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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 -
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 -
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 -
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 -
International Journal of Infectious... May 2019Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-toff MS) is a reliable method for diagnosing a number of bacterial and fungal... (Review)
Review
INTRODUCTION
Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-toff MS) is a reliable method for diagnosing a number of bacterial and fungal infections. It is also effective as a method of rapid diagnosis of several parasitic agents. We used MALDI-toff MS to study the protein profiles of four nematodes: Dirofilaria repens, Dirofilaria. immitis, Ascaris suum and Ascaris lumbricoides.
METHODS
We studied the protein profiles of dirofilaria (five of each species: D. repens and D. immitis) and ascaris (five of each species: A. suum and A. lumbricoides), using a proteomic analysis based on MALDI-toff MS.
RESULTS
Analysis of protein extracts of dirofilaria and ascaris showed spectra with high-intensity peaks in the range of 2-20 kDa. The quality of the spectra (clear graphical reflection of mass/charge to luminous intensity, consistent in repeated analyzes) and the intensity of the spectral peaks were consistent in all samples of the same species. The spectra profiles of D. repens and D. immitis differed in eight major peaks which makes it possible to differentiate species according to the protein profile. The spectra profiles obtained from A. suum and A. lumbricoides proteins differed slightly in 3 major peaks in both species and were discovered in m/z 13000; 13400 and 14400. The protein peaks in diapason 3000 kD-7300 kD specific for all genus ascaris are constant.
CONCLUSIONS
MALDI-toff MS-based proteomic analysis can serve as an effective taxonomic tool for parasitological studies.
Topics: Animals; Ascaris; Dirofilaria immitis; Dirofilaria repens; Female; Proteomics; Species Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 30849497
DOI: 10.1016/j.ijid.2019.02.047 -
Quarterly Journal of Experimental... Dec 19891. The structure and physiological properties of the somatic neuromuscular system of the nematode Ascaris lumbricoides var. suum are discussed taking into account early... (Review)
Review
1. The structure and physiological properties of the somatic neuromuscular system of the nematode Ascaris lumbricoides var. suum are discussed taking into account early work from this laboratory, the results of other workers, and experiments in progress. 2. Anatomically, the central feature of the somatic musculature is the presence of a specialized muscular, but not contractile, structure: the syncytium or sarcopile, formed by the terminal processes of the muscle cell arms that contact the nerve cord. In this region, they are electrically coupled to one another and form chemical synapses with the nerve fibres. 3. The syncytium serves, primarily, as a nerve-muscle manifold, or device which allows the neural control of the muscle fields with great economy in the amount of nervous tissue, numbers of chemical junctions and quantities of synaptic transmitters. 4. The structure of the syncytium is being studied with the scanning electron microscope. The results reveal the convergence of the arms on discrete sites as they approach the cords, as well as a longitudinal arrangement of the terminal processes as they course over the cords, at least in the posterior region of the animal. 5. The characteristics of the electrical coupling between the muscle cells are being investigated. A pattern has been observed that is dependent on the position of the cell pairs with respect to the longitudinal axis of the animal. 6. A study of signal propagation in the arms has revealed that the morphology of the muscle cells contributes to the extent and preferential direction of propagation.
Topics: Animals; Ascaris; Muscles; Nervous System; Nervous System Physiological Phenomena
PubMed: 2697017
DOI: 10.1113/expphysiol.1989.sp003334 -
Parasitology 1991
Comparative Study Review
Topics: Amino Acid Sequence; Animals; Ascaris; Cell Communication; Chromatography, High Pressure Liquid; Electrophysiology; Immunoenzyme Techniques; Molecular Sequence Data; Nematoda; Neurons; Neuropeptides
PubMed: 2057216
DOI: 10.1017/s0031182000073339 -
Parasitology Mar 2007Ascaris is a large parasitic roundworm (nematode) of the small intestine of humans and pigs, which causes the socio-economically important disease, ascariasis. To better... (Review)
Review
Ascaris is a large parasitic roundworm (nematode) of the small intestine of humans and pigs, which causes the socio-economically important disease, ascariasis. To better understand the relationship of Ascaris between the 2 host species, recent studies in China have focused on investigating the genetics and epidemiology of Ascaris from humans and pigs using a mutation scanning-based approach. Findings provided support for a low level of gene flow between the human and porcine Ascaris populations. Extending the studies of genotypic variability within Ascaris from humans and pigs, experimental infections of mice and pigs with selected genotypes of Ascaris were carried out. Initial results indicate that there is a significant difference in the ability of Ascaris eggs of genotype G1 (derived from human) and G3 (derived from pig) to infect and establish as adults in pigs, supporting the difference in the frequencies of these genotypes in natural Ascaris populations between pigs and humans in China. Taken together, current information supports that there is limited cross-infection of Ascaris between humans and pigs in endemic regions and that pigs are not a significant reservoir of human infection with the adult nematode in such areas.
Topics: Animals; Ascariasis; Ascaris; China; DNA, Helminth; DNA, Mitochondrial; DNA, Ribosomal; Genotype; Humans; Mice; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Polymorphism, Single-Stranded Conformational; Swine; Swine Diseases
PubMed: 17052373
DOI: 10.1017/S0031182006001521 -
Parasitology Feb 1968
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Journal of Helminthology Jul 2015To shed light on the epidemiology of ascariasis in Ecuador and Zanzibar, 177 adult worms retrieved by chemo-expulsion from either people or pigs were collected, measured...
To shed light on the epidemiology of ascariasis in Ecuador and Zanzibar, 177 adult worms retrieved by chemo-expulsion from either people or pigs were collected, measured and subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the ribosomal internal transcribed spacer (ITS) region. Upon double digestion with RsaI and HaeIII, PCR-RFLP analysis revealed the presence of A. lumbricoides in people and A. suum in pigs in Ecuador. In contrast, while there are no pigs on Zanzibar, of the 56 worms obtained from people, one was genotyped as A. suum. No additional genetic variation was detected upon further PCR-RFLP analysis with several other restriction enzymes. Upon measurement, worm mass and length differed by location and by species, A. suum being lighter and longer. While there is no evidence to suggest zoonotic transmission in Ecuador, an enduring historical signature of previous zoonotic transmission remains on Zanzibar.
Topics: Animals; Ascariasis; Ascaris; Child; Ecuador; Humans; Swine; Swine Diseases; Tanzania
PubMed: 26017334
DOI: 10.1017/S0022149X14000431