Search Results (1,033)

Sexually transmitted infections (STIs) are a significant global health concern, affecting millions of people worldwide, particularly sexually active adolescents and young adults. These infections, caused by various pathogens, including bacteria, viruses, parasites, and fungi, can have profound implications for women’s reproductive health and fertility. This review explores the role of vaginal and uterine infections in women’s infertility, focusing on the most common pathogens and their impact on reproductive outcomes. Bacterial infections, such as those caused by intracellular bacteria (Mycoplasma, Ureaplasma, and Chlamydia), Neisseria gonorrhoeae, and bacterial vaginosis, are among the most prevalent causes of infertility in women. Studies have shown that these infections can lead to pelvic inflammatory disease, tubal occlusion, and endometrial damage, all of which can impair fertility. Mycobacterium tuberculosis, in particular, is a significant cause of genital tuberculosis and infertility in high-incidence countries. Viral infections, such as Human papillomavirus (HPV) and Herpes simplex virus (HSV), can also affect women’s fertility. While the exact role of HPV in female infertility remains unclear, studies suggest that it may increase the risk of endometrial implantation issues and miscarriage. HSV may be associated with unexplained infertility. Parasitic infections, such as trichomoniasis and schistosomiasis, can directly impact the female reproductive system, leading to infertility, ectopic pregnancy, and other complications. Fungal infections, such as candidiasis, are common but rarely have serious outcomes related to fertility. The vaginal microbiome plays a crucial role in maintaining reproductive health, and alterations in the microbial balance can increase susceptibility to STIs and infertility. Probiotics have been proposed as a potential therapeutic strategy to restore the vaginal ecosystem and improve fertility outcomes, although further research is needed to establish their efficacy. In conclusion, vaginal and uterine infections contribute significantly to women’s infertility, with various pathogens affecting the reproductive system through different mechanisms. Early diagnosis, appropriate treatment, and preventive measures are essential to mitigate the impact of these infections on women’s reproductive health and fertility. Full article

Human cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is a complex parasitic disease marked by dynamic host–parasite interactions and immunomodulation. Extracellular vesicles (EV) derived from immune cells have emerged as key mediators of intercellular communication and potential biomarkers in infectious diseases. In this study, we combined a modified lymphocyte proliferation assay with nano-flow cytometry to quantify and phenotype EV released by CD4⁺, CD8⁺, and CD14⁺ cells in PBMC cultures from CL patients at different clinical stages: before treatment (PBT), during treatment (PDT), and post-treatment (PET) with antimonial. Healthy individuals (HI) were included as physiological controls. Upon stimulation with L. (V.) braziliensis antigens, we observed a distinct modulation of EV subsets. In the PBT group, CD4⁺ and CD14⁺ EV were significantly reduced, while CD8⁺ EV remained elevated. During PDT and PET, EV concentrations were restored across all subsets. These findings suggest that L. (V.) braziliensis selectively modulates the release of immune cell–derived EV, possibly as an immune evasion mechanism. The restoration of EV release following antimonial therapy highlights their potential as sensitive biomarkers for disease activity and treatment monitoring. This study offers novel insights into the immunoregulatory roles of EV in CL and underscores their relevance in host–parasite interactions. Full article

Background: Toxoplasma gondii is a globally widespread parasite responsible for toxoplasmosis, a zoonotic disease with significant impact on both human and animal health. The current lack of safe and effective treatments underscores the need for new drugs. Earlier, thiosemicarbazones (TSCs) and their metal complexes have shown promising activities against T. gondii. This study evaluated a gold (III) complex C3 and its TSC ligand C4 for safety in host immune cells and zebrafish embryos, followed by efficacy assessment in a murine model for chronic toxoplasmosis. Methods: The effects on viability and proliferation of murine splenocytes were determined using Alamar Blue assay and BrdU ELISA, and potential effects of the drugs on zebrafish (Danio rerio) embryos were detected through daily light microscopical inspection within the first 96 h of embryo development. The parasite burden in treated versus non-treated mice was measured by quantitative real-time PCR in the brain, eyes and the heart. Results: Neither compound showed immunosuppressive effects on the host immune cells but displayed dose-dependent toxicity on early zebrafish embryo development, suggesting that these compounds should not be applied in pregnant animals. In the murine model of chronic toxoplasmosis, C4 treatment significantly reduced the parasite load in the heart but not in the brain or eyes, while C3 did not have any impact on the parasite load. Conclusions: These results highlight the potential of C4 for further exploration but also the limitations of current approaches in effectively reducing parasite burden in vivo. Full article

Leishmaniasis, caused by protozoan parasites of the genus Leishmania, is one of the most neglected human diseases, affecting millions worldwide. A detailed understanding of the molecular mechanisms that govern the outcome of macrophage–Leishmania interactions is crucial for a comprehensive understanding of leishmaniasis; however, our current knowledge of these mechanisms remains limited. It is clear that Leishmania has co-evolved to engage several clever strategies to regulate the cell biology of host macrophages to survive and multiply in phagolysosomes of these cells. In this review, we discuss how Leishmania exploits the macrophage Yin-Yang 1 protein as a critical proxy virulence factor to promote its survival. Additionally, we discuss an atlas of YY1-dependent proteins in human macrophages, which could serve as a valuable resource for researchers studying the role of YY1 in macrophage cell biology. Full article

Congenital Chagas disease (CCD) is caused when Trypanosoma cruzi crosses the placental barrier during pregnancy and reaches the fetus, which can lead to serious consequences in the developing fetus. Current treatment is carried out with nifurtimox or benznidazole, but their effectiveness is limited, and they cause side effects, requiring the search for new therapeutic strategies. In this sense, many studies have demonstrated the potential of different compounds of the Copaifera genus in the control of parasitic diseases. Here, we aimed to evaluate the effect of oleoresin (OR) and leaf hydroalcoholic extract (LHE) of Copaifera multijuga on Trypanosoma cruzi infection in human villous trophoblast cells (BeWo line) and human placenta explants. Treatment with both compounds reduced invasion, proliferation, and release of trypomastigotes. Furthermore, OR and LHE affected the trypomastigotes and amastigote morphology, compromising their ability to invade and proliferate in BeWo cells, respectively. Also, treatment with OR decreased ROS production in infected BeWo cells, while LHE induced an increase. In addition, both compounds induced pro-inflammatory and anti-inflammatory cytokine production. In human placental explants, both compounds also decreased T. cruzi infection, in addition to inducing the production of pro-inflammatory cytokines. Thus, both OR and LHE of C. multijuga control T. cruzi infection at the human maternal–fetal interface, highlighting the possible therapeutic potential of these compounds for the treatment of CCD. Full article

Cryptosporidium spp. are protozoan parasites that cause cryptosporidiosis, an enteric disease that can affect a wide range of vertebrate hosts. Pigs play a potential role in the transmission of Cryptosporidium spp. to humans, although infections are most often subclinical. This study aimed to assess the occurrence and molecular characterization of Cryptosporidium spp. in swine farms located in Aragón, northeastern Spain. Fecal samples (n = 72) were collected from 10 breeding farms, encompassing various production stages (lactation, nursery, fattening, and/or wean-to-finish). Data regarding the type of production system (two- or three-stage), production stages, and farming facilities (the type of flooring and water source) associated with the parasite presence were also analyzed using a questionnaire. The results showed that Cryptosporidium spp. were more frequently detected in fecal samples originating from three-stage production systems (21.9%) compared to two-stage systems (12.5%). Samples from the fattening stage exhibited the highest positivity rate and estimated oocyst count (3.0 oocyst/microscopic field). Furthermore, the molecular characterization of Cryptosporidium spp. revealed the circulation of multiple species both among farms and within the same pig production flow, with Cryptosporidium scrofarum being the most prevalent species (7/72; 9.7%), followed by Cryptosporidium suis (1/72; 1.4%). These findings underscore the importance of the surveillance and molecular characterization of Cryptosporidium spp. for controlling infections in pigs, considering the potential for the zoonotic transmission of this parasite to humans. Full article

Fungi are ubiquitous organisms that are capable of transient or persistent colonization in humans. Their polymorphic nature and complex host–mycobiome interactions remain incompletely understood. Emerging evidence highlights the role of resident fungi in modulating immune responses and adapting to host changes, which can trigger a shift from commensalism to parasitism, particularly in immunocompromised individuals. This study evaluated the effects of two major β-glucans—zymosan and curdlan—on the expression of pattern recognition receptors (Dectin1, Dectin2, TLR2, TLR4) in human peripheral blood mononuclear cells (PBMCs). It also examined their impact on reactive oxygen species (ROS) production, cytokine/chemokine gene expression, and antioxidant enzyme expression. Both β-glucans significantly increased the mRNA levels of all tested receptors and enhanced ROS generation. Curdlan downregulated key antioxidant enzymes (SOD1, CAT, GPX1), while zymosan markedly upregulated SOD1. These findings demonstrate that the β-glucans zymosan and curdlan have a substantial influence on PBMC reactivity and oxidative stress responses. Further studies are needed to deepen our understanding of host–fungal interactions and their implications in health and disease. Full article

Climate change, mining activities, pollution and other human impacts on the natural environment cause significant changes in the concentrations and mixtures of metallic elements found in different ecosystems. Metals such as cadmium, copper, lead and mercury affect multiple aspects of host–pathogen interactions, influencing the risk of infectious diseases caused by various classes of pathogens. Notably, exposure to metals in doses and combinations toxic to the immune system can favor the dissemination of pathogens in natural environments, threatening the reproduction, well-being and survival of varied animal species. However, these problems remain neglected, since the influences of metals on infectious diseases are studied with a primary focus on human medicine. Therefore, this article aims to review the influence of metals/metalloids (e.g., arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, zinc) on infectious and parasitic diseases in animals living in natural environments. The potential impact of metals on the risk of zoonotic spillover events is also discussed. Metal pollution tends to increase as the demand for elements used in the manufacture of industrial products, batteries, and electronic devices increases globally. This problem can aggravate the biodiversity crisis and facilitate the emergence of infectious diseases. Considering the interconnections between pollution and immunity, measures to limit metal pollution are necessary to protect human health and biodiversity from the risks posed by pathogens. This review helps fill the gap in the literature regarding the connections between metal pollution and various aspects of infectious diseases. Full article

(1) Background: As a prominent zoonotic parasitic disease, fascioliasis threatens the sustainable development of animal husbandry and public health. Current research focuses mainly on individual species (parasite or intermediate host), neglecting systematic evaluation of the transmission chain and exposure risks to animal husbandry. Thus, comprehensive studies are urgently needed, especially in the ecologically fragile alpine region of the Qinghai-Tibet Plateau; (2) Methods: Distribution data of Radix spp. and Fasciola hepatica in the Qinghai-Tibet Plateau and adjacent areas were gathered to establish a potential distribution model, which was overlaid on a map of livestock farming in the region; (3) Results: The key environmental factors influencing Radix spp. distribution were temperature seasonality (21.4%), elevation (16.4%), and mean temperature of the driest quarter (14.7%). For F. hepatica, the main factors were elevation (41.3%), human footprint index (30.5%), and Precipitation of the driest month (12.1%), with all AUC values exceeding 0.9. Both species exhibited extensive suitable habitats in Qinghai and Tibet, with higher F. hepatica transmission risk in Qinghai than Tibet; (4) Conclusions: The significant transmission risk and its impacts on the livestock industry in the Qinghai-Tibet Plateau highlight the need for proactive prevention and control measures. This study provides a scientific foundation for targeted alpine diseases control, establishes an interdisciplinary risk assessment framework, fills gaps in high-altitude eco-epidemiology, and offers insights for ecological conservation of the plateau. Full article

The metalloid arsenic (As) and the metals lead (Pb) and mercury (Hg), which together we call the “Toxic Triad”, are among the pollutants of greatest global concern, harming the health of millions of people and contributing to biodiversity loss. The widespread distribution of As, Pb and Hg facilitates the exposure of humans and other species to these elements simultaneously, potentially amplifying their individual toxic effects. While As, Pb and Hg are well established as toxic elements, the mechanisms by which they interact with genetic material and impact the health of various species remain incompletely understood. This is particularly true regarding the combined effects of these three elements. In this context, the objective of this work was to perform a toxicogenomic analysis of As, Pb and Hg to highlight multiple aspects of element-gene interactions, in addition to revisiting information on the genotoxicity and carcinogenicity of the Toxic Triad. By using The Comparative Toxicogenomics Database, it was possible to identify that As interacts with 7666 genes across various species, while Pb influences 3525 genes, and Hg affects 692 genes. Removing duplicate gene names, the three elements interact with 9763 genes across multiple species. Considering the top-20 As/Pb/Hg-interacting genes, catalase (CAT), NFE2 like bZIP transcription factor 2 (NFE2L2), caspase 3 (CASP3), heme oxygenase (HMOX1), tumor necrosis factor (TNF), NAD(P)H quinone dehydrogenase 1 (NQO1) and interleukin 6 (IL6) were the most frequently observed. In total, 172 genes have the potential to interact with the three elements. Gene ontology analysis based on those genes evidenced that the Toxic Triad affects several cellular compartments and molecular functions, highlighting its effect on stimulation of toxic stress mechanisms. These 172 genes are also associated with various diseases, especially those of the urogenital tract, as well as being related to biological pathways involved in infectious diseases caused by viruses, bacteria and parasites. Arsenic was the element with the best-substantiated genotoxic and carcinogenic activity. This article details, through a toxicogenomic approach, the genetic bases that underlie the toxic effects of As, Pb and Hg. Full article

APOL1 is the most recent member of the APOL gene family and is expressed exclusively in humans and a few higher primates. More than twenty years ago, it was discovered that APOL1 protects humans from infections by trypanosome subspecies that cause African sleeping sickness. Interestingly, by a co-evolutionary process between parasite and host, two APOL1 variants emerged, which, in addition to their trypanotoxic effects, are simultaneously associated with a significantly increased risk for various different kidney diseases, which are now summarized as APOL1-mediated kidney diseases (AMKDs). The aim of this review is to highlight and formulate key aspects of APOL1’s cell biologic features, including questions and unaddressed aspects. This perspective may contribute to a deeper understanding of APOL1-associated cytotoxicity as well as AMKDs. Full article

Estimating the human impact on parasites in wildlife is essential to create efficient strategies to control diseases and improve public health. This study assessed the human influence on the parasite burden of the two commonest canine mesocarnivores, the red fox (N = 194) and the golden jackal (N = 151), in Europe. We compared the infracommunity crowding index, parasite diversity, prevalence, and abundance of different parasite taxa, and the presence of Echinococcus multilocularis between groups of hosts, such as jackals and foxes hunted at different distances from human settlements. The analysis of hosts’ distribution ascertained that 61.2% of the investigated wild canids were hunted in a 500–1750 m ring around the human settlements. Ancylostomatidae proved the most prevalent taxon (>60%), while Echinococcus multilocularis and Dipylidium caninum occurred least frequently. The two taxa that mostly contributed to the crowding of infracommunities were Ancylostomatidae and Toxocaridae, with a negative correlation between their abundances (Spearman’s ρ = −0.445, p < 0.001). Parasite infracommunities were more crowded in Echinococcus multilocularis infected foxes (p = 0.02) and jackals (p = 0.001). Our study highlighted that human modification of landscapes worsened the parasite burden of wild mesocarnivores, which could increase the public health risk of zoonotic parasites. Full article

Lagochilascariasis is a neglected zoonotic helminthiasis, caused by Lagochilascaris minor, characterized by a complex and not well understood transmission cycle. This parasitic disease is endemic to Latin America, particularly Brazil, and is associated with rural and forested areas, where humans may serve as accidental hosts. The southeastern region of Pará state reports the highest number of cases, highlighting its epidemiological significance. Wildlife species, especially carnivores and rodents, play crucial roles as definitive and intermediate hosts, respectively. Although lagochilascariasis can lead to severe clinical manifestations, including chronic soft tissue infections and potential central nervous system involvement, it is likely underdiagnosed due to its similarity to fungal and bacterial diseases. The anthropization of the Amazon Biome, through deforestation and habitat fragmentation, coupled with increased human–wildlife interactions, may be influencing the epidemiology of this parasitosis. This review aims to summarize current knowledge of L. minor transmission routes, the role of wildlife in maintaining its cycle, and the impact of environmental changes on disease patterns. Such insights are vital for One Health strategies, which integrate human, animal, and environmental health approaches to mitigate the disease burden. Full article

Vector-borne parasitic diseases represent a critical public health challenge in Africa, disproportionately impacting vulnerable populations and linking human, animal, and environmental health through the One Health framework. In this review, we explore the existing burden of these diseases, particularly those that are underreported. Climate change, urbanization, the introduction of alien species, and deforestation exacerbate the emergence and reemergence of arthropod-borne zoonotic parasitic diseases like malaria, leishmaniasis, and trypanosomiasis, complicating control and disease elimination efforts. Despite progress in managing certain diseases, gaps in surveillance and funding hinder effective responses, allowing many arthropod zoonotic parasitic infections to persist unnoticed. The increased interactions between humans and wildlife, driven by environmental changes, heighten the risk of spillover events. Leveraging comprehensive data on disease existence and distribution coupled with a One Health approach is essential for developing adaptive surveillance systems and sustainable control strategies. This review emphasizes the urgent need for interdisciplinary collaboration among medical professionals, veterinarians, ecologists, and policymakers to effectively address the challenges posed by vector-borne zoonotic parasitic diseases in Africa, ensuring improved health outcomes for both humans and animals. Full article