Parasitology Research最新文献_第4页

Association between Toxoplasma gondii seropositivity and Alzheimer's disease: a case-control study. 刚地弓形虫血清阳性与阿尔茨海默病的关系：一项病例对照研究

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-08 DOI: 10.1007/s00436-026-08711-4

Maryam Aldaghi, Ali Alizadeh Khatir, Mahdi Sepidarkish, Delaram Arjmandi, Faribourz Mousavi, Saeed Aghapour, Masomeh Bayani, Ali Rostami

{"title":"Association between Toxoplasma gondii seropositivity and Alzheimer's disease: a case-control study.","authors":"Maryam Aldaghi, Ali Alizadeh Khatir, Mahdi Sepidarkish, Delaram Arjmandi, Faribourz Mousavi, Saeed Aghapour, Masomeh Bayani, Ali Rostami","doi":"10.1007/s00436-026-08711-4","DOIUrl":"10.1007/s00436-026-08711-4","url":null,"abstract":"Alzheimer's disease (AD) is a progressive neurodegenerative condition marked by declining cognitive function and memory deterioration. Emerging evidence suggests that infectious agents, including Toxoplasma gondii, may contribute to the risk of developing this disorder. Because previous studies on this association have produced limited and inconsistent results, we examined the link between T. gondii infection and Alzheimer's disease. This case-control study included 90 recently diagnosed AD patients from Ayatollah Rouhani Hospital and Clinic in Babol, Iran, and 91 healthy individuals as controls. After obtaining written informed consent, serum samples were collected from both groups. AD was determined through expert clinical evaluation, and the Mini-Mental State Examination (MMSE) was used to assess cognitive status and disease severity. Anti-T. gondii IgG antibodies were detected using ELISA. Data were analyzed in SPSS using chi-square tests, and odds ratios with 95% confidence intervals were calculated. The seroprevalence of T. gondii was 77.7% in cases and 89.0% in healthy controls. T. gondii seropositivity showed a significant inverse association with AD in both univariate analysis (OR: 0.43, 95% CI: 0.18-0.98; P = 0.04) and multivariate analysis (OR: 0.35, 95% CI: 0.14-0.92; P = 0.03). Additionally, T. gondii seropositivity was significantly associated with lower odds of greater AD severity in multivariate analysis (OR: 0.44, 95% CI: 0.20-0.97; P = 0.04). Our findings suggest an inverse association between T. gondii seropositivity and AD. Moreover, seropositivity was associated with lower odds of more severe disease. Further research is warranted to clarify the biological basis and clinical significance of this association.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13468854/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148205554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gastrointestinal protozoan and helminth parasite infections in captive chameleons in Germany. 德国圈养变色龙胃肠道原生动物和寄生虫感染。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-08 DOI: 10.1007/s00436-026-08704-3

Paula Sapion-Miranda, Anja Taubert, Carlos Hermosilla, Malek J Hallinger

{"title":"Gastrointestinal protozoan and helminth parasite infections in captive chameleons in Germany.","authors":"Paula Sapion-Miranda, Anja Taubert, Carlos Hermosilla, Malek J Hallinger","doi":"10.1007/s00436-026-08704-3","DOIUrl":"10.1007/s00436-026-08704-3","url":null,"abstract":"Within lizards, chameleons (family Chamaeleonidae) represent a distinctive and highly specialized clade of insectivorous reptiles. Chameleons have become more popular as reptile pets in recent years worldwide, due to their feasible husbandry and attractiveness. To date, not only reptile pet numbers but also health-compromising endoparasite infections are rising. In the current study, we analyzed a total of 670 faecal samples of 25 different chameleon species kept as pet animals all over Germany. In total, 223 animals (33%) were found to harbor gastrointestinal parasites. In total, 10 different parasite taxa were diagnosed in chameleon faecal samples. The most prevalent parasite stages were oxyurid eggs (14.1%), followed by coccidia oocysts (7.8%) (e.g. Isospora jaracimrmani, Isospora spp., Choleoeimeria spp., Eimeria spp.), flagellated protozoan trophozoites (6.3%) (e.g. Leptomonas spp., Tritrichomonas spp., Proteromonas spp.), heterakid eggs (3.6%), thin-shelled nematode eggs (3.6%), digenean trematode eggs (0.6%), pentastomid eggs (0.3%), ascarid eggs (0.2%), Entamoeba spp. cysts (0.2%) and physalopteroid eggs (0.2%). Among current chameleon species, veiled chameleons (Chamaleo calyptratus) showed a significantly higher prevalence of oxyurid infections (64%) than other chameleon species. Co-infections were diagnosed in 9.8% (22/223) of faecal samples. When performing necropsies, 19/31 chameleons showed parasite-induced pathologies based on histopathological examinations, including one animal being infected with 4 parasite species (Leptomonas spp., Tritrichomonas spp., Foleyella furcata and Hexametra angusticaecoides), thereby most likely impacting animal's welfare.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13249703/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148199764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Essential oils compromise tegumental integrity in Sparicotyle chrysophrii: Insights from SEM and histological analyses. 精油损害金翅草被皮完整性：从扫描电镜和组织学分析的见解。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-05 DOI: 10.1007/s00436-026-08708-z

Teresa Pirollo, Perla Tedesco, Andrea Gustinelli, Ana Leon, Oswaldo Palenzuela, Itziar Estensoro, Monica Caffara

{"title":"Essential oils compromise tegumental integrity in Sparicotyle chrysophrii: Insights from SEM and histological analyses.","authors":"Teresa Pirollo, Perla Tedesco, Andrea Gustinelli, Ana Leon, Oswaldo Palenzuela, Itziar Estensoro, Monica Caffara","doi":"10.1007/s00436-026-08708-z","DOIUrl":"10.1007/s00436-026-08708-z","url":null,"abstract":"This study investigates the morphological effects of various essential oils (EOs) on the monogenean Sparicotyle chrysophrii, a major gill parasite of gilthead sea bream (Sparus aurata), through scanning electron microscopy (SEM) and histological analyses. Adult parasites obtained from experimental infections were exposed in vitro to different EOs at concentrations ranging from 62.5 to 500 ppm. Cinnamomum zeylanicum, Origanum vulgare, Thymus vulgaris, and a commercial blend (Mix Gill) exhibited the highest antiparasitic efficacy, achieving complete mortality at 500 ppm within one hour. SEM observations revealed extensive tegumental disruption, including surface erosion, deep wrinkling, and clamp detachment, which increased in severity with EO concentration and exposure time. Histological analyses confirmed widespread tissue degeneration, characterized by vacuolization, cytoplasmic rarefaction, and loss of the neodermal and muscular organization. Even at sublethal concentrations, lesions consistent with swelling, vesicle formation, and tegumental disorganization indicated progressive degeneration. These structural alterations suggest that EOs compromise the parasite's external integrity, leading to functional collapse of the tegument and haptor. The results support a time- and concentration-dependent mechanism, likely involving disruption of membrane integrity and osmotic imbalance. Collectively, to the best of our knowledge, this is among the first studies to provide detailed ultrastructural evidence of EO-induced damage in S. chrysophrii and highlights their potential as eco-friendly antiparasitic agents for aquaculture. Further studies integrating ultrastructural and biochemical analyses are warranted to elucidate the molecular pathways underlying these effects.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13534214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148176577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reconsidering the risks of Linguatula in Australia: A review of an overlooked introduced parasite. 重新考虑扁蝽在澳大利亚的风险：对一种被忽视的引进寄生虫的回顾。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-05 DOI: 10.1007/s00436-026-08705-2

Shokoofeh Shamsi, Diane P Barton

{"title":"Reconsidering the risks of Linguatula in Australia: A review of an overlooked introduced parasite.","authors":"Shokoofeh Shamsi, Diane P Barton","doi":"10.1007/s00436-026-08705-2","DOIUrl":"10.1007/s00436-026-08705-2","url":null,"abstract":"Linguatula serrata is a globally distributed zoonotic parasite that remains largely overlooked in public health. Although traditionally described as having an indirect life cycle involving carnivorous definitive hosts and herbivorous intermediate hosts, emerging evidence suggests greater complexity in transmission pathways and host associations, with some observations raising the possibility of a direct life cycle. In Australia, L. serrata, likely introduced through domestic animals and livestock during colonisation, is now well established across both introduced and native hosts, indicating sustained transmission at the wildlife-livestock-human interface, although human infection has not been reported. Recognised transmission pathways, via ingestion of eggs from environmental contamination or infective nymphs in raw or undercooked offal, are plausible in Australia. This Perspective synthesises current knowledge of its biology, transmission, and host range, and highlights its role as both a foodborne and environmentally transmitted zoonosis. We argue that the absence of reported human cases likely reflects under-recognition due to non-specific clinical presentation, diagnostic limitations, and limited awareness among health professionals. Together, these observations suggest that L. serrata may be more epidemiologically relevant in Australia than currently recognised and should be reconsidered within Australia's One Health and zoonotic disease frameworks.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13461942/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148176567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reduced centrifugation duration improves diagnostic performance of an equine tapeworm egg counting technique. 缩短离心时间可提高马绦虫卵计数技术的诊断性能。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-05 DOI: 10.1007/s00436-026-08706-1

Malena Hughes, Nichol E Ripley, Mackenzie A Smith, Carlo Carta, Martin K Nielsen

{"title":"Reduced centrifugation duration improves diagnostic performance of an equine tapeworm egg counting technique.","authors":"Malena Hughes, Nichol E Ripley, Mackenzie A Smith, Carlo Carta, Martin K Nielsen","doi":"10.1007/s00436-026-08706-1","DOIUrl":"10.1007/s00436-026-08706-1","url":null,"abstract":"Anoplocephala perfoliata, can cause severe health problems in horses. Standard coprological tests have performed poorly for detecting A. perfoliata, and while a centrifugation-enhanced flotation technique is superior to other techniques, it is time consuming due to three 10-minute centrifugation steps. This study aimed to evaluate modifications of this technique that reduce the centrifugation durations to 5 and 1 min, respectively. Fecal samples were collected from ten adult A. perfoliata egg count positive mares and divided into 9 subsamples to allow for three replicate counts for each of the three protocols. The standard 10-minute centrifugation had a mean coefficient of variation (CV) of 76.8% and a 95% confidence interval of 61.4% - 92.1%, while the 5-min and 1-min protocols had CVs of 68.6% (53.7%-83.4%) and 59.0% (48.7% - 69.4%), respectively. Furthermore, the 10-min protocol yielded 70.7% positive counts compared to 82.9% and 86.2% for the 5-min and 1-min protocols, respectively. The 5-min and 1-min protocols were also superior in egg count magnitude, with significantly higher medians compared to the 10-min protocol. Overall, these data demonstrate that reducing the centrifugation time to one minute will improve test performance for detecting and quantifying equine tapeworm eggs in fecal samples.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13457277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Global patterns of parasite sharing among freshwater turtles. 淡水龟之间寄生虫共享的全球模式。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-02 DOI: 10.1007/s00436-026-08702-5

Maria Silva, João Rato, Pedro Brandão, Rita Rocha, Pedro Anastácio, Filipe Banha

{"title":"Global patterns of parasite sharing among freshwater turtles.","authors":"Maria Silva, João Rato, Pedro Brandão, Rita Rocha, Pedro Anastácio, Filipe Banha","doi":"10.1007/s00436-026-08702-5","DOIUrl":"10.1007/s00436-026-08702-5","url":null,"abstract":"Freshwater turtles represent a highly diverse and ecologically important group, yet they are among the most threatened vertebrates worldwide due to habitat loss, overexploitation, and the introduction of non-native species. In this study, we conducted a systematic literature review, following PRISMA guidelines, to assess parasite sharing among native and non-native freshwater turtles globally, compiling data from 294 publications spanning 1939 to 2025. Our analyses, including multiple correspondence analysis (MCA) and clustering analysis, revealed that parasite communities are strongly structured by host phylogeny, biogeography, and the presence of non-native species. In North America, Asia, and South America, both native and introduced turtles share extensive parasite networks, whereas Oceania and Africa show mostly endemic, intra-native associations. Non-native species such as Trachemys scripta may act as epidemiological bridges in Europe, facilitating parasite spillover to native hosts. These findings underscore the influence of evolutionary history, species introductions, and geographic isolation on host-parasite dynamics and highlight the need for targeted monitoring and management strategies to mitigate ecological and health risks.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13260133/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148144309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Echinococcus granulosus sensu stricto hydatid cysts in human and livestock from northeastern Algeria: Molecular characterization based on nad5 and cox1 and fertility assessment. 阿尔及利亚东北部人类和牲畜的严格感细粒棘球绦虫包囊：基于nad5和cox1的分子特征和生育评估。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-06-01 DOI: 10.1007/s00436-026-08703-4

Amina Kheninef, Ilaria Bellini, Silvia Rondòn, Claudia Chiovoloni, Lynda Aissaoui, Serena Cavallero, Stefano D'Amelio

{"title":"Echinococcus granulosus sensu stricto hydatid cysts in human and livestock from northeastern Algeria: Molecular characterization based on nad5 and cox1 and fertility assessment.","authors":"Amina Kheninef, Ilaria Bellini, Silvia Rondòn, Claudia Chiovoloni, Lynda Aissaoui, Serena Cavallero, Stefano D'Amelio","doi":"10.1007/s00436-026-08703-4","DOIUrl":"10.1007/s00436-026-08703-4","url":null,"abstract":"Cystic Echinococcosis (CE) is a major helminthic zoonosis caused by the larval stage of Echinococcus granulosus, particularly highly endemic in several Mediterranean regions, including Algeria. Humans are accidental hosts, while animals such as livestock act as intermediate hosts. This study aimed to update the fragmented epidemiological picture of CE in Algeria, by combining the knowledge on cysts fertility, and protoscolex viability with molecular strains assignment. In particular, the genetic typing of Echinococcus granulosus from humans (n = 16), cattle (n = 15), sheep (n = 15), and goat (n = 1) collected in the northeastern Setif region, were performed using two partial mitochondrial markers used for a precise strains and variant call, the classic partial cox1 and the recently developed nad5, used in this area for the first time. Results revealed a predominance of E. granulosus sensu stricto strain G1, with haplotype variants circulating in both humans and animals. Interestingly, G3 strain was reported only in a human patient, while G3 haplotype variants in both humans and animals. Fertility rate was lower but not negligible in cattle (18.2%), and high in sheep and humans (80.9% and 95.6%, respectively), and the viable cysts showed different anatomical distributions across species: in cattle, 43% were pulmonary and 57% hepatic; in sheep, 74.5% were located in the lungs and 25.5% in the liver. Such data highlights the crucial role of livestock in maintaining E. granulosus transmission in the area.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13447339/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of albendazole treatment on sperm parameters of ram experimentally infected with cystic echinococcosis. 阿苯达唑对实验感染囊性包虫病公羊精子参数的影响。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-05-29 DOI: 10.1007/s00436-026-08697-z

Figen Celik, Ibrahim Halil Gungor, Muhammet Uslug, Aslıhan Cakır-Cihangiroglu, Mustafa Sonmez, Sami Simsek

{"title":"Effects of albendazole treatment on sperm parameters of ram experimentally infected with cystic echinococcosis.","authors":"Figen Celik, Ibrahim Halil Gungor, Muhammet Uslug, Aslıhan Cakır-Cihangiroglu, Mustafa Sonmez, Sami Simsek","doi":"10.1007/s00436-026-08697-z","DOIUrl":"10.1007/s00436-026-08697-z","url":null,"abstract":"Cystic echinococcosis (CE) is a chronic zoonotic disease caused by Echinococcus granulosus, primarily affecting the liver and lungs of livestock but also capable of inducing systemic alterations through oxidative stress and metabolic imbalance. These systemic effects may impair reproductive physiology in male animals. This study aimed to investigate the effects of CE infection and subsequent albendazole (ABZ) treatment on sperm quality parameters in rams. Fourteen male lambs were experimentally infected with E. granulosus eggs, and after the establishment of infection, six were treated orally with ABZ (7.5 mg/kg) every 30 days for three months, while others served as untreated controls. Semen samples were evaluated using computer-assisted sperm analysis (CASA) for motility and kinematic parameters, as well as for sperm concentration, viability, and abnormality rates. CE infection alone led to decreased motility, sperm concentration, and alterations in kinematic parameters such as linearity (LIN), straightness (STR), and amplitude of lateral head displacement (ALH), reflecting impaired sperm trajectory and coordination. ABZ-treated animals exhibited a more pronounced decline in total and progressive motility and in kinematic parameters (straight-line velocity-VSL-, average path velocity-VAP-), suggesting potential microtubule- or mitochondria-associated functional alterations. No significant changes were detected in sperm viability. These findings indicate that both CE and ABZ may adversely influence sperm function, possibly through oxidative and cytoskeletal mechanisms. However, the absence of an uninfected ABZ -only control group limits the ability to distinguish independent drug-related effects from infection-associated alterations.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13424461/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148056198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hitching a ride across the continental divide of Mexico: the twospot livebearer Pseudoxiphophorus bimaculatus carried its Gyrodactylus spp. when translocated from the Atlantic to the Pacific Ocean versant. 搭上横跨墨西哥大陆分界线的便车：双点寄生的伪剑鱼带着它的Gyrodactylus类从大西洋转移到太平洋。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-05-27 DOI: 10.1007/s00436-026-08701-6

Ismael Edoardo Sánchez-González, Miguel Rubio-Godoy, Carlos Daniel Pinacho-Pinacho

{"title":"Hitching a ride across the continental divide of Mexico: the twospot livebearer Pseudoxiphophorus bimaculatus carried its Gyrodactylus spp. when translocated from the Atlantic to the Pacific Ocean versant.","authors":"Ismael Edoardo Sánchez-González, Miguel Rubio-Godoy, Carlos Daniel Pinacho-Pinacho","doi":"10.1007/s00436-026-08701-6","DOIUrl":"10.1007/s00436-026-08701-6","url":null,"abstract":"We studied flatworm parasites of the genus Gyrodactylus associated with twospot livebearer Pseudoxiphophorus bimaculatus both in this host's native distribution in the Gulf of Mexico (Atlantic Ocean) versant, as well as in its invasive range across the continental divide, in the Pacific Ocean watershed. We surveyed 12 river basins, six on each slope of the continent, and recorded -apparently- overdispersed parasite distributions, both in terms of localities within basins and on fish hosts. Six gyrodactylid species were previously known to infect this poeciliid host, and we add five taxa to the list, three known and two undescribed species. From the 11 parasite species we characterized molecularly (cox 2 mDNA and ITS rDNA sequences), 9-10 species (depending on the markers used for species delimitation; cox 2 + ITS, nine species; cox 2, 10 species) were recorded in river basins draining into the Atlantic, and only four in rivers flowing into the Pacific. Only one species, Gyrodactylus takoke, was recorded frequently on both sides of the country, and cox 2 haplotype networks suggest that parasites co-translocated with their fish hosts originated from the central Gulf of Mexico slope and successfully invaded two river basins draining into the Pacific. We hypothesize that following the translocation of P. bimaculatus across the continental divide of Mexico, different types of host-parasite interactions (enemy release, spill-over and spill-back) may involve particular parasite species, some of which are known to be pathogenic.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13391752/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148034091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

First record of nymphal larvae of Alofia sp. (Pentastomida: Sebekidae) in Megalechis thoracata from the Western Amazon (Brazil). 巴西西部亚马逊河流域胸大背蝇幼虫首次记录（Pentastomida: Sebekidae）。

IF 1.9 3区医学

Parasitology Research Pub Date : 2026-05-26 DOI: 10.1007/s00436-026-08691-5

Lucena R Virgilio, Ricardo M Takemoto, Mayara D Passere, Alessandra V de Oliveira, Dionatas U O Meneguetti

{"title":"First record of nymphal larvae of Alofia sp. (Pentastomida: Sebekidae) in Megalechis thoracata from the Western Amazon (Brazil).","authors":"Lucena R Virgilio, Ricardo M Takemoto, Mayara D Passere, Alessandra V de Oliveira, Dionatas U O Meneguetti","doi":"10.1007/s00436-026-08691-5","DOIUrl":"10.1007/s00436-026-08691-5","url":null,"abstract":"Pentastomids of the family Sebekidae utilize fish as intermediate hosts. In Brazil, records of the genus Alofia Giglioli, 1922 remain scarce and fragmented. This study reports the first occurrence of Alofia sp. nymphs in the armored catfish Megalechis thoracata (Valenciennes, 1840) from the western Amazon, Acre State, Brazil. Of 33 fish examined, 42.42% were parasitized, with a mean intensity of 1.57 parasites per infected host and a mean abundance of 0.66. Nymphs were recovered from the coelomic cavity, associated with the serosa of internal organs. Morphological identification was supported by scanning electron microscopy (SEM), revealing diagnostic characters consistent with the genus. Molecular analysis of the cytochrome c oxidase subunit I (cox1) gene generated a 647 bp sequence, representing one of the few available molecular records for Alofia in the Neotropical region. The observed genetic divergence highlights the potential presence of an uncharacterized lineage. These findings expand the known host range and geographical distribution of Alofia, while providing novel molecular data that contribute to the systematics and phylogenetic understanding of Neotropical Sebekidae.","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13391739/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148034134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0