-
The Journal of Allergy and Clinical... Jun 2022Ascaris infections, with a worldwide prevalence above 10%, can cause respiratory pathology. However, long-term effects on lung function in humans are largely unknown.
BACKGROUND
Ascaris infections, with a worldwide prevalence above 10%, can cause respiratory pathology. However, long-term effects on lung function in humans are largely unknown.
OBJECTIVE
We investigated the associations of Ascaris exposure with lung function, asthma, and DNA methylation.
METHODS
Serum Ascaris IgG antibodies were measured in 671 adults aged 18 to 47 years (46% women) from Aarhus, Bergen, and Tartu RHINESSA study centers. Seropositivity was defined as IgG above the 90th percentile. Linear and logistic regressions were used to analyze Ascaris seropositivity as associated with lung function and asthma, adjusted for age, height, and smoking and clustered by center. DNA methylation in blood was profiled by a commercial methylation assay.
RESULTS
Ascaris seropositivity was associated with lower FEV (-247 mL; 95% CI, -460, -34) and higher odds for asthma (adjusted odds ratio, 5.84; 95% CI, 1.67, 20.37) among men but not women, also after further adjusting for house dust mite sensitivity, consistent across study centers. At a genome-wide level, Ascaris exposure was associated with 23 differentially methylated sites in men and 3 in women. We identified hypermethylation of the MYBPC1 gene, which can regulate airway muscle contraction. We also identified genes linked to asthma pathogenesis such as CRHR1 and GRK1, as well as a differentially methylated region in the PRSS22 gene linked to nematode infection.
CONCLUSION
Ascaris exposure was associated with substantially lower lung function and increased asthma risk among men. Seropositive participants had sex-specific differences in DNA methylation compared to the unexposed, thus suggesting that exposure may lead to sex-specific epigenetic changes associated with lung pathology.
Topics: Adult; Animals; Ascaris; Asthma; DNA Methylation; Female; Humans; Immunoglobulin G; Lung; Male
PubMed: 34996616
DOI: 10.1016/j.jaci.2021.11.013 -
Parasites & Vectors Nov 2019Many parasites migrate through different tissues during their life-cycle, possibly with the aim to enhance their fitness. This is true for species of three parasite... (Review)
Review
Many parasites migrate through different tissues during their life-cycle, possibly with the aim to enhance their fitness. This is true for species of three parasite genera of global importance, Ascaris, Schistosoma and Plasmodium, which cause significant global morbidity and mortality. Interestingly, these parasites all incorporate the liver in their life-cycle. The liver has a special immune status being able to preferentially induce tolerance over immunity. This function may be exploited by parasites to evade host immunity, with Plasmodium spp. in particular using this organ for its multiplication. However, hepatic larval attrition occurs in both ascariasis and schistosomiasis. A better understanding of the molecular mechanisms involved in hepatic infection could be useful in developing novel vaccines and therapies for these parasites.
Topics: Animals; Ascaris; Humans; Life Cycle Stages; Liver; Plasmodium; Schistosoma
PubMed: 31703729
DOI: 10.1186/s13071-019-3791-2 -
Microbes and Infection 2021Ascaris lumbricoides and Ascaris suum are two closely related parasites that infect humans and pigs. The zoonotic potential of A. suum has been a matter of debate for...
Ascaris lumbricoides and Ascaris suum are two closely related parasites that infect humans and pigs. The zoonotic potential of A. suum has been a matter of debate for decades. Here we sought to investigate the potential human infection by A. suum and its immunological alterations. We orally infected five healthy human subjects with eggs embraced by A. suum. The infection was monitored for symptoms and possible respiratory changes, by an interdisciplinary health team. Parasitological, hematological analyses, serum immunoglobulin, cytokine profiles, and gene expression were evaluated during the infection. Our results show that A. suum is able to infect and complete the cycle in humans causing A. lumbricoides similar symptoms, including, cough, headache, diarrhea, respiratory discomfort and chest x-ray alterations coinciding with larvae migration in the lungs. We also observed activation of the immune system with production of IgM and IgG and a Th2/Th17 response with downregulation of genes related to Th1 and apoptosis. PCA (Principal componts analysis) show that infection with A. suum leads to a change in the immune landscape of the human host. Our data reinforce the zoonotic capacity of A. suum and bring a new perspective on the understanding of the immune response against this parasite.
Topics: Animals; Ascariasis; Ascaris suum; Humans; Larva; Swine; Swine Diseases
PubMed: 34020024
DOI: 10.1016/j.micinf.2021.104836 -
Transactions of the Royal Society of... Aug 2022A large number of studies have assessed risk factors for infection with soil-transmitted helminths (STH), but few have investigated the interactions between the...
BACKGROUND
A large number of studies have assessed risk factors for infection with soil-transmitted helminths (STH), but few have investigated the interactions between the different parasites or compared these between host species across hosts. Here, we assessed the associations between Ascaris, Trichuris, hookworm, strongyle and Toxocara infections in the Philippines in human and animal hosts.
METHODS
Faecal samples were collected from humans and animals (dogs, cats and pigs) in 252 households from four villages in southern Philippines and intestinal helminth infections were assessed by microscopy. Associations between worm species were assessed using multiple logistic regression.
RESULTS
Ascaris infections showed a similar prevalence in humans (13.9%) and pigs (13.7%). Hookworm was the most prevalent infection in dogs (48%); the most prevalent infection in pigs was strongyles (42%). The prevalences of hookworm and Toxocara in cats were similar (41%). Statistically significant associations were observed between Ascaris and Trichuris and between Ascaris and hookworm infections in humans, and also between Ascaris and Trichuris infections in pigs. Dual and triple infections were observed, which were more common in dogs, cats and pigs than in humans.
CONCLUSIONS
Associations are likely to exist between STH species in humans and animals, possibly due to shared exposures and transmission routes. Individual factors and behaviours will play a key role in the occurrence of co-infections, which will have effects on disease severity. Moreover, the implications of co-infection for the emergence of zoonoses need to be explored further.
Topics: Ancylostomatoidea; Animals; Ascaris; Cats; Coinfection; Dogs; Feces; Helminthiasis; Helminths; Hookworm Infections; Humans; Intestinal Diseases, Parasitic; Philippines; Prevalence; Soil; Swine; Trematode Infections; Trichuris
PubMed: 35169848
DOI: 10.1093/trstmh/trac002 -
Veterinary Medicine and Science May 2022Worldwide, intestinal parasites significantly affect the health and production of pigs.
BACKGROUND
Worldwide, intestinal parasites significantly affect the health and production of pigs.
OBJECTIVE
This study assessed the prevalence of Ascaris and Cryptosporidium infection in pigs in the Ejisu-Juaben Municipality of Ghana.
METHOD
Faecal samples from two hundred (200) pigs on four different farms (labelled A, B, C, D) were processed using the Kinyoun modified Ziehl-Neelsen method for Cryptosporidium and the Formol-ether sedimentation method for Ascaris and microscopically examined to identify parasites to the genus level.
RESULTS
The prevalence of Ascaris and Cryptosporidium in the pigs was 76% and 77%, respectively. The weaners had the highest Ascaris prevalence (96.15%) with the piglets recording the least (59.25%). On the other hand, the piglets had the highest prevalence (88.89%) for Cryptosporidium with the boars, sows and weaners recording 75.86%, 75.42% and 73.08% respectively. The prevalence of Ascaris was high in farm D (78.57%) while Cryptosporidium was highest in farm C (86.11%). Generally, there was a significant difference (p = 0.044) in the mean distribution of Cryptosporidium in the pigs.
CONCLUSION
The high burden of Ascaris and Cryptosporidium infections in the pigs suggest the need to adopt and implement effective control measures.
Topics: Animals; Ascaris; Cryptosporidiosis; Cryptosporidium; Farms; Female; Ghana; Male; Parasites; Swine; Swine Diseases
PubMed: 35106957
DOI: 10.1002/vms3.756 -
Parasites & Vectors Dec 2022Ascaris lumbricoides causes human ascariasis, the most prevalent helminth disease, infecting approximately 1 billion individuals globally. In 2019 the global disease...
BACKGROUND
Ascaris lumbricoides causes human ascariasis, the most prevalent helminth disease, infecting approximately 1 billion individuals globally. In 2019 the global disease burden was estimated to be 754,000 DALYs and resulted in 2090 deaths. In the absence of a vaccination strategy, treatment of ascariasis has relied on anthelminthic chemotherapy, but drug resistance is a concern. The propensity for reinfection is also a major challenge to disease control; female worms lay up to 200,000 eggs daily, which contaminate surrounding environments and remain viable for years, resulting in high transmission rates. Understanding the molecular mechanisms of reproductive processes, including control of egg production, spermatogenesis, oogenesis and embryogenesis, will drive the development of new drugs and/or vaccine targets for future ascariasis control.
METHODS
Transcriptome profiles of discrete reproductive and somatic tissue samples were generated from adult male and female worms using Illumina HiSeq with 2 × 150 bp paired-end sequencing. Male tissues included: testis germinal zone, testis part of vas deferens, seminal vesicle and somatic tissue. Female tissues included: ovary germinal zone, ovary part of the oviduct, uterus and somatic tissue. Differentially expressed genes (DEGs) were identified from the fragments per kilobases per million reads (FPKM) profiles. Hierarchical analysis was performed to identify tissue-specific genes. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were employed to identify significant terms and pathways for the DEGs.
RESULTS
DEGs involved in protein phosphorylation and adhesion molecules were indicated to play a crucial role in spermatogenesis and fertilization, respectively. Those genes associated with the G-protein-coupled receptor (GPCR) signaling pathway and small GTPase-mediated signal transduction pathway play an essential role in cytoskeleton organization during oogenesis. Additionally, DEGs associated with the SMA genes and TGF-β signaling pathway are crucial in adult female embryogenesis. Some genes associated with particular biological processes and pathways that were identified in this study have been linked to defects in germline development, embryogenesis and reproductive behavior. In the enriched KEGG pathway analysis, Hippo signaling, oxytocin signaling and tight junction pathways were identified to play a role in Ascaris male and female reproductive systems.
CONCLUSIONS
This study has provided comprehensive transcriptome profiles of discrete A. lumbricoides reproductive tissue samples, revealing the molecular basis of these functionally important tissues. The data generated from this study will provide fundamental knowledge on the reproductive biology of Ascaris and will inform future target identification for anti-ascariasis drugs and/or vaccines.
Topics: Animals; Male; Female; Humans; Ascaris lumbricoides; Gene Expression Profiling; Transcriptome; Ascariasis; Ovary
PubMed: 36539906
DOI: 10.1186/s13071-022-05602-2 -
Acta Parasitologica Mar 2024Ascariasis caused by the helminth Ascaris suum is the most common parasitosis of swine worldwide and it may involve all age categories of pigs. The present study reports...
PURPOSE
Ascariasis caused by the helminth Ascaris suum is the most common parasitosis of swine worldwide and it may involve all age categories of pigs. The present study reports an unusual localization of A. suum worms in the biliary system of a piglet slaughtered for human consumption.
METHODS
The liver was subjected to ultrasound scan and pathological examination. The isolated worms were morphologically examined and the DNA was extracted for the molecular identification of the species involved.
RESULTS
A total of 43 preadult nematodes were found within the gallbladder and the bile ducts. Parasites were morphologically identified as belonging to the genus Ascaris and molecularly as A. suum. At gross examination, the liver was moderately enlarged, with the bile ducts severely dilated. A chronic inflammatory infiltrate was noted, often centered around ectatic bile ducts (up to 5 mm in diameter), lined by hyperplastic epithelium and filled with sections of nematodes. The worm sections showed smooth cuticle, coelomyarian musculature, and an intestinal tract lined by columnar, uninucleated cells within a pseudocoelom. The ex vivo ultrasonographic examination of the liver allowed the visualization of several nematodes in the bile duct lumen and could be suggested for in vivo diagnosis. Unfortunately, the absence of the intestine did not allow to define the pathogenesis of the infection.
CONCLUSION
Although, given the unusual nature of this finding, it is difficult to identify predisposing factors for this A. suum localization, it suggests that ascariasis should be considered in the differential diagnosis of pigs with hepatobiliary disease.
Topics: Animals; Ascariasis; Swine; Swine Diseases; Ascaris suum; Liver; Ultrasonography; Liver Diseases, Parasitic; Gallbladder; Bile Ducts
PubMed: 38424402
DOI: 10.1007/s11686-024-00813-2 -
Frontiers in Genetics 2022Circular RNAs (circRNAs) are a recently identified RNA species with emerging functional roles as microRNA (miRNA) and protein sponges, regulators of gene transcription...
Circular RNAs (circRNAs) are a recently identified RNA species with emerging functional roles as microRNA (miRNA) and protein sponges, regulators of gene transcription and translation, and modulators of fundamental biological processes including immunoregulation. Relevant to this study, circRNAs have recently been described in the parasitic nematode, , suggesting they may have functionally important roles in parasites. Given their involvement in regulating biological processes, a better understanding of their role in parasites could be leveraged for future control efforts. Here, we report the use of next-generation sequencing to identify 1,997 distinct circRNAs expressed in adult female stages of the gastrointestinal parasitic nematode, We describe spatial expression in the ovary-enriched and body wall muscle, and also report circRNA presence in extracellular vesicles (EVs) secreted by the parasite into the external environment. Further, we used an approach to predict that a subset of circRNAs bind both endogenous parasite miRNAs as well as human host miRNAs, suggesting they could be functional as both endogenous and exogenous miRNA sponges to alter gene expression. There was not a strong correlation between circRNA length and endogenous miRNA interactions, indicating circRNAs are enriched for miRNA binding sites, but that human miRNAs were predicted form a more thermodynamically stable bond with circRNAs. These results suggest that secreted circRNAs could be interacting with host miRNAs at the host-parasite interface and influencing host gene transcription. Lastly, although we have previously found that therapeutically relevant concentrations of the anthelmintic drug ivermectin inhibited EV release from parasitic nematodes, we did not observe a direct effect of ivermectin treatment on circRNAs expression or secretion.
PubMed: 35711944
DOI: 10.3389/fgene.2022.884052 -
Frontiers in Cellular and Infection... 2021Soil-transmitted helminths (STH) affect hundreds of millions worldwide and are some of the most important neglected tropical diseases in terms of morbidity. Due to the... (Review)
Review
Soil-transmitted helminths (STH) affect hundreds of millions worldwide and are some of the most important neglected tropical diseases in terms of morbidity. Due to the difficulty in studying STH human infections, rodent models have become increasingly used, mainly because of their similarities in life cycle. and have been proven appropriate and low maintenance models for the study of ascariasis and trichuriasis. In the case of hookworms, despite most of the murine models do not fully reproduce the life cycle of , their proteomic similarity makes them highly suitable for the development of novel vaccine candidates and for the study of hookworm biological features. Furthermore, these models have been helpful in elucidating some basic aspects of our immune system, and are currently being used by numerous researchers to develop novel molecules with immunomodulatory proteins. Herein we review the similarities in the proteomic composition between , and and their respective human counterpart with a focus on the vaccine candidates and immunomodulatory proteins being currently studied.
Topics: Animals; Ascaris lumbricoides; Helminths; Mice; Prevalence; Proteomics; Rodentia; Soil; Trichuriasis
PubMed: 33968800
DOI: 10.3389/fcimb.2021.639573 -
Nature Communications Feb 2022Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We...
Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We analyzed small RNA pathways in the divergent parasitic nematode Ascaris. Ascaris has ten Argonautes with five worm-specific Argonautes (WAGOs) that associate with secondary 5'-triphosphate 22-24G-RNAs. These small RNAs target repetitive sequences or mature mRNAs and are similar to the C. elegans mutator, nuclear, and CSR-1 small RNA pathways. Even in the absence of a piRNA pathway, Ascaris CSR-1 may still function to "license" as well as fine-tune or repress gene expression. Ascaris ALG-4 and its associated 26G-RNAs target and likely repress specific mRNAs during testis meiosis. Ascaris WAGO small RNAs demonstrate target plasticity changing their targets between repeats and mRNAs during development. We provide a unique and comprehensive view of mRNA and small RNA expression throughout spermatogenesis. Overall, our study illustrates the conservation, divergence, dynamics, and flexibility of small RNA pathways in nematodes.
Topics: Animals; Argonaute Proteins; Ascaris; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Gene Expression Regulation, Developmental; Gene Silencing; Germ Cells; Phylogeny; RNA, Messenger; RNA, Small Interfering; Spermatogenesis
PubMed: 35149688
DOI: 10.1038/s41467-022-28482-7