Giardia lamblia

Giardia lamblia
Giardia cell, SEM
Klasifikimi shkencor
Domeni:	Eukaryota
Pa klasifikuar:	Excavata
Filumi:	Metamonada
Rendi:	Diplomonadida
Familja:	Hexamitidae
Gjinia:	Giardia
Lloji:	G. lamblia
Emri binomial
Giardia intestinalis (Lambl, 1859) Kofoid & Christiansen, 1915
Sinonimet
Lamblia intestinalis Giardia duodenalis

Giardia lamblia (synonim me Giardia intestinalis, Lamblia intestinalis dhe Giardia duodenalis) është një parazit flagellated protozoan që kolonizon dhe riprodhohet në intestine të vogla, që shkakton giardiasis. Paraziti i giardia njgjitet te epithelium te një ventral adhesive disc, dhe riprodhohet përmes binary fission. Giardiasis nuk përhapet përmes rrugëve të gjakut, nor does it spread to other parts of the gastro-intestinal tract, but remains confined to the lumen of the small intestine. Giardia trophozoites absorb their nutrients from the lumen of the small intestine, and are anaerobes. If the organism is split and stained, it has a very characteristic pattern that resembles a familiar "smiley face" symbol. Chief pathways of human infection include ingestion of untreated sewage, a phenomenon particularly common in many developing countries; contamination of natural waters also occurs in watersheds where intensive grazing occurs.

Ambjenti ku rritet

Giardia infects humans, but is also one of the most common parasites infecting cats, dogs and birds. Mammalian hosts also include cows, beavers, deer, and sheep.

Cikli i jetës

Parasite life cycle.

" This organelle is now termed a mitosome.

Metabolizmin intracellular dhe biokimik

Giardia relies on glucose as its major energy source and breaks glucose down into ethanol, acetate and carbon dioxide. However, it can also use arginine as an energy source. Giardia possesses unique biochemical pathways that suggest that it diverged from other eukaryotes at an early stage in evolution.

B vitamins and bile salts, as well as glucose, are necessary for Giardia to survive, and a low-carbohydrate diet was shown in mice to reduce the number of Giardia organisms present.

Manifestimi i infeksionit

Giardia lamblia seen in a cytologic preparation (cytospin of formalin from small bowel biopsy of a patient with giardia).

Giardiasis on a duodenal biopsy.

Nomenclature of Giardia species is difficult, as humans and other animals appear to have morphologically identical parasites.

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People with recurring Giardia infections, particularly those with a lack of the Immunoglobulin A antibody, may develop chronic disease.

Lactase deficiency may develop in an infection with Giardia, however this usually does not persist for more than a few weeks, and a full recovery is the norm.

Some studies have shown that giardiasis should be considered as a cause of vitamin B₁₂ deficiency, this a result of the problems caused within the intestinal absorption system.

Menyra si të ruhemi

Treatment of drinking water for Giardia is ordinarily indicated in wilderness regions in North America, although at least four researchers disagree with this statement, including Robert W. Derlet, a professor at the University of California-Davis School of Medicine, Timothy P. Welch and Thomas R. Welsh of Tulane Medical School and the Children's Hospital of Cincinnati respectively, and Robert Rockwell, a widely quoted writer who is an engineer by training.

Boiling suspect water for one minute is the surest method to make water safe to drink and kill disease-causing microorganisms like Giardia lamblia if in doubt about whether water is infected with the Giardia parasite.

Trajtimi dhe diagnoza

Giardia lamblia infection in humans is frequently misdiagnosed. Accurate diagnosis requires an antigen test or, if that is unavailable, an ova and parasite examination of stool. Multiple stool examinations are recommended, since the cysts and trophozoites are not shed consistently. Given the difficult nature of testing to find the infection, including many false negatives, some patients should be treated on the basis of empirical evidence; treating based on symptoms.

Human infection is conventionally treated with metronidazole, tinidazole or nitazoxanide. Although Metronidazole is the current first-line therapy, it is mutagenic in bacteria and carcinogenic in mice, so should be avoided during pregnancy. It has not directly been linked to causing cancer in humans, only in other mammals, therefore appears safe. One of the most common alternative treatments is berberine sulfate (found in Oregon grape root, goldenseal, yellowroot, and various other plants). Berberine has been shown to have an antimicrobial and an antipyretic effect. Berberine compounds cause uterine stimulation, and so should be avoided in pregnancy. Continuously high dosing of berberine may lead to bradycardia and hypotension in some individuals.

Drug	Treatment duration	Possible Side Effects
Metronidazole	5–7 ditë	Shije metalike; të përzihet; vomiting; dizziness; headache; disulfiram-like effect; neutropenia
Tinidazole	Një dozë evetme	Shije metalike; të përzihet; vomiting; belching; dizziness; headache; disulfiram-like effect
Nitazoxanide	3 ditë	Abdominal pain; diarrhea; vomiting; headache; yellow-green discolouration of urine
Albendazole	5 ditë	Dizziness; headache; fever; të përzihet; vomiting; temporary hair loss

Table adapted from Huang, White.

Mikroskopia

This picture shows multiple views of a single Giardia lamblia (intestinalis) cyst as imaged at different instrument settings by confocal microscopy.Bar = 10 micrometers.
(A) is the cyst imaged by transmission (differential interference contrast), only.
(B) is the cyst wall selectively imaged through use of fluorescent-labelled (TRITC) antibody that is cyst wall specific.
(C) is the cyst imaged through use of carboxy fluorescein diacetate, a viability stain.
(D) is a composite image of (B) and (C).
(E) is a composite image of (A), (B), and (C).

Genomics

Seven genotypes have been recognised to date (A-G). Of these B is the most widespread. Only types A and B have been shown to be infectious to humans.

Referime

 Commons: Giardia lamblia – Album me fotografi dhe/apo video dhe materiale multimediale