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1.
J Helminthol ; 97: e14, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36718640

RESUMO

A new species of the genus Metaxonchium is described from a natural habitat in Iran. Metaxonchium magnum sp. n. is characterized by its 3.62-4.65 mm long body, lip region cap-like and offset by constriction and 13-16 µm wide, odontostyle fusiform and 14-17 µm long, neck 1016-1359 µm long, both parts of the pharynx separated by a short isthmus-like narrowing, pharyngeal expansion occupying 74.2 (73-77)% of total neck length in females and 70.4 (66-72)% in males, female genital system mono-opistho-ovarian, didelphic, anterior genital branch a large uterine sac with a small terminal mass occupying 7-14% of body length, posterior uterus long and tripartite with a Z-like differentiation, V = 50-52, caudal region short and rounded (24-41 µm, c = 99-161, c' = 0.5-0.7), spicules 90-105 µm long and 10-13 spaced ventromedian supplements with hiatus. Analysis of D2-D3 28S rDNA sequences of the new species suggests that Metaxonchium might not be a monophyletic taxon, a matter that should be confirmed after future research.


Assuntos
Helmintos , Nematoides , Masculino , Animais , Feminino , Filogenia , Irã (Geográfico) , Helmintos/genética , DNA Ribossômico/genética
2.
Proc Biol Sci ; 290(1991): 20222204, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36651047

RESUMO

Helminth transmission and morbidity are dependent on the number of mature parasites within a host; however, observing adult worms is impossible for many natural infections. An outstanding challenge is therefore relating routine diagnostics, such as faecal egg counts, to the underlying worm burden. This relationship is complicated by density-dependent fecundity (egg output per worm reduces due to crowding at high burdens) and the skewed distribution of parasites (majority of helminths aggregated in a small fraction of hosts). We address these questions for the carcinogenic liver fluke Opisthorchis viverrini, which infects approximately 10 million people across Southeast Asia, by analysing five epidemiological surveys (n = 641) where adult flukes were recovered. Using a mechanistic model, we show that parasite fecundity varies between populations, with surveys from Thailand and Laos demonstrating distinct patterns of egg output and density-dependence. As the probability of observing faecal eggs increases with the number of mature parasites within a host, we quantify diagnostic sensitivity as a function of the worm burden and find that greater than 50% of cases are misdiagnosed as false negative in communities close to elimination. Finally, we demonstrate that the relationship between observed prevalence from routine diagnostics and true prevalence is nonlinear and strongly influenced by parasite aggregation.


Assuntos
Helmintos , Parasitos , Trematódeos , Animais , Fertilidade , Contagem de Ovos de Parasitas , Fezes/parasitologia
3.
J Helminthol ; 97: e13, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36700418

RESUMO

Mexico possesses a large diversity of amphibians partly due to its complex topography and transitional position between the Nearctic and Neotropical biogeographical regions. However, its helminth parasite fauna has been relatively poorly studied. Specimens of the Vaillant's frog, Lithobates vaillanti (Brocchi) were sampled in the tropical rain forest of Nahá, in the Chiapas Highlands, and examined for parasites. Two trematode species were collected from their hosts; morphologically, specimens were allocated to the genera Langeronia Caballero and Bravo-Hollis, 1949 and Haematoloechus Looss, 1899, respectively. Individuals were sequenced for two molecular markers (the mitochondrial cytochrome c oxidase gene, and the ribosomal gene 28S), and processed for morphological analyses, including scanning electron microscopy. The new evidence was not enough to accomplish the identification at species level of Langeronia sp. due to the lack of sequence data from the type localities of Langeronia parva Christian, 1970 and Langeronia macrocirra Caballero and Bravo-Hollis, 1949. Likewise, the newly generated data were useful to properly identify the adult specimens of lung flukes as Haematoloechus complexus Seely, 1906.


Assuntos
Helmintos , Parasitos , Trematódeos , Humanos , Animais , México , Ranidae/parasitologia , Filogenia
4.
PLoS Negl Trop Dis ; 17(1): e0010984, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36626399

RESUMO

BACKGROUND: Despite the significant success of deworming programs in reducing morbidity due to soil-transmitted helminth (STH) infections globally, efforts to achieve elimination of STH as a public health problem or to potentially interrupt transmission will require improving and intensifying surveillance. However, non-participation in surveillance threatens the ability of programs to adequately monitor program status and limited research has been conducted to investigate drivers of non-participation in stool-based surveillance. METHODOLOGY/PRINCIPAL FINDINGS: This mixed-methods exploratory sequential study took place in Comé, Benin in association with the DeWorm3 Project. Six focus group discussions were conducted with individuals invited to participate in annual DeWorm3 stool surveillance. Thematic analysis was used to identify facilitators and barriers to participation and inform the quantitative analysis. A mixed-effects logistic regression model was built using baseline DeWorm3 survey data to identify factors associated with non-participation. Qualitative and quantitative findings were merged for interpretation. Among the 7,039 individuals invited to participate in baseline stool surveillance, the refusal rate was 8.1%. Qualitative themes included: community members weighing community-level benefits against individual-level risks, circulating rumors about misuse of stool samples, interpersonal communication with field agents, and cultural norms around handling adult feces. The quantitative analysis demonstrated that adults were significantly less likely to provide a stool sample than school-aged children (OR:0.69, 95%CI: 0.55-0.88), a finding that converged with the qualitative results. Individuals from areas in the highest quartile of population density were more likely to refuse to participate (OR:1.71, 95%CI:1.16-2.52). Several variables linked to community-affinity aligned with qualitative results; residing mainly in the community (OR:0.36, 95%CI:0.20-0.66) and having lived in the community for more than 10 years (OR:0.82, 95%CI:0.54-1.25) decreased likelihood of refusal. CONCLUSIONS/SIGNIFICANCE: Optimizing STH surveillance will require that programs reimagine STH surveillance activities to address community concerns and ensure that no subpopulations are inadvertently excluded from surveillance data.


Assuntos
Helmintíase , Helmintos , Criança , Animais , Humanos , Solo , Benin/epidemiologia , Prevalência , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Fezes
5.
Sci Rep ; 13(1): 1444, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36697451

RESUMO

The rate of soil-transmitted helminth (STH) infection is estimated to be around 20% in Indonesia. Health promotion and health education are cost-effective strategies to supplement STH prevention and control programs. Existing studies suggest that quantitative tools for knowledge, attitudes and practices (KAP) are important to monitor effective community-based STH interventions. However, evidence is limited regarding the applicability of such tools. This study aims to identify the socio-demographic predictors for STH-related knowledge and practices and validate the quantitative tools in population use. A cross-sectional study design was conducted among residents of 16 villages in Central Java, Indonesia. Adult and child respondents were interviewed to assess general knowledge and practices in relation to STH. Two mixed effects models identified the significant factors in predicting knowledge and practice scores. The model predicted knowledge and practice scores were compared with the observed scores to validate the quantitative measurements developed in this study. Participants' socio-demographic variables were significant in predicting an individual's STH-related knowledge level and their hand washing and hygiene practices, taking into account household-level variability. Model validation results confirmed that the quantitative measurement tools were suitable for assessing STH associated knowledge and behaviour. The questionnaire developed in this study can be used to support school- and community-based health education interventions to maximize the effect of STH prevention and control programs.


Assuntos
Helmintíase , Helmintos , Criança , Adulto , Humanos , Animais , Solo , Indonésia/epidemiologia , Estudos Transversais , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Inquéritos e Questionários , Prevalência , Fezes
6.
Adv Parasitol ; 119: 1-64, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36707173

RESUMO

Data on human gastrointestinal parasites (GIP) infections in the african sub-regions and countries are mainly lacking in terms of prevalence and population stratification by afflicted age group, symptomatology, multi-parasitism, and diagnostic methods. This study aims to describe the GIP reported in african countries and discuss the extent of the burden in the african context. Only 68.42% (39/57) of african countries reported human cases of GIP with helminths (45%, CI: 40-50%, I2: 99.79%) as the predominant parasitic group infecting the african population. On a regional scale, Central Africa had the highest pooled prevalence for GIP (43%, CI: 32-54%, I2: 99.74%), while the Central African Republic led all countries with a pooled prevalence of 90% (CI: 89-92%, I2: 99.96%). The vulnerable population (patients who are minorities, children, old, poor, underfunded, or have particular medical conditions) was the most affected (50%, CI: 37-62%, I2: 99.33%), with the predominance of GIP in the 6 to <20 years age group (48%, CI: 43-54%, I2: 99.68%). Reports on multi-parasitism (44%, CI: 40-48%, I2: 99.73%) were almost double the reports of single infections (43%, CI: 27-59%, I2: 99.77%) with combined molecular and non-molecular techniques demonstrating the best performance for GIP identification. The current review spans more than 40 years of GIP reports from the african continent. Geographical characteristics, environmental factors, habits of its inhabitants, and their health status play a crucial role in GIP modulation and behaviour in its captive hosts. Strategies for regular and enhanced surveillance, policy formation, and high-level community awareness are necessary to identify the true incidence in Africa and the transmission of the pathogens via water and food.


Assuntos
Helmintos , Enteropatias Parasitárias , Parasitos , Criança , Animais , Humanos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , África/epidemiologia , Prevalência , Fezes/parasitologia
7.
PLoS Negl Trop Dis ; 17(1): e0011094, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36662839

RESUMO

BACKGROUND: Interferon-γ (IFN-γ) is a key cytokine inducing protective immune responses during tuberculosis (TB) infection. Helminth-induced immune responses may affect IFN-γ production by T cells, although its connection with disease severity and immune recovery during treatment is unexplored. We investigated the species-specific effect of helminths on the IFN-γ production by T cells in relation to disease severity during active and latent TB infection (LTBI). METHODS: In this study, 69 active pulmonary TB patients (PTB), 28 with LTBI and 66 healthy controls were included. Active TB was diagnosed using GenXpert MTB/RIF while QuantiFERON test (QFT) was used for the screening of healthy community controls (CCs) and for the diagnosis of LTBI. Helminth infection was identified by routine diagnosis whereas clinical disease severity was evaluated by the TB score. Intracellular IFN-γ production of T cells in stimulated peripheral blood mononuclear cells (PBMCs) was analyzed by flow cytometry using TB antigens (PPD), the polyclonal T cell activator staphylococcal enterotoxin B (SEB), or medium as unstimulated control. RESULTS: Helminth infected CCs and LTBI subjects showed a significant reduction of IFN-γ+ CD4+ T cells by PPD-stimulation compared to non-helminth infected control groups. The significant reduction in the frequency of IFN-γ+ T cells in both latent and active PTB patients following SEB stimulation was mostly attributed to Schistosoma mansoni infection, whereas Ascaris lumbricoides, Schistosoma mansoni, and hookworm infection contributed equally in CCs. Following anti-helminthic and anti-TB treatment for 2 months, the frequency of IFN-γ+ CD4 T cells in helminth coinfected PTB was restored to levels of helminth negative PTB before treatment. Helminth coinfected PTB patients with an intermediate and severe clinical course had reduced capacity for production of IFN-γ+ T cells compared to the corresponding non-helminth infected PTB. CONCLUSION: We found a reduction in IFN-γ producing T cells by helminth coinfection which was restored following anti-helminthic treatment. This reduction was helminth species-dependent in an exploratory sub-analysis and correlated to increased disease severity.


Assuntos
Helmintos , Tuberculose Latente , Mycobacterium tuberculosis , Tuberculose , Humanos , Animais , Interferon gama , Tuberculina , Leucócitos Mononucleares , Tuberculose/diagnóstico , Linfócitos T CD4-Positivos , Antígenos de Bactérias
8.
Vet Parasitol Reg Stud Reports ; 37: 100819, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36623907

RESUMO

Helminth infections have been re-emerging with the growing popularity of free-range and floor-based chicken production systems. The aim of this study was to determine the prevalence and worm burdens of intestinal helminth infection in cage-free laying chickens in Australia. In an online survey about worm prevalence, a high proportion of respondents reported the detection of Ascaridia galli (77%), followed by tapeworms (69%) and caecal worms (Heterakis gallinarum) (62%), whereas fewer respondents (23%) reported the presence of hair worms (Capillaria spp.) in their flocks. Total worm recovery from 407 laying hens on four farms found that 92.1% of hens harboured one or more helminth parasite with a prevalence of 73 to 100% across farms. Mixed infections were common with 79% of hens harbouring two or more helminth species. The prevalence of nematode species H. gallinarum, A. galli and Capillaria spp. was 87, 82 and 35% respectively. Five cestode species were found with a low individual chicken prevalence (Raillietina tetragona 4.7%, Raillietina echinobothrida 3.2%, Raillietina cesticillus 5.2%, Choanotaenia infundibulum 4.4%, and Hymenolepis cantaniana 4.4%). The hens harboured an average of 71 worms with H. gallinarum having the highest mean burden (45.5 worms/hen) followed by A. galli (22.0 worms/hen), Capillaria spp. (2.7 worms/hen) and cestodes (0.8 worms/hen). The sex ratio (female:male worms) was 1.38:1 for A. galli, and 1.77:1 for H. gallinarum. There was a strong positive correlation between A. galli female worm count and excreta egg count (EECs) (rs = 0.94, P < 0.0001) and also between total nematode worm count and EEC (rs = 0.82, P < 0.0001) in individual hens. When investigating intestinal excreta (n = 10) and caecal excreta (n = 10) of 16 chicken flocks the prevalence of infection with ascarid worms in intestinal and caecal excreta was 71 and 78% respectively and 27% prevalence of Capillaria spp. in intestinal excreta with mean EECs of 407, 404, and 18 eggs/g of excreta (EPG), respectively. These results suggest that most chickens kept in free-range or floor production systems are infected with one or more helminth parasite species. Heavy worm infections would likely affect the production performance and welfare of birds with adverse economic impact. Strategic or tactical anthelmintic treatment with effective anthelmintic could reduce this impact.


Assuntos
Anti-Helmínticos , Gastroenteropatias , Helmintos , Nematoides , Animais , Feminino , Masculino , Galinhas/parasitologia , Prevalência , Gastroenteropatias/veterinária
9.
Biomed Res Int ; 2023: 6553913, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36647545

RESUMO

Background: Soil-transmitted helminths (STHs) are parasitic worms that are widely distributed in the tropical and subtropical regions. In Ethiopia, one of the tropical countries, STH infections are high and cause a huge burden. Several STH species show a pattern of household clustering with regard to prevalence and intensity. However, there is a scarcity of data on the status of STH infection among family contacts of STH-infected individuals in Ethiopia in general and in the study area in particular. Objective: This study is aimed at assessing the prevalence of soil-transmitted helminths and associated factors among STH-infected household contacts in Burie Zuria district, northwest Ethiopia. Method: A community-based cross-sectional study was conducted among 422 study participants from March to May 2021. Study participants were traced to their residences by following STH-infected patients. A convenient sampling technique was used to recruit the study participants. The stool samples were processed using duplicate Kato-Katz thick smears and a modified Ritchie's technique. The data were entered and analyzed using the Statistical Package for Social Sciences, version 26 of the software package. A P value <0.05 was considered a statistically significant association. Results: The overall prevalence of STHs was 36.5% (95% CI: 31.7%-41.5%). Two STHs, namely hookworm species (33.2%, 140/422) at (95% CI: 28.9%-37.8%) and Ascaris lumbricoides (4.3%, 18/422) at (95% CI: 2.7%-6.6%), were identified, with a double infection of 2.6% (4/154) at (95% CI: 1.0%-6.5%). Almost the majority (96.9%) of hookworm species and all Ascaris lumbricoides infections were categorized under a light intensity of infection. Family size >5 (AOR = 1.74; 95% CI: 1.15-2.60; P = 0.008) and lack of latrine facility (AOR = 1.86; 95% CI: 1.17-2.90; P = 0.02) were significantly associated with STH infections. Conclusion: A high prevalence of hookworms was found in the study area, where the majority of the study participants were adults. This finding may provide a basis for revising the school-based deworming programs that exclude the adult population. Public health interventions like accessing latrines, health education, and deworming programs should be regularly implemented for all age groups in the areas.


Assuntos
Helmintíase , Helmintos , Animais , Ancylostomatoidea , Estudos Transversais , Solo/parasitologia , Prevalência , Etiópia/epidemiologia , Fatores de Risco , Helmintíase/epidemiologia , Fezes/parasitologia
10.
J Extracell Vesicles ; 12(1): e12298, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36604533

RESUMO

Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well-recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth-derived EVs in these processes and highlights EVs as an important participant in cross-phylum communication. While the mammalian EV field is guided by a community-agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplementary set of principles due to the additional challenges that accompany working with such divergent organisms. These challenges include, but are not limited to, generating sufficient quantities of EVs for descriptive or functional studies, defining pan-helminth EV markers, genetically modifying these organisms, and identifying rigorous methodologies for in vitro and in vivo studies. Here, we outline best practices for those investigating the biology of helminth-derived EVs to complement the MISEV guidelines. We summarise community-agreed standards for studying EVs derived from this broad set of non-model organisms, raise awareness of issues associated with helminth EVs and provide future perspectives for how progress in the field will be achieved.


Assuntos
Vesículas Extracelulares , Helmintos , Animais , Humanos , Vesículas Extracelulares/fisiologia , Reprodutibilidade dos Testes , Mamíferos
11.
J Helminthol ; 97: e6, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36633512

RESUMO

Many of the most contentious questions that concern the ecology of helminths could be resolved with data on helminth abundance over the past few decades or centuries, but unfortunately these data are rare. A new sub-discipline - the historical ecology of parasitism - is resurrecting long-term data on the abundance of parasites, an advancement facilitated by the use of biological natural history collections. Because the world's museums hold billions of suitable specimens collected over more than a century, these potential parasitological datasets are broad in scope and finely resolved in taxonomic, temporal and spatial dimensions. Here, we set out best practices for the extraction of parasitological information from natural history collections, including how to conceive of a project, how to select specimens, how to engage curators and receive permission for proposed projects, standard operating protocols for dissections and how to manage data. Our hope is that other helminthologists will use this paper as a reference to expand their own research programmes along the dimension of time.


Assuntos
Helmintos , Parasitos , Animais , Ecologia , Museus
12.
Parasit Vectors ; 16(1): 32, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36703152

RESUMO

BACKGROUND: Central European aerial insectivores are long-distance migrants that winter in sub-Saharan Africa. Most of them employ the fly-and-forage migrating strategy and differ in their food composition. The composition and structure of helminth component communities of these hosts are poorly understood, and information regarding seasonality and long-term changes is unavailable. METHODS: From 1963 to 2022, we analyzed the population trends of helminths in five aerial insectivore species. Namely, we examined Apus apus, Hirundo rustica, Delichon urbicum, Riparia riparia, and Ficedula albicollis; all originated from the Czech Republic. RESULTS: We identified central European aerial insectivores as hosts that are parasitized mostly by helminths that cannot complete their life-cycles in the nesting quarters of their hosts. This phenomenon is unknown in other bird host species. In contrast, only a single dominant trematode species that completes its life-cycle locally colonized the central European aerial insectivores. All other dominant species of Trematoda, all Nematoda, and all Acanthocephala were dependent on intermediate hosts unavailable in the nesting quarters of the examined bird hosts. Surprisingly, these helminths transmitted from winter quarters or migratory routes were diverse, and many of them were abundant in terms of both prevalence and intensity of infection. The helminth component communities of aerial insectivores were dynamic systems. During the study period, three species became new and regularly encountered members of helminth fauna of examined hosts, and other species gradually increased or decreased their intensity of infection. In contrast to other groups of bird hosts, the dominant helminth species of aerial insectivores did not experience local extinctions or rapid population losses. CONCLUSIONS: The analysis of helminths of five central European aerial insectivores revealed component communities that heavily rely on completing host-parasite cycles at migration routes or wintering grounds. The composition of the analyzed component communities changed dynamically during the 60-year-long study period, but there was no evidence of large-scale declines in abundance or prevalence.


Assuntos
Acantocéfalos , Helmintíase Animal , Helmintos , Animais , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Aves/parasitologia , República Tcheca/epidemiologia , Estágios do Ciclo de Vida
13.
PLoS Negl Trop Dis ; 17(1): e0011043, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36602986

RESUMO

BACKGROUND: Accurate mapping of schistosomiasis (SCH) and soil transmitted helminths (STH) is a prerequisite for effective implementation of the control and elimination interventions. A precision mapping protocol was developed and implemented in the coastal region of Kenya by applying the current World Health Organization (WHO) mapping guide at a much lower administrative level (ward). METHODS: A two-stage cluster survey design was undertaken, with 5 villages in each ward selected. From within each village 50 households were randomly selected, and a single child between the ages of 8 and 14 sampled following appropriate assent. The prevalence and intensity of infection of Schistosoma mansoni and STH were determined using the Kato-Katz method (single stool, duplicate slides) and urine filtration for S. haematobium. RESULTS: Of the 27,850 school age children sampled, 6.9% were infected with at least one Schistosoma species, with S. haematobium being the most common 6.1% (95% CI: 3.1-11.9), and Tana River County having highest prevalence 19.6% (95% CI: 11.6-31.3). Prevalence of any STH infection was 5.8% (95% CI: 3.7-8.9), with Lamu County having the highest prevalence at 11.9% (95% CI: 10.0-14.1). The most prevalent STH species in the region was Trichuris trichiura at 3.1% (95% CI: 2.0-4.8). According to the WHO threshold for MDA implementation, 31 wards (in 15 sub-Counties) had a prevalence of ≥10% for SCH and thus qualify for annual MDA of all age groups from 2 years old. On the other hand, using the stricter Kenya BTS MDA threshold of ≥2%, 72 wards (in 17 sub-Counties) qualified for MDA and were targeted for treatment in 2021. CONCLUSIONS: The precision mapping at the ward level demonstrated the variations of schistosomiasis prevalence and endemicity by ward even within the same sub-counties. The data collected will be utilized by the Kenyan Ministry of Health to improve targeting.


Assuntos
Helmintíase , Helmintos , Esquistossomose , Animais , Humanos , Criança , Adolescente , Pré-Escolar , Quênia/epidemiologia , Solo/parasitologia , Helmintíase/epidemiologia , Esquistossomose/epidemiologia , Schistosoma mansoni , Fezes/parasitologia , Prevalência
14.
Rev Bras Parasitol Vet ; 32(1): e017022, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36629665

RESUMO

Gastrointestinal parasites are well-documented in small mammals from north-central Chile, but little is known about endoparasites of rodents in southern Chile. A survey was conducted between January and February 2018 to evaluate gastrointestinal parasites and risk factors of wild rodents that live in rural areas in Northern Chiloé Island, Chile. A total of 174 fecal samples from rodents of six native and one introduced species were collected and examined using the Mini-FLOTAC method. Also, 41 individuals of four native wild rodent species were examined furtherly to determinate adult parasites from gastrointestinal tracts. The overall prevalence of endoparasites was 89.65% (156). Helminth egg types included: Rodentolepis spp., Capillariidae, Trichuris sp., Syphacia sp., oxyurid-type eggs, Strongyloides sp., Spirurid-type eggs, Strongilid-type eggs, Moniliformis sp., and an unidentified nematode egg and larvae. Protozoa comprised coccidia, amoeba, and unidentified cysts. From necropsies, adult parasites involved Syphacia sp. Trichuris sp., Protospirura sp. and Physaloptera sp. In Abrothrix olivacea, individuals with low-body-mass index exhibited reduced infection probability for Spirurid-type and Strongilid-type eggs. Some parasites in this study may affect human health. In rural settings where environmental conditions are changing, more research should be undertaken to understand parasitic infections in wildlife and implications for public health and conservation.


Assuntos
Helmintos , Enteropatias Parasitárias , Parasitos , Doenças dos Roedores , Animais , Chile/epidemiologia , Fezes/parasitologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/veterinária , Enteropatias Parasitárias/parasitologia , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/parasitologia , Roedores/parasitologia
15.
Vet Parasitol ; 313: 109851, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521296

RESUMO

This review is aimed to (i) appraise the literature on the use of molecular techniques for the detection, quantification and differentiation of gastrointestinal helminths (GIH) of equids, (ii) identify the knowledge gaps and, (iii) discuss diagnostic prospects in equine parasitology. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, we retrieved 54 studies (horses: 50/54; donkeys and zebras: 4/54) from four databases. Polymerase chain reaction (PCR) was employed in all of the studies whereas PCR amplicons were sequenced in only 18 of them. Other techniques used (including modifications of PCR) were reverse line blot, quantitative (q)PCR, restriction fragment length polymorphism, nested-PCR, PCR-directed next-generation sequencing, Southern blotting, single strand conformation polymorphism, PCR-enzyme linked immunosorbent assay, matrix-assisted laser desorption/ionisation-time of flight and random amplification of polymorphic DNA. Most of the studies (53/54) used nuclear ribosomal RNA (including the internal transcribed spacers, intergenic spacer, 5.8 S, 18 S, 28 S and 12 S) as target loci while cytochrome c oxidase subunit 1 and random genomic regions were targeted in only three and one studies, respectively. Overall, to date, the majority of molecular studies have focused on the diagnosis and identification of GIHs of equids (i.e. species of Anoplocephala, Craterostomum, cyathostomins, Oesophagodontus, Parascaris, Strongylus, Strongyloides and Triodontophorus), with a recent shift towards investigations on anthelmintic resistance and the use of high-throughput nemabiome metabarcoding. With the increasing reports of anthelmintic resistance in equid GIHs, it is crucial to develop and apply techniques such as advanced metabarcoding for surveillance of parasite populations in order to gain detailed insights into their diversity and sustainable control. To the best of our knowledge, this is the first systematic review that evaluates molecular investigations published on the diagnosis and quantification of equid GIHs and provides useful insights into important knowledge gaps and future research directions in equid molecular parasitology.


Assuntos
Anti-Helmínticos , Helmintos , Doenças dos Cavalos , Animais , Helmintos/genética , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/parasitologia , Cavalos , Patologia Molecular , Strongyloidea , Strongylus
16.
Am J Trop Med Hyg ; 108(2): 335-339, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36509060

RESUMO

Polymerase chain reaction (PCR) is increasingly used in the diagnosis of soil-transmitted helminth infections. Despite this, few studies have evaluated the impact of different fecal fixatives on the outcome of fecal helminth qPCR analysis, and none have evaluated the effect of commercial parasitology fixatives commonly used in diagnostic laboratories. We fixed dog feces containing Ancylostoma spp. hookworm eggs in zinc polyvinyl alcohol (Zn-PVA) and Total-Fix, and with 70% ethanol (EtOH) as a control. DNA was extracted at timepoints 11, 33, 64, and 94 days and subjected to Ancylostoma spp. quantitative PCR (qPCR). A linear regression model was created to assess the effect of preservative types on the temporal change of qPCR quantification cycle number (Cq) values, accounting for variances among individual animals. Fixation in 70% EtOH least affected Cq values over 94 days. Total-Fix preservation yielded a higher Cq overall, but there was no significant difference compared with 70% EtOH fixation. Fixation in Zn-PVA resulted in significantly (P < 0.001) higher Cq values than 70% EtOH after only 33 days and loss of amplification at 64 days. Consistent with other helminth fixation studies, 70% EtOH performed well in preserving hookworm DNA over 94 days. Total-Fix provided a comparable alternative for qPCR analysis for hookworm. Fixation in Zn-PVA resulted in loss of detectable hookworm DNA at 64 days, as determined by qPCR.


Assuntos
Helmintíase , Helmintos , Infecções por Uncinaria , Animais , Cães , Ancylostomatoidea/genética , Fixadores , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções por Uncinaria/diagnóstico , Helmintíase/diagnóstico , Ancylostoma/genética , Fezes/parasitologia , Álcool de Polivinil
17.
J Immunol ; 210(3): 297-309, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36524995

RESUMO

CD8 virtual memory T (TVM) cells are Ag-naive CD8 T cells that have undergone partial differentiation in response to common γ-chain cytokines, particularly IL-15 and IL-4. TVM cells from young individuals are highly proliferative in response to TCR and cytokine stimulation but, with age, they lose TCR-mediated proliferative capacity and exhibit hallmarks of senescence. Helminth infection can drive an increase in TVM cells, which is associated with improved pathogen clearance during subsequent infectious challenge in young mice. Given the cytokine-dependent profile of TVM cells and their age-associated dysfunction, we traced proliferative and functional changes in TVM cells, compared with true naive CD8 T cells, after helminth infection of young and aged C57BL/6 mice. We show that IL-15 is essential for the helminth-induced increase in TVM cells, which is driven only by proliferation of existing TVM cells, with negligible contribution from true naive cell differentiation. Additionally, TVM cells showed the greatest proliferation in response to helminth infection and IL-15 compared with other CD8 T cells. Furthermore, TVM cells from aged mice did not undergo expansion after helminth infection due to both TVM cell-intrinsic and -extrinsic changes associated with aging.


Assuntos
Helmintos , Interleucina-15 , Camundongos , Animais , Camundongos Endogâmicos C57BL , Linfócitos T CD8-Positivos , Citocinas , Receptores de Antígenos de Linfócitos T , Memória Imunológica
18.
J Microbiol Methods ; 204: 106661, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36565938

RESUMO

Although several protocols were developed to extract DNA for soil-transmitted helminthiasis diagnostic, amplifying these extracts remains challenging due to DNA polymerase inhibitors. This study aimed to assess a DNA extraction method for efficient detection of soil-transmitted helminth species by determining stool mass and the type of DNA polymerase that can be used for this extraction method. For this study, 141 stool samples harbouring soil-transmitted eggs and 50 samples without egg were obtained from school-aged children of Makenene in the Centre region of Cameroon. DNA was extracted from 10, 20, 40 and 80 mg of stool using commercial kit and/or cetyltrimethylammonium bromide (CTAB)-based method. The amount of stool for molecular diagnostic of soil-transmitted helminthiasis was determined by amplifying Ascaris lumbricoides DNA. The performances of three DNA polymerases and CTAB-based method were assessed by amplifying DNA of different soil-transmitted helminth species. For this study, 94 stools with A. lumbricoides eggs, 39 with Trichuris trichuria and 15 with hookworm were analyzed. DNA of A. lumbricoides, T. trichuria, Necator americanus and Ancylostoma duodenale were detected in 97.9% of extracts from stools harbouring soil-transmitted helminth eggs. Soil-transmitted helminth DNAs were significantly (X2 = 17.66; df = 3; p ã€ˆ00001) more amplified in extracts from 10 and 20 mg than those from 40 and 80 mg. The amplification rate with "Q5 high fidelity DNA polymerase" was significantly (X2 = 30.54; df = 2; p < 0.00001) higher than that of other DNA polymerases. Multiplex-PCR confirmed co-infections of A. lumbricoides with either T. trichuria or N. americanus. The extraction cost for the CTAB-based method was $1.45. This method appearedis reliable and 3 times cost effective than commercial kit. Its combination with the "Q5 high fidelity DNA polymerase" may improve soil-transmitted helminthiasis diagnostic.


Assuntos
Helmintíase , Helmintos , Criança , Animais , Humanos , Cetrimônio , DNA de Helmintos , Solo , Helmintíase/diagnóstico , Fezes , Prevalência
19.
Trends Parasitol ; 39(2): 91-100, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36503639

RESUMO

Gastrointestinal helminths have developed multiple mechanisms by which they manipulate the host microbiome to make a favorable environment for their long-term survival. While the impact of helminth infections on vertebrate host immunity and its gut microbiota is relatively well studied, little is known about the structure and functioning of microbial populations supported by metazoan parasites. Here we argue that an integrated understanding of the helminth-associated microbiome and its role in the host disease pathogenesis may facilitate the discovery of specific microbial and/or genetic patterns critical for parasite biology and subsequently pave the way for the development of alternative control strategies against parasites and parasitic disease.


Assuntos
Microbioma Gastrointestinal , Helmintíase , Helmintos , Microbiota , Parasitos , Animais , Humanos , Helmintos/genética , Helmintíase/parasitologia
20.
Trends Parasitol ; 39(2): 139-151, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36526548

RESUMO

Helminth infections of cattle place significant burdens on livestock production and farm economic efficiency. Heavy infections are relatively easy to detect and treat with anthelmintics. However, subclinical infections have major but often hidden impacts on animals, necessitating more refined diagnostics to detect them and ideally inform farmers about the likely impact of anthelmintic treatment on animal and herd performance. Here, we review recent advances in diagnosing three major cattle helminth infections - gastrointestinal nematodes (GINs), liver flukes, and lungworms - and the search for subclinical infection thresholds to guide treatment decisions. Combining refined diagnostic thresholds with farm-specific information on grazing systems and animal history enables farmers to tailor helminth treatments to specific epidemiological circumstances, thereby limiting anthelmintic resistance (AR) and boosting agricultural efficiency and food security.


Assuntos
Anti-Helmínticos , Doenças dos Bovinos , Fasciolíase , Helmintos , Nematoides , Infecções por Nematoides , Animais , Bovinos , Infecções Assintomáticas , Anti-Helmínticos/uso terapêutico , Fasciolíase/tratamento farmacológico , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/tratamento farmacológico , Infecções por Nematoides/diagnóstico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia
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