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Trophozoites
A trophozoite (G. ''trope'', nourishment + ''zoon'', animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing '' Plasmodium falciparum'' and those of the '' Giardia'' group. (The complement of the trophozoite state is the thick-walled cyst form). Life cycle stages Trophozoite and cyst stages are shown in the life cycle of '' Balantidium coli'' the causative agent of balantidiasis. In the apicomplexan life cycle the trophozoite undergoes schizogony (asexual reproduction) and develops into a schizont which contains merozoites Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is .... The trophozoite life stage of '' Giardia'' colonizes and proliferates in the small intestine. Trophozoites develop during the course of the infection into cysts wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giardia Lamblia
''Giardia duodenalis'', also known as ''Giardia intestinalis'' and ''Giardia lamblia'', is a flagellated parasitic microorganism of the genus '' Giardia'' that colonizes the small intestine, causing a diarrheal condition known as giardiasis. The parasite attaches to the epithelium by a ventral adhesive disc or sucker, and reproduces via binary fission. Giardiasis does not spread via the bloodstream, nor does it spread to other parts of the gastrointestinal tract, but remains confined to the lumen of the small intestine. Giardia has an outer membrane that makes it possible to retain life, even when outside of the host body, and which can make it tolerant to chlorine disinfection. ''Giardia'' trophozoites absorb their nutrients from the lumen, and are anaerobes. If the organism is split and stained, its characteristic pattern resembles the familiar "smiley face" symbol. Chief pathways of human infection include ingestion of untreated drinking water (which is the most common m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balantidium Coli
''Balantidium coli'' is a parasitic species of ciliate alveolates that causes the disease balantidiasis. It is the only member of the ciliate phylum known to be pathogenic to humans. Morphology ''Balantidium coli'' has two developmental stages, a trophozoite stage and a cyst stage. In trophozoites, the two nuclei are visible. The macronucleus is long and sausage-shaped, and the spherical micronucleus is nested next to it, often hidden by the macronucleus. The opening, known as the peristome, at the pointed anterior end leads to the cytostome, or the mouth. Cysts are smaller than trophozoites and are round and have a tough, heavy cyst wall made of one or two layers. Usually only the macronucleus and sometimes cilia and contractile vacuoles are visible in the cyst, however, both nuclei are present because nuclear multiplication does not occur when the organism is a cyst. Living trophozoites and cysts are yellowish or greenish in color. Transmission ''Balantidium'' is the only ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodium Falciparum
''Plasmodium falciparum'' is a Unicellular organism, unicellular protozoan parasite of humans, and the deadliest species of ''Plasmodium'' that causes malaria in humans. The parasite is transmitted through the bite of a female ''Anopheles'' mosquito and causes the disease's most dangerous form, falciparum malaria. It is responsible for around 50% of all malaria cases. ''P. falciparum'' is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer (Burkitt's lymphoma) and is classified as a List of IARC Group 2A carcinogens, Group 2A (probable) carcinogen. The species originated from the malarial parasite ''Laverania'' found in gorillas, around 10,000 years ago. Alphonse Laveran was the first to identify the parasite in 1880, and named it ''Oscillaria malariae''. Ronald Ross discovered its transmission by mosquito in 1897. Giovanni Battista Grassi elucidated the complete transmission from a female Anopheles, anopheline mosquit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balantidiasis
Balantidiasis is a protozoan infection caused by infection with ''Balantidium coli''. Symptoms and signs Usually asymptomatic in immunocompetent individuals, but the symptoms of balantidiasis include: * Intermittent diarrhea * Constipation * Vomiting * Abdominal pain * Anorexia * Weight loss * Headache * Colitis * Marked fluid loss The most common ones are intermittent diarrhea and constipation or inflammation of the colon combined with abdominal cramps and bloody stools. Transmission ''Balantidium'' is the only ciliated protozoan known to infect humans. Balantidiasis is a zoonotic disease and is acquired by humans via the feco-oral route from the normal host, the pig, where it is asymptomatic. “Contaminated water is the most common mechanism of transmission. Equally dangerous, however, is the ingestion of contaminated food.” Morphology ''Balantidium coli'' exists in either of two developmental stages: trophozoites and cysts.Ramachandran, Ambili. "Morphology." The Parasite: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giardia
''Giardia'' ( or ) is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada that colonise and reproduce in the small intestines of several vertebrates, causing the disease giardiasis. Their life cycle alternates between a swimming trophozoite and an infective, resistant cyst. ''Giardia'' were first described by the Dutch microscopist Antonie van Leeuwenhoek in 1681. The genus is named after French zoologist Alfred Mathieu Giard. Characteristics Like other diplomonads, ''Giardia'' have two nuclei, each with four associated flagella, and were thought to lack both mitochondria and Golgi apparatuses. However, they are now known to possess a complex endomembrane system as well as mitochondrial remnants, called mitosomes, through mitochondrial reduction. The mitosomes are not used in ATP synthesis the way mitochondria are, but are involved in the maturation of iron-sulfur proteins. The synapomorphies of genus ''Giardia'' include cells with duplicate org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbial Cyst
A microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist or rarely an invertebrate animal, that helps the organism to survive in unfavorable environmental conditions. It can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed and the cell ceases all activities like feeding and locomotion. Encystment, the formation of the cyst, also helps the microbe to disperse easily, from one host to another or to a more favorable environment. When the encysted microbe reaches an environment favorable to its growth and survival, the cyst wall breaks down by a process known as excystation. In excystment, the exact stimulus is unknown for most protists. Unfavorable environmental conditions such as lack of nutrients or oxygen, extreme temperatures, lack of moisture and presence of toxic chemicals, which are not conducive for the growth of the microbeEugene W. Nester, Denise G. Anderson, C. Evans Roberts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten by an infected mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria. Malaria is caused by single-celled microorganisms of the ''Plasmodium'' group. It is spread exclusively through bites of infected ''Anopheles'' mosquitoes. The mosquito bite introduces the parasites from the mosquito's saliva into a person's blood. The parasites travel to the liver where they mature and reproduce. Five species of ''Plasmodium'' can infect and be spread by h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balantidium LifeCycle
''Balantidium'' is a genus of ciliates. It contains the parasitic species ''Balantidium coli'', the only known cause of balantidiasis. History The first-described species of ''Balantidium'', ''B. entozoon'', was described in 1838 by Ehrenberg as a member of the genus ''Bursaria''. ''Balantidium coli'' observed in patients with dysentery was originally described as ''Paramecium coli'' by Malmstein in 1857. In 1858, Edouard Claparède and Johannes Lachmann created the genus ''Balantidium'' and reclassified ''B. entozoon'' as its type species. Stein in 1863 reclassified ''Paramecium coli'' into the genus ''Balantidium''. Transcriptomics Transcriptome data for ''Balantidium ctenopharyngodoni'', from single-cell transcriptome sequencing, were published in 2017 and were the first omics data within the subclass Trichostomatia. Taxonomy A separate genus – '' Neobalantidium'' – has been created for several of these species. ''Balantidium coli'' is one of the species that has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apicomplexan Life Cycle
Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is typified by a ''cellular variety'' with a distinct morphology and biochemistry. Not all apicomplexa develop all the following cellular varieties and division methods. This presentation is intended as an outline of a hypothetical generalised apicomplexan organism. Methods of asexual replication Apicomplexans (sporozoans) replicate via ways of multiple fission (also known as schizogony). These ways include , and , although the latter is sometimes referred to as schizogony, despite its general meaning. Merogony is an asexually reproductive process of apicomplexa. After infecting a host cell, a trophozoite ( see glossary below) increases in size while repeatedly replicating its nucleus and other organelles. During this process, the or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protozoal Merogony
Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is typified by a ''cellular variety'' with a distinct morphology and biochemistry. Not all apicomplexa develop all the following cellular varieties and division methods. This presentation is intended as an outline of a hypothetical generalised apicomplexan organism. Methods of asexual replication Apicomplexans (sporozoans) replicate via ways of multiple fission (also known as schizogony). These ways include , and , although the latter is sometimes referred to as schizogony, despite its general meaning. Merogony is an asexually reproductive process of apicomplexa. After infecting a host cell, a trophozoite ( see glossary below) increases in size while repeatedly replicating its nucleus and other organelles. During this process, the orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merozoites
Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is typified by a ''cellular variety'' with a distinct morphology and biochemistry. Not all apicomplexa develop all the following cellular varieties and division methods. This presentation is intended as an outline of a hypothetical generalised apicomplexan organism. Methods of asexual replication Apicomplexans (sporozoans) replicate via ways of multiple fission (also known as schizogony). These ways include , and , although the latter is sometimes referred to as schizogony, despite its general meaning. Merogony is an asexually reproductive process of apicomplexa. After infecting a host cell, a trophozoite ( see glossary below) increases in size while repeatedly replicating its nucleus and other organelles. During this process, the org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
