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Frontiers in Cellular and Infection... 2023Malaria is a parasitic disease of global health significance and a leading cause of death in children living in endemic regions. Although various Plasmodium species are... (Review)
Review
Malaria is a parasitic disease of global health significance and a leading cause of death in children living in endemic regions. Although various Plasmodium species are responsible for the disease, infection accounts for most severe cases of the disease in humans. The mechanisms of cerebral malaria pathogenesis have been studied extensively in humans and animal malaria models; however, it is far from being fully understood. Recent discoveries indicate a potential role of bradykinin and the kallikrein kinin system in the pathogenesis of cerebral malaria. The aim of this review is to highlight how bradykinin is formed in cerebral malaria and how it may impact cerebral blood-brain barrier function. Areas of interest in this context include Plasmodium parasite enzymes that directly generate bradykinin from plasma protein precursors, cytoadhesion of infected red blood cells to brain endothelial cells, and endothelial cell blood-brain barrier disruption.
Topics: Animals; Humans; Bradykinin; Brain; Endothelial Cells; Malaria, Cerebral; Malaria, Falciparum
PubMed: 37637466
DOI: 10.3389/fcimb.2023.1184896 -
Immunity, Inflammation and Disease Sep 2023Ascaridia galli is the largest gut-dwelling helminth of chickens, which confers adverse effects on meat and egg production; thus, on the animal protein supply and the... (Review)
Review
BACKGROUND
Ascaridia galli is the largest gut-dwelling helminth of chickens, which confers adverse effects on meat and egg production; thus, on the animal protein supply and the economy. Both adult and immature parasites affect gut health, but larval stages play a major role in pathology.
AIMS
Here, we present immunology and pathology of A. galli in chickens.
MATERIALS AND METHODS
Literatures were surveyed through online platforms such as PubMed, Google Scholar and Researchgate.
RESULTS
The larvae cause excessive mucus production, damage to the intestinal gland, hemorrhage, anemia, diarrhea, and malnutrition. The adult worms can cause death by intestinal obstruction and intussusception. Although both cellular and humoral immunity are involved in fighting against ascariasis, the role of naturally acquired immunity is poorly defined. In cellular immunity, Th-2 cytokines (IL-4, IL-5, IL-9, and IL-13), goblet cells (mucin), gut-associated lymphoid tissues, CD8α+ intraepithelial cells, TCRγδ + T cells, and TGF-β4 form a protective band. Type 2 immunity provides protection by forming a network of endogenous damage-associated molecular patterns, chitin, and parasitic antigens. Among antibodies, IgY is the most prominent in chickens and provides temporary humoral protection. During parasitic infection, infiltration of various immune cells is evident, especially in the intestinal epithelium, lamina propria, and crypts of the duodenum and jejunum. In chickens older than 12 weeks, gradual reduction of worm burden is more successful than the younger birds. Female chickens exert a short-lived but higher level of protection by passing IgY to chicks in the form of egg yolk antibodies. In laying conditions, immunity differs between breeds. This review provides an overview of the silent but inevitable pathological changes induced by A. galli and the interaction of host immunity with the parasite.
Topics: Animals; Female; Ascaridia; Ascaridiasis; Chickens; Cytokines; Intestinal Mucosa; Antibodies
PubMed: 37773698
DOI: 10.1002/iid3.1001 -
Revista Da Sociedade Brasileira de... 2023Enterobius vermicularis, an intestinal helminth, is transmitted through the ingestion of eggs found in food, water, dust, or other fomites, including infected... (Review)
Review
Enterobius vermicularis, an intestinal helminth, is transmitted through the ingestion of eggs found in food, water, dust, or other fomites, including infected individuals. This review aimed to examine the frequency and distribution of E. vermicularis infections in Brazil between 1991 and 2022. The conducted bibliographic survey revealed that the frequency of E. vermicularis infections in Brazil ranged from 0.1 to 26.1%, depending on factors such as population ethnicity, individual age group, geographic area, time frame, and diagnostic method. However, these findings were based on a limited number of publications, suggesting that the actual prevalence rates of E. vermicularis infection may still be unknown and potentially underestimated.
Topics: Humans; Animals; Enterobius; Brazil; Helminthiasis; Intestinal Diseases, Parasitic; Prevalence; Enterobiasis
PubMed: 37792827
DOI: 10.1590/0037-8682-0073-2023 -
Marine Drugs Nov 2023Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable... (Review)
Review
Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable efficacy, and long treatment, which have encouraged drug resistance. There is an urgent need to find new, safe, effective, and affordable antiparasitic drugs. Marine-derived cyclic peptides have been increasingly screened as candidates for developing new drugs. Therefore, in this review, a systematic analysis of the scientific literature was performed and 25 marine-derived cyclic peptides with antiparasitic activity (-) were found. Antimalarial activity is the most reported (51%), followed by antileishmanial (27%) and antitrypanosomal (20%) activities. Some compounds showed promising antiparasitic activity at the nM scale, being active against various parasites. The mechanisms of action and targets for some of the compounds have been investigated, revealing different strategies against parasites.
Topics: Humans; Antiparasitic Agents; Peptides, Cyclic; Leishmaniasis; Antiprotozoal Agents; Parasitic Diseases
PubMed: 38132930
DOI: 10.3390/md21120609 -
A versatile microfluidic platform for malaria infection screening and Plasmodium species genotyping.EBioMedicine Dec 2023Malaria, a widespread parasitic disease caused by Plasmodium species, remains a significant global health concern. Rapid and accurate detection, as well as species...
BACKGROUND
Malaria, a widespread parasitic disease caused by Plasmodium species, remains a significant global health concern. Rapid and accurate detection, as well as species genotyping, are critical for effective malaria control.
METHODS
We have developed a Flexible, Robust, Equipment-free Microfluidic (FREM) platform, which integrates recombinase polymerase amplification (RPA) and clustered regularly interspaced short palindromic repeats (CRISPR)-based detection, enabling simultaneous malaria infection screening and Plasmodium species genotyping. The microfluidic chip enabled the parallel detection of multiple Plasmodium species, each amplified by universal RPA primers and genotyped by specific crRNAs. The inclusion of a sucrose solution effectively created spatial separation between the RPA and CRISPR assays within a one-pot system, effectively resolving compatibility issues.
FINDINGS
Clinical assessment of DNA extracts from patients with suspected malaria demonstrates the FREM platform's superior sensitivity (98.41%) and specificity (92.86%), yielding consistent results with PCR-sequencing for malaria detection, which achieved a positive predictive agreement of 98.41% and a negative predictive agreement of 92.86%. Additionally, the accuracy of species genotyping was validated through concordance rates of 90.91% between the FREM platform and PCR-sequencing.
INTERPRETATION
The FREM platform offers a promising solution for point-of-care malaria screening and Plasmodium species genotyping. It highlights the possibility of improving malaria control efforts and expanding its applicability to address other infectious diseases.
FUNDING
This work was financially supported by International Joint Laboratory on Tropical Diseases Control in Greater Mekong Subregion, National Natural Science Foundation of China, the Natural Science Foundation of Shanghai, Bill & Melinda Gates Foundation and National Research and Development Plan of China.
Topics: Humans; Microfluidics; Genotype; China; Plasmodium; Malaria; Sensitivity and Specificity
PubMed: 38029461
DOI: 10.1016/j.ebiom.2023.104898 -
Trends in Parasitology Jul 2023Regulatory T cells (Tregs) are essential to control immune system responses to innocuous self-specificities, intestinal and environmental antigens. However, they may... (Review)
Review
Regulatory T cells (Tregs) are essential to control immune system responses to innocuous self-specificities, intestinal and environmental antigens. However, they may also interfere with immunity to parasites, particularly in chronic infection. Susceptibility to many parasite infections is, to a greater or lesser extent, controlled by Tregs, but often they play a more prominent role in moderating the immunopathological consequences of parasitism, and dampening bystander reactions in an antigen-nonspecific manner. More recently, Treg subtypes have been defined which may preferentially act in different contexts; we also discuss the degree to which this specialisation is now being mapped onto how Tregs maintain the delicate balance between tolerance, immunity, and pathology in infection.
Topics: Humans; T-Lymphocytes, Regulatory; Parasitic Diseases; Intestines
PubMed: 37225557
DOI: 10.1016/j.pt.2023.04.002 -
Scientific Reports Sep 2023Intestinal parasitic infections (IPIs) caused by protozoan and helminth parasites are among the most common infections in humans in low-and-middle-income countries. IPIs...
Intestinal parasitic infections (IPIs) caused by protozoan and helminth parasites are among the most common infections in humans in low-and-middle-income countries. IPIs affect not only the health status of a country, but also the economic sector. Over the last decade, pattern recognition and image processing techniques have been developed to automatically identify parasitic eggs in microscopic images. Existing identification techniques are still suffering from diagnosis errors and low sensitivity. Therefore, more accurate and faster solution is still required to recognize parasitic eggs and classify them into several categories. A novel Chula-ParasiteEgg dataset including 11,000 microscopic images proposed in ICIP2022 was utilized to train various methods such as convolutional neural network (CNN) based models and convolution and attention (CoAtNet) based models. The experiments conducted show high recognition performance of the proposed CoAtNet that was tuned with microscopic images of parasitic eggs. The CoAtNet produced an average accuracy of 93%, and an average F1 score of 93%. The finding opens door to integrate the proposed solution in automated parasitological diagnosis.
Topics: Parasites; Datasets as Topic; Neural Networks, Computer; Ovum; Microscopy; Humans; Intestinal Diseases, Parasitic; Animals
PubMed: 37660120
DOI: 10.1038/s41598-023-41711-3 -
Acta Tropica Jul 2023Annexins (ANXs) exert different functions in cell biological and pathological processes and are thus known as double or multi-faceted proteins. These sophisticated... (Review)
Review
Annexins (ANXs) exert different functions in cell biological and pathological processes and are thus known as double or multi-faceted proteins. These sophisticated proteins might express on both parasite structure and secretion and in parasite-infected host cells. In addition to the characterization of these pivotal proteins, describing their mechanism of action can be also fruitful in recognizing their roles in the pathogenesis of parasitic infections. Accordingly, this study presents the most prominent ANXs thus far identified and their relevant functions in parasites and infected host cells during pathogenesis, especially in the most important intracellular protozoan parasitic infections including leishmaniasis, toxoplasmosis, malaria and trypanosomiasis. The data provided in this study demonstrate that the helminth parasites most probably express and secret ANXs to develop pathogenesis while the modulation of the host-ANXs could be employed as a crucial strategy by intracellular protozoan parasites. Moreover, such data highlight that the use of analogs of both parasite and host ANX peptides (which mimic or regulate ANXs physiological functions through various strategies) might suggest novel therapeutic insights into the treatment of parasitic infections. Furthermore, due to the prominent immunoregulatory activities of ANXs during most parasitic infections and the expression levels of these proteins in some parasitic infected tissues, such multifunctional proteins might be also potentially relevant as vaccine and diagnostic biomarkers. We also suggest some prospects and insights that could be useful and applicable to form the basis of future experimental studies.
Topics: Animals; Humans; Annexins; Parasitic Diseases; Protozoan Infections; Malaria; Leishmaniasis; Parasites
PubMed: 37172709
DOI: 10.1016/j.actatropica.2023.106942 -
Scientific Reports Jun 2023In areas of moderate to intense Plasmodium falciparum transmission, malaria in pregnancy remains a significant cause of low birth weight, stillbirth, and severe anaemia.... (Meta-Analysis)
Meta-Analysis
In areas of moderate to intense Plasmodium falciparum transmission, malaria in pregnancy remains a significant cause of low birth weight, stillbirth, and severe anaemia. Previously, fetal sex has been identified to modify the risks of maternal asthma, pre-eclampsia, and gestational diabetes. One study demonstrated increased risk of placental malaria in women carrying a female fetus. We investigated the association between fetal sex and malaria in pregnancy in 11 pregnancy studies conducted in sub-Saharan African countries and Papua New Guinea through meta-analysis using log binomial regression fitted to a random-effects model. Malaria infection during pregnancy and delivery was assessed using light microscopy, polymerase chain reaction, and histology. Five studies were observational studies and six were randomised controlled trials. Studies varied in terms of gravidity, gestational age at antenatal enrolment and bed net use. Presence of a female fetus was associated with malaria infection at enrolment by light microscopy (risk ratio 1.14 [95% confidence interval 1.04, 1.24]; P = 0.003; n = 11,729). Fetal sex did not associate with malaria infection when other time points or diagnostic methods were used. There is limited evidence that fetal sex influences the risk of malaria infection in pregnancy.
Topics: Infant, Newborn; Female; Pregnancy; Humans; Plasmodium falciparum; Placenta; Malaria; Infant, Low Birth Weight; Stillbirth; Malaria, Falciparum
PubMed: 37365258
DOI: 10.1038/s41598-023-37431-3 -
PLoS Neglected Tropical Diseases Oct 2023Entamoeba histolytica, Giardia, and Cryptosporidium are common intestinal protozoan parasites that contribute to a high burden of childhood morbidity and mortality. Our...
Symptomatic and asymptomatic enteric protozoan parasitic infection and their association with subsequent growth parameters in under five children in South Asia and sub-Saharan Africa.
BACKGROUND
Entamoeba histolytica, Giardia, and Cryptosporidium are common intestinal protozoan parasites that contribute to a high burden of childhood morbidity and mortality. Our study quantified the association between intestinal protozoan parasites and child anthropometric outcomes among children under-5.
METHODS
We analyzed data from 7,800 children enrolled in the Global Enteric Multicenter Study (GEMS) across seven study sites that were positive for intestinal protozoan parasites between December 2007 and March 2011. Parasites were assessed using stool immunoassays (ELISA). We applied multiple linear regression to test the association between any or concurrent parasite and child anthropometric outcomes: length/height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length/height (WHZ) z-score after 60 days of enrollment. Models were stratified by diarrheal symptoms, driven by the study design, and adjusted for potential covariates.
FINDINGS
During the follow-up at day 60 after enrollment, child anthropometric outcomes, among the asymptomatic children showed, negative associations between Giardia with HAZ [β: -0.13; 95% CI: -0.17, -0.09; p<0.001] and WAZ [β -0.07; 95% CI: -0.11, -0.04; p<0.001], but not WHZ [β: -0.02; 95% CI:-0.06, 0.02; p = 0.36]; Cryptosporidium with WAZ [β: -0.15; 95% CI: -0.22, -0.09; p<0.001] and WHZ [β: -0.18; 95%CI: -0.25, -0.12; p<0.001], but not with HAZ [β: -0.03; 95% CI: -0.09, 0.04; p = 0.40]. For symptomatic children, no associations were found between Giardia and anthropometry; negative associations were found between Cryptosporidium with HAZ [β: -0.17; 95% CI: -0.23, -0.11; p<0.001], WAZ [β: -0.25; 95% CI: -0.31, -0.19; p<0.001] and WHZ [β: -0.23; 95% CI: -0.30, -0.17; p<0.001]. Among the asymptomatic 24-59 months children, Giardia had a negative association with HAZ [β: -0.09; 95% CI: -0.15, -0.04; p = 0.001]. No significant associations were found between E. histolytica with child growth.
CONCLUSIONS
While some studies have found that Giardia is not associated with (or protective against) acute diarrhea, our findings suggest that it is associated with growth shortfall. This observation underscores the need for preventive strategies targeting enteric protozoan parasites among young children, to reduce the burden of childhood malnutrition.
Topics: Animals; Child, Preschool; Humans; Infant; Africa South of the Sahara; Asia, Southern; Asymptomatic Infections; Cryptosporidiosis; Cryptosporidium; Diarrhea; Giardiasis; Parasites
PubMed: 37816031
DOI: 10.1371/journal.pntd.0011687