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Research in Veterinary Science Mar 2021This is a review on the current status of Ascaris and Toxocara as agents of disease as a foodborne pathogen that is often transmitted onto produce via contaminated... (Review)
Review
This is a review on the current status of Ascaris and Toxocara as agents of disease as a foodborne pathogen that is often transmitted onto produce via contaminated water. The paper introduces the parasites, their biology, disease caused, and mode of transmission. It summarizes recent research on methods for the detection of the parasites on crops, their prevalence in recent surveys of ready to eat plants in different parts of the world, and potential aspects of their means for remediation on vegetable crops. Also discussed is the ubiquitous nature of the presence of these eggs in the environment due to the many humans infected and means currently underway to control these parasites though improve water quality, sanitation, and hygiene.
Topics: Animals; Ascariasis; Ascaris; Food Parasitology; Humans; Toxocara; Toxocariasis; Water
PubMed: 33412474
DOI: 10.1016/j.rvsc.2020.12.017 -
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 -
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 -
Frontiers in Immunology 2020Parasitic helminths infect over one-fourth of the human population resulting in significant morbidity, and in some cases, death in endemic countries. Despite mass drug... (Review)
Review
Parasitic helminths infect over one-fourth of the human population resulting in significant morbidity, and in some cases, death in endemic countries. Despite mass drug administration (MDA) to school-aged children and other control measures, helminth infections are spreading into new areas. Thus, there is a strong rationale for developing anthelminthic vaccines as cost-effective, long-term immunological control strategies, which, unlike MDA, are not haunted by the threat of emerging drug-resistant helminths nor limited by reinfection risk. Advances in vaccinology, immunology, and immunomics include the development of new tools that improve the safety, immunogenicity, and efficacy of vaccines; and some of these tools have been used in the development of helminth vaccines. The development of anthelminthic vaccines is fraught with difficulty. Multiple lifecycle stages exist each presenting stage-specific antigens. Further, helminth parasites are notorious for their ability to dampen down and regulate host immunity. One of the first significant challenges in developing any vaccine is identifying suitable candidate protective antigens. This review explores our current knowledge in lead antigen identification and reports on recent pre-clinical and clinical trials in the context of the soil-transmitted helminths , the hookworms and . Ultimately, a multivalent anthelminthic vaccine could become an essential tool for achieving the medium-to long-term goal of controlling, or even eliminating helminth infections.
Topics: Animals; Ascariasis; Child; Helminthiasis; Humans; Immunity; Population; Soil; Trichuriasis; Vaccines
PubMed: 33133094
DOI: 10.3389/fimmu.2020.576748 -
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 -
Khirurgiia 2022Ascaris lumbricoides is nematode localized in human small bowel in most cases. This nematode is capable for migration. Pancreatitis is one of the most common surgical...
Ascaris lumbricoides is nematode localized in human small bowel in most cases. This nematode is capable for migration. Pancreatitis is one of the most common surgical diseases. One of the causes of this pancreatitis may be migration of Ascaris lumbricoides from small bowel through the major duodenal papilla to the pancreatic ducts. This migration is provided by complex of morphological and functional disorders of digestive system associated with this helminthiasis, as well as certain risk factors. These are previous cholecystectomy, sphincterotomy, living in endemic areas, massive Ascaris lumbricoides invasion, pregnancy. Damage of the pancreas develops due to direct mechanical effect of nematodes and allergic reactions, papillitis and functional disorders of digestive tract. Pancreatitis is usually mild, but severe course of disease is also possible. A typical symptom of pancreatitis caused by Ascaris lumbricoides is helminths in vomit and/or feces.
Topics: Animals; Ascariasis; Ascaris lumbricoides; Female; Humans; Pancreas; Pancreatic Neoplasms; Pancreatitis; Pregnancy
PubMed: 35775847
DOI: 10.17116/hirurgia202207171 -
Veterinary Parasitology, Regional... Aug 2022Ascaris roundworms are of public health and socio-economic importance worldwide. They are conventionally attributed to two taxa - A. lumbricoides infecting principally...
Ascaris roundworms are of public health and socio-economic importance worldwide. They are conventionally attributed to two taxa - A. lumbricoides infecting principally human and A. suum infecting principally pig. Phylogenomic analysis has revealed that Ascaris worms from both human and pig are represented in Clades A and B. A recent study indicates that the Ascaris worms from human and pig in Thailand belong to Clade A. We examined adult Ascaris worms from human and pig in Thailand by means of the partial sequences of three mitochondrial genes (cox1, cox2 and nad1) and concatenation of these genes. Phylogenomic analysis indicates that two isolates (H1,H2) of A. lumbricoides from human belonged to Clade B; one isolate (H3) belonged to Clade A (based on cox1, cox2 and concatenated sequences) or as an outlier to Clades A and B (based on nad1 sequences). All the eight isolates of A. suum from pig clustered in Clade A. The partial nad1 and the concatenated sequences revealed two lineages of A. suum isolates which were distinct from the two A. lumbricoides isolates of Clade B. It is evident that greater genetic diversity, and a more robust phylogeny, could be uncovered by the application of multiple genes. In sum, the present study reveals the presence in Thailand of A. lumbricoides from human in Clades A and B which necessitates appropriate treatment and control measures; Clades A and B have been reported to contain haplotypes of Ascaris worms from both human and pig in other parts of the world. A country wide study is needed to elucidate the identity, distribution, prevalence, cross transmission, genetic diversity and phylogeny of the Ascaris worms in Thailand.
Topics: Animals; Ascariasis; Ascaris; Ascaris lumbricoides; Ascaris suum; Cyclooxygenase 2; Genetic Variation; Humans; Swine; Thailand
PubMed: 35820723
DOI: 10.1016/j.vprsr.2022.100752 -
Acta Tropica Mar 2023It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human... (Review)
Review
It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human soil-transmitted helminthic diseases, despite their high prevalence globally, particularly in developing countries and rural areas with tropical climates and poor sanitation. The development of vaccines against helminths is riddled with obstacles. Helminths have a complex life cycle, multiple stages within the same host with stage-specific antigen expression, and the ability to regulate host immune reactions to evade the immune response. These elements contribute to the main challenge of helminthic vaccines: the identification of effective vaccine candidates. Therefore, this article reviews the current progress and potential future direction of soil-transmitted helminthic vaccines, particularly against Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercoralis, Necator americanus and Ancylostoma duodenale. The study design employed was a systematic review, using qualitative meta-summary synthesis. Preclinical studies and clinical trials on the development of protein subunit vaccines against the five soil-transmitted helminths were searched on PubMed and Scopus. Effectiveness was indicated by a reduction in worm burden or larval output, an increase in specific IgG levels, or an increase in cytokine production. Our findings show that only the hookworm vaccine against N. americanus is in the clinical trial phase, while the rest is still in exploratory research and pre-clinical development phase.
Topics: Animals; Humans; Soil; Hookworm Infections; Ascaris lumbricoides; Ancylostomatoidea; Necator americanus; Vaccines; Helminthiasis; Feces
PubMed: 36586174
DOI: 10.1016/j.actatropica.2022.106796 -
Veterinary Parasitology Feb 2022The discovery of hybrids between Ascaris lumbricoides and Ascaris suum has complicated our understanding of the relationship between the two species. We examined the...
The discovery of hybrids between Ascaris lumbricoides and Ascaris suum has complicated our understanding of the relationship between the two species. We examined the same Ascaris specimens (48 from humans and 48 from pigs) using two methods: microsatellite markers combined with Bayesian clustering and PCR-RFLP of the nuclear internal transcribed spacer region. The results obtained by the two methods were inconsistent but showed that hybrid Ascaris identified through both approaches could infect pigs. The results of this study suggest that PCR-RFLP of ITS alone is not suitable for molecular identification of human-type and pig-type Ascaris hybrids. Use of multiple SSR markers combined with Bayesian analysis was the most reliable method in our study. Our results indicate that, in addition to host-specific Ascaris types, there may be some that do not show host specificity. Our results show for the first time that hybrid individuals can infect pigs as well as humans. This study has important theoretical and practical implications, including suggesting the need to re-evaluate long-term ascariasis control strategies.
Topics: Animals; Ascariasis; Ascaris; Ascaris lumbricoides; Ascaris suum; Bayes Theorem; Humans; Swine; Swine Diseases
PubMed: 34999317
DOI: 10.1016/j.vetpar.2021.109646 -
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