A free-living soil amoeba pathogenic to humans and animals. It occurs also in water and sewage. The most commonly found species in man is NAEGLERIA FOWLERI which is the pathogen for primary amebic meningoencephalitis in primates.

A species of parasitic protozoa having both an ameboid and flagellate stage in its life cycle. Infection with this pathogen produces PRIMARY AMEBIC MENINGOENCEPHALITIS.

Infection with any of various amebae. It is an asymptomatic carrier state in most individuals, but diseases ranging from chronic, mild diarrhea to fulminant dysentery may occur.

A genus of ameboid protozoa. Characteristics include a vesicular nucleus and the formation of several lodopodia, one of which is dominant at a given time. Reproduction occurs asexually by binary fission.

Infections of the brain, spinal cord, or meninges by single celled organisms of the former subkingdom known as protozoa. The central nervous system may be the primary or secondary site of protozoal infection. These diseases may occur as OPPORTUNISTIC INFECTIONS or arise in immunocompetent hosts.

An inflammatory process involving the brain (ENCEPHALITIS) and meninges (MENINGITIS), most often produced by pathogenic organisms which invade the central nervous system, and occasionally by toxins, autoimmune disorders, and other conditions.

Agents which are destructive to amebae, especially the parasitic species causing AMEBIASIS in man and animal.

One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.

'Swimming pools' in a medical context typically refers to man-made bodies of water designed for swimming and other recreational activities, which can also serve as potential reservoirs for various infectious diseases if not properly maintained, including those transmitted through waterborne pathogens, fecal contamination, or poor water chemistry.

A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.

A genus of free-living amoebae found in fresh water. The cysts usually pass harmlessly through the intestinal tract of man and may thus be found in feces. Occasionally, these organisms cause respiratory tract infections or generalized fatal meningoencephalitis.

Infections with unicellular organisms formerly members of the subkingdom Protozoa.

Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the MEROZOITE and then splits into the SCHIZONT. Trophozoites that are left over from cell division can go on to form gametocytes.

Deoxyribonucleic acid that makes up the genetic material of protozoa.

Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)

A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)

The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.