Search Results (83)

Background: Anaemia in adolescents can be influenced by parasitic infections, systemic inflammation, and nutritional status. Objective: To determine whether C-reactive protein (CRP), nutritional status, and infection with Ascaris lumbricoides, Giardia lamblia, or Trichuris trichiura are associated with anaemia in adolescent athletes from Tacna compared to non-athletes. Methods: A cross-sectional study was conducted involving 250 male football players aged 13–18 years and 150 age-matched non-athletes. Haemoglobin, haematocrit, ferritin, serum iron, CRP, and parasitic status were measured; mean comparisons and logistic regression were applied. Results: Anaemia was more prevalent among athletes than non-athletes (30% vs. 18%; p < 0.001). Infected athletes showed lower haemoglobin (11.9 ± 1.1 g/dL) and higher CRP (5.0 ± 1.9 mg/L) levels compared to non-infected athletes (13.8 ± 1.0 g/dL and 2.2 ± 1.1 mg/L; p < 0.001). Logistic regression identified CRP as an independent predictor of anaemia (adjusted OR = 1.20; 95% CI: 1.08–1.38; p < 0.001), while parasitic infections showed no direct association after adjustment. Underweight status was associated with a higher prevalence of anaemia (36%). Conclusions: Systemic inflammation emerged as the main factor associated with anaemia in this population, with parasitic infections contributing indirectly by increasing inflammation. Periodic deworming, iron supplementation, and CRP monitoring are recommended to reduce the burden of anaemia in adolescent athletes from endemic regions. Full article

Giardia lamblia is a flagellated protozoan and the etiological agent of giardiasis, a leading cause of epidemic and sporadic diarrhoea globally. The clinical and public health relevance of giardiasis underscores the need for robust methodologies to investigate and manage this pathogen. This study reviews the main methodologies described in the literature for studying the life cycle of G. lamblia, focusing on isolation, purification, axenization, excystation, and encystation. A systematic literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) statement. Searches were performed in MEDLINE, ScienceDirect, and Web of Science Core Collection databases. A total of 43 studies were included, revealing 58 methods for isolation and purification, 7 for excystation, 2 for axenization, and 5 for encystation. Isolation and purification methods exhibited significant variability, often involving two phases: an initial separation (e.g., filtration and centrifugation) followed by purification using a density gradient for faecal samples or immunomagnetic separation for water samples. Method effectiveness differed depending on the sample source and type, limiting comparability across studies. In contrast, methods used for other life cycle stages were more consistent. These findings underscore the need for standardised methodologies to enhance the reproducibility and reliability of research outcomes in this field. Full article

Giardiasis is a common intestinal infection caused by Giardia lamblia. The standard treatment for this parasitic infection involves the administration of nitroimidazoles, albendazoles, and nitrothiazoles. However, in recent years, Giardia lamblia strains resistant to these treatments have been reported. Additionally, the current therapies exhibit considerable side effects, highlighting the need for new compounds that specifically target this parasite. The aim of this study was to evaluate nitrothiazole analogs and assess their impact on the metabolic, redox, and structural gene expression of this parasite. First, the compounds CNZ-7, CNZ-8, FLP-2, FLP-6, and FLP-8 were tested at concentrations ranging from 0 to 50 µM to determine their IC₅₀ in G. lamblia cultures. Subsequently, gene expression changes and structural cell damage in trophozoites were analyzed following incubation with the IC₅₀ of each compound. The giardicidal activity of the compounds was also evaluated in a nitazoxanide-resistant strain. The results showed that FLP-2, FLP-6, and FLP-8 exhibited a stronger effect on trophozoite viability compared to nitazoxanide (NTZ) and metronidazole (MTZ). Both compounds induced an increase in the expression of phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PK), pyruvate phosphate dikinase (PPDK), and pyruvate:ferredoxin oxidoreductase (PFOR). Additionally, FLP-2 caused ultrastructural alterations in trophozoites. Furthermore, FLP-2, FLP-6, and FLP-8 demonstrated efficacy against drug-resistant strains. These findings suggest that FLP-2, FLP-6, and FLP-8 are promising candidates for the treatment of giardiasis, as they effectively reduce parasite viability, modify gene expression, and exhibit activity against drug-resistant G. lamblia strains. Full article

Infections from the protozoa Entamoeba histolytica (E. histolytica), Giardia lamblia (G. lamblia), and Trichomonas vaginalis (T. vaginalis) pose a public health issue, with albendazole and mebendazole serving as the second-line medications for treating these parasitic infections. However, the low aqueous solubility of these compounds has led to the exploration of new strategies to enhance their solubility, with the formation of salts being a commonly employed strategy. The sulfonates A1, A2, and A3 of albendazole, along with M1, M2, and M3 of mebendazole, were synthesized. The antiparasitic activity in vitro was assessed against the trophozoites of E. histolytica, G. lamblia, and T. vaginalis. The salts A2, A3, M2, and M3 demonstrated a greater antiparasitic effect (IC₅₀ 37.95–125.53 µM) compared to the positive controls albendazole and mebendazole. The salts A1, A3, M2, and M3 do not exhibit cytotoxic effects at concentrations of 500 µM on the Vero cell line. Taken together, these findings indicate that the formation of these new solid saline phases enhances the antiparasitic effects in vitro, which is crucial in the current search for improved, safe, and effective antiparasitic agents. Full article

Background: Microscopy is the conventional method for the identification of gastrointestinal parasitic pathogens in fecal specimens; however, it presents numerous challenges, including high technical expertise burden, multiple staining procedures, and prolonged turnaround time. Molecular methods provide higher throughput and potentially higher sensitivity and specificity. Methods: We validated a commercial, automated DNA extraction platform and multiplex parasitic real-time PCR panel (Seegene Allplex^TM GI-Parasite Assay) detecting six protozoal pathogens: Blastocystis hominis (Bh), Cryptosporidium spp., Cyclospora cayetanensis (Cc), Dientamoeba fragilis (Df), Entamoeba histolytica (Eh), and Giardia lamblia (Gl) in unpreserved fecal specimens submitted for diagnostic parasitology. Microscopy was the reference standard for all organisms, with stool ELISA as an additional reference assay for Eh. Results: Among 461 unpreserved fecal specimens, sensitivity, specificity, positive predictive and negative predictive values of the enteric multiplex for fresh specimens were as follows: 93%, 98.3%, 85.1%, 99.3% for Bh; 100% for all measures in Cryptosporidium and Cc; 100%, 99.3%, 88.5%, 100% for Df; 33.3%, 100%, 100%, 99.6% for Eh; and 100%, 98.9%, 68.8%, 100% for Gl, respectively. With the addition of 17 frozen specimens, the sensitivity for Eh increased to 75%. On a per-batch basis, the molecular platform reduced pre-analytical and analytical testing turnaround time by 7 h. Conclusions: The enteric multiplex platform provides a useful diagnostic tool for clinically relevant enteric protozoa, including Cryptosporidium spp., Cyclospora cayetanensis, Dientamoeba fragilis, and Giardia lamblia. Further evaluation of the assay is required for Entamoeba histolytica prior to clinical use; however, given the widespread availability of confirmatory serology and stool antigen testing for E. histolytica, such performance limitations are of lesser concern. Full article

Objetive: The aim of this study was to describe the impact of non-pharmaceutical interventions (NPIs) against SARS-CoV-2 in patients with symptoms of enteric protozoa (EP), including Blastocystis spp., Dientamoeba fragilis, Giardia lamblia, Cryptosporidium spp., Entamoeba histolytica, and Cyclospora cayetanensis, in the overall population and in patients who were consulted at a National Referral Center for Imported Tropical Diseases (NRCITD patients) from a healthcare area in Madrid (Spain). Method: Data on patients with positive RT-PCR results for EP were collected. The periods analyzed were prepandemic (P0, 1 April 2019–31 March 2020), and the first (P1, 1 April 2020–31 March 2021), second (P2, 1 April 2021–31 March 2022), and third (P3, 1 April 2022–31 March 2023) pandemic years. We compared the prevalence, median age, absolute incidence (EP per 100,000 population of each period), and patient profile (NRCITD vs. non-NRCITD) during the study periods using Fisher’s test (p < 0.05) and the T-test (p < 0.001). Results: During P0, 24.8%, [95% CI: 23.9–25.6] of patients tested for EP RT-PCR were positive, 22.6% [95% CI: 21.5–23.7] were positive in P1, 20.4%, [95% CI: 19.5–21.3] were positive during P2, and 20% [95% CI: 19.2–20.9] of patients tested during P3 were positive. During the study, there was no difference in the median ages. The prevalence and absolute incidence of EP showed a decreasing trend during the pandemic for the NRCITD and non-NRCITD patients (p < 0.05). Conclusion: Blastocystis spp. and D. fragilis showed a lower decrease in prevalence during P1 (p > 0.05) due to the higher detection of colonized patients during the SARS-CoV-2 pandemic. However, G. lamblia and Cryptosporidium spp. showed the highest decrease in prevalence and absolute incidence during P2 (p < 0.05) because of the NPIs implemented during the SARS-CoV-2 pandemic. The NTRCID patients showed a higher prevalence of Blastocystis spp. than the non-NTRCID patients during every period studied (p < 0.001). E. histolytica and C. cayetanensis showed a homogeneous trend. Full article

Giardiasis and cryptosporidiosis, caused by Giardia lamblia and Cryptosporidium spp., are parasitic infections transmitted through faecal–oral routes or contaminated water. Although less common in Spain compared to developing countries, they pose a public health concern, particularly for vulnerable groups like children and immunocompromised individuals. This study aims to analyse the cases reported to the Microbiological Information System (MIS) in children between 2012 and 2021, as well as their distribution across sociodemographic variables. Proportions and infectivity rates were determined for epidemiological and sociodemographic data, and the incidence rate for giardiasis and cryptosporidiosis was calculated annually and by health sector. The variables analysed included sex, age, health sector and weather. For both diseases, there was a significant decrease in the number of cases in 2020, suggesting the importance of person-to-person transmission. Children were infected by Giardia in significantly higher proportion (p < 0.001), being the majority in age groups 5–14 years, while the proportion of boys and girls infected by Cryptosporidium was almost identical (1.4% vs. 1.3%), in children aged 2–4 years. Periodically there was a significant increase in cases of cryptosporidiosis, apparently related to the presence of torrential rains. Transmission is related to increased temperature and rainfall. Person-to-person transmission in the paediatric population needs further investigation. This study provides the foundation for future research on the evolution of cases of giardiasis and cryptosporidiosis in Spanish children. The data emphasise the need for informational campaigns on hygienic measures and efforts by public health authorities to maintain water resources in optimal condition to prevent parasite spread. Full article

Pathogen infection in animals and plants is recognized in a relatively similar manner by the interaction of pattern recognition receptors on the host cell surface with pathogen-associated molecular patterns on the pathogen surface. Previous work demonstrates that animal pathogenic bacteria can be recognized by plant receptors and alter transcriptome. In this work, we have hypothesized that exposure to human parasites, Cryptosporidium parvum and Giardia lamblia, would also trigger pathogen response in plants, leading to changes in transcriptome. Detached Arabidopsis leaves were exposed for one hour to heat-inactivated Cryptosporidia or Giardia. The transcriptome profile showed large changes in gene expression with significant overlap between two parasites, including upregulated GO terms “cellular response to chitin”, “response to wounding”, “response to oomycetes”, “defense response to fungus”, “incompatible interaction”, and “activation of innate immune response”, and downregulated GO terms “positive regulation of development”, “cell surface”, “regulation of organ growth”, “wax biosynthetic process”, “leaf and shoot morphogenesis”. Uniquely downregulated GO terms in response to Cryptosporidia were GO terms related to chromatin remodelling, something that was not reported before. To conclude, it appears that while Cryptosporidia or Giardia are not pathogens of Arabidopsis, this plant possesses various mechanisms of recognition of pathogenic components of parasites. Full article

Anemia is a health problem of concern among schoolchildren in underprivileged rural regions, where recurrent parasitic infections are common. A cross-sectional study was conducted in 229 schoolchildren in rural highland Bolivia in the department of La Paz, an area with a high prevalence of protozoan and helminth infections, to determine the types and mechanisms of anemia. A substantial proportion of children (40.2%) were found to be anemic based on hemoglobin measurements. No associations were found between low hemoglobin levels and helminth or protozoan infections when evaluating infectious causes of anemia, nor with Giardia lamblia or Blastocystis hominis, which are associated with iron deficiency and nutrient malabsorption and were highly prevalent in this study. The significant association between anemia and hypochromia suggests iron deficiency, aligned with low hemoglobin levels. A total of 39 out of 150 children (26%) had markers consistent with iron deficiency anemia (IDA), 26 out of 127 children (20%) met the criteria for anemia of inflammation (AI). Furthermore, 12 of the 127 tested children (9.4%) met the criteria for mixed AI with IDA according to the soluble transferrin receptor (sTfR)/log ferritin levels, which increased significantly due to overall infections by Hymenolepis nana and Ascaris lumbricoides helminths. The findings highlight the need for integrated public health interventions to address iron nutrition and parasitic infections to effectively prevent anemia in this vulnerable population. 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

It has been suggested that parasitic infections, common in Latin American populations, may amplify the inflammatory response of the airways. There are several reports of atopic and asthmatic patients but few reports of parasitic infection in COPD patients. This study aimed to determine the prevalence of parasitic infections in COPD patients compared with atopic and asthmatic patients attending the Institute of Immunology outpatient clinics and the pneumology service of the University hospital. A case-control study was conducted compising 100 patients with bronchial asthma, 100 patients with COPD, 100 individuals with atopy without respiratory symptoms, and 100 healthy individuals. Serum-specific IgG antibodies against the parasites Ascaris lumbricoides (Al), Strongyloides stercolaris (Ss), and Toxocara canis (Tc) were measured by ELISA. IgE levels were used as an indirect indicator of atopy. Positive IgG for Al was observed in all groups, predominantly in the atopic cohort; Ss positiveness was recorded only in four COPD patients, and Tc positiveness was observed in all groups except in controls. Significant correlations exist between the values of Al and IgE in controls, atopic, and asthmatic patients without COPD. No correlation was found for Tc. IgE levels and the forced expiratory volume in 1 s (FEV1) correlate only in atopic and asthmatic patients. Parasitic infections are common in atopic patients and moderate and severe asthmatic and COPD patients. Anti-inflammatory treatment may be responsible for the increased frequency of infection in moderate and severe asthmatic and COPD patients. Full article

Lymphangioleiomyomatosis (LAM) is a rare genetic lung disease. Unfortunately, treatment with the mTORC1 inhibitor Rapamycin only slows disease progression, and incomplete responses are common. Thus, there remains an urgent need to identify new targets for the development of curative LAM treatments. Nitazoxanide (NTZ) is an orally bioavailable antiprotozoal small molecule drug approved for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum in children and adults, with a demonstrated mTORC1 inhibitory effect in several human cell lines. NTZ’s excellent safety profile characterized by its more than 20 years of clinical use makes it a promising candidate for repurposing. Our rationale for this study was to further investigate NTZ’s effect using in vitro and in vivo LAM models and to elucidate the underlying molecular mechanism beyond mTORC1 inhibition. For this purpose, we investigated cell proliferation, cell viability, and changes in protein phosphorylation and expression in primary human cell cultures derived from LAM lung samples before translating our results into a syngeneic mouse model utilizing Tsc2-null cells. NTZ reduced cell growth for all tested cell lines at a dose of about 30 µM. Lower doses than that had no effect on cell viability, but doses above 45 µM lowered the viability by about 10 to 15% compared to control. Interestingly, our western blot revealed no inhibition of mTORC1 and only a mild effect on active ß-Catenin. Instead, NTZ had a pronounced effect on reducing pAkt. In the mouse model, prophylactic NTZ treatment via the intraperitoneal and oral routes had some effects on reducing lung lesions and improving body weight retention, but the results remain inconclusive. Full article

Giardia doudenalis (lamblia, intestinalis) is a protozoan parasite that inhabits the lumen of the upper small intestine of vertebrates, causing chronic abdominal pains and severe diarrhea, symptoms of giardiasis, a persistent and recurrent infection. This characteristic is mainly due to the presence of membrane variant-specific surface proteins (VSPs) that give this parasite the ability to successively infect the host through antigenic variation. Using high-resolution scanning microscopy (HR-SM), we observed the presence, formation, and extension of tunneling-nanotube-like surface structures in Giardia, especially following parasite challenges with VSP antibodies. They were seen all over the parasite surface, both in vitro and in vivo, showing that G. duodenalis nanotube formation occurs in complex environments such as the gut. In addition, we also observed that some of these nanotubes displayed a periodic strangulation that produces 100 nm vesicles that seemed to be released in a process similar to that previously observed in Trypanosoma brucei. The presence of nanotube-like structures in G. duodenalis highlights yet another strategy of cellular communication utilized by these parasites, whether between themselves or with the host cell. Full article

Autoimmune pancreatitis type 2 is a relatively novel entity with some still controversial issues. The current diagnostic algorithm relies on imaging studies and histology. Therapy includes corticosteroids with consequently low risk of relapse in the following year. However, the pathogenesis remains unclear, and data are insufficient for long-term prognosis. We have treated a 17-year-old boy whose autoimmune pancreatitis type 2 was revealed during surgery for a pre-existing biliary tract anomaly with concurrent protozoal infection. We discuss the co-occurrence of these conditions in terms of eventual pathogenesis correlation and combined effect on long-term prognosis. Full article

Giardia lamblia, the cause of giardiasis, significantly impacts patients with metabolic disorders related to insulin resistance (IR). Both giardiasis and metabolic disorders share elements such as chronic inflammation and intestinal dysbiosis, which substantially affect the metabolic and cytokine profiles of patients. This review discusses the mechanisms of virulence of G. lamblia, its influence on the immune system, and its association with metabolic disorders. The review aims to show how G. lamblia invasion acts on the immune system and the glucose and lipid metabolism. Key findings reveal that G. lamblia infection, by disrupting intestinal permeability, alters microbiota composition and immune responses, potentially impairing metabolic status. Future research should focus on elucidating the specific mechanisms by which G. lamblia influences the metabolism, exploring the long-term consequences of chronic infection, and developing targeted therapeutic strategies that include both parasitic and metabolic aspects. These insights underscore the need for a multidisciplinary approach to the treatment of giardiasis in patients with metabolic disorders. Full article