Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Entamoebiasis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

Entamoeba histolytica as a commensal intestinal parasite in homosexual men.

Entamoeba histolytica is considered to be an uncommon, imported organism in the United Kingdom and in many parts of North America, but recent attention has been drawn to the possibility of sexual transmission of this parasite among homosexual men. To determine the prevalence and clinical importance of enteric parasitic infections in men attending a clinic in London for the treatment of sexually transmitted diseases, we studied 354 randomly selected patients who provided a single stool sample that was examined for E. histolytica and other intestinal parasites. Forty-five of the 225 homosexual patients (20 percent) were infected with E. histolytica, but no such infections were found among the 129 heterosexual subjects (P less than 0.0001). With the use of isoenzyme electrophoresis, 34 of the 45 E. histolytica isolates were classified according to zymodeme. All were Zymodeme I or III, which are considered to be nonpathogenic. There was no correlation between the presence of E. histolytica and gastrointestinal symptoms. These findings suggest that E. histolytica is a common commensal in the homosexual population and that, in the absence of evidence of invasive disease, treatment of persons passing cysts of the organism may have little practical benefit.

Adult↗

Amebiasis.

Explore the source record for details and available documents.

Amebicides↗

Genomic DNA differences between pathogenic and nonpathogenic Entamoeba histolytica.

cDNA libraries were constructed from pathogenic (HM-1:IMSS) and nonpathogenic (SAW 1734) isolates of Entamoeba histolytica. A cDNA clone (cEH-P1) specific for pathogenic amoebae was identified by screening with a pool of sera from patients with invasive amoebiasis that had been absorbed with nonpathogenic amoebae. This clone was used for the identification of a homologous clone (cEH-NP1) in the cDNA from nonpathogenic amoebae. Sequence analysis and comparison of the predicted amino acid sequences for both clones disclosed 12% evolutionary divergence in structure. Hybridization of both cDNA probes to genomic DNA from four pathogenic and five nonpathogenic E. histolytica isolates revealed two distinct Southern blot patterns, one characteristic for pathogenic amoebae and the other for nonpathogenic amoebae. Further, the complex pattern of restriction fragments hybridizing to an actin cDNA probe was also different between pathogenic and nonpathogenic isolates but was conserved within each group of amoebae. The results indicate that pathogenic isolates of E. histolytica are genetically distinct from nonpathogenic isolates.

Amino Acid Sequence↗

Intestinal amebiasis: a diagnosis not to be missed.

Entamoeba histolytica is a well-recognized cause of infectious colitis and disseminated amebic abscesses. Most prevalent in the tropics and subtropics, E. histolytica infections may also occur in the developed world. We describe a case of a North American traveler with intestinal amebiasis, a diagnosis first made by colonic biopsy. We review the available diagnostic tools and the role of the surgical pathologist in the detection of this infection.

Adult↗

Prospective evaluation of lactose malabsorption by lactose hydrogen breath test in individuals infected with Entamoeba histolytica and passing cysts.

The aim of the present prospective study was to detect lactose malabsorption in subjects in northern India infected with Entamoeba histolytica and passing cysts. The study group included forty-one patients with E. histolytica cysts in at least one of three consecutive faecal samples. Lactose malabsorption was detected by a lactose H2 breath test. The results were compared with those of forty controls subjects. Thirty-two of forty-one (78.0 %) subjects passing E. histolytica cysts had lactose malabsorption compared with seventeen of forty (42.5 %) control subjects (P<0.01). In conclusion, the present study shows that lactose malabsorption is significantly more common in individuals infected with E. histolytica and passing cysts compared with control subjects.

Adult↗

A nested, multiplex, PCR assay for the simultaneous detection and differentiation of Entamoeba histolytica and Entamoeba dispar in faeces.

The detection of and differentiation between Entamoeba histolytica and Entamoeba dispar are of great importance, both for diagnosis and for epidemiological studies. Most PCR-based methods for the discrimination of these two species employ complex procedures for DNA extraction and require different protocols for E. histolytica and E. dispar, leading to relatively high expenditure, labour costs and turnaround times. A simple, rapid, cost-effective and yet sensitive and specific multiplex PCR technique has now been developed for the simultaneous detection and differentiation of E. histolytica and E. dispar in faecal samples. The detection limit is 200 trophozoites of E. dispar or 1000 trophozoites of E. histolytica/g stool sample. The sensitivity of the assay remains practically unchanged, even in the presence of 20,000 trophozoites of the other species/g stool sample. Thus, this technique may also easily reveal mixed infections, without the danger of misdiagnosis caused by one strain displacing the other in culture.

Animals↗

Fine structural changes at Entamoeba histolytica rabbit kidney cell (RK 13) interface.

When bacteria-free trophozoites of Entamoeba histolytica were added to a monolayer of rabbit kidney cells, cellular injury occurred at the sites of contact. Changes appeared within the cell cytoplasm before there was any generalized cell membrane damage. At some points of contact there was apparent fusion of amoebic and cell cytoplasm. Electron-dense bodies, here interpreted as liposomes, were present in the amoebic cytoplasm and beneath the surface membrane. No surface lysosomes were seen. Various modes of cell damage and enzyme transfer from amoeba to cell are suggested, together with the possibility that cytopathic amoebae are infected with virus particles.

Amebiasis↗

Restoration of virulence to rat of axenically grown Entamoeba histolytica by cholesterol and hamster liver passage.

A virulent strain of Entamoeba histolytica (NIH-200) from a symptomatic human case, cultured in vitro for more than three years, was unable to infect rat caecum or hamster liver. When grown with a mixed bacterial flora, it infected rat caecum but did not produce ulceration. After passaging amoebae growing with bacteria in hamster liver, amoebic hepatic lesions were regularly produced. The amoebae from liver lesions produced ulceration in the caeca of rats. Expoxure to cholesterol of amoebae growing with bacteria or feeding rats orally with cholesterol and injecting these amoebae along with bacteria also led to the production of ulcers in rats. Thus virulent amoebae which have been cultured in vitro for a long time become attenuated but their virulence can be revived.

Animals↗