Search Results (103)

Background: Recent studies have shown that digital microscopy (DM) combined with a convolutional neural network (CNN) model is a valid approach for detecting intestinal protozoa and helminth ova or larvae in both trichrome-stained and wet-mount stool preparations. This study evaluated the diagnostic performance of a DM/CNN workflow for routine detection of intestinal parasites in a clinical microbiology laboratory. Methods: A clinical validation was conducted using the Grundium Ocus 40 scanner combined with the Techcyte Human Fecal Wet Mount (HFW) algorithm. The system was evaluated on (a) 135 reference samples and (b) 208 routine clinical samples submitted for intestinal parasite testing. Analytical sensitivity, precision, and limit of detection (LOD) were assessed. Results: For reference samples, the DM/CNN workflow achieved a positive slide-level agreement of 97.6% (95% CI: 94.4–100%), following a confidence threshold adjustment for Schistosoma mansoni, and a negative agreement of 96.0% (95% CI: 86.6–98.9%) compared with light microscopy (LM). Dilution series with reference samples revealed slightly lower analytical sensitivity of the DM/CNN at higher dilutions. Both intra- and inter-run precision studies demonstrated high reproducibility and stability. In prospective testing on 208 routine samples, overall agreement between DM/CNN and LM was 98.1% (95% CI: 95.2–99.2%) with a Cohen’s Kappa coefficient of κ = 0.915. Minor discrepancies involved Blastocystis spp., with DM/CNN showing slightly higher sensitivity. Conclusions: For the first time, we show that the combination of the Grundium Ocus 40 scanner and the Techcyte HFW algorithm provides a reliable, low-throughput screening solution that can effectively assist diagnostic technicians by pre-classifying putative parasitic structures for targeted expert review. Despite its lower throughput, the system substantially reduces the manual review process and simplifies the parasitological workflow. Implementation in a clinical microbiology laboratory requires extensive site-specific validation to account for differences in sample processing and imaging conditions. Moreover, optimization of confidence thresholds for specific classifiers is essential to ensure consistent analytical performance across different laboratory settings. Full article

Intestinal protozoa are a common cause of morbidity in people living with HIV (PWH), particularly in tropical regions with poor sanitation. We conducted a cross-sectional study in 315 PWH from Iquitos, Peru, between October 2023 and May 2024, to assess their prevalence and risk factors. Stool samples were examined using Lugol’s iodine, modified Ziehl–Neelsen (MZN) staining, and immunochromatography (ICT). The mean age was 41 years, with a median CD4+ count of 431 cells/µL; 12.4% were in the AIDS stage, and 21.5% had a detectable viral load. 51.4% of the participants tested positive for any intestinal protozoa. The overall Cryptosporidium spp. prevalence (by combining MZN and ICT results) was 25.7%. The overall Giardia spp. and Entamoeba spp. prevalences (by combining Lugol’s iodine and ICT results) were 2.9% and 1.9%, respectively. Blastocystis spp. was frequently isolated, though its pathogenicity remains uncertain. Diagnostic agreement was almost perfect between Lugol and ICT for Giardia and Entamoeba (κ = 0.87; p < 0.001 and κ = 0.91; p < 0.001, respectively), but only slight between MZN and ICT. Homosexual practices were identified as a significant risk factor for pathogenic protozoa infection (AOR 2.52; 95% CI: 1.04–6.12). In conclusion, the high prevalence of protozoa infection reflects ongoing fecal–oral exposure, underscoring the need for public health education, routine diagnosis, and treatment in similar settings. Full article

Captive reptiles bred for economic and medicinal purposes are often susceptible to intestinal parasites that undermine their health and overall farm productivity. In many regions, their economic value largely derives from medicinal use; accordingly, they are described as reptiles with medicinally driven economic value. In this study, we applied high-throughput sequencing to characterize gut eukaryotic communities and assess parasite prevalence in tokay geckos (Gekko gecko) and Chinese blue-tailed skinks (Plestiodon chinensis). Across both host species, six pathogenic genera were identified: Cryptosporidium (P. chinensis: 57.1%, 12/21; G. gecko: 0%), Eimeria (P. chinensis: 14.3%, 3/21; G. gecko: 0%), Oswaldofilaria (P. chinensis: 0%, G. gecko: 4.8%, 1/21), Strongyloides (P. chinensis: 14.3%, 3/21; G. gecko: 19.1%, 4/21), Spironucleus (P. chinensis: 14.3%, 3/21; G. gecko: 9.5%, 2/21), Spauligodon (P. chinensis: 0%, G. gecko: 14.3%, 3/21). Among these, Cryptosporidium exhibited a striking host-specific pattern, occurring exclusively in Chinese blue-tailed skinks (Fisher’s exact test, p = 5.32 × 10⁻⁵). Principal component analysis (PCA) demonstrated clear host-associated segregation along PC1, which accounted for 58.2% of total variance. Furthermore, co-occurrence network analysis revealed significant positive associations (all p < 0.01) between parasites and other eukaryotes, particularly fungi and protozoa. Collectively, these findings underscore the value of high-throughput sequencing for parasite surveillance in reptile farming and point to the importance of integrated diagnostic approaches and enhanced biosecurity measures for maintaining animal health. Full article

Visceral leishmaniasis caused by Leishmania donovani is one of the major neglected tropical diseases attributable to parasitic protozoa. In the absence of an effective vaccine, chemotherapy remains the only available therapeutic option. However, current treatments rely on a limited number of drugs that are largely obsolete, highly toxic or require intravenous administration, and their extensive use has led to the emergence of drug resistance. Consequently, the discovery of new antileishmanial agents is an urgent priority. In this study, a commercial library of 449 alkaloids in a high-throughput screening format was evaluated against both axenic bone marrow-derived amastigotes and intramacrophagic amastigotes from mice infected with L. donovani IRFP, a strain engineered to emit infrared fluorescence in its viable form. Six isoquinoline-type alkaloids showed the best antileishmanial efficacy against intramacrophagic amastigotes while exhibiting minimal cytotoxicity toward RAW 264.7 and HepG2 cell lines, with a promising selective index higher than four, and good mouse intestinal tolerance in mouse organoids. Among these compounds, the protoberberine scaffold emerged as the most promising candidate for further drug development. Full article

Human milk, especially colostrum, is a biologically complex fluid with potent protective properties against gastrointestinal disturbances in infants. Among intestinal protozoa transmitted via the fecal–oral route, this review focuses on Giardia lamblia and Entamoeba histolytica, as the protective role of milk-derived factors against these parasites is the most extensively documented. Its protective effects result from a wide range of bioactive components, including mucins, lactoferrin, human milk oligosaccharides, melatonin, and secretory IgA, which support the integrity of the intestinal barrier, regulate immune responses, and inhibit the adhesion and activity of pathogens. The composition of human milk can be influenced by maternal factors such as nutritional status, stress, sleep quality, and physical activity, which may modulate its immunological potential. Dietary intake of micronutrients, fermentable fibers, and fermented foods also appears to play a role in shaping the milk’s protective properties. This review discusses the molecular mechanisms by which selected milk components contribute to the defense against protozoan infections in early life and considers how maternal health and lifestyle may affect the effectiveness of these protective mechanisms. Full article

Background: The microscopic examination of stool samples remains the reference method for the diagnosis of intestinal protozoal infections; however, this technique is time consuming and requires experienced and well-trained operators. Therefore, there is a growing interest in molecular diagnostic techniques, including commercial PCR assays. The aim of this multicentric study was to evaluate a commercial real-time PCR for the detection of intestinal protozoa in fecal samples. Methods: The samples were routinely examined using conventional techniques, such as macro- and microscopic examination after concentration, Giemsa or Trichromic stain, Giardia duodenalis, Entamoeba histolytica/dispar or Cryptosporidium spp. antigens research, and amoebae culture. The samples were frozen by the participating laboratories, retrospectively extracted and examined with one-step real-time PCR multiplex using the Allplex™ GI-Parasite Assay (Seegene Inc., Seoul, Korea). Results: A total of 368 samples were analyzed from 12 Italian laboratories. Compared to traditional techniques, the sensibility and specificity of the real-time PCR kit were as follows: 100% and 100% for Entamoeba histolytica, 100% and 99.2% for Giardia duodenalis, 97.2% and 100% for Dientamoeba fragilis, and 100% and 99.7% for Cryptosporidium spp., respectively. Conclusions: The Allplex™ GI-Parasite Assay exhibited excellent performance in the detection of the most common enteric protozoa. 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

The gut microbiota constitutes a complex community of microorganisms (including bacteria, viruses, fungi, and protozoa) within the intestinal tract. Over the years, an increasing number of studies have highlighted the bidirectional communication between the gut microbiota and the central nervous system (CNS), a relationship commonly referred to as the “microbiota–gut–brain axis”. In particular, the crosstalk between the gut microbiota and the brain has been associated with the pathogenesis and progression of various CNS disorders. Phages, or bacteriophages, viruses that specifically infect bacteria, constitute the most abundant viral component within the gut microbiota. However, despite their abundance and significance in the gut microbial community, studies exploring the relationship between phages and the CNS remain surprisingly limited. This review examines the biological interplay between gut-resident phages and the CNS. Furthermore, we discuss the current literature linking phages to CNS-related pathologies. Full article

Coccidiosis, caused by Eimeria protozoa, is a severe intestinal parasitic disease that results in substantial economic losses to the global poultry industry annually. The gut microbiota plays a crucial role in host health, metabolism, immune function, and nutrient absorption in chickens. Recent studies have focused on the effects of Eimeria tenella’s (E. tenella) acute infection period on host health. However, recovery conditions, cecal microbiota composition, and functional differences in the ceca of chickens with varying resistance to E. tenella remain poorly understood during the recovery period after infection. This study aimed to compare growth performance, cecal histopathology, and the cecal microbiota characteristics in control (R_JC), resistant (R_JR), and susceptible (R_JS) chickens during recovery, using metagenomic sequencing. The results revealed significant differences in both cecal tissue structure and growth performance between the different groups during recovery. Although no significant differences were observed in microbial alpha diversity among the groups, sequencing analysis highlighted notable changes in microbial composition and abundance. Bacteroidetes, Firmicutes, and Proteobacteria were the predominant phyla in chicken cecal contents; however, Firmicutes abundance was lower in the R_JS group than in the R_JC and R_JR groups. Further analysis, combining linear discriminant analysis effect size (LEfSe) and differential heatmap analysis, identified Bacteroides_fluxus, Ruminococcus_flavefaciens, and Bacteroides_sp_CACC_737 as dominant microorganisms in the R_JR group (p < 0.05) compared to both the R_JC and R_JS groups. In contrast, Sutterella_sp_AM11-39, Bacteroides_sp_43_108, Mycobacterium, Mycoplasma_arginini, and Chlamydia dominated in the R_JS group, while Butyricimonas, Butyricimonas_sp_Marseille-P3923, and Flavonifractor_plautii were significantly reduced in the R_JS group (p < 0.05). Additionally, beneficial cecal microorganisms such as Flavonifractor_sp__An10, Pseudoflavonifractor, and Faecalicoccus were significantly decreased in both the R_JR and R_JS groups (p < 0.05) compared to the R_JC group. Predictive functional analysis using the KEGG and CAZy databases further indicated that the cecal microbiota in the R_JR group exhibited enhanced metabolism-related pathways, whereas these pathways were significantly diminished in the R_JS group, potentially influencing the recovery process from coccidial infection. These findings provide valuable insights into the cecal microbiota’s role during recovery from E. tenella infection and deepen our understanding of the impact of coccidial infections on host health. Full article

Entamoeba spp. are common zoonotic intestinal protozoa, which can lead to serious intestinal diseases in both humans and animals through fecal–oral transmission, leading to significant economic losses and public health challenges. To reveal the prevalence of Entamoeba in sheep and cattle in Shanxi Province, North China, fecal samples were collected from 311 sheep, 392 dairy cattle, and 393 beef cattle from three representative counties in the northern, central, and southern regions of Shanxi Province. DNA was extracted from the fecal samples and amplified by PCR with primers targeting the nuclear small subunit ribosomal RNA (SSU rRNA) gene of Entamoeba spp., followed by the sequencing of the positive products. The overall infection rates of Entamoeba were 51.5% (160/311), 82.9% (325/392), and 79.1% (311/393) in sheep, dairy cattle, and beef cattle, respectively. Statistical analysis showed a significant correlation between the infection rate of Entamoeba and the location factor in sheep, dairy cattle, and beef cattle (p < 0.001). According to the obtained SSU rRNA sequences, several Entamoeba species, namely Entamoeba bovis, Entamoeba Ribosomal Lineage (RL) 2, Entamoeba RL4, and Entamoeba RL8, were identified. This study represents the first molecular survey of Entamoeba prevalence in sheep, beef cattle, and dairy cattle in Shanxi Province. The findings extend the geographical distribution of Entamoeba spp. and provide valuable scientific data for the prevention and control of amoebiasis in Shanxi Province. Full article

The mammalian gastrointestinal tract is a stage for dynamic inter-kingdom interactions among bacteria, fungi, viruses, and protozoa, which collectively shape the gut micro-ecology and influence host physiology. Despite being a modest fraction, the fungal community, also referred to as mycobiota, represents a critical component of the gut microbiota. Emerging evidence suggests that fungi act as early colonizers of the intestine, exerting a lasting influence on gut development. Meanwhile, the composition of the mycobiota is influenced by multiple factors, with diet, nutrition, drug use (e.g., antimicrobials), and physical condition standing as primary drivers. During its establishment, the mycobiota forms both antagonistic and synergistic relationships with bacterial communities within the host. For instance, intestinal fungi can inhibit bacterial colonization by producing alcohol, while certain bacterial pathogens exploit fungal iron carriers to enhance their growth. However, the regulatory mechanisms governing these complex interactions remain poorly understood. In this review, we first introduce the methodologies for studying the microbiota, then address the significance of the mycobiota in the mammalian intestine, especially during weaning when all ‘primary drivers’ change, and, finally, discuss interactions between fungi and bacteria under various influencing factors. Our review aims to shed light on the complex inter-kingdom dynamics between fungi and bacteria in gut homeostasis and provide insights into how they can be better understood and managed to improve host health and disease outcomes. Full article

Objective: The study aims to assess the overall safety of cultured tilapias in Jeddah City, Saudi Arabia by assessing the impact of infection and anthropogenic pollution on farmed tilapias based on fish sex, body weight, length, and heavy metals contamination. Materials and methods: A total of 111 fish were collected from an aquaculture farm in Hada Al-Sham, Jeddah, Saudi Arabia. Physicochemical parameters of water from the culture system were evaluated. Both ecto- and endoparasites were checked. Haematological, biochemical and histopathological investigations were evaluated. In addition, heavy metals, namely, cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) were evaluated in different fish tissues and water samples from the aquaculture system. Results: The study revealed stressed aquaculture system. Tilapias were infested by both ectoparasites including Trichodina, Icthyophthirius multifiliis, Dactylogrus, and Cichlidogyrus, and endoparasites as Icthyophonus hoferi, the nematode Capillaria and coccidian protozoa. The study showed that male tilapias had greater infestation rates than females and longer and heavier male fish tended to be more susceptible to Dactylogyrus infection. Infected fish showed altered biochemical markers with subsequent increases in inflammatory and oxidative stress markers. The post-mortem lesion in the skin, gill lamellae, intestine, spleen, and liver showed significant pathological remarks. All investigated fish tissues revealed higher rates of heavy metals bioaccumulation compared to the surrounding waters. On the other hand, infected Nile tilapia tissues showed higher rate of metals accumulation compared to non-infected ones. Metals accumulated at a higher rate in the liver followed by kidney, intestine, gills, and muscles, respectively. Conclusions: This study is recognized as the first to address the food safety of farmed tilapias in Jeddah, Saudi Arabia. The results emphasized a significant relation between parasites and heavy metal in disrupting fish defense systems and harming fish’s physiological homeostasis and the histological state of tissues. The parasitized and polluted farmed fish pose health risk to humans due to possible zoonosis from parasitic infections and its subsequent bacterial infections with long-term exposure to toxic chemicals. Addressing the need for a combination of improved aquaculture practices, and stringent regulatory oversight. Full article

Acute gastroenteritis (AGE) in cattle significantly impacts the economy due to relatively high morbidity and mortality and decreased production. Its multifactorial nature drives its global persistence, involving enteric viruses, bacteria, protozoa, and environmental factors. Bovine Rotavirus A (BoRVA) and bovine coronavirus (BCoV) are among the most important enteric RNA viruses causing AGE in cattle. These viruses infect intestinal enterocytes, leading to cell damage and consequently to malabsorption and diarrhea. BoRVA primarily affects calves under 14 days old with gastrointestinal clinical signs, while BCoV affects all ages, causing gastrointestinal and respiratory distress. The economic impact of BoRVA and BCoV, along with their interspecies transmission potential, warrants attention. This concise review discusses the molecular structure, epidemiology, pathogenesis, clinical signs, diagnosis, treatment, and preventive measures of BoRVA and BCoV while providing a comparative analysis. By offering practical guidance on managing such viral infections in cattle, these comparative insights may prove valuable for veterinarians in clinical practice. Full article

Diseases caused by intestinal parasites such as protozoa represent a worldwide problem mainly for developing countries. From morbidity in different groups of people to cases of mortality in children and/or immunocompromised patients. In addition to the above, there is growing resistance to the drugs used in the treatment of these diseases, as well as undesirable side effects in patients. Therefore, there is an interest in the search for new alternatives for the base and/or development of new drugs with antiparasitic activities without harmful effects. In this sense, natural products offer to be a diverse source of compounds with biological activities. In this work, we describe the isolation and elucidation by 1D and 2D NMR spectroscopy of three cyclopeptides obtained from seeds of A. diversifolia Saff.: cherimolacyclopeptide D (1), squamin D (2), and squamin C (3). The fractions enriched in cyclopeptides, as well as a pure compound (1), showed antiprotozoal activity against E. hystolitica Schaudinn and Giardia lamblia Kunstler in vitro assays, with values of IC₅₀ = 3.49 and 5.39 μg mL⁻¹, respectively. The molecular docking study revealed that 1 has a strong interaction with targets used, including aldose reductase and PFOR enzymes. The antiprotozoal activity of cherimolacyclopeptide D is reported for the first time in this study. Full article

The human gut hosts a diverse and active community of bacteria that symbiotically support the physiology, metabolism, and immunity of the intestinal lining. Nevertheless, a dynamic community of parasites (helminths and protozoa) may share a habitat with gut-dwelling microbiota. Both microbiota and parasites can significantly change the physical and immunological environment of the gut, thus generating several mechanisms of interaction. Studying this field is crucial for understanding the pathogenesis of parasitic diseases. Additionally, intestinal microbiota and gut-dwelling parasites may interact with each other and with the host immunity to alleviate or exacerbate the disease. These interactions can alter the pathogenicity of both parasites and microbiota, thereby changing the infection outcomes and the overall disease profile. Parasites and microbiota interactions occur via several mechanisms, including physical alteration in both the gastrointestinal microenvironment and the adaptive and innate immune responses. By modulating the microbiota, treating parasitic infections and microbiota dysbiosis may be improved through knowing the mechanisms and consequences of the interactions between intestinal parasites and the microbiota. Thus, new biological tools of treatment including probiotics can be introduced, particularly with the emergence of drug resistance and adverse effects. Full article