted with the DNA of the target organism, eventually leading to sequence contamination in public databases. We identified a diversity of bacterial species associated with <em>T. putrescentiae</em>, including those capable of rapidly developing antibiotic resistance, such as <em>Escherichia coli</em>. Despite the presence of diverse bacterial communities in <em>T. putrescentiae</em>, we did not detect any recent horizontal gene transfers in this mite species and/or in astigmatid (domestic) mites in general. Our phylogenomic analysis of <em>Wolbachia</em> recovered a basal, mite-specific lineage (supergroup Q) represented by two <em>Wolbachia</em> spp. from the mould mite and a gall-inducing plant mite. Fluorescence in situ hybridization confirmed the presence of <em>Wolbachia</em> inside the mould mite<em>.</em> The discovery of an early derivative <em>Wolbachia</em> lineage (supergroup Q) in two phylogenetically unrelated and ecologically dissimilar mites suggests that this endosymbiotic bacterial lineage formed a long-term association with mites. This finding provides a unique insight into the early evolution and host associations of <em>Wolbachia</em>. Further discoveries of <em>Wolbachia</em> diversity in acariform mites are anticipated.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 13","pages":"Pages 661-674"},"PeriodicalIF":3.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590232","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}