Entamoeba histolytica is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. Entamoeba histolytica is an anaerobic parasitic protozoan, part of the genus entamoeba. Although the majority of individuals infected with e. With increased travel and emigration to developed countries, infection is becoming more common in nonendemic areas. Predominantly infecting humans and other primates causing amoebiasis, e. Clinical manifestations of amebic infection range widely from asymptomatic to severe symptoms, including dysentery and extraintestinal abscesses. It may also occur in the liver, lungs and rarely invades brain, spleen, etc. Of these entamoeba histolytica is the only species found to be associated with intestinal disease. Entamoeba histolytica is a an anaerobic parasitic protozoan that is responsible for the development of amoebiasis. In a small percentage of infections, the trophozoites become. However, trophozoites can invade the colonic epithelium. Entamoeba medium himedia leading biosciences company. Entamoeba histolytica is an invasive, pathogenic protozoan, causing amoebiasis, and an important cause of diarrhea in developing countries.
In endemic developing countries where resources are limited, microscopic examinations based on wheatley trichrome staining is commonly used for diagnosis of intestinal amoebiasis. Differentiating entamoeba histolytica, entamoeba dispar. Entamoeba histolytica is an intestinal parasite and the causative agent of amoebiasis, which is a significant source of morbidity and mortality in. Entamoeba histolytica modes of transmission human being is the principle host source of infection.
Entamoeba histolytica is a pseudopodforming nonflagellate protozoan parasite. Cysts are usually found in stool, whereas trophozoites are found only during diarrheal phases trophozoites can be carried to the liver via. Entamoeba histolytica, the causative agent of amebiasis, is a protozoan parasite that accounts for an estimated 100,000 annual deaths globally. Infection ranges from mostly asymptomatic colonization of the large bowel to invasive and potentially fatal intestinal and extraintestinal disease, with a special predilection for liver abscess formation. Itis taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. Life cycle of entamoeba histolytica infective cysts are ingested excystation occurs in small intestine, releasing 4 amoebae which divide into 8 amoebae pass to large intestine and divide into trophozoites form cysts that pass with feces. It is estimated approximately 1% of humans are infected with e. Overexpression of differentially expressed genes identified in nonpathogenic and pathogenic entamoeba histolytica clones allow identification of new pathogenicity factors involved in amoebic liver abscess. Jun 10, 2011 entamoeba histolytica is an important protozoan intestinal infection in resourcepoor settings, including vietnam. It inhabits the mucous and submucous layers of the large intestine. Entamoeba phylogeny and mitosome discovery entamoeba histolytica is an intestinal parasite of humans that colonises the large intestine. Entamoeba histolytica and entamoeba dispar basic guidelines a. Entamoeba histolytica pathogenic yes disease amoebiasis acquired faecaloral transmission.
It feeds mainly on the tissues of the intestinal wall and often produces severe ulcers and abscesses. Entamoeba histolytica is a protozoan endoparasite inhabiting the mucosa and submucosa layers of the large intestine of human beings, causing dysentery and liver abscess. Over the same period it has also become clear that the true incidence of e. Ingestion of fecally contaminated food or water is the primary mode of transmission. May 12, 2016 entamoeba histolytica is a protozoan parasite and the causative agent of amebiasis. Entamoeba histolytica occurs in the following forms, the trophozoites,precyst,cyst,metacyst,andmetacystictrophozoite. However, it is not a legal authority for statutory or regulatory purposes. Entamoeba histolytica, the causative agent of amebiasis, was first described in 1875. Entamoeba histolytica an overview sciencedirect topics.
Entamoeba histolytica is a protozoan parasite and the causative agent of amebiasis. Entamoeba histolytica introduction there is a large number of species of amoebae which parasitise the human intestinal tract. Entamoeba histolytica is an anaerobic parasitic amoebozoan, part of the genus entamoeba. Genus entamoeba contains the most important of the amoebae causing disease in humans. Entamoeba histolytica and entamoeba dispar realtime pcr 2,3 principle the e. The other species are important because they may be confused with e. Although many people harbour this organism world wide, only about 10% develop clinically. Entamoeba histolytica is an endoparasite and the parasite inhabits the mucous and submucous layers of the large intestine of man. This study aimed to determine the frequency of entamoeba histolytica and entamoeba dispar infection in school children in the community of tlaltizapan, in order to understand the dynamics of infection within the school and family spheres of this population. Identification of entamoeba histolytica trophozoites in. Entamoeba histolytica frequently infest as a commensal within the human large intestines with no overt clinical manifestations. While every effort has been made to provide the most reliable and uptodate information available, ultimate legal requirements with respect to species are contained in. Previously, it was thought that 10% of the world population was infected, but these.
Entamoeba histolytica is an anaerobic parasitic protozoan that infects the digestive tract of predominantly humans and other primates. Multiple stool samples at least 3 should be tested before a negative result is reported. Ingestion of contaminated food or water with amoebae cyst infective stage. Nov 15, 20 entamoeba histolytica distribution parasite has worldwide distribution but is most common in the tropical and subtropical areas of the world. Entamoeba histolytica a number of outbreaks have resulted from a breakdown in sanitation or behavioral practices of people. The study objective was to assess risk factors of e. Entamoeba histolytica is well recognized as a pathogenic ameba, associated with intestinal and extraintestinal infections. Life cycle cysts ingested by man reach the colon where reversion to trophozoites occurs and multiplication ensues. It is a parasite that infects an estimated 50 million people around the world and is a significant cause of morbidity and mortality in developing countries. Several protozoan species in the genus entamoeba colonize humans, but not all of them are associated with disease. Entamoeba histolytica is an intestinal parasite and the causative agent of amoebiasis, which is a significant source of morbidity and mortality in developing countries 1.
Entamoeba histolytica infection was defined as a positive test for amebic antigen in stool. Our understanding of its epidemiology has dramatically changed since this amoeba was distinguished from another morphologically similar one, entamoeba dispar, a non pathogenic and commensal parasite. In man, the main reservoir of infection, this species inhabits the lumen of colon and caecum. Entamoeba histolytica infection in children and protection. The occurrence of entamoeba histolytica as a human intestinal parasite is a serious problem especially in developing countries.
In most infected individuals the trophozoites exist as commensals. It contains four nuclei when mature, one nucleus when immature with glycogen in a. Entamoeba histolytica trophozoite islamic university of gaza. Entamoeba histolytica, a protozoan parasite, is the etiologic agent of amoebiasis in humans. View entamoeba histolytica research papers on academia. Molecular differentiation of entamoeba histolytica and entamoeba dispar from stool and culture samples obtained from polish citizens infected in tropics and in poland przemysaw myjak 1, jozef kur 2, halina pietkiewicz, andrzej kot. Entamoeba histolytica causes about 50 million infections worldwide with a death rate of over 100,000 annually. Analysis of the genome allows new insight into the. To maximize recovery of cysts, stool samples in formalin, or other fixatives, should be concentrated prior to microscopic examination e. Entamoeba polecki is an intestinal protozoan which is best known for its infection and never identified or were misdiagnosed as e. Although a large number of people throughout the world are infected with this organism, only a small.
Pathogenesis of infection by entamoeba histolytica. A casecontrol study was conducted among residents of hanam province, northern vietnam. Entamoeba coli life cycle and location identical to. The genome of the protist parasite entamoeba histolytica. Risk factors for entamoeba histolytica infection in an. Amoebiasis is an unsolved public health problem and an endemic disease in. This blood test tells your healthcare provider whether you have antibodies in your blood to the parasite entamoeba histolytica. Thus, reducing this contamination is the best method of prevention. The structure and life cycle of entamoeba with diagram. In a small percentage of infections, the trophozoites become invasive and. Entamoeba histolytica distribution parasite has worldwide distribution but is most common in the tropical and subtropical areas of the world. Entamoeba histolytica is a histozoic, pathogenic and monogenetic parasite invading the mucosal and submucosal layers of the large intestine in man.
Entamoeba histolytica is a pathogenic parasite in the intestine of human beings and many other primates. Entamoeba histolytica antibody health encyclopedia. Entamoeba histolytica and giardia lamblia were isolated from the stool sample of a 45 year old man, and shigella sonnei was isolated from the stool sample of an 18 year old woman. Entamoeba histolytica and another ameba, entamoeba dispar, which is about 10 times more common, look the same when seen under a microscope. Differentiating entamoeba histolytica, en tamoeba dispar and.
Prevention and control of amoebic dysentery in hong kong. Research article open access entamoeba histolytica and. Infections with entamoeba species can result in either a harmless colonization of the intestine or invasion of the colonic wall and damage of other host tissues such as liver, lung and brain. House flies and cockroaches mechanical transmission. The genus entamoeba comprises six species, namely entamoeba histolytica, e. Explanations usually entail one of two general theories. Entamoeba medium formulated by cleveland and sanders 3 and cleveland and collier 4, is used for the cultivation of e. Right upper quadrant pain, fever clinical specimen intestinal. Extraintestinal localizations in liver, lung, brain, skin and other tissues are always secondary to an invasive amoebic colitis infection with entamoeba histolytica is acquired by indirect fecaloral route or by sexual intercourse.
Entamoeba coli is a nonpathogenic species of entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract. Entamoeba histolytica is an important protozoan intestinal infection in resourcepoor settings, including vietnam. Both patients experienced diarrhea and severe abdominal cramps, and prior to onset of digestive symptoms both had been treated by the same chiropractor. Molecular differentiation of entamoeba histolytica.1334 281 380 1050 977 421 1042 1218 972 879 590 604 279 1442 1437 434 1542 27 624 259 546 1462 1432 1070 988 487 1036 1471 749 1530 1297 728 305 103 1326 972 2 1365 725 645 58 1488 697 879 607 789