Frontiers in parasitology最新文献

{"title":"Hidden in plain sight: How helminths manage to thrive in host blood","authors":"Maude Dagenais, Lucienne Tritten","doi":"10.3389/fpara.2023.1128299","DOIUrl":"https://doi.org/10.3389/fpara.2023.1128299","url":null,"abstract":"Parasitic helminths have evolved a plethora of elegant stratagems to regulate and evade the host immune system, contributing to their considerable persistence and longevity in their vertebrate hosts. Various mechanisms to achieve this state have been described, ranging from interfering with or actively modulating host immune responses to hiding from immune recognition. Because they damage surrounding vessels and disturb blood flow, blood-borne and blood-feeding parasites in particular must deal with much more than immune effector cells. Management of the host complement system and coagulation cascade, as well as the development of processes of hiding and masking, represent hallmarks of life in blood. Here we review recent findings on putative evasion strategies employed by blood-borne parasitic helminths, focusing on the interaction with and utilisation of host serum components by nematodes and trematodes.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42040701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of Gabonese gorillas and their pathogens: Diversity, transfer and One Health approach to avoid future outbreaks?","authors":"Larson Boundenga, Patrice Makouloutou-Nzassi, B. Ngoubangoye","doi":"10.3389/fpara.2023.1115316","DOIUrl":"https://doi.org/10.3389/fpara.2023.1115316","url":null,"abstract":"In Africa, great apes, among which gorillas, are the reservoir of several infectious agents, some of which have zoonotic potential. However, scientific reports summarizing data on the pathogens harbored by some primate species still need to be published for the scientific community, conservation, and public health actors. In the case of Gabon, despite its outstanding biodiversity, particularly in great apes, and the history of outbreaks involving wildlife, there is a lack of reports on pathogens found in some ape species living in the vicinity of the human being. Thus, it is becoming urgent for us to synthesize the available data on pathogens (parasites, bacteria, and viruses) identified in gorillas living in different ecosystems of Gabon to assess the risks for the human population. Therefore, this review article presents the diversity of pathogens identified in gorillas in Gabon, their impact on primates’ health, the cases of transfer between gorillas and humans, and the interest in a One Health approach for prevention and a better understanding of the ecology of gorilla’s diseases infection in Gabon.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46800716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The luminal domain of Toxoplasma gondii sortilin adopts a ring-shaped structure exhibiting motifs specific to apicomplexan parasites","authors":"Ariane Honfozo, Rania Ghouil, T. Alayi, M. Ouldali, A. Arteni, Cynthia Menonve Atindehou, Lucie Ayi Fanou, Y. Hathout, S. Zinn-Justin, S. Tomavo","doi":"10.3389/fpara.2023.1103772","DOIUrl":"https://doi.org/10.3389/fpara.2023.1103772","url":null,"abstract":"Rhoptries and micronemes are essential for host cell invasion and survival of all apicomplexan parasites, which are composed of numerous obligate intracellular protozoan pathogens including Plasmodium falciparum (malaria) and Toxoplasma gondii (toxoplasmosis) that infect humans and animals causing severe diseases. We identified Toxoplasma gondii TgSORT as an essential cargo receptor, which drives the transport of rhoptry (ROP) and microneme (MIC) proteins to ensure the biogenesis of these secretory organelles. The luminal domain of 752 amino acid long situated at the N-terminus end of TgSORT has been described to bind to MIC and ROP proteins. Here, we present an optimized protocol for expression of the entire luminal N-terminus of TgSORT (Tg-NSORT) in the yeast Pichia pastoris. Optimization of its coding sequence, cloning and transformation of the yeast P. pastoris allowed the secretion of Tg-NSORT. The protein was purified and further analyzed by negative staining electron microscopy. In addition, molecular modeling using AlphaFold identified key differences between the human and the T gondii sortilin. The structural features that are only present in T. gondii and other apicomplexan parasites were highlighted. Elucidating the roles of these specific structural features may be useful for designing new therapeutic agents against apicomplexan parasites","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43641299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serology reveals micro-differences in Plasmodium falciparum transmission in the Hohoe municipality of Ghana","authors":"Eric Kyei-Baafour, K. Kusi, Mavis Oppong, A. Frempong, Belinda Aculley, E. Ofori, M. Theisen, M. Kweku, B. Adu, L. Hviid, M. Ofori","doi":"10.3389/fpara.2023.1081083","DOIUrl":"https://doi.org/10.3389/fpara.2023.1081083","url":null,"abstract":"Background With the decline in malaria transmission due to global efforts, a more sensitive tool is needed to monitor transmission intensity and pattern at the micro-level. Though transmission in a broader area may be similar, factors such as sanitation, practices of open water storage, early morning and evening activities, outdoor sleeping and agricultural practices within communities could cause differences in exposure and thus transmission. This study thus probed malaria transmission at a micro-level using serology in the Hohoe Municipality of Ghana. Methods This cross-sectional study involved 327 asymptomatic children aged 1-12 years in both rural (196) and urban (131) communities in the Hohoe municipality. Total IgG responses specific for three P. falciparum antigens (CSP, MSP2-FC27, MSP2-3D7) were determined in plasma eluted from dried blood spots using indirect ELISA. Results A higher proportion of individuals in the rural area had parasites by both microscopy and PCR. Total IgG levels and seroprevalence were higher in rural compared to urban communities (p<0.05). In a multiple regression model, adjusting for confounders, levels of PfMSP2-3D7-specific IgG was associated with the higher transmission which occurs in the rural community. Conclusion The results suggest that though the district is categorized as having medium malaria transmission, differences within settlements may influence malaria transmission reflecting in antibody levels and prevalence of malaria antigen-specific IgG.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49290019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunomodulators secreted from parasitic helminths act on pattern recognition receptors","authors":"Daigo Tsubokawa","doi":"10.3389/fpara.2022.1091596","DOIUrl":"https://doi.org/10.3389/fpara.2022.1091596","url":null,"abstract":"Excretory-secretory (ES) products from parasitic helminths contain immunomodulatory molecules, which can regulate host immune responses. These immunomodulatory molecules are crucial for successful parasitism, and play roles in tissue migration, maturation, and reproduction. Some target pattern recognition receptors (PRRs), including toll-like receptor, C-type lectin receptor, receptor for advanced glycation end products, and nucleotide-binding oligomerization domain-like receptor. PRRs trigger activation of signaling cascades, inducing innate inflammatory responses and adaptive immunity in hosts. This article reviews ES immunomodulators identified in parasitic helminths that act on PRRs, and their PRR-facilitated immune-regulatory mechanisms. In addition, we describe the therapeutic potential of ES immunomodulators for allergic and inflammatory diseases.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47874269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early immune and host cell responses to <i>Cryptosporidium</i> infection.","authors":"Jan R Mead","doi":"10.3389/fpara.2023.1113950","DOIUrl":"https://doi.org/10.3389/fpara.2023.1113950","url":null,"abstract":"<p><p><i>Cryptosporidium</i> spp. are opportunistic protozoan parasites that infect epithelial cells of the small intestine and cause diarrheal illness in both immunocompetent and immunodeficient individuals. These infections may be more severe in immunocompromised individuals and young children, especially in children under 2 in developing countries. The parasite has a global distribution and is an important cause of childhood diarrhea where it may result in cognitive impairment and growth deficits. Current therapies are limited with nitazoxanide being the only FDA-approved drug. However, it is not efficacious in immunocompromised patients. Additionally, there are no vaccines for cryptosporidiosis available. While acquired immunity is needed to clear <i>Cryptosporidium</i> parasites completely, innate immunity and early responses to infection are important in keeping the infection in check so that adaptive responses have time to develop. Infection is localized to the epithelial cells of the gut. Therefore, host cell defenses are important in the early response to infection and may be triggered through toll receptors or inflammasomes which induce a number of signal pathways, interferons, cytokines, and other immune mediators. Chemokines and chemokine receptors are upregulated which recruit immune cells such neutrophils, NK cells, and macrophages to the infection site to help in host cell defense as well as dendritic cells that are an important bridge between innate and adaptive responses. This review will focus on the host cell responses and the immune responses that are important in the early stages of infection.</p>","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10269812/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9671941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of molecular surveillance methods to assess changes in the population genetics of <i>Plasmodium falciparum</i> in high transmission.","authors":"Anita Ghansah, Kathryn E Tiedje, Dionne C Argyropoulos, Christiana O Onwona, Samantha L Deed, Frédéric Labbé, Abraham R Oduro, Kwadwo A Koram, Mercedes Pascual, Karen P Day","doi":"10.3389/fpara.2023.1067966","DOIUrl":"10.3389/fpara.2023.1067966","url":null,"abstract":"<p><p>A major motivation for developing molecular methods for malaria surveillance is to measure the impact of control interventions on the population genetics of <i>Plasmodium falciparum</i> as a potential marker of progress towards elimination. Here we assess three established methods (i) single nucleotide polymorphism (SNP) barcoding (panel of 24-biallelic loci), (ii) microsatellite genotyping (panel of 12-multiallelic loci), and (iii) <i>var</i>coding (fingerprinting <i>var</i> gene diversity, akin to microhaplotyping) to identify changes in parasite population genetics in response to a short-term indoor residual spraying (IRS) intervention. Typical of high seasonal transmission in Africa, multiclonal infections were found in 82.3% (median 3; range 1-18) and 57.8% (median 2; range 1-12) of asymptomatic individuals pre- and post-IRS, respectively, in Bongo District, Ghana. Since directly phasing multilocus haplotypes for population genetic analysis is not possible for biallelic SNPs and microsatellites, we chose ~200 low-complexity infections biased to single and double clone infections for analysis. Each genotyping method presented a different pattern of change in diversity and population structure as a consequence of variability in usable data and the relative polymorphism of the molecular markers (i.e., SNPs < microsatellites < <i>var</i>). <i>Var</i>coding and microsatellite genotyping showed the overall failure of the IRS intervention to significantly change the population structure from pre-IRS characteristics (i.e., many diverse genomes of low genetic similarity). The 24-SNP barcode provided limited information for analysis, largely due to the biallelic nature of SNPs leading to a high proportion of double-allele calls and a view of more isolate relatedness compared to microsatellites and <i>var</i>coding. Relative performance, suitability, and cost-effectiveness of the methods relevant to sample size and local malaria elimination in high-transmission endemic areas are discussed.</p>","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10686283/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47093572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulatory void for vaccines targeting eukaryotic parasites of farmed and domestic animals and fish","authors":"P. Holdsworth, M. Fisher","doi":"10.3389/fpara.2022.1073801","DOIUrl":"https://doi.org/10.3389/fpara.2022.1073801","url":null,"abstract":"COPYRIGHT © 2022 Holdsworth and Fisher. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Opinion PUBLISHED 05 December 2022 DOI 10.3389/fpara.2022.1073801","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42048089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using qPCR to compare the detection of Plasmodium vivax oocysts and sporozoites in Anopheles farauti mosquitoes between two DNA extraction methods","authors":"L. Timinao, E. W. Jamea, M. Katusele, T. Burkot, S. Karl","doi":"10.3389/fpara.2023.1063452","DOIUrl":"https://doi.org/10.3389/fpara.2023.1063452","url":null,"abstract":"Background Currently, the gold standard to assess parasite developmental stages in mosquitoes is light microscopy. Microscopy can miss low-density infections, is time-consuming and not species-specific. Enzyme-linked immunosorbent assay (ELISA) has been the alternative technique to evaluate the infectivity of mosquitoes especially in field studies however it is semi-quantitative. Molecular techniques that have been used to detect the mosquito stages of malaria parasites including P. vivax. Here, we present a quantitative real-time assay (qPCR) that can be used to detect low-density P. vivax oocyst and sporozoite infections while comparing parasites extracted by the conventional DNA extraction and heating methods. Methods Colony reared Anopheles farauti mosquitoes were exposed to blood samples collected from infected individuals using a direct membrane feeding assay. The fully fed mosquitoes were kept for 7 and 14 days post-feed before dissection to confirm presence of oocysts and sporozoites. Infected mosquito guts and the salivary glands (with the head and thorax) were stored and DNA was extracted either by heating or by performing conventional column-based DNA extraction. Following DNA extraction the infected samples were subjected to qPCR to detect P. vivax parasites. Results DNA extraction of 1 or more oocysts by heating resulted in an overall sensitivity of 78% (57/73) and single oocysts infections were detected with a sensitivity of 82% (15/17) in the heating arm. We observed a 60% (18/30) sensitivity with sporozoites where DNA was extracted using the conventional DNA extraction method. We show that the heating method significantly improved the detection of oocysts over conventional DNA extraction. There was no significant difference in the DNA copy numbers when comparing the detection of oocysts from the conventional DNA extraction versus heating. However, we observed that the DNA copy numbers of the sporozoites detected in the heating arm was significantly higher than in the conventional DNA extraction arm. Conclusion We have adapted a qPCR assay which, when coupled with heating to release DNA reduces sample processing time and cost. Direct qPCR after heating will be a useful tool when investigating transmission blocking vaccines or antimalarials or when evaluating field caught mosquitoes for the presence of malaria parasites.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46111052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The immunology of parasite infections: Grand challenges","authors":"S. Donnelly","doi":"10.3389/fpara.2022.1069205","DOIUrl":"https://doi.org/10.3389/fpara.2022.1069205","url":null,"abstract":"COPYRIGHT © 2022 Donnelly. This is an openaccess article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Specialty Grand Challenge PUBLISHED 08 November 2022 DOI 10.3389/fpara.2022.1069205","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44550980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}