Parasites & Vectors最新文献

{"title":"Analysis of the 24-h biting patterns and human exposures to malaria vectors in south-eastern Tanzania.","authors":"Muwonge C Mukisa, Jibsam J Kassano, Yohana A Mwalugelo, Charles Ntege, Najat F Kahamba, Marceline F Finda, Betwel J Msugupakulya, Halfan S Ngowo, Fredros O Okumu","doi":"10.1186/s13071-024-06521-0","DOIUrl":"10.1186/s13071-024-06521-0","url":null,"abstract":"<p><strong>Background: </strong>Afrotropical malaria vectors are generally believed to bite nocturnally, leading to the predominant use of insecticide-treated nets (ITNs), which target indoor, nighttime-biting mosquitoes. This focus is reinforced by biases in entomological surveys, which largely overlook daytime mosquito activity. However, recent evidence challenges this paradigm, showing that Anopheles biting can extend way into the daytime, coinciding with human activities at dawn, daytime and evenings, suggesting a broader risk spectrum and potential protection gaps. We have therefore investigated the diurnal and nocturnal biting patterns of the malaria vectors Anopheles arabiensis and Anopheles funestus in south-eastern Tanzania, to better understand the scope of residual transmission and inform strategies for improved control.</p><p><strong>Methods: </strong>Host-seeking mosquitoes were collected hourly using miniaturized double net traps, both indoors and outdoors over 24-h periods between June 2023 and February 2024. Concurrently, human activities indoors and outdoors were monitored half-hourly to correlate with mosquito collections. A structured questionnaire was used to assess household members' knowledge, perceptions and experiences regarding exposure to mosquito bites during both nighttime and daytime.</p><p><strong>Results: </strong>Nocturnal biting by An. arabiensis peaked between 7 p.m. and 11 p.m. while that of An. funestus peaked later, between 1 a.m. and 3 a.m. Daytime biting accounted for 15.03% of An. arabiensis catches, with peaks around 7-11 a.m. and after 4 p.m., and for 14.15% of An. funestus catches, peaking around mid-mornings, from 10 a.m. to 12 p.m. Nighttime exposure to An. arabiensis was greater outdoors (54.5%), while daytime exposure was greater indoors (80.4%). For An. funestus, higher exposure was observed indoors, both at nighttime (57.1%) and daytime (69%). Plasmodium falciparum sporozoites were detected in both day-biting and night-biting An. arabiensis. Common daytime activities potentially exposing residents during peak biting hours included household chores, eating, sleeping (including due to sickness), resting in the shade or under verandas and playing (children). From evenings onwards, exposures coincided with resting, socializing before bedtime and playtime (children). Nearly all survey respondents (95.6%) reported experiencing daytime mosquito bites, but only 28% believed malaria was transmissible diurnally.</p><p><strong>Conclusions: </strong>This study updates our understanding of malaria vector biting patterns in south-eastern Tanzania, revealing considerable additional risk in the mornings, daytime and evenings. Consequently, there may be more gaps in the protection provided by ITNs, which primarily target nocturnal mosquitoes, than previously thought. Complementary strategies are needed to holistically suppress vectors regardless of biting patterns (e.g. using larval source management) and to extend","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"445"},"PeriodicalIF":3.0,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11526538/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546711","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":"Correction: A case of mistaken identity: a systematic review, meta-analysis, and reinvestigation of hemotropic Mycoplasma spp. infection in Ctenocephalides felis (cat flea).","authors":"Charlotte O Moore, Erin Lashnits, Michael Lappin, Jennifer Hawley, Edward B Breitschwerdt","doi":"10.1186/s13071-024-06536-7","DOIUrl":"10.1186/s13071-024-06536-7","url":null,"abstract":"","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"444"},"PeriodicalIF":3.0,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11526609/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546713","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":"Bartonella infections are rare in blood-fed Ixodes scapularis and Ixodes pacificus ticks collected from rodents in the United States.","authors":"Ying Bai, Lynn M Osikowicz, Jacoby Clark, Erik Foster, Christina Parise, Sarah Maes, Rebecca J Eisen","doi":"10.1186/s13071-024-06541-w","DOIUrl":"10.1186/s13071-024-06541-w","url":null,"abstract":"<p><strong>Background: </strong>Ixodes scapularis and Ixodes pacificus are important vectors of multiple pathogens in the United States. However, their role in transmission of Bartonella spp., which are commonly reported in rodents and fleas, has been debated. Our previous investigation on Bartonella spp. in host-seeking I. scapularis and I. pacificus showed Bartonella spp. were absent in the ticks, suggesting the two species are unlikely to contribute to Bartonella transmission. It is unclear whether the absence of Bartonella spp. in the host-seeking ticks was attributable to ticks not being exposed to Bartonella in nature or being exposed but unable to acquire or transstadially transmit the bacterium. To assess the likelihood of exposure and acquisition, we tested Ixodes spp. ticks collected from rodents for Bartonella infections.</p><p><strong>Methods: </strong>Blood-fed I. scapularis ticks (n = 792; consisting of 645 larvae and 147 nymphs), I. pacificus ticks (n = 45, all larvae), and Ixodes angustus ticks (n = 16, consisting of 11 larvae and 5 nymphs) collected from rodents from Minnesota and Washington were tested for Bartonella spp. using a quadruplex polymerase chain reaction (PCR) amplicon next-generation sequencing approach that targets Bartonella-specific fragments on gltA, ssrA, rpoB, and groEL. In parallel, rodents and fleas collected from the same field studies were investigated to compare the differences of Bartonella distribution among the ticks, fleas, and rodents.</p><p><strong>Results: </strong>Bartonella spp. were commonly detected in rodents and fleas, with prevalence of 25.6% in rodents and 36.8% in fleas from Minnesota; 27.9% in rodents and 45.2% in fleas from Washington. Of all tested ticks, Bartonella DNA was detected by gltA in only one larval I. scapularis tick from Minnesota.</p><p><strong>Conclusions: </strong>The high prevalence of Bartonella spp. in rodents and fleas coupled with extremely low prevalence of Bartonella spp. in blood-fed ticks suggests that although Ixodes ticks commonly encounter Bartonella in rodents, they rarely acquire the infection through blood feeding. Notably, ticks were at various stages of feeding on rodents when they were collected. Laboratory transmission studies are needed to assess acquisition rates in fully blood-fed ticks and to assess transstadial transmission efficiency if ticks acquire Bartonella infections from feeding to repletion.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"442"},"PeriodicalIF":3.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520693/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546712","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":"Survey of sand fly fauna in six provinces of Southern Vietnam with species identification using DNA barcoding.","authors":"Trang Thuy Nguyen, Yudhi Ratna Nugraheni, Hoang Lan Anh Nguyen, Apinya Arnuphapprasert, Theerakamol Pengsakul, Le Quang Thong, Rinnara Ampol, Padet Siriyasatien, Morakot Kaewthamasorn","doi":"10.1186/s13071-024-06509-w","DOIUrl":"10.1186/s13071-024-06509-w","url":null,"abstract":"<p><strong>Background: </strong>Sand flies, belonging to the Psychodidae family, represent small, hairy insects that serve as significant vectors in various important medical and veterinary diseases. Despite being recognized by the World Health Organization as an endemic area for leishmaniasis, Southeast Asia lacks comprehensive information on the species composition and biology of sand flies. To address this, the current study aimed to survey sand fly biodiversity.</p><p><strong>Methods: </strong>Sand flies from six provinces in Southern Vietnam were collected using CDC light traps. Sand flies were subsequently identified morphologically and confirmed molecularly using mitochondrial cytochrome oxidase c subunit I (COI) and cytochrome b (cytb) sequences. BLASTN searches were conducted, and the species identity of sand flies was further confirmed through a Barcode of Life Database (BOLD) search utilizing COI sequences. Subsequently, nucleotide sequences were subjected to a panel of analyses including intraspecific variation, phylogenetic relationships and haplotype network. The average densities of collected sand flies (sand flies/trap/night) and species richness were also recorded.</p><p><strong>Results: </strong>A total of 753 sand flies were collected. After excluding damaged specimens, six sand fly species, namely Phlebotomus stantoni, Sergentomyia khawi, Se. silvatica, Se. barraudi, Se. bailyi and Grassomyia indica, were identified. All conspecific sand fly sequences, including Ph. stantoni, Se. barraudi, Gr. indica, Se. bailyi, Se. khawi and Se. silvatica, clustered with their reference sequences, corroborating the results of morphology-based identification, BLASTN analysis and BOLD search. For intraspecific variation of sand flies obtained from the current study, COI diversity indices were consistently higher than those of cytb.</p><p><strong>Conclusions: </strong>This study provides the first updates on morphological and molecular characterization of sand flies in Southern Vietnam. This acquired knowledge on sand fly species composition is essential for controlling sand fly-borne diseases in this potentially endemic region.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"443"},"PeriodicalIF":3.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11523761/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546715","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 report of Angiostrongylus vasorum in an African golden wolf (Canis lupaster) in Algeria.","authors":"Noureddine Mechouck, Georgiana Deak, Angela Monica Ionică, Corina Toma, Andrada Gabriela Negoescu, Marian Taulescu, Zihad Bouslama, Andrei Daniel Mihalca","doi":"10.1186/s13071-024-06534-9","DOIUrl":"10.1186/s13071-024-06534-9","url":null,"abstract":"<p><strong>Background: </strong>Angiostrongylus vasorum, commonly known as the \"French heartworm,\" is a nematode belonging to the Metastrongyloidea superfamily. This parasite was first identified in Toulouse, France in 1853 infecting the pulmonary arteries and the right side of the heart of a Pointer dog. Angiostrongylosis is an important infection due its severe clinical signs and potential for causing high morbidity and mortality in domestic dogs. This nematode has not been studied in Algeria. The aim of this study was investigate the presence of lungworms among different mammal species in a number of Algerian regions.</p><p><strong>Methods: </strong>Between February 2022 and September 2023, 47 road-killed animals were collected from six administrative units (departments) in Algeria. All carcasses underwent a full parasitological necropsy, and lung tissues were preserved in 10% buffered formalin and concentrated ethanol for further study. All collected samples were subjected to histological and PCR (cytochrome c oxidase subunit 1 gene) analyses for lungworm identification.</p><p><strong>Results: </strong>Histological examination revealed the presence of nematode eggs and larvae in the alveolar space and chronic obstructive vascular changes were detected in a single golden African wolf (Canis lupaster) collected from the department of Constantine. First-stage larvae were collected and morphologically identified as Angiostrongylus spp. The molecular identification confirmed the presence of A. vasorum. All other animals tested were negative for lungworms.</p><p><strong>Conclusions: </strong>To the best of our knowledge, this is the first report of A. vasorum infection in an African golden wolf (Canis lupaster). We report a new host association, highlighting the importance of further studies to update the geographical distribution of A. vasorum and its epidemiology across Algeria.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"441"},"PeriodicalIF":3.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520683/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142522638","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":"From host individual traits to community structure and composition: Bartonella infection insights.","authors":"Gabriella Lima Tabet Cruz, Jonathan Gonçalves-Oliveira, Elba Regina Sampaio de Lemos, Paulo Sergio D'Andrea, Cecilia Siliansky de Andreazzi","doi":"10.1186/s13071-024-06523-y","DOIUrl":"10.1186/s13071-024-06523-y","url":null,"abstract":"<p><strong>Background: </strong>Phylogeny, combined with trait-based measures, offers insights into parasite sharing among hosts. However, the specific traits that mediate transmission and the aspects of host community diversity that most effectively explain parasite infection rates remain unclear, even for the Bartonella genus, a vector-borne bacteria that causes persistent blood infections in vertebrates.</p><p><strong>Methods: </strong>This study investigated the association between rodent host traits and Bartonella infection, as well as how rodent community diversity affects the odds of infection in the Atlantic Forest, using generalized linear models. Additionally, we assessed how host traits and phylogenetic similarities influence Bartonella infection among mammal species in Brazil. To this end, rodents were sampled from ten municipalities in Rio de Janeiro, southeastern Brazil. Then, we calculated several diversity indices for each community, including Rényi's diversity profiles, Fisher's alpha, Rao's quadratic entropy (RaoQ), Functional Diversity (FDis), Functional Richness (FRic), and Functional Evenness (FEve). Finally, we compiled a network encompassing all known interactions between mammal species and Bartonella lineages recorded in Brazil.</p><p><strong>Results: </strong>We found no significant relationship between diversity indices and the odds of Bartonella infection in rodent communities. Furthermore, there was no statistical support for the influence of individual-level traits (e.g., body length, sex, and age) or species-level ecological traits (e.g., locomotor habitat, dietary guild, and activity period) on Bartonella infection in rodents. A country-scale analysis, considering all mammal species, revealed no effect of host traits or phylogeny on Bartonella infection.</p><p><strong>Conclusions: </strong>This study highlighted wild mammals that share Bartonella lineages with livestock, synanthropic, and domestic animals, underscoring the complexity of their maintenance cycle within the One Health framework. A key question arising from our findings is whether molecular host-cell interactions outweigh host body mass and ecological traits in influencing Bartonella infection, potentially opening new avenues for understanding host-parasite relationships and infection ecology.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"440"},"PeriodicalIF":3.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514747/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142522639","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 single treatment with a fluralaner injectable suspension (Bravecto^® injectable) provides 1-year efficacy against Rhipicephalus sanguineus sensu lato and Ctenocephalides felis in dogs.","authors":"Marie-Kristin Raulf, Katharina Raue, Anna Schwarz, Ivo Petersen, Eva Zschiesche, Lea Heinau, Christina Strube","doi":"10.1186/s13071-024-06535-8","DOIUrl":"10.1186/s13071-024-06535-8","url":null,"abstract":"<p><strong>Background: </strong>Rhipicephalus sanguineus sensu lato (s.l.) and Ctenocephalides felis are among the most important year-round ectoparasites of dogs. The persistent efficacy of one treatment with fluralaner injectable suspension (Bravecto^® 150 mg/ml powder and solvent for suspension for dogs, referred to as Bravecto^® injectable) was investigated in a negative-controlled, randomised, partially blinded 12-month laboratory study.</p><p><strong>Methods: </strong>A total of 20 dogs were randomly allocated to two equal groups (treatment and control). Treatment-group dogs were injected subcutaneously on study day 0 with the investigational veterinary product at the recommended dose of 15 mg fluralaner/kg body weight (0.1 mL/kg), whereas the control group dogs received saline solution (0.1 mL/kg). Each dog was infested with 50 (25 female, 25 male) adult R. sanguineus s.l. and 100 adult C. felis 2 days before treatment, 5 and 28 days after treatment, and then once monthly for a 12-month period. Live tick and flea counts were performed 48 h after treatment or subsequent infestation, respectively. Efficacy was determined by comparing arithmetic means of the treatment group tick and flea counts with those of the control group. Infestation was considered adequate if at least 25.0% of ticks and 40.0% of fleas were recovered from at least six dogs in the control group at the respective assessment times.</p><p><strong>Results: </strong>Adequate R. sanguineus s.l. and C. felis infestations of control group dogs were observed at each time point. Arithmetic mean treatment group values were significantly lower than those of the control group at all time points. The immediate efficacy when treating existing infestations of R. sanguineus s.l. and C. felis (infestation 2 days before treatment), was 49.7% and 89.7%, respectively. The persistent efficacy against post-treatment re-infestations was 94.4-100% against R. sanguineus s.l. and 92.2-100% against C. felis. Seven dogs in the control group developed flea allergy dermatitis due to the repeated re-infestations over the study period, whereas no dogs in the treatment group were affected. No clinically relevant side effects were observed over the entire study period.</p><p><strong>Conclusions: </strong>The fluralaner injectable suspension (Bravecto^® injectable) provides 1 year of efficacy against R. sanguineus s.l. and C. felis infestations in dogs following a single treatment, allowing once-yearly treatment, which can significantly improve owner compliance with year-round protection of dogs.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"438"},"PeriodicalIF":3.0,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514862/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142505468","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":"Characterization of NFDQ1 in Cryptosporidium parvum.","authors":"Yangsiqi Ao, Xiaoqing Gong, Jieping Li, Ruiming Zhao, Shujiao Song, Yaqiong Guo, Yaoyu Feng, Lihua Xiao, Rui Xu, Na Li","doi":"10.1186/s13071-024-06532-x","DOIUrl":"10.1186/s13071-024-06532-x","url":null,"abstract":"<p><strong>Background: </strong>Cryptosporidium spp. are important zoonotic parasites that can cause moderate to severe diarrhea in humans and animals. Among the three Cryptosporidium species infecting the intestines of calves, Cryptosporidium parvum has a broad host range and causes severe diarrhea in calves, while Cryptosporidium bovis and Cryptosporidium ryanae mainly infect calves without obvious clinical symptoms. Comparative genomic analysis revealed differences in the copy number of genes encoding the nonfinancial disclosure quality (NFDQ) secretory protein family among the three species, suggesting that this protein family may be associated with the host range or pathogenicity of Cryptosporidium spp. To understand the function of cgd8_10 encoded NFDQ1, tagged and knockout strains were constructed and characterized in this study.</p><p><strong>Methods: </strong>To determine the localization of NFDQ1, we used clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology to tag the C-terminus of NFDQ1 with three hemagglutinin epitopes (3 × HA). The tagged strain was constructed, and the genomic insertion was confirmed by polymerase chain reaction (PCR). Immunofluorescence assays were performed to observe the localization of NFDQ1 both in extracellular sporozoites and at various intracellular developmental stages. Immunoelectron microscopy was used to study the ultrastructural localization of NFDQ1. Then, the ΔNFDQ1 strain was generated by CRISPR/Cas9 and the in vitro growth assay on HCT-8 cells was used to analyze of phenotypic changes after knockout NFDQ1 in parasites.</p><p><strong>Results: </strong>The NFDQ1 tagging and knockout stains were successfully constructed by CRISPR/Cas9 technology and the insertions of transgenic strains were validated by PCR. The expression of NFDQ1 was validated in parasite by western blot. Immunofluorescence and immune-electron microscopy assay showed that NFDQ1 expressed in both asexual and sexual stages of C. parvum, where it was localized to the cytoplasm of the parasite. Upon ablation of NFDQ1, the ΔNFDQ1 strain showed an apparent growth retardation during sexual replication in vitro.</p><p><strong>Conclusions: </strong>NFDQ1 is a cytoplasmic protein without specific localization to secretory organelles, and it may participate in C. parvum growth during sexual reproduction. Future study should determine the role of NFDQ1 following C. parvum infection in vivo.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"439"},"PeriodicalIF":3.0,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142505369","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":"High PD-1 and CTLA-4 expression correlates with host immune suppression in patients and a mouse model infected with Echinococcus multilocularis.","authors":"Ting Sun, Yi Yang, Yiwen Qiu, Tao Wang, Ming Yang, Shu Shen, Wentao Wang","doi":"10.1186/s13071-024-06511-2","DOIUrl":"10.1186/s13071-024-06511-2","url":null,"abstract":"<p><strong>Background: </strong>Alveolar echinococcosis (AE), a fatal disease caused by Echinococcus multilocularis, often affects the liver, with tumor-like growth. However, the mechanism by which E. multilocularis evades host immune surveillance remains unclear.</p><p><strong>Methods: </strong>We collected liver specimens from hepatic alveolar echinococcosis (HAE) patients and established a mouse model of E. multilocularis infection. Immunofluorescence staining and flow cytometry were performed to analyze programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte associated antigen 4 (CTLA-4) expression in human samples, while flow cytometry and quantitative real-time polymerase chain reaction (PCR) were performed for similar analyses in mouse samples. Cell proliferation and protoscolex (PSC) killing assays were designed to explore how E. multilocularis induces host immunosuppression.</p><p><strong>Results: </strong>An inflammatory reaction band with high PD-1 and CTLA-4 expression was found in close liver tissue (CLT). The ratio of regulatory T cells (Tregs) was higher in CLT than in distant liver tissue (DLT), and Tregs in CLT tended to express higher levels of PD-1 and CTLA-4 than those in DLT from HAE patients. Echinococcus multilocularis-infected mice showed significantly elevated expression of PD-1 and CTLA-4 on splenocytes and peritoneal cells. PD-1/PD-L1 or CTLA-4 pathway blockade could relieve the immunosuppressive effects of Tregs from infected mice and enhance PSC killing by mouse splenocytes.</p><p><strong>Conclusions: </strong>E. multilocularis regulated the function of T cells via the PD-1/PD-L1- and CTLA-4-dependent pathways and subsequently evaded host immune attacks. These findings provide insights for investigating the pathogenic mechanism of AE.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"437"},"PeriodicalIF":3.0,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142505372","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":"Comparison of different diagnostic protocols for the detection of Toxocara spp. in faecal samples of cats and dogs.","authors":"Deliah Tamsyn Winterfeld, Birgit Schauer, Majda Globokar, Nikola Pantchev, Susan Mouchantat, Franz Josef Conraths, Helge Kampen, Johanna Dups-Bergmann, Gereon Schares, Pavlo Maksimov","doi":"10.1186/s13071-024-06524-x","DOIUrl":"10.1186/s13071-024-06524-x","url":null,"abstract":"<p><strong>Background: </strong>Toxocara canis and Toxocara cati are parasitic nematodes that occur worldwide. As embryonated Toxocara spp. eggs in the environment pose a zoonotic risk, especially for children, optimal diagnostic approaches are necessary for effective disease response and management, including surveillance. However, little is known about the performance of different diagnostic protocols for detecting Toxocara spp. in the faeces of cats and dogs, hampering movement towards an optimal diagnostic process. This study aimed to compare detection methods, including a newly developed sequential sieving protocol (SF-SSV) and a high-throughput multiplex qPCR-based method to facilitate epidemiological studies.</p><p><strong>Methods: </strong>Species-specific Toxocara spp. egg suspensions and canine and feline faecal samples from the field were used to estimate analytical and diagnostic sensitivity of the protocols. The performance of two automated DNA extraction protocols using enzymatic and mechanical lysis were compared by multiplex qPCR, targeting both T. canis and T. cati-specific genomic sequences. All samples were examined by microscopy-based techniques, the sedimentation flotation technique (SF) and a newly developed SF-SSV for the detection, enrichment and purification of parasite eggs. The costs and processing times necessary for all protocols were estimated and compared for both single samples and sets of 100 samples.</p><p><strong>Results: </strong>To detect Toxocara spp. eggs, SF-SSV showed the highest analytical sensitivity and a significantly higher diagnostic sensitivity than the DNA detection methods. Mechanical lysis performed better than enzymatic lysis for automated DNA extraction. In automated DNA extraction, 96-well plates performed better than 24-well plates. DNA detection and microscopy-based parasitological methods showed substantial agreement between the results generated by each method. Microscopy-based techniques required the lowest costs and least hands-on time for a single sample. However, when costs and labour were estimated for a set of 100 samples, the DNA detection protocol using 96-well plates for extraction revealed costs similar to SF-SSV and the fastest processing times.</p><p><strong>Conclusions: </strong>SF-SSV was superior in terms of analytical and diagnostic sensitivity for the detection of Toxocara spp. eggs. For larger sets of samples, multiplex qPCR-based DNA detection represents an alternative to microscopy-based methods, based on the possibility of faster sample processing at similar costs to SF-SSV, and the ability to provide species-specific diagnoses.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"17 1","pages":"436"},"PeriodicalIF":3.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515329/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142505371","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}