A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.
Infections with nematodes of the order ASCARIDIDA.
Thin-walled sacs or spaces which function as a part of the respiratory system in birds, fishes, insects, and mammals.
Infection with nematodes of the superfamily OXYUROIDEA.
A genus of nematodes of the superfamily ASCARIDOIDEA. Its organisms are found in the stomachs of marine animals and birds. Human infection occurs by ingestion of raw fish that contain larvae.
A superfamily of nematodes of the order STRONGYLIDA. Characteristics include a fluid-filled outer layer of cuticle and a reduced mouth and bursa.
An order of nematodes consisting of many species which are plant parasites. Female worms lay eggs that hatch either in soil or in the host plant.
Infection with roundworms of the genus ANISAKIS. Human infection results from the consumption of fish harboring roundworm larvae. The worms may cause acute NAUSEA; VOMITING; or penetrate into the wall of the DIGESTIVE TRACT where they give rise to EOSINOPHILIC GRANULOMA in the STOMACH; INTESTINES; or the OMENTUM.
Infection with nematodes of the genus MANSONELLA. Symptoms include pruritus, headache, and articular swelling.
Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).
A genus of nematode worms in the superfamily Heterakoidea. A. galli and A. lineata are important intestinal parasites of domestic fowl.
A superfamily of nematodes. Most are intestinal parasites of ruminants and accidentally in humans. This superfamily includes seven genera: DICTYOCAULUS; HAEMONCHUS; Cooperia, OSTERTAGIA; Nematodirus, TRICHOSTRONGYLUS; and Hyostrongylus.
A phylum of microscopic ecdysozoan invertebrates, closely related to ARTHROPODS. Members exhibit anabiosis and cryptobiosis, dormant states where metabolic activity is reduced or absent, thus making them tolerant to extreme environmental conditions. They are distributed worldwide and most are semi-aquatic.
Infection of the intestinal tract with worms of the genus OESOPHAGOSTOMUM. This condition occurs mainly in animals other than man.
Infections with nematodes of the order STRONGYLIDA.
A genus of parasitic nematodes found in the digestive tract of herbivorous animals. They cause incidental infections in humans from the following species: Trichostrongylus colubriformis, T. orientalis, T. axei, and T. probolurus.
A superfamily of parasitic nematodes which were formerly considered a part of TRICHOSTRONGYLOIDEA. It includes the following genera: Heligmosomum, NEMATOSPIROIDES, and NIPPOSTRONGYLUS. The hosts are rodents.
Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.
A species of intestinal nematode parasites which occur most commonly in mice. Infection is by ingesting larvae. This particular species is used extensively in immunological research.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
Microscopy, Electron, Scanning
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
DNA, Ribosomal Spacer
Sequence Analysis, DNA
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.