Search Results (876)

The successful transmission of Trypanosoma cruzi, the causative agent of Chagas disease, depends on intricate interactions with its insect vector. In Mexico, Meccus pallidipennis is a relevant triatomine species involved in the parasite’s life cycle. In the gut of these insects, the parasite moves from the anterior midgut (AMG) to the posterior midgut (PMG), where it multiplies. Finally, T. cruzi differentiates into its infective form by metacyclogenesis in the proctodeum or rectum (RE). This study aimed to characterize and compare the protein and glycoprotein profiles of the anterior midgut (AMG) and rectum (RE) of M. pallidipennis, and to assess their potential association with T. cruzi metacyclogenesis, with special attention to sex-specific differences. Insects were infected with the T. cruzi isolate ITRI/MX/12/MOR (Morelos). Protein profiles were analyzed by polyacrylamide gel electrophoresis, while glycoproteins were detected using ConA, WGA, and PNA lectins. The metacyclogenesis index was calculated for male and female triatomines. A lower overlap of protein fractions was found in the RE compared to the AMG between sexes, suggesting functional sexual dimorphism. Infected females showed greater diversity in glycoprotein patterns in the RE, potentially related to higher blood intake and parasite burden. The metacyclogenesis index was significantly higher in females than in males. These findings highlight sex-dependent differences in gut protein and glycoprotein profiles in M. pallidipennis, which may influence the efficiency of T. cruzi development within the vector. Further proteomic studies are needed to identify the molecular components involved and clarify their roles in parasite differentiation and suggest new targets for disrupting parasite transmission within the vector. Full article

Equestrian sports play a significant economic role in the horse industry. In recent years, numerous equine viruses have emerged, among which are equine Pegiviruses and the re-emerging Equine coronavirus (ECoV). These viruses are distributed globally and primarily cause subclinical infections with unknown morbidity, even if ECoV can occasionally induce febrile and diarrheic episodes. To broaden the data on the Italian equine population, a study was conducted to assess their prevalence in two distinct horse populations belonging to the Carabinieri Corps (CC) and the Italian Army (IA) of the Italian Armed Forces (IAF). Samples consisted of blood serum and rectal swabs of 436 horses collected within the national surveillance program for equine infectious anemia and gastrointestinal parasite monitoring and analyzed for Pegivirus (caballi and equi) and ECoV by Real-Time RT PCR. The prevalence detected were 6.56% and 3.53%, respectively, for Pegivirus caballi and equi for the IA, while for the CC, they were 10.13% and 0.84%. Only one sample tested positive for ECoV belonging to a horse of the CC. Phylogenetic analyses were carried out on the PCR-positive samples that were sequenced using Sanger protocols. Understanding the epidemiology of these viruses is essential for evaluating the implementation of effective prevention strategies. Full article

Background: Polyparasitic infections remain widespread in endemic regions, yet its contributing factors and health impact are not well understood. This study aims to estimate the prevalence and associated factors and examines the effect of polyparasitic infection on haemoglobin levels among children. Methods: A cross-sectional study was conducted in Lambaréné, Gabon, among children aged 2–17 years from November 2019 to December 2020. Haemoglobin levels, environmental conditions, and sociodemographic data were collected. Stool, urine, and blood samples were analysed using light microscopy for parasite detection. Factors associated with polyparasitism were explored. Results: Out of 656 participants, 65.4% had at least one infection, with intestinal protozoa species (21.3%), Trichuris trichiura (33%), Ascaris lumbricoides (22%), Schistosoma haematobium (20%), and Plasmodium falciparum (10%) being the most common. Polyparasitic infection was identified in 26% of children, mostly as bi-infections (69.2%), and was negatively associated with haemoglobin levels (β = −0.06). Conclusions: These findings emphasise the burden of polyparasitic infections and adverse health effects in Lambaréné, Gabon. Full article

In Brazil, Plasmodium infections in non-human primates (NHPs) have been associated with P. simium and P. brasilianum, which are morphologically and genetically similar to the human-infecting species P. vivax and P. malariae, respectively. Surveillance and monitoring of wild NHPs are crucial for understanding the distribution of these parasites and assessing the risk of zoonotic transmission. This study aimed to detect the presence of Plasmodium spp. genetic material in Platyrrhini primates from 47 municipalities in the states of Bahia and Minas Gerais. The animals were captured using Tomahawk-type live traps baited with fruit or immobilized with tranquilizer darts. Free-ranging individuals were chemically restrained via inhalation anesthesia using VetBag^® or intramuscular anesthesia injection. Blood samples were collected from the femoral vein. A total of 298 blood and tissue samples were collected from 10 primate species across five genera: Alouatta caraya (25), Alouatta guariba clamitans (1), Callicebus melanochir (1), Callithrix geoffroyi (28), Callithrix jacchus (4), Callithrix kuhlii (31), Callithrix penicillata (175), Callithrix spp. hybrids (15), Leontopithecus chrysomelas (16), Sapajus robustus (1), and Sapajus xanthosthernos (1). Molecular diagnosis was performed using a nested PCR targeting the 18S small subunit ribosomal RNA (18S SSU rRNA) gene, followed by sequencing. Of the 298 samples analyzed, only one (0.3%) from Bahia tested positive for Plasmodium brasilianum/P. malariae. This represents the first detection of this parasite in a free-living C. geoffroyi in Brazil. These findings highlight the importance of continued surveillance of Plasmodium infections in NHPs to identify regions at risk for zoonotic transmission. Full article

Toxoplasma gondii is an intracellular protozoan found worldwide that is capable of infecting nearly all warm-blooded animals, including humans. Its parasitic success lies in its capacity to create chronic infections while avoiding immune detection, altering host immune responses, and disrupting programmed cell death pathways. This review examines the complex relationship between T. gondii and host immunity, focusing on how the parasite influences innate and adaptive immune responses to survive in immune-privileged tissues. We present recent findings on the immune modulation specific to various parasite strains, the immunopathology caused by imbalanced inflammation, and how the parasite undermines host cell death mechanisms such as apoptosis, necroptosis, and pyroptosis. These immune evasion tactics enable prolonged intracellular survival and pose significant challenges for treatment and vaccine development. We also review advancements in therapeutic strategies, including host-directed approaches, nanoparticle drug delivery, and CRISPR-based technologies, along with progress in vaccine development from subunit and DNA vaccines to live-attenuated candidates. This review emphasizes the importance of T. gondii as a model for chronic infections and points out potential avenues for developing innovative therapies and vaccines aimed at toxoplasmosis and similar intracellular pathogens. Full article

Acaricide usage has led to the growing problem of resistance in ticks. A heavy tick burden and the presence of ticks on animals throughout the year, despite the monthly application of acaricides, in farms in the United Arab Emirates formed the motivation for this study. The objectives of this research were as follows: (a) to assess the acaricide resistance status of the most prevalent tick Hyalomma spp. to widely used acaricides Cypermethrin and Deltamethrin; (b) to identify the association of farm management practices and farm-level risk factors with the failure of tick treatment (acaracide resistance). A total of 1600 ticks were collected from 20 farms located in three different regions of Abu Dhabi Emirate including Al Ain (n = 10), Al Dhafra (n = 5), and Abu Dhabi (n = 5). The ticks were subjected to an in vitro bioassay adult immersion test (AIT) modified with a discriminating dose (AIT-DD) against commercial preparations of Cypermethrin and Deltamethrin. A questionnaire was designed to collect metadata and information on farm management and the farm-level risk factors associated with routine farm practices relating to the treatment and control of tick and blood parasite infections in camels and small ruminant populations. Hyalomma anatolicum and Hyalomma dromedarii were identified among the collected ticks, with H. anatolicum being the most prevalent tick species (70%) in the present study. The test results of the in vitro bioassay revealed varied emerging resistance to both of the acaricides in the majority of the three regions; fully susceptible tick isolates with zero resistance to Deltamethrin were recorded in one farm at Al Ain and two farms in the Abu Dhabi region. A questionnaire analysis showed that the failure of tick treatment in farms varied with the presence or absence of vegetation areas, types of animal breeds, and management practices. This study reports the emergence of resistance in ticks to Cypermethrin and Deltamethrin across the Abu Dhabi Emirate, indicating a strict warning for the cautious use of acaricides. There is also a need to improve awareness about sound tick management and control practices among farm owners through a multidisciplinary approach adopting integrated pest management strategies that engage farmers, veterinarians, and policy makers. Full article

Cerebral malaria (CM) is the severe progression of an infection with Plasmodium falciparum, causing detrimental damage to brain tissue and is the most frequent cause of Plasmodium falciparum mortality. The critical role of brain-infiltrating CD8⁺ T cells in the pathophysiology of CM having been revealed, our investigation focuses on the role of NR2F6, an established immune checkpoint, as a candidate driver of CM pathology. We employed an experimental mouse model of CM based on Plasmodium berghei ANKA (PbA) infection to compare the relative susceptibility of Nr2f6-knock-out and wild-type C57BL6/N mice. As a remarkable result, Nr2f6 deficiency confers a significant survival benefit. In terms of mechanism, we detected less severe endotheliopathy and, hence, less damage to the blood–brain barrier (BBB), accompanied by decreased sequestered parasites and less cytotoxic T-lymphocytes within the brain, manifesting in a better disease outcome. We present evidence that NR2F6 deficiency renders mice more resistant to experimental cerebral malaria (ECM), confirming a causal and non-redundant role for NR2F6 in the progression of ECM disease. Consequently, pharmacological inhibitors of the NR2F6 pathway could be of use to bolster BBB integrity and protect against CM. Full article

Bisphenol A (BPA) is an endocrine-disrupting chemical with estrogen-like activity, known to impair immune function. BPA may act as a pro-inflammatory agent, reducing immune response efficacy, increasing bacterial load in E. coli infections, and altering immune responses in parasitic infections (Leishmania major, Nippostrongylus brasiliensis, Toxocara canis) through cytokine and regulatory T-cell modulation. Following its ban in food contact materials in Europe, several analogs have been introduced. This study assessed the immunotoxicity of BPA and six analogs, namely BPAP, BPE, BPP, BPS-MAE, BPZ, and TCBPA, by evaluating in vitro the antibody production. Peripheral blood mononuclear cells from healthy male and female donors were exposed to increasing concentrations of each compound for 24 h. After stimulation with rhIL-2 and ODN2006, IgM and IgG secretion were measured on day six. All compounds suppressed antibody production in a concentration-dependent manner, with some sex-related differences. IC₅₀ values showed BPP as the most potent suppressor, and BPE as the weakest. Similarly, IC₂₀ values confirmed these differences in potency, except for BPA being the weakest for IgM in males. Overall, te results do not support the idea that BPA analogs are safer than BPA. Full article

Porcine circovirus type 3 (PCV3) has been detected in wild boars across many countries in Europe, Asia, and South America. However, data regarding the presence of porcine circoviruses in wild boars and ticks remain limited. In this study, we investigated the presence and genetic characteristics of PCV3 in wild boars and parasitizing ticks in Jiangsu, China. Samples, including whole blood, serum, tissues, feces, and oral fluids from wild boars, as well as ticks collected from 47 wild boars, were obtained between March 2021 and November 2022. PCR results indicated that 34.0% (16/47) of wild boars tested positive for PCV3, while ELISA detected 41.9% (18/43) seropositivity. RT-qPCR results showed that 7.2% (6/83) were positive for PCV3 in 83 analyzed tick samples, with all positive samples identified as Amblyomma testudinarium. The PCV3 genome obtained from wild boars was classified as PCV3a and was closely related to the strain identified in domestic pigs in Nanjing, Jiangsu Province. Collectively, these findings confirm the presence of PCV3 in wild boars in Jiangsu and suggest a possible link of PCV3 infection among domestic pigs, wild boars, and ticks, providing new insights into the transmission risk of PCV3 at wildlife–livestock–human interfaces and highlighting the genetic homology between strains from wild and domestic pigs. Full article

The protozoan parasite Toxoplasma gondii (T. gondii) has been implicated in various neuropsychiatric disorders, including depression. Our aim in this study was to assess the seroprevalence of T. gondii IgG antibodies as well as potential risk factors associated with seropositivity in patients with depression compared to healthy blood donors. This seroepidemiological study included 230 participants from Western Romania, divided equally into two groups: 115 patients diagnosed with depressive disorders which represented the study group and 115 age and gender-matched healthy blood donors, representing the control group. A structured questionnaire was used to assess risk factors potentially linked to T. gondii infection. The T. gondii IgG antibodies overall seroprevalence was significantly higher in the depression group (70.43%) compared to the control group (45.22%) (OR = 2.89; 95% CI: 1.68–4.97; p < 0.001). Higher seropositivity was noted in patients aged 50–59, 60+ years and in females. Patients with lower educational attainment showed significantly increased odds of T. gondii seropositivity (72.29% vs. 44.3%, OR = 3.28; 95% CI: 1.71–6.31; p < 0.001) compared with the control group. Stratification by ICD-10 diagnostic subtypes revealed significantly higher seropositivity in all categories, with the strongest association in patients with recurrent severe depressive episodes without psychotic symptoms (F33.2) (81.25%, OR = 3.5; 95% CI: 1.51–8.13; p = 0.004). These findings suggest a possible link between T. gondii infection and depression, particularly in relation to disease severity and sociodemographic factors. To our knowledge, this is the first study to investigate T. gondii seroprevalence and associated risk factors in Romanian patients with depression, providing a foundation for future longitudinal and preventive research. Full article

Cyclopes, the smallest of all known anteaters, has an insectivorous diet and is arboreal, rarely descending to the ground. There are scarce reports on diseases and pathogenic agents affecting this taxon. Hemopathogens are pathogenic agents that inhabit the blood of various vertebrate species. Protozoa such as Trypanosoma spp., Leishmania spp., Hepatozoon spp., and members of the order Piroplasmida, as well as hemoplasmas and Rickettsial bacteria of the genera Anaplasma and Ehrlichia, are among the most important in this group. The transmission of these pathogens generally occurs through arthropod vectors, which act as intermediate hosts. In addition, infections caused by hemopathogens can have adverse effects on host health, contributing to population declines in susceptible species. This study investigated infection by protozoa and hemotropic bacteria in blood samples from free-ranging silky anteaters from Brazil, Peru, and Colombia using molecular detection methods. Sixteen samples were obtained during expeditions conducted in these countries. DNA was extracted from blood samples, and PCR assays were performed to detect parasites from the order Piroplasmida, Hepatozoon spp., trypanosomatid agents including Leishmania spp., Trypanosoma evansi, T. cruzi, and T. vivax, as well as hemotropic bacteria of the genera Ehrlichia, Anaplasma, and Mycoplasma sp. Nucleotide sequencing was performed on positive samples. Of the total samples analyzed, 62.5% (10/16) tested positive for hemotropic Mycoplasma, 50% (8/16) for T. evansi, and 6.2% (1/16) for T. cruzi. There is a significant gap in knowledge regarding the diversity of hemopathogens affecting the genus Cyclopes, and future studies are needed to understand how these infections may impact the health of individuals. Full article

Feather mites play an important role in bird communities, covering a wide spectrum of associations with their hosts, ranging from parasitic to mutualistic relations. As a result of long co-evolution with their warm-blooded hosts, this diverse group of arthropods can be found in a wide range of environments where their hosts occur, including the high Arctic. The feather mite fauna of Greenland is poorly known. Herein, we present new data on feather mites found on three species of passerine birds, which were captured on Disko Island (Qeqertarsuaq), West Greenland. The feather mite species Analges longispinosus was found on Snow Bunting (Plectrophenax nivalis); Proctophyllodes plectrophenax on Snow Bunting and Lapland Longspur (Calcarius lapponicus); and Proctophyllodes hipposideros on Northern Wheatear (Oenanthe oenanthe). The two Proctophyllodes species represent new records for Greenland. Further studies are needed to reveal the diversity of feather mite species in this remote Arctic region. Full article

Ecdysterone controls moulting and reproduction in insects, crustaceans, and helminths. It is also produced by many plants, probably as an insect deterrent. The steroid is not made by vertebrates but has anabolic effects in mammals and could be useful for treating sarcopenia in aged horses. However, ecdysterone is banned in horseracing and equestrian sports, and with no limit of reporting, the risk of unintended exposure to this naturally occurring prohibited substance is a concern. To explore this risk, pasture plants and hay samples were analysed for ecdysterone content, as well as samples of blood, faeces, and intestinal mucosa from horses (euthanized for non-research purposes) with varying degrees of endo-parasite infestation. The variability in serum ecdysterone concentrations between different horses after administering a fixed dose was also examined. Ecdysterone was detected in 24 hay samples (0.09 to 3.74 µg/g) and several weeds, with particularly high concentrations in Chenopodium album (244 µg/g) and Solanum nigrum (233 µg/g). There was a positive correlation between faecal ecdysterone and faecal egg counts, but no effect of anthelmintic treatment and no relation to the number of encysted cyathostome larvae in the large intestine mucosa. Certain horses maintained an unusually high serum ecdysterone concentration over several weeks and/or displayed an abnormally large response to oral ecdysterone administration. Thus, the risk of environmental exposure to ecdysterone is apparent, and several factors must be considered when determining an appropriate dosage for clinical studies or setting a reporting threshold for equine sports. Full article

Malaria remains a major public health issue, especially near hydroelectric dams that often promote mosquito breeding. This study aimed to establish baseline epidemiological data during the construction of the Singrobo–Ahouaty dam to support assessment and decision-making for short- and long-term health impacts on surrounding communities. A cross-sectional survey was carried out in randomly selected households. Blood samples were analyzed using thick/thin smears and rapid diagnostic tests, while sociodemographic and behavioral data were collected via questionnaires. Statistical analyses included chi-square, Mann–Whitney, Kruskal–Wallis tests, and logistic regression. The malaria prevalence was 43.1% (394/915). The parasite density averaged 405.7 parasites/µL. School-age children (6–13 years) showed the highest prevalence (74.3%, p < 0.0001), while younger children (0–5 years) had the highest parasite density (1218.0 parasites/µL, p < 0.0001). Highly elevated infection rates (>51%) occurred in Sokrogbo, N’Dènou, and Amani-Menou, with the highest density in Ahérémou 1 (5663.9 parasites/µL). Risk factors included being an informal worker (ORa = 1.5), working in the raw material sector (ORa = 1.4) or market gardening/rice farming (ORa = 0.9; p = 0.043), and frequent mosquito bites (OR = 0.4; p = 0.017). These results underscore the need for stronger vector control strategies, improved bed net distribution and follow-up, and enhanced intersectoral collaboration in dam-influenced areas to reduce malaria transmission. Full article

Toxoplasma gondii, a parasitic protozoan, causes zoonotic infections with severe health impacts in humans and warm-blooded animals, underscoring the urgent need for effective vaccines to control these infections. In this study, a DNA vaccine encoding TgROP5, TgROP18, TgGRA7, TgGRA15, and TgMIC6 was formulated using the eukaryotic expression vector pVAX I. IL-24 was delivered as a molecular adjuvant using plasmid pVAX-IL-24. BALB/c, C57BL/6, and Kunming mouse strains received the DNA immunization, after which antibody levels, cytokine production, and lymphocyte surface markers were analyzed to assess immune responses. Additionally, survival rates and brain cyst counts were measured 1 to 2 months post-vaccination in experimental models of toxoplasmosis. As a result, compared to controls, the DNA vaccine cocktail significantly increased serum IgG levels, Th1 cytokine production, and proportions of CD4+/CD8+ T cells, leading to extended survival and reduced brain cyst counts post-challenge with T. gondii ME49. Furthermore, the five-gene DNA vaccine cocktail conferred greater protection compared to single-gene immunizations. Co-administration of IL-24 significantly enhanced the immune efficacy of the multi-gene DNA vaccination. Our findings suggest that IL-24 is an effective molecular adjuvant, enhancing the protective immunity of DNA vaccines against T. gondii, supporting its potential role in vaccine strategies targeting other apicomplexan parasites. Full article