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Microbes and Infection Jul 2011Ascaris lumbricoides and Ascaris suum are widespread parasitic nematodes of humans and pigs respectively. Recent prevalence data suggests that approximately 1.2 billion... (Review)
Review
Ascaris lumbricoides and Ascaris suum are widespread parasitic nematodes of humans and pigs respectively. Recent prevalence data suggests that approximately 1.2 billion people are infected. Adult worms exhibit an overdispersed frequency distribution in their hosts and individuals harbouring heavy burdens display associated morbidity. In this review, we describe the parasite, its distribution and measures undertaken to control infection.
Topics: Animals; Ascariasis; Ascaris; Feces; Humans; Intestinal Diseases, Parasitic; Life Cycle Stages; Liver Diseases, Parasitic; Prevalence; Swine
PubMed: 20934531
DOI: 10.1016/j.micinf.2010.09.012 -
Current Biology : CB May 2020Wang and Davis provide an overview of the parasite nematode Ascaris, including the history of its role in biological research.
Wang and Davis provide an overview of the parasite nematode Ascaris, including the history of its role in biological research.
Topics: Animals; Ascariasis; Ascaris; Female; Humans; Male; Reproduction
PubMed: 32428467
DOI: 10.1016/j.cub.2020.02.064 -
Frontiers in Cellular and Infection... 2022Helminth infections remain a global public health issue, particularly in low- and middle-income countries, where roundworms from the and genera are most prevalent.... (Review)
Review
Helminth infections remain a global public health issue, particularly in low- and middle-income countries, where roundworms from the and genera are most prevalent. These geohelminths not only impact human health but most importantly also affect animal well-being, in particular the swine industry. Host-helminth parasite interactions are complex and at the same time essential to understand the biology, dynamics and pathophysiology of these infections. Within these interactions, the immunomodulatory capacity of these helminths in the host has been extensively studied. Moreover, in recent years a growing interest on how helminths interact with the intestinal microbiota of the host has sparked, highlighting how this relationship plays an essential role in the establishment of initial infection, survival and persistence of the parasite, as well as in the development of chronic infections. Identifying the changes generated by these helminths on the composition and structure of the host intestinal microbiota constitutes a field of great scientific interest, since this can provide essential and actionable information for designing effective control and therapeutic strategies. Helminths like and are a focus of special importance due to their high prevalence, higher reinfection rates, resistance to anthelmintic therapy and unavailability of vaccines. Therefore, characterizing interactions between these helminths and the host intestinal microbiota represents an important approach to better understand the nature of this dynamic interface and explore novel therapeutic alternatives based on management of host microbiota. Given the extraordinary impact this may have from a biological, clinical, and epidemiological public health standpoint, this review aims to provide a comprehensive overview of current knowledge and future perspectives examining the parasite-microbiota interplay and its impact on host immunity.
Topics: Animals; Ascaris; Gastrointestinal Microbiome; Helminthiasis; Helminths; Swine; Trichuris
PubMed: 35694539
DOI: 10.3389/fcimb.2022.852900 -
Genes Mar 2021Nematodes of the genus are important parasites of humans and swine, and the phylogenetically related genera (, and infect mammals of veterinary interest. Over the last... (Review)
Review
Nematodes of the genus are important parasites of humans and swine, and the phylogenetically related genera (, and infect mammals of veterinary interest. Over the last decade, considerable genomic resources have been established for , including complete germline and somatic genomes, comprehensive mRNA and small RNA transcriptomes, as well as genome-wide histone and chromatin data. These datasets provide a major resource for studies on the basic biology of these parasites and the host-parasite relationship. and its relatives undergo programmed DNA elimination, a highly regulated process where chromosomes are fragmented and portions of the genome are lost in embryonic cells destined to adopt a somatic fate, whereas the genome remains intact in germ cells. Unlike many model organisms, transcription drives early development beginning prior to pronuclear fusion. Studies on demonstrated a complex small RNA network even in the absence of a piRNA pathway. Comparative genomics of these ascarids has provided perspectives on nematode sex chromosome evolution, programmed DNA elimination, and host-parasite coevolution. The genomic resources enable comparison of proteins across diverse species, revealing many new potential drug targets that could be used to control these parasitic nematodes.
Topics: Animals; Ascariasis; Ascaris; Databases, Genetic; Gene Expression Regulation, Developmental; Genome, Protozoan; Humans; Swine; Transcriptome
PubMed: 33800545
DOI: 10.3390/genes12040493 -
Trends in Parasitology Mar 2021Ascariasis is a globally spread intestinal nematode infection of humans and a considerable concern in pig husbandry. Ascaris accomplishes a complex body migration from... (Review)
Review
Ascariasis is a globally spread intestinal nematode infection of humans and a considerable concern in pig husbandry. Ascaris accomplishes a complex body migration from the intestine via the liver and lung before returning to the intestine. Tissue migration and the habitat shared with a complex microbial community pose the question of how the nematode interacts with microbes and host cells from various tissues. This review addresses the current knowledge of the trilateral relationship between Ascaris, its microbial environment, and host cells, and discusses novel approaches targeting these interactions to combat this widespread infection of livestock and man.
Topics: Animals; Ascariasis; Ascaris; Environment; Gastrointestinal Microbiome; Host-Parasite Interactions; Swine; Swine Diseases
PubMed: 33008723
DOI: 10.1016/j.pt.2020.09.002 -
Ugeskrift For Laeger Jul 2023
Topics: Humans; Animals; Ascaris; Capsule Endoscopy
PubMed: 37539804
DOI: No ID Found -
Parasites & Vectors Feb 2012Since the original description and naming of Ascaris lumbricoides from humans by Linnaeus in 1758 and later of Ascaris suum from pigs by Goeze 1782, these species have... (Review)
Review
Since the original description and naming of Ascaris lumbricoides from humans by Linnaeus in 1758 and later of Ascaris suum from pigs by Goeze 1782, these species have been considered to be valid. Four hypotheses relative to the conspecificity or lack thereof (and thus origin of these species) are possible: 1) Ascaris lumbricoides (usually infecting humans) and Ascaris suum (recorded mostly from pigs) are both valid species, with the two species originating via a speciation event from a common ancestor sometime before the domestication of pigs by humans, or 2) Ascaris lumbricoides in humans is derived directly from the species A. suum found in pigs with A. suum then existing as a persistent ancestor after formation of A. lumbricoides, or 3) Ascaris suum is derived directly from A. lumbricoides with the persistent ancestor being A. lumbricoides and A. suum being the newly derived species, and finally, 4) Ascaris lumbricoides and A. suum are the same species, this hypothesis being supported by studies showing both low morphological and low genetic divergence at several genes. We present and discuss paleoparasitological and genetic evidence that complement new data to evaluate the origin and evolution of Ascaris spp. in humans and pigs, and the uniqueness of the species in both hosts. Finally, we conclude that Ascaris lumbricoides and A. suum are a single species and that the name A. lumbricoides Linnaeus 1758 has taxonomic priority; therefore A. suum Goeze 1782 should be considered a synonym of A. lumbricoides.
Topics: Animals; Ascariasis; Ascaris lumbricoides; Ascaris suum; Biological Evolution; Genetic Speciation; Humans; Swine; Swine Diseases
PubMed: 22348306
DOI: 10.1186/1756-3305-5-42 -
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 -
Parasitology Research Mar 2022The use of fertilizers based on sewage sludge is common practice. Due to the possible presence of pathogens and eggs of intestinal parasites like Ascaris sp., Toxocara...
The use of fertilizers based on sewage sludge is common practice. Due to the possible presence of pathogens and eggs of intestinal parasites like Ascaris sp., Toxocara sp., and Trichuris sp. in these products, it is necessary to control them. The aim of the study was to determine the presence of parasite eggs in commercial organic fertilizers available on the market. Selected commercial products were tested using the Quinn flotation method and a method dedicated to the study of dewatered sewage sludge. Assessment of the viability of helminth eggs was carried out on the basis of staining with calcein and propidium iodide. In 57% of the tested samples, the presence of live eggs of the abovementioned parasites was detected, and in 21% of samples, the eggs with live larvae were detected. Eggs of Trichuris sp. (50%) and Ascaris sp. (36%) were the most common. The obtained results clearly indicate that the process of hygienization of the sewage sludge before the production of fertilizers was not effective enough and it is necessary to standardize the prophylaxis against the spread of parasitic nematodes in commercially available products.
Topics: Animals; Ascaris; Fertilizers; Parasites; Sewage; Toxocara; Trichuris
PubMed: 35118511
DOI: 10.1007/s00436-022-07451-5 -
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