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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 -
PLoS Pathogens Feb 2023In most organisms, the whole genome is maintained throughout the life span. However, exceptions occur in some species where the genome is reduced during development... (Review)
Review
In most organisms, the whole genome is maintained throughout the life span. However, exceptions occur in some species where the genome is reduced during development through a process known as programmed DNA elimination (PDE). In the human and pig parasite Ascaris, PDE occurs during the 4 to 16 cell stages of embryogenesis, when germline chromosomes are fragmented and specific DNA sequences are reproducibly lost in all somatic cells. PDE was identified in Ascaris over 120 years ago, but little was known about its molecular details until recently. Genome sequencing revealed that approximately 1,000 germline-expressed genes are eliminated in Ascaris, suggesting PDE is a gene silencing mechanism. All germline chromosome ends are removed and remodeled during PDE. In addition, PDE increases the number of chromosomes in the somatic genome by splitting many germline chromosomes. Comparative genomics indicates that these germline chromosomes arose from fusion events. PDE separates these chromosomes at the fusion sites. These observations indicate that PDE plays a role in chromosome karyotype and evolution. Furthermore, comparative analysis of PDE in other parasitic and free-living nematodes illustrates conserved features of PDE, suggesting it has important biological significance. We summarize what is known about PDE in Ascaris and its relatives. We also discuss other potential functions, mechanisms, and the evolution of PDE in these parasites of humans and animals of veterinary importance.
Topics: Humans; Animals; Swine; Ascaris; Chromosomes; Nematoda; Base Sequence; DNA
PubMed: 36730159
DOI: 10.1371/journal.ppat.1011087 -
Veterinary Medicine and Science May 2023Migration of Ascaris lumbricoides through the papilla of Vater in humans, and entry into the biliary tree, is well-recognised. Ascaris suum and Toxocara vitulorum have...
Migration of Ascaris lumbricoides through the papilla of Vater in humans, and entry into the biliary tree, is well-recognised. Ascaris suum and Toxocara vitulorum have been recovered from the liver of swine and buffalo. We necropsied a Persian Kurdish filly at age 6 months, weighing ∼100 kg. Death evidently was caused by oleander (Nerium oleander) intoxication. An 8-cm adult male Parascaris was found at the lobar-left hepatic bile duct junction. We suggest that the nematode entered anteriorly into the hepatic tree, via the duodenum, major duodenal papilla, bile duct, left hepatic duct and finally the lobar duct. Considering the brief 4-h elapsed time between death and necropsy, and the 18-cm distance from the major duodenal papilla to the location of the parasite, we conclude that entry into the biliary tree likely occurred ante-mortem. We advise consideration of Parascaris infection in differential diagnosis of equine hepatic and pancreatic dysfunction.
Topics: Humans; Animals; Horses; Female; Swine; Biliary Tract; Liver
PubMed: 36723790
DOI: 10.1002/vms3.1087 -
PLoS Neglected Tropical Diseases Dec 2020Ascaris is a soil-transmitted nematode that causes ascariasis, a neglected tropical disease affecting predominantly children and adolescents in the tropics and...
Ascaris is a soil-transmitted nematode that causes ascariasis, a neglected tropical disease affecting predominantly children and adolescents in the tropics and subtropics. Approximately 0.8 billion people are affected worldwide, equating to 0.86 million disability-adjusted life-years (DALYs). Exploring the molecular biology of Ascaris is important to gain a better understanding of the host-parasite interactions and disease processes, and supports the development of novel interventions. Although advances have been made in the genomics, transcriptomics and proteomics of Ascaris, its lipidome has received very limited attention. Lipidomics is an important sub-discipline of systems biology, focused on exploring lipids profiles in tissues and cells, and elucidating their biological and metabolic roles. Here, we characterised the lipidomes of key developmental stages and organ systems of Ascaris of porcine origin via high throughput LC-MS/MS. In total, > 500 lipid species belonging to 18 lipid classes within three lipid categories were identified and quantified-in precise molar amounts in relation to the dry weight of worm material-in different developmental stages/sexes and organ systems. The results showed substantial differences in the composition and abundance of lipids with key roles in cellular processes and functions (e.g. energy storage regulation and membrane structure) among distinct stages and among organ systems, likely reflecting differing demands for lipids, depending on stage of growth and development as well as the need to adapt to constantly changing environments within and outside of the host animal. This work provides the first step toward understanding the biology of lipids in Ascaris, with possibilities to work toward designing new interventions against ascariasis.
Topics: Animals; Ascaris suum; Chromatography, Liquid; Lipidomics; Lipids; Mass Spectrometry
PubMed: 33264279
DOI: 10.1371/journal.pntd.0008848 -
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 -
Water Research X Jan 2023The safe management of fecal sludge from the 3.4 billion people worldwide that use onsite sanitation systems can greatly reduce the global infectious disease burden.... (Review)
Review
The safe management of fecal sludge from the 3.4 billion people worldwide that use onsite sanitation systems can greatly reduce the global infectious disease burden. However, there is limited knowledge about the role of design, operational, and environmental factors on pathogen survival in pit latrines, urine diverting desiccation toilets, and other types of onsite toilets. We conducted a systematic literature review and meta-analysis to characterize pathogen reduction rates in fecal sludge, feces, and human excreta with respect to pH, temperature, moisture content, and the use of additives for desiccation, alkalinization, or disinfection. A meta-analysis of 1,382 data points extracted from 243 experiments described in 26 articles revealed significant differences between the decay rates and T values of pathogens and indicators from different microbial groups. The overall median T values were 4.8 days, 29 days, >341 days, and 429 days for bacteria, viruses, protozoan (oo)cysts, and eggs, respectively. As expected, higher pH values, higher temperatures, and the application of lime all significantly predicted greater pathogen reduction rates but the use of lime by itself was more effective for bacteria and viruses than for eggs, unless urea was also added. In multiple lab-scale experiments, the application of urea with enough lime or ash to reach a pH of 10 - 12 and a sustained concentration of 2,000 - 6,000 mg/L of non-protonated NHN reduced eggs more rapidly than without urea. In general, the storage of fecal sludge for 6 months adequately controls hazards from viruses and bacteria, but much longer storage times or alkaline treatment with urea and low moisture or heat is needed to control hazards from protozoa and helminths. More research is needed to demonstrate the efficacy of lime, ash, and urea in the field. More studies of protozoan pathogens are also needed, as very few qualifying experiments were found for this group.
PubMed: 37250291
DOI: 10.1016/j.wroa.2023.100171 -
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 -
Jornal de Pediatria Mar 2024Complications of ascariasis are a significant cause of abdominal pain in pediatric emergencies, especially where it is endemic. A literature review was conducted with... (Review)
Review
OBJECTIVE
Complications of ascariasis are a significant cause of abdominal pain in pediatric emergencies, especially where it is endemic. A literature review was conducted with the aim of improving diagnostic and therapeutic approaches for these patients.
DATA SOURCES
A PubMed search was conducted using the key terms "ascariasis complications" and "hepatobiliary ascariasis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, case reports, and reviews published up to December 2023.
SUMMARY OF FINDINGS
Obstruction of the small bowel is the most common complication. Others that are, rarer and more difficult to properly identify and treat, such as biliary, hepatic, and pancreatic complications, acute appendicitis, Meckel's diverticulitis, or peritoneal granulomas. Hepatic and pancreatic complications are rarer and more serious in children than in adults. While plain radiography is usually the only option in cases of intestinal obstruction, ultrasonography is the examination of choice in cases of hepatobiliary, pancreatic, and appendicular ascariasis complications in childhood. The treatment is clinical and conservative in most patients. Surgical treatment is indicated if conservative therapy fails, or if there are signs of complications. Laparoscopy has been used as an excellent technical alternative in adults with hepatobiliary complications of ascariasis, but further studies on its use in children are still needed.
CONCLUSION
The creation of protocols and greater debate on this subject should be encouraged for a better understanding of the disease and to establish an early diagnosis and adequate treatment for children with complications resulting from massive infestation by Ascaris lumbricoides.
PubMed: 38522478
DOI: 10.1016/j.jped.2024.02.001 -
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