Parasites & Vectors最新文献

{"title":"Catechin gallate triggers metabolomic and lipidomic alteration in Toxoplasma gondii.","authors":"Jazmyn R Greggs, Homa Nath Sharma, Daniel A Abugri","doi":"10.1186/s13071-025-06869-x","DOIUrl":"10.1186/s13071-025-06869-x","url":null,"abstract":"<p><strong>Background: </strong>Toxoplasma gondii is a zoonotic parasite, the causative agent of toxoplasmosis, which has global importance owing to its significant socioeconomic, public health, and veterinary burdens. Toxoplasmosis is currently treated with a combination of pyrimethamine and sulfadiazine. These drugs have treatment failures and toxicity and are ineffective against the bradyzoite stage. Hence, there is a need for new inhibitors against T. gondii. Catechin gallate (CG) is a known antioxidant with demonstrated antiparasitic properties. However, little is known about its anti-Toxoplasma gondii activity and mechanism of action.</p><p><strong>Methods: </strong>Here, we assess the effect of CG on human telomerase reverse transcriptase immortalized foreskin fibroblast (hTERT) cells, cytotoxicity, and inhibitory activity of the RH-RFP (type I) strain of T. gondii tachyzoite. Inhibitory and cytotoxicity activities were measured by a fluorescent plate reader, and the data were analyzed using Graph Pad Prism software. In addition, to predict the possible mechanism of CG action, hTERT cells were cultured in a T25 flask and infected with RH-RFP parasites, followed by CG administration and incubation for 48 h. Parasites were quenched under ice, and the parasites were purified from host cells and extracted with chloroform-methanol. The extracts containing the lipids and metabolites were analyzed using liquid chromatography-mass spectrometry (LC-MS).</p><p><strong>Results: </strong>To address this research question, we tested the in vitro inhibitory activity of CG against parasite growth at 48 h and 72 h. The half-maximal inhibitory concentration (IC₅₀) values against tachyzoite growth were calculated to be 10.07 (8.31-12.20) µM and 7.057 (5.98-8.32) µM for 48 h and 72 h, respectively. We identified 5-formyl-tetrahydromethanopterin; 5-(6-hydroxy-6-methyloctyl)-2,5-dihydrofuran-2-one; trans-3-indoleacrylic acid; 5,5-dimethyl-2-{[(2-phenylacetyl)amino]methyl}-1,3-thiazolane-4-carboxylic acid; 5'-S-Ethyl-5'-thioadenosine; L-Norleucine; and norepinephrine sulfate as the most produced during the CG treatment. For the lipidomics analysis, we identified the production of several sphingolipid species, including ceramides, dihydroceramide, and sphingosine, which are associated with apoptosis and autophagy. The limited number of sphingomyelin and sphingosine-1-phosphate identified, which are known to promote proliferation, suggests that CG may be affecting T. gondii parasites' proliferation. In addition, oxidized fatty acids (3-hydroxypropyl stearate and (R)-3-hydroxy myristic acid) were observed in both treatments with low production, which confers oxidative stress induction on parasites.</p><p><strong>Conclusions: </strong>The study showed that CG had inhibitory activity against T. gondii growth and caused metabolite and lipid alterations in T. gondii. This requires future studies on the enzymes associated with the biosynthesis of these metab","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"317"},"PeriodicalIF":3.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12315274/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144760759","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":"Investigating the role of stable flies (Stomoxys calcitrans) and biting midges of the genus Culicoides as potential mechanical vectors of African swine fever virus in Lithuania, Poland and Romania.","authors":"Sofie Dhollander, Oana-Maria Balmoș, Eleonora Cattaneo, José Abrahantes Cortiñas, Anette Ella Boklund, Anna Szczotka-Bochniarz, Andrei Daniel Mihalca, Lina Mur, Maciej Frant, Anna Gal-Cisoń, Malgorzata Kwasnik, Wojciech Rozek, Alvydas Malakauskas, Marius Masiulis, Jurga Turcinaviciene, Theodora Chesnoiu, Krzysztof Jazdzewski, Jerzy Rola, Florica Barbuceanu, Miguel Ángel Miranda, Jan Arend Stegeman","doi":"10.1186/s13071-025-06816-w","DOIUrl":"10.1186/s13071-025-06816-w","url":null,"abstract":"<p><strong>Background: </strong>Since its emergence in Georgia in 2007, the seasonal pattern of African swine fever virus (ASFV) genotype II outbreaks in European pig populations has been evident. It is hypothesized that summer-related farming practices, along with the increased activity and abundance of arthropod vectors during warmer months, contribute to the increased incidence of these outbreaks during this period. This study investigated the potential role of stable flies (Stomoxys calcitrans) and biting midges of the genus Culicoides as mechanical vectors of ASFV. In addition, the potential distribution and abundance of different species of Culicoides biting midges on pig farms was investigated.</p><p><strong>Methods: </strong>From August 2021 to August 2023, vector surveillance was conducted as part of a case-control study on 42 outbreak farms and 70 control farms across Romania, Lithuania, and Poland. Collected insect specimens were pooled and tested for ASFV DNA using real-time polymerase chain reaction (PCR).</p><p><strong>Results: </strong>A total of 8604 biting midges of the genus Culicoides specimens and 742 S. calcitrans flies were collected, with ASF DNA detected in 27 out of 1219 insect pools. Positive pools were predominantly observed in Culicoides punctatus, C. newsteadi, and the Obsoletus complex, with most detections occurring in August. However, ASFV isolation was unsuccessful. Statistical analyses revealed no significant association between farm status (outbreak versus control) and ASFV DNA detection in pools of biting midges of the genus Culicoides, likely due to limited sample size. Additionally, two ASFV-positive S. calcitrans pools were identified, supporting their potential role as mechanical vehicles for ASFV. The findings highlight the affinity of C. punctatus, C. newsteadi, and the Obsoletus complex and S. calcitrans for pig farms - an aspect that was previously undocumented. This association may increase the likelihood of ASFV acquisition and dissemination by these species. Environmental factors, such as pig farm density and proximity to other hosts, likely influence this risk.</p><p><strong>Conclusions: </strong>These results emphasize the importance of vector control strategies, including insect netting, to mitigate ASFV transmission risks. Further research is needed to understand the dynamics of ASFV infection in arthropods. Notably, this study also reports the first identification of Culicoides riethi and Culicoides salinarius in Lithuania.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"312"},"PeriodicalIF":3.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12312455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144760761","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":"Pulmonary hypertension and NT-proBNP dynamics during the course of adulticide treatment in dogs naturally infected by Dirofilaria immitis.","authors":"Noelia Costa-Rodríguez, Daniel Julio Vera-Rodríguez, Soraya Falcón-Cordón, Beatriz Regina Morales, José Alberto Montoya-Alonso, Rodrigo Morchón, Elena Carretón","doi":"10.1186/s13071-025-06945-2","DOIUrl":"10.1186/s13071-025-06945-2","url":null,"abstract":"<p><strong>Background: </strong>Pulmonary hypertension (PH) is a frequent complication in dogs with heartworm disease caused by Dirofilaria immitis. Although echocardiography remains the main diagnostic tool, its operator- and preload-dependence may limit accuracy. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker that increases in response to ventricular wall stress and may be useful for monitoring right-sided heart disease. This study aimed to evaluate NT-proBNP concentrations in dogs with precapillary PH due to heartworm disease during adulticide treatment.</p><p><strong>Methods: </strong>In total, 90 dogs diagnosed with heartworm disease were prospectively enrolled and classified according to the presence of PH based on echocardiographic criteria. NT-proBNP concentrations were measured on days 0, 30, 60, and 90 of adulticide treatment. Additional data collected included the presence/absence of microfilariae, clinical signs, parasite burden, and renal values. Dogs received adulticidal therapy following current international guidelines. Statistical analyses assessed correlations between NT-proBNP levels, epidemiological, clinical and echocardiographic classification, and treatment progression.</p><p><strong>Results: </strong>Dogs with PH had significantly higher NT-proBNP concentrations at baseline compared with those without PH (2038 ± 1671 versus 583 ± 185 pmol/L, P < 0.001). NT-proBNP levels were also positively correlated with parasite burden (r = 0.530, P < 0.05), presence of clinical signs (r = 0.456, P < 0.05), and age (r = 0.29, P < 0.05). During treatment, a progressive decrease in NT-proBNP concentrations was observed in dogs with PH, while levels remained stable in dogs without PH. Receiver operating characteristic (ROC) analysis identified a cut-off of 1524.8 pmol/L for detecting moderate-to-severe PH (sensitivity: 99%, specificity: 87%).</p><p><strong>Conclusions: </strong>NT-proBNP is a valuable noninvasive biomarker for detecting and monitoring PH in dogs with heartworm disease. Its concentrations seem to reflect parasite burden, clinical status, and echocardiographic severity, and decline progressively with adulticide therapy. Integration of NT-proBNP into diagnostic and therapeutic protocols may enhance management of heartworm-infected dogs with suspected PH.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"313"},"PeriodicalIF":3.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12312376/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144760762","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":"Individual host factors and co-infections affect the probability and excretion intensity of endoparasite infections in dairy cows.","authors":"Anna Sophie Hecker, Marie-Kristin Raulf, Sven König, Katharina May, Christina Strube","doi":"10.1186/s13071-025-06974-x","DOIUrl":"10.1186/s13071-025-06974-x","url":null,"abstract":"<p><strong>Background: </strong>Endoparasite infections cause economic losses in dairy farming. Understanding the factors that influence endoparasite prevalence and egg/oocyst excretion is essential for effective parasite control. Environmental and management factors play an important role at herd level; however, factors related to the individual cow, such as the parity number or lactation stage, also contribute to infection. In addition, it is still unclear to what extent co-infections with other endoparasites influence prevalence and egg/oocyst excretion rates.</p><p><strong>Methods: </strong>Faecal samples from 1,126 cows from 24 dairy herds were copromicroscopically examined for endoparasite infections. Hurdle models were applied to test the effect of parity number, lactation stage and co-infections on the probability and intensity of egg/oocyst excretion of strongyles, Fasciola hepatica, rumen flukes and coccidia.</p><p><strong>Results: </strong>Strongyle eggs were present in all herds and 45.9% of individual cows, F. hepatica eggs in 75.0% of herds and 9.9% of cows, rumen fluke eggs in 62.5% of herds and 26.5% of cows and coccidian oocysts in 91.7% of herds and 18.7% of cows. Eggs of Moniezia spp., Trichuris spp. and Capillaria spp. were detected sporadically. Model analysis revealed that the probability of strongyle egg excretion decreased after the first parity, presumably as a result of developing immunity, yet an increase was observed after the fourth parity. With increasing parity number, excretion probability of F. hepatica and excretion intensity of rumen flukes increased. Coccidian oocysts excretion was highest in first-parity cows. The lactation stage affected strongyle egg excretion, with the highest probability in early lactation, possibly linked to the negative energy balance in this period. Strongyle co-infections increased the probability of coccidian oocyst excretion (P = 0.008), and coccidian co-infections increased both the probability (P = 0.011) and intensity (P = 0.007) of strongyle egg excretion. Furthermore, coccidian co-infections were associated with a decreased excretion intensity of rumen fluke eggs (P = 0.022).</p><p><strong>Conclusions: </strong>The identification of age groups that are more susceptible to or more likely to spread certain endoparasite taxa and the synergism between strongyle egg and coccidian oocyst excretion can help to implement effective targeted monitoring and control strategies to optimise parasite management in dairy herds.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"311"},"PeriodicalIF":3.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12309137/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144753974","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":"Proline dehydrogenase, a rate-limiting catabolic enzyme, affecting the growth and pathogenicity of Toxoplasma gondii tachyzoites by regulating the proline metabolism and mitochondrial function of the parasite.","authors":"Xiao-Ling Geng, Jing-Yu Li, Huan-Yu Xu, Jiang-Ping Wu, De-Liang Tao, Jin-Ming Chen, Ying-Ying Fan, Xin Yang, Jun-Ke Song, Guang-Hui Zhao","doi":"10.1186/s13071-025-06966-x","DOIUrl":"10.1186/s13071-025-06966-x","url":null,"abstract":"<p><strong>Background: </strong>The pathogenicity of Toxoplasma gondii is closely associated with its intracellular lytic cycle in host cells. Currently, the mechanisms by which T. gondii completes the lytic cycle remain unclear. The proline metabolism has been reported to be crucial for intracellular growth of pathogens by providing energy and nutrients. However, it remains unclear whether the intracellular growth and pathogenicity of T. gondii are related to proline metabolism.</p><p><strong>Methods: </strong>The gene-edited strains of proline dehydrogenase (Tgprodh) were constructed by using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR-Cas9) technology. The effects of the Tgprodh gene on the growth in vitro and pathogenicity in vivo of the tachyzoites for T. gondii were studied through proliferation, plaque, invasion, egress and virulence assays. The effects of the Tgprodh gene on mitochondrial function were studied by using reactive oxygen species (ROS), mitochondrial membrane potential (∆Ψm), adenosine triphosphate (ATP) assay kits, mitochondrial DNA (mtDNA) copy numbers, transmission electron microscopy (TEM) analysis, and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). The effects of the Tgprodh gene on proline metabolism were studied by using L-proline (L-Pro), L-glutamic acid (L-Glu), L-glutamine (L-Gln) assay kits, and RT-qPCR.</p><p><strong>Results: </strong>TgPRODH, the first rate-limiting enzyme in proline metabolism, was identified to be encoded by T. gondii and localized in the cytoplasm of T. gondii. Deletion of the Tgprodh gene resulted in significant growth inhibition in vitro and reduced pathogenicity in vivo of T. gondii. Further study found that deletion of the Tgprodh gene caused damage to the mitochondrial morphology, decreased membrane potential, mtDNA copy numbers, and the production of ATP and ROS. The expression of genes for maintaining mitochondrial integrity was downregulated in the Tgprodh-knockout strain of T. gondii, while complementation of the Tgprodh gene restored these defects in this parasite. Meantime, the deletion of the Tgprodh gene resulted in the accumulation of proline, reduced the contents of glutamate and glutamine, and affected the expression of genes related to proline catabolism in T. gondii.</p><p><strong>Conclusions: </strong>The present study found the significance of the Tgprodh gene for the intracellular growth and pathogenicity of T. gondii through regulating mitochondrial function and the proline metabolism and provided a novel insight to reveal intracellular survival strategies of T. gondii.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"309"},"PeriodicalIF":3.5,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12308898/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144743918","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":"Impact of temperature on vector competence of Culex pipiens molestus: implications for Usutu virus transmission in temperate regions.","authors":"Nicola Seechurn, Jack Pilgrim, Ken Sherlock, Jolanta Tanianis-Hughes, Marcus Blagrove, Grant L Hughes, Jolyon M Medlock, Nicholas Johnson, Matthew Baylis","doi":"10.1186/s13071-025-06948-z","DOIUrl":"10.1186/s13071-025-06948-z","url":null,"abstract":"<p><strong>Background: </strong>Usutu virus (USUV) has been detected annually in the southeast of England since 2020. USUV RNA has been identified in wild birds and mosquito populations, and exposure of captive birds to USUV has also been confirmed in the UK. Since its first detection in London, USUV's distribution has expanded across the South East, highlighting necessity to understand USUV transmission dynamics in the UK. The primary vectors of USUV in the UK are likely Culex pipiens mosquitoes. Culex pipiens molestus is one biotype which shows no restriction in host preference and may play an important role in transmitting USUV from birds to humans.</p><p><strong>Methods: </strong>A laboratory colony of Cx. pipiens molestus mosquitoes were orally infected with the London strain of USUV and incubated at 22 ℃, 20 ℃ and 18 ℃ for up to 28 days. Body samples and mosquito saliva samples were collected and analysed using a quantitative real-time reverse transcription PCR to determine infection and transmission potential, respectively.</p><p><strong>Results: </strong>USUV RNA was detected in all sample times at all temperatures assessed, with the 22 ℃ showing the greatest proportion of saliva and body positive samples. At this temperature, there was also an eight-fold increase in the relative viral copy number in the mosquito bodies, which was unobserved at other experimental temperatures. When a more sensitive PCR assay was used at the lowest experimental temperature used (18 ℃), USUV RNA was present in the mosquito saliva and body samples for longer and showed a greater proportion of positive samples compared to 20 ℃.</p><p><strong>Conclusions: </strong>This study has demonstrated that Cx. pipiens molestus may be able to transmit USUV at 22 ℃. Active replication of USUV was identified in the mosquito bodies at 22 ℃ but not at lower temperatures, suggesting that 20 ℃ to 22 ℃ may be an important threshold in USUV replication and transmission. Utilisation of a more sensitive assay for the lower experimental temperatures revealed that USUV was detectable at 18 ℃. Therefore, when conducting infection studies on temperate mosquito-borne viruses, it is important to consider assay sensitivity.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"310"},"PeriodicalIF":3.5,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12309054/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144743967","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":"Protein phosphorylation networks in Baylisascaris procyonis revealed by phosphoproteomic analysis.","authors":"Qin Meng, Zhikang Li, Qiguan Qiu, Shuyu Chen, Haiyan Gong, Xiaoruo Tan, Xiaoheng Liu, Zhaoguo Chen, Wei Liu","doi":"10.1186/s13071-025-06949-y","DOIUrl":"10.1186/s13071-025-06949-y","url":null,"abstract":"<p><strong>Background: </strong>Baylisascaris procyonis is an intestinal ascarid worm that parasitizes in raccoons and causes fatal neural, visceral, and ocular larva migrans in humans. Phosphorylated proteins and protein kinases have been studied as vaccine and drug target candidates against parasitic infections. However, no data are available on protein phosphorylation in the raccoon roundworm.</p><p><strong>Methods: </strong>In this study, the entire proteome of adult B. procyonis was enzymatically digested. Then, phosphopeptides were enriched using immobilized metal affinity chromatography (IMAC) and analyzed by liquid chromatography-mass spectrometry (LC-MS/MS).</p><p><strong>Results: </strong>Our phosphoproteome analysis displayed 854 unique phosphorylation sites mapped to 450 proteins in B. procyonis (3308 phosphopeptides total). The annotated phosphoproteins were associated with various biological processes, including cytoskeletal remodeling, supramolecular complex assembly, and developmental regulation. The phosphopeptide functional enrichment revealed that B. procyonis phosphoproteins were mostly involved in the cytoskeleton cellular compartment, protein binding molecular function, and multiple biological processes, including regulating supramolecular fiber and cytoskeleton organization and assembling cellular protein-containing complexes and organelles. The significantly enriched pathways of phosphoproteins included the insulin signaling pathway, tight junction, endocytosis, longevity-regulating, glycolysis/gluconeogenesis, and apelin signaling pathways. Domain analysis revealed that the Src homology 3 domain was significantly enriched.</p><p><strong>Conclusions: </strong>This study presents the first phosphoproteomic landscape of B. procyonis, elucidating phosphorylation-mediated regulation of cytoskeletal dynamics, host interaction pathways, and metabolic adaptations. The identified 450 phosphoproteins and enriched functional domains establish a foundation for targeting conserved mechanisms critical to B. procyonis survival.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"307"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12305901/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144732598","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":"First record of mermithid parasitism in adult biting midges, Culicoides huffi (Diptera: Ceratopogonidae), collected from Southern Thailand, with ultrastructural and molecular characterization.","authors":"Chulaluk Promrangsee, Vivornpun Sanprasert, Arunrat Thepparat, Sakone Sunantaraporn, Rinnara Ampol, Rungfar Boonserm, Padet Siriyasatien, Kanok Preativatanyou","doi":"10.1186/s13071-025-06958-x","DOIUrl":"10.1186/s13071-025-06958-x","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Culicoides biting midges are known vectors of several pathogens, including arboviruses, protozoa, and filarial worms. Additionally, mermithid nematodes have been found to parasitize Culicoides midges, causing pathogenic effects that reduce host fitness and often lead to death. Consequently, mermithids have potential as biocontrol agents to reduce midge populations. However, the biology of these entomopathogenic nematodes infecting Culicoides in Thailand remains unknown.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;As part of the leishmaniasis surveillance program in Nakhon Si Thammarat Province, Southern Thailand, we collected Culicoides midges near the residence of a leishmaniasis patient in November 2024. The Culicoides samples were morphologically identified and examined microscopically for parasitic nematodes. Infected midges were dissected to isolate nematodes from each individual. The nematodes were then characterized morphologically using scanning electron microscopy (SEM) and identified molecularly via polymerase chain reaction (PCR) targeting the non-filarial hypervariable region I of the small subunit ribosomal RNA gene (SSU HVR-I) and mermithid small subunit ribosomal RNA (SSU rRNA) gene, followed by nanopore sequencing, phylogenetic analysis, and species delimitation testing.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;A total of 263 field-caught adult Culicoides midges were collected, with Culicoides huffi of the Calvipalpis group being the most abundant species (n = 155, 58.9%). Among these, 35 C. huffi samples, including 4 males, 11 females, and 20 intersex males, were infected with nematodes, resulting in an overall infection rate of 13.3%. The parasitized intersex males, presumably genetically male, exhibited a high degree of feminization in their antennae and wings, which likely enhances female-like behaviors such as detecting and flying toward breeding sites, possibly facilitating parasite transmission and reproductive success. The SEM analysis revealed key morphological features consistent with parasitic nematode larvae of the Mermithidae family, including a long, slender body, a stylet, cephalic papillae, amphids, and a trophosome. Basic Local Alignment Search Tool for nucleotide (BLASTn) analysis of non-filarial SSU HVR-I and mermithid-specific SSU rRNA gene sequences identified all nematodes as mermithids, showing 94.2-94.4% similarity to Pheromermis sp. from the hornet and 97.3% similarity to Mermis sp. from Culicoides obsoletus. Phylogenetic analysis and species delimitation suggest that these sequences represent a single putative species distinct from other known mermithids.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;This study is the first to report mermithid parasitism in Culicoides midges in Thailand, incorporating both ultrastructural and molecular characterization. The novel morphological and molecular insights provided here contribute to a more comprehensive understanding of the biology of entomopathogenic nematode","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"303"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12302758/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144732651","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":"A comparison of manual and carbon dioxide trap sampling of Ornithodoros soft ticks from warthog resting sites in South Africa.","authors":"Cynthia Mapendere, Armanda D S Bastos, Etter Eric, Livio Heath, Ferran Jori","doi":"10.1186/s13071-025-06896-8","DOIUrl":"10.1186/s13071-025-06896-8","url":null,"abstract":"<p><strong>Background: </strong>In East and Southern Africa, the African swine fever (ASF) virus is maintained in an ancient sylvatic cycle involving warthogs (Phacochoerus spp.) and Ornithodoros soft ticks inhabiting warthog burrows. Although carbon dioxide (CO₂) traps have previously been used to collect ticks from pigsties in Portugal, this method has never been tested in the context of the ASF sylvatic cycle in Africa. As warthogs adapt their resting site preferences in response to different levels of habitat transformation, our study aimed to evaluate the effectiveness of CO₂ traps versus traditional manual collection of soft ticks inhabiting two warthog resting sites: warthog burrows (natural) and house decks (anthropogenic).</p><p><strong>Methods: </strong>The study was performed in Mjejane Game Reserve, a wildlife conservancy adjacent to the Kruger National Park in South Africa. Sixty-one warthog resting sites (31 natural burrows and 30 house decks) were sampled to compare Ornithodoros tick numbers using manual and CO₂ trap methods during wet (summer) and dry (winter) seasons.</p><p><strong>Results: </strong>The number of ticks collected with CO₂ traps (n = 2024) was significantly higher than those collected with the manual method (n = 885, P < 0.001) for both resting site types. Moreover, the number of ticks collected using CO₂ traps from house decks (n = 1399) was significantly higher (P < 0.001) compared to burrows (n = 625). There were no differences in the number of ticks collected between seasons. Our results suggest that CO₂ traps are highly efficient for collecting Ornithodoros ticks from the two warthog resting site types evaluated in our study area. They also confirm that warthogs can adapt to different levels of habitat transformation and human presence.</p><p><strong>Conclusions: </strong>The standardised use of the CO₂ trap method facilitates investigations on the distribution of tick-related ASF cycles in sub-Saharan Africa and improves our understanding of the eco-epidemiology of ASF and other Ornithodoros tick-borne diseases.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"306"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12305943/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144732649","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":"Incriminating vectors of deer malaria (Plasmodium odocoilei) at a Florida deer farm.","authors":"Morgan Rockwell, Samantha M Wisely, Derrick K Mathias, Nathan D Burkett-Cadena","doi":"10.1186/s13071-025-06942-5","DOIUrl":"10.1186/s13071-025-06942-5","url":null,"abstract":"<p><strong>Background: </strong>Plasmodium odocoilei, the only nonhuman Plasmodium parasite of native mammals in North America, infects white-tailed deer (WTD) throughout the eastern USA. Although deer malaria is not a significant cause of disease in healthy deer, infection with P. odocoilei may increase susceptibility to infection with and mortality due to epizootic hemorrhagic disease virus in deer fawns. The incrimination of the vector(s) of deer malaria is an essential step in developing management plans for reducing the incidence of deer malaria.</p><p><strong>Methods: </strong>At a deer farm in Gadsden County, FL, with previously documented evidence of deer malaria transmission, mosquitoes were collected using carbon-dioxide-baited light traps, aspirators, and resting shelters. White-tailed deer host use and P. odocoilei infection rates were quantified in potential vector mosquito samples using polymerase chain reaction and Sanger sequencing.</p><p><strong>Results: </strong>Diverse mosquito species (n = 38) were active at the deer farm. Four mosquito species or species complexes specialized in feeding on WTD were observed, taking at least 75% of blood meals from this one host species: Anopheles quadrimaculatus s.l. (88.9%), Anopheles punctipennis (83.3%), Anopheles crucians s.l. (81.4%), and Culex erraticus (87.7%). The highest infection rate of P. odocoilei was found in An. quadrimaculatus s.l. (4.1%), followed by An. punctipennis (3.1%), and An. crucians s.l. (0.47%). No other mosquito species were found to be infected with P. odocoilei.</p><p><strong>Conclusions: </strong>Anopheles quadrimaculatus s.l., An. punctipennis, and An. crucians s.l. met three of the criteria for vector incrimination. These species were present in areas inhabited by WTD, specialized in feeding on WTD, and were naturally infected with P. odocoilei. Anopheles quadrimaculatus s.l. and Anopheles punctipennis are the most likely natural vectors of deer malaria in Florida, as indicated by their high percentages of WTD blood meals (> 83%) and relatively high infection rates (> 3%). To fully incriminate the vector(s) for P. odocoilei, laboratory vector competence studies are needed to determine their ability to biologically transmit the parasites.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"308"},"PeriodicalIF":3.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12305987/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144732653","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}