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Molecular diagnosis of Entamoeba spp. versus microscopy in the Great Cairo. Acta Parasitol 2017; 62:188-191. [PMID: 28030342 DOI: 10.1515/ap-2017-0022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/10/2016] [Indexed: 01/07/2023]
Abstract
Amoebiasis is a human disease produced by Entamoeba histolytica which causes widespread mortality and morbidity worldwide through diarrheal disease and abscess establishment in parenchymal tissues such as liver, lung, and brain. The true prevalence of infection is unknown for most areas of the world due to the difficulty to characterise Entamoeba histolytica versus other non-pathogenic amoebas with identical morphology, as Entamoeba dispar, and Entamoeba moshkovskii. To overcome microscopy misidentification issues, we tested a nested multiplex polymerase chain reaction (PCR) and a real-time PCR on 194 stool samples collected from incoming dysentery patients in Cairo hospitals diagnosed with E. histolytica by microscopy. Nested PCR showed only 20 (10.3%) samples positive to E. histolytica and 17 (8.7%) to E. dispar. The real-time PCR detected only 19 and 11 samples positive to E. histolytica and E. dispar respectively, showing less sensitivity than the nested PCR. The data show that prevalence of E. histolytica in Cairo is lower when specific diagnosis methods are used instead of traditional microscopy, allowing to differentiate between morphologically identical human amoebas species.
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Morphological and molecular characterization of an uninucleated cyst-producing Entamoeba spp. in captured Rangeland goats in Western Australia. Vet Parasitol 2017; 235:41-46. [PMID: 28215866 DOI: 10.1016/j.vetpar.2017.01.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 11/17/2022]
Abstract
Uninucleated Entamoeba cysts measuring 7.3×7.7μm were detected in faecal samples collected from wild Rangeland goats (Capra hircus) after arrival at a commercial goat depot near Geraldton, Western Australia at a prevalence of 6.4% (8/125). Sequences were obtained at the 18S rRNA (n=8) and actin (n=5) loci following PCR amplification. At the 18S locus, phylogenetic analysis grouped the isolates closest with an E. bovis isolate (FN666250) from a sheep from Sweden with 99% similarity. At the actin locus, no E. bovis sequences were available, and the isolates shared 94.0% genetic similarity with E. suis from a pig in Western Japan. This is the first report to describe the morphology and molecular characterisation of Entamoeba from Rangeland goats in Western Australia and the first study to produce actin sequences from E. bovis-like Entamoeba sp.
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Erythrophagocytosis in Entamoeba histolytica and Entamoeba dispar: a comparative study. BIOMED RESEARCH INTERNATIONAL 2014; 2014:626259. [PMID: 25003123 PMCID: PMC4066688 DOI: 10.1155/2014/626259] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/09/2014] [Accepted: 05/09/2014] [Indexed: 01/08/2023]
Abstract
Entamoeba histolytica is the causative agent of human intestinal and liver amebiasis. The extraordinary phagocytic activity of E. histolytica trophozoites has been accepted as one of the virulence mechanisms responsible for their invasive capacity. The recognition of the noninvasive Entamoeba dispar as a different species has raised the question as to whether the lack of pathogenic potential of this ameba correlates with a limited phagocytic capacity. We have therefore compared the process of erythrophagocytosis in both species by means of light and video microscopy, hemoglobin measurement, and the estimation of reactive oxygen species (ROS). In the present study, we confirmed that E. dispar has lower erythrophagocytic capacity. We also observed by video microscopy a new event of erythrocyte opsonization-like in both species, being more characteristic in E. histolytica. Moreover, E. dispar showed a lower capacity to produce ROS compared with the invasive species and also showed a large population of amoebae that did not engulf any erythrocyte over time. Our results demonstrate that E. histolytica has a higher phagocytic capacity than E. dispar, including a higher rate of production of ROS in the course of ingesting red blood cells.
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Abstract
We report the implementation of a fully on-chip, lensless, sub-pixel resolving optofluidic microscope (SROFM). The device utilizes microfluidic flow to deliver specimens directly across a complementary metal oxide semiconductor (CMOS) sensor to generate a sequence of low-resolution (LR) projection images, where resolution is limited by the sensor's pixel size. This image sequence is then processed with a pixel super-resolution algorithm to reconstruct a single high resolution (HR) image, where features beyond the Nyquist rate of the LR images are resolved. We demonstrate the device's capabilities by imaging microspheres, protist Euglena gracilis, and Entamoeba invadens cysts with sub-cellular resolution and establish that our prototype has a resolution limit of 0.75 microns. Furthermore, we also apply the same pixel super-resolution algorithm to reconstruct HR videos in which the dynamic interaction between the fluid and the sample, including the in-plane and out-of-plane rotation of the sample within the flow, can be monitored in high resolution. We believe that the powerful combination of both the pixel super-resolution and optofluidic microscopy techniques within our SROFM is a significant step forwards toward a simple, cost-effective, high throughput and highly compact imaging solution for biomedical and bioscience needs.
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Compounds of the upper gastrointestinal tract induce rapid and efficient excystation of Entamoeba invadens. Int J Parasitol 2009; 40:751-60. [PMID: 20018192 DOI: 10.1016/j.ijpara.2009.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/24/2009] [Accepted: 11/25/2009] [Indexed: 11/20/2022]
Abstract
The infective stage of Entamoeba parasites is an encysted form. This stage can be readily generated in vitro, which has allowed identification of stimuli that trigger the differentiation of the parasite trophozoite stage into the cyst stage. Studies of the second differentiation event, emergence of the parasite from the cyst upon infection of a host, have been hampered by the lack of an efficient means to excyst the parasite and complete the life cycle in vitro. We have determined that a combination of exposures to water, bicarbonate and bile induces rapid excystment of Entamoeba invadens cysts. The high efficiency of this method has allowed the visualization of the dynamics of the process by electron and confocal microscopy, and should permit the analysis of stage-specific gene expression and high-throughput screening of inhibitory compounds.
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Autophagy during proliferation and encystation in the protozoan parasite Entamoeba invadens. Infect Immun 2008; 76:278-88. [PMID: 17923513 PMCID: PMC2223641 DOI: 10.1128/iai.00636-07] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 06/13/2007] [Accepted: 09/29/2007] [Indexed: 11/20/2022] Open
Abstract
Autophagy is one of the three systems responsible for the degradation of cytosolic proteins and organelles. Autophagy has been implicated in the stress response to starvation, antigen cross-presentation, the defense against invading bacteria and viruses, differentiation, and development. Saccharomyces cerevisiae Atg8 and its mammalian ortholog, LC3, play an essential role in autophagy. The intestinal protozoan parasite Entamoeba histolytica and a related reptilian species, Entamoeba invadens, possess the Atg8 conjugation system, consisting of Atg8, Atg4, Atg3, and Atg7, but lack the Atg5-to-Atg12 conjugation system. Immunofluorescence imaging revealed that polymorphic Atg8-associated structures emerged in the logarithmic growth phase and decreased in the stationary phase and also increased in the early phase of encystation in E. invadens. Immunoblot analysis showed that the increase in phosphatidylethanolamine-conjugated membrane-associated Atg8 was also accompanied by the emergence of Atg8-associated structures during the proliferation and differentiation mentioned above. Specific inhibitors of class I and III phosphatidylinositol 3-kinases simultaneously inhibited both the growth of trophozoites and autophagy and also both encystation and autophagy in E. invadens. These results suggest that the core machinery for autophagy is conserved and plays an important role during proliferation and differentiation in Entamoeba.
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Overdiagnosis of Entamoeba histolytica and Entamoeba dispar in Nicaragua: a microscopic, triage parasite panel and PCR study. Arch Med Res 2006; 37:529-34. [PMID: 16624654 DOI: 10.1016/j.arcmed.2005.10.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 10/11/2005] [Indexed: 11/18/2022]
Abstract
BACKGROUND Based on stool microscopy, an E. histolytica/E. dispar prevalence of 18.6% was found in León, Nicaragua about 10 years ago. Since then, new non-microscopic methods have been developed to discriminate between pathogenic E. histolytica and nonpathogenic E. dispar. The main objectives of the present study were to evaluate the true prevalence of E. histolytica among individuals with diarrhea and to assess the diagnostic procedures carried out at the health center level. METHODS A descriptive study was carried out on patients with diarrhea. Parasite detection was performed by conventional microscopy on native preparations or concentrated and stained specimens, Triage Parasite Panel and by PCR for both E. histolytica and E. dispar. RESULTS In 134 individuals with diarrhea, the prevalence of intestinal parasites was 69% as detected by direct stool examination. E. histolytica/E. dispar was found in eight (6%) of the samples, but the health centers reported 24%. In the Triage Parasite Panel only one case of E. histolytica/E. dispar was found. Analysis by PCR showed E. dispar in ten (7.5%) and E. histolytica in two cases (1.5%). The detection of intestinal coccidia and Dientamoeba fragilis required additional staining methods. CONCLUSIONS PCR results showed that E. histolytica is a rare finding in patients with diarrhea. At the health centers, E. histolytica, E. histolytica/E. dispar were clearly overdiagnosed, with the consequence of overtreatment.
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Abstract
Secretory processes play an important role on the biology and life cycles of parasitic protozoa. This review focus on basic aspects, from a cell biology perspective, of the secretion of (a) micronemes, rhoptries and dense granules in members of the Apicomplexa group, where these organelles are involved in the process of protozoan penetration into the host cell, survival within the parasitophorous vacuole and subsequent egress from the host cell, (b) the Maurer's cleft in Plasmodium, a structure involved in the secretion of proteins synthesized by the intravacuolar parasite and transported through vesicles to the erythrocyte surface, (c) the secretion of macromolecules into the flagellar pocket of trypanosomatids, and (d) the secretion of proteins which make the cyst wall of Giardia and Entamoeba, with the formation of encystation vesicles.
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Midwifery and assisted reproduction in Dictyostelium and Entamoeba. J Biosci 2003; 28:139-40. [PMID: 12711803 DOI: 10.1007/bf02706210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
The cell division cycle of Entamoeba invadens was studied during vegetative growth of trophozoites and during their differentiation into cysts. During vegetative growth of trophozoites, it was observed that DNA synthesis typically continued after one genome content had been duplicated. During encystation, DNA synthesis was arrested after 4n genome content had been synthesised. Using multi-parameter flow cytometry, the light scattering properties of cysts and trophozoites were studied. The cytoplasmic granularity, reflected by the side scatter of light, was proportional to DNA content of trophozoites, whereas cysts with similar DNA contents showed heterogeneity in their cytoplasmic granularity. Dynamic changes in the intracellular calcium pools were observed during differentiation of trophozoites to cysts. Comparison of E. invadens and Entamoeba histolytica cell cycles suggest that both organisms may have similar regulatory processes during cell division and differentiation. Since E. histolytica cannot be induced to encyst in axenic culture, analysis of the E. invadens cell cycle during encystation may be useful for identifying homologous processes in E.histolytica.
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Entamoeba sp. (Sarcomastigophora: Endamoebidae) from ostriches (Struthio camelus) (Aves: Struthionidae). Vet Parasitol 2000; 92:173-9. [PMID: 10962154 DOI: 10.1016/s0304-4017(00)00314-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first case of Entamoeba of the 1-nucleate mature cyst group in birds is described. Trophozoites and cysts of Entamoeba have been found in ostriches (Struthio camelus) from farms located all over Spain. The cysts are large (13.47microm mean diameter); they possess one nucleus when mature, with a large endosome and peripheral chromatine arranged in small granules; chromatoid bodies, when present, are large and elongated. Trophozoites are large (19. 88microm mean diameter), with a clear differentiation between ecto- and endoplasm, this containing numerous vacuoles; the nucleus is large and diffuse. The characteristics of this amoeba resembles but do not completely fulfill those of E. suis and E. chattoni; also, these species are from mammals.
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Molecular epidemiology of Entamoeba spp.: evidence of a bottleneck (Demographic sweep) and transcontinental spread of diploid parasites. J Clin Microbiol 2000; 38:3815-21. [PMID: 11015408 PMCID: PMC87481 DOI: 10.1128/jcm.38.10.3815-3821.2000] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Entamoeba histolytica causes amebic colitis and liver abscess in developing countries such as Mexico and India. Entamoeba dispar is morphologically identical but is not associated with disease. Here we determined the ploidy of E. histolytica and developed PCR-based methods for distinguishing field isolates of E. histolytica or E. dispar. Fluorescence in situ hybridization showed that E. histolytica trophozoites are diploid for five "single-copy" probes tested. Intergenic sequences between superoxide dismutase and actin 3 genes of clinical isolates of E. histolytica from the New and Old Worlds were identical, as were those of E. dispar. These results suggest a bottleneck or demographic sweep in entamoebae which infect humans. In contrast, E. histolytica and E. dispar genes encoding repeat antigens on the surface of trophozoites (Ser-rich protein) or encysting parasites (chitinase) were highly polymorphic. chitinase alleles suggested that the early axenized strains of E. histolytica, HM-1 from Mexico City, Mexico, and NIH-200 from Calcutta, India, are still present and that similar E. dispar parasites can be identified in both the New and Old Worlds. Ser-rich protein alleles, which suggested the presence of the HM-1 strain in Mexico City, included some E. histolytica genes that predicted Ser-rich proteins with very few repeats. These results, which suggest diversifying selection at chitinase and Ser-rich protein loci, demonstrate the usefulness of these alleles for distinguishing clinical isolates of E. histolytica and E. dispar.
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Comparative study of Entamoeba invadens differentiation in three different axenic encystation media. Arch Med Res 2000; 31:S190-1. [PMID: 11070278 DOI: 10.1016/s0188-4409(00)00115-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Effect of agents that modify cAMP levels on growth and differentiation of Entamoeba invadens. Arch Med Res 2000; 31:S198-9. [PMID: 11070282 DOI: 10.1016/s0188-4409(00)00194-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
In this work, we describe the ability of living cells of Entamoeba histolytica to hydrolyze extracellular ATP. In these intact parasites, whose viability was determined by motility and by the eosin method, ATP hydrolysis was low in the absence of any divalent metal (78 nmol P(i)/h/10(5) cells). Interestingly, in the presence of 5 mM MgCl(2) an ecto-ATPase activity of 300 nmol P(i)/h/10(5) cells was observed. The addition of MgCl(2) to the extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 1.23 mM MgCl(2). Both activities were linear with cell density and with time for at least 1 h. The ecto-ATPase activity was also stimulated by MnCl(2) and CaCl(2) but not by SrCl(2), ZnCl(2), or FeCl(3). In fact, FeCl(3) inhibited both Mg(2+)-dependent and Mg(2+)-independent ecto-ATPase activities. The Mg(2+)-independent ATPase activity was unaffected by pH in the range between 6.4 and 8. 4, in which the cells were viable. However, the Mg(2+)-dependent ATPase activity was enhanced concomitantly with the increase in pH. In order to discard the possibility that the ATP hydrolysis observed was due to phosphatase or 5'-nucleotidase activities, several inhibitors for these enzymes were tested. Sodium orthovanadate, sodium fluoride, levamizole, and ammonium molybdate had no effect on the ATPase activities. In the absence of Mg(2+) (basal activity), the apparent K(m) for ATP(4-) was 0.053 +/- 0.008 mM, whereas at saturating MgCl(2) concentrations, the corresponding apparent K(m) for Mg-ATP(2-) for Mg(2+)-dependent ecto-ATPase activity (difference between total and basal ecto-ATPase activity) was 0.503 mM +/- 0.062. Both ecto-ATPase activities were highly specific for ATP and were also able to hydrolyze ADP less efficiently. To identify the observed hydrolytic activities as those of an ecto-ATPase, we used suramin, a competitive antagonist of P(2) purinoreceptors and an inhibitor of some ecto-ATPases, as well as the impermeant agent 4'-4'-diisothiocyanostylbenzene-2'-2'-disulfonic acid. These two reagents inhibited the Mg(2+)-independent and the Mg(2+)-dependent ATPase activities to different extents, and the inhibition by both agents was prevented by ATP. A comparison among the ecto-ATPase activities of three amoeba species showed that the noninvasive E. histolytica and the free-living E. moshkovskii were less efficient than the pathogenic E. histolytica in hydrolyzing ATP. As E. histolytica is known to have a galactose-specific lectin on its surface, which is related to the pathogenesis of amebiasis, galactose was tested for an effect on ecto-ATPase activities. It stimulated the Mg(2+)-dependent ecto-ATPase but not the Mg(2+)-independent ATPase activity.
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The pyruvate:ferredoxin oxidoreductase enzyme is located in the plasma membrane and in a cytoplasmic structure in Entamoeba. Microb Pathog 1998; 25:1-10. [PMID: 9705244 DOI: 10.1006/mpat.1998.0202] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This work investigated the cellular location of the pyruvate:ferredoxin oxidoreductase (PFO) enzyme in Entamoeba. A 1.9 kb fragment located at the 3' end of the Ehpfo gene was cloned in the pRSETB vector and expressed. The recombinant peptide was purified and inoculated in rabbits. By Western blot assays the antibodies detected a single 130 kDa band in all E. histolytica strains tested and in E. moshkovskii. By immunofluorescence, the antibodies showed the presence of PFO in the plasma membrane and in a cytoplasmic structure that appeared as a ring or as a compact small body in E. histolytica strains. In E. invadens and E. moshkovskii (strains FIC and Laredo) PFO was located in the plasma membrane showing different fluorescence patterns. Immunofluorescence on E. histolytica synchronized cultures showed that the cytoplasmic structure appeared in 85, 60, 20 and 10% of the trophozoites in mitosis, G1, S and G2 phases, respectively. By in situ hybridization the Ehpfo gene was found in the nuclei and the trophozoites of the clone A, strain HM1:IMSS, differed in the Ehpfo gene content.
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The differential identification of Blastocystis hominis cysts. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1998; 92:233-5. [PMID: 9625921 DOI: 10.1080/00034989860094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Entamoeba invadens differentiation and Entamoeba histolytica cyst-like formation induced by CO2. Arch Med Res 1997; 28 Spec No:150-1. [PMID: 9033049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Differentiation of Entamoeba histolytica and E. dispar DNA from cysts present in stool specimens by polymerase chain reaction: its field application in the Philippines. Parasitol Res 1996; 82:585-9. [PMID: 8875564 DOI: 10.1007/s004360050169] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
It has been established that two distinct species exist within what was originally known as Entamoeba histolytica. These are E. dispar and E. histolytica, for the nonpathogenic and pathogenic forms, respectively. Differentiation of these two organisms is of great clinical importance since they are morphologically indistinguishable and both forms can infect the human intestinal cavity to different degrees. A simple and rapid DNA-extraction method that can be used directly on formalin-fixed stool specimens has been developed. The extracted DNA was used for the identification of the species existing in the stools by polymerase chain reaction (PCR). A total of 72 randomly collected stool samples from the Philippines were analyzed. In all, 19 samples reacted with E. dispar primers, resulting in the expected 101-bp PCR products; however, none reacted with E. histolytica primers. Furthermore, sensitivity assay suggests that genomic DNA from as few as five cysts can be used as a template for PCR. These observations imply that the use of genomic DNA directly extracted from formalin-fixed stool specimens for PCR amplification is a useful tool for obtaining a sensitive and accurate diagnosis that can be applied even in epidemiology studies.
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Abstract
Entamoeba gingivalis is found only in its trophozoite form and it is postulated that its main transmission mechanism is through the kiss. E. gingivalis is considered pathogenic by some authors and commensal to others. It does not have a defined role in the installation of disease. To address some of this questions we studied a 100 patients who were seen through the Odontological Hospital from the Universidade Federal de Uberlândia in order to determine its frequency in the buccal cavity. The material were collected using swabs from four different buccal sites and the smears were stained by a modified Papanicolaou technique. The results revealed positivity index of 62%. The affinity of the dye to the food vacuole contents and to the ingested bacterias prevents clear visualisation of the central and peripherical chromatin constituents of the parasite's nucleus. Mouth washes with 3ml of saline from 10 patients, were used to evaluate which parasitological method of diagnosis (fresh, iron-haematoxylin stained, Giemsa and Papanicolaou) gives better visualisation of the parasite. The mouth washes sediment from fresh material revealed 100% of positivity and clear visualisation of the free form and locomotion of the trophozoites. No stained technique of the smear showed adequate visualisation, presenting the nucleus partially covered by the food vacuoles. In stained preparations by toluidine blue ultrastructure analysis of the morphology of parasite can be observed.
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Elucidation of the DNA synthetic cycle of Entamoeba spp. using flow cytometry and mathematical modeling. J Eukaryot Microbiol 1995; 42:610-6. [PMID: 7581336 DOI: 10.1111/j.1550-7408.1995.tb05915.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We developed a method to study the DNA synthetic cycles of Entamoeba histolytica and Entamoeba invadens by flow cytometry (FCM) based on a preparative procedure to reduce both high levels of natural fluorescence and non-specific adsorption of fluorochromes. We modeled G1, S, and G2 phases as a series of overlapping Gaussian curves. Both E. histolytica and E. invadens displayed G1, S, and G2 proportions that are consistent with eukaryotic cell populations in exponential or stationary growth phase. Exponential phase E. histolytica populations contained a hypodiploid subset with a mass of about 20% less than the diploid value which we estimate by FCM to be 24 x 10(-14) g DNA/cell. Exponential phase E. invadens populations contained a hypodiploid subset with a mass of about 6% less than the diploid value which we estimate by FCM to be 30 x 10(-14) g DNA/cell.
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Laboratory diagnosis of amebiasis. Clin Lab Med 1991; 11:829-59. [PMID: 1724953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The procedure used to diagnose amebiasis varies depending on the geographic location of the laboratory. However, in general, the microscopic diagnosis and differentiation of E. histolytica from other intestinal amebae is most satisfactorily achieved when the specimen is preserved immediately and both a concentration and stained smear are examined. The number of additional positive findings achieved by the cultivation of fecal material does not justify the time and cost involved. On the other hand, serology is a useful adjunct to diagnosis, especially in patients with extraintestinal amebiasis. The commercial development of antigen detection kits and DNA probes may provide more rapid, accurate, and less costly diagnostic procedures for the future. New guidelines need to be formulated regarding the number of specimens to be submitted, and the cost effectiveness of various diagnostic procedures should be evaluated.
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[Morphology and diagnosis of Entamoeba gingivalis and Trichomonas tenax and their occurrence in children and adolescents]. BRATISL MED J 1991; 92:241-6. [PMID: 2043965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Specimens obtained from 176 eight- to nineteen-year-old subjects were cultured for oral protozoa. Of the given series, 25 subjects (14.2%) had in their mouth only E. gingivalis, 5 (2.9%) had a mixed invasion of E. gingivalis and T. tenax, and 2 subjects (1.1%) had only T. tenax. A total of 32 subjects (18.2%) were infested by oral protozoa. The following conclusions were made: oral protozoa occur also in children and teenagers with a cured or intact dentition; their occurrence rate was higher in 11- to 19-year-old subjects than in the lower age groups; both protozoa can occur simultaneously; their occurrence rate was age dependent (increasing with age) with the rate of E. gingivalis rising significantly more rapidly with age than that of T. tenax; their occurrence was found to be sex dependent with higher rates in boys than in girls. In the light of the high recovery rate (83.3%) of E. gingivalis from dental and periodontal swabs, not only specimens of saliva should be collected but also dental nad periodontal swabs should be taken and cultured when studying the occurrence of oral protozoa in the population. (Tab.4,Fig.2,Ref.7).
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Molecular biology of DNA in Acanthamoeba, Amoeba, Entamoeba, and Naegleria. INTERNATIONAL REVIEW OF CYTOLOGY 1986; 99:311-41. [PMID: 3514511 DOI: 10.1016/s0074-7696(08)61430-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Oral amoebiasis: the role of Entamoeba gingivalis in periodontal disease. QUINTESSENCE INTERNATIONAL, DENTAL DIGEST 1983; 14:1245-8. [PMID: 6585855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Abstract
A survey was made of gingival scrapings stained by the Papanicolaou method to assess the occurrence of Entamoeba gingivalis, a nonpathogenic-oral amoeba. Positive findings were recorded in 59% of 113 dental patients, and 32% of 96 healthy controls. These figures showed no significant changes during the last 20 years when compared with data published in 1960 and 1963. The existence of E. gingivalis and its rare appearance in the sputum should be known to cytologists because of the morphologic resemblance to Entamoeba histolytica, a pathogenic amoeba. Morphologic features are described to differentiate E. gingivalis from similar structures found in sputum.
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The nonpathogenic intestinal protozoa. Am Fam Physician 1983; 28:215-8. [PMID: 6684386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Nonpathogenic intestinal protozoa are frequently reported in fecal specimens sent to laboratories for parasitologic examination. Family physicians should be familiar with the most commonly encountered species.
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28
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[Nuclear division and presence of microtubules in the differentiation of Entamoeba invadens]. ARCHIVOS DE INVESTIGACION MEDICA 1982; 13 Suppl 3:211-216. [PMID: 7181602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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29
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Amebae resembling Entamoeba gingivalis in the genital tracts of IUD users. Acta Cytol 1980; 24:413-20. [PMID: 6933802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A total of 2,252 vaginopancervical (Fast) smears were studied as a continuation of an ongoing program to further investigate the occurrence of amebae in the genital tracts of women using intrauterine devices (IUDs). Of the 947 IUD users, 1% harbored trophic amebae. No amebae, however, were found in any of the 1,164 smears from non-IUD wearers. In all instances the amebae were associated with Actinomyces. Both organisms disappeared promptly after removal of the IUD. In preparations stained according to the Papanicolaou, iron-hematoxylin and Gomori-Wheatley trichrome methods, the amebae could be diagnosed as belonging to the genus Entamoeba. These trophozoites failed to stain with fluorescein-labeled anti-Entamoeba-histolytica serum. Although on the basis of the presently available evidence these trophozoites cannot be assigned with certainty to any known species, they appear to share many morphologic characteristics with Entamoeba gingivalis.
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30
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[Life cycle of Entamoeba invadens studied by means of spatial cinematography]. ARCHIVOS DE INVESTIGACION MEDICA 1980; 11:31-40. [PMID: 7469648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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31
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The relationship of DNA synthesis and cell cycle events to encystation by Entamoeba invadens. ARCHIVOS DE INVESTIGACION MEDICA 1980; 11:3-10. [PMID: 7469646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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32
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[Oral protozoans and diabetes: study in 117 patients]. JOURNAL DE BIOLOGIE BUCCALE 1979; 7:27-30. [PMID: 372177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A study on the presence of oral Entamoeba gingivalis and Trichomonas tenax has been carried out on calculus or dental plaque from 117 diabetic subjects. Statistical analysis of results shows no correlation between diabetes and protozoa. The same frequency was found between diabetic and normal subjects. Nevertheless, a significant relation has been found between the diabetes and the yeasts.
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33
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Two species of Entamoeba from white-tailed deer, Odocoileus virginianus, from Georgia. J Parasitol 1978; 64:14-6. [PMID: 564402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Large numbers of 2 species of Entamoeba, Entamoeba coli and Entamoeba bovis, were recovered from captive white-tailed deer from Georgia. The trophozoite of the first ameba was a large form with a well-defined vesicular nucleus bearing a prominent eccentric endosome, abundant peripheral chromatin, and numerous periendosomal granules. Cytoplasmic vacuoles containing bacteria and other substances were common. Mature cysts were octonucleate. Glycogen vacuoles and irregularly shaped chromatoids were frequently present. This ameba was identified as Entamoeba coli. The trophozoite of the second ameba was small, with a typical Entamoeba nucleus. Cysts were uninucleate, containing numerous chromatoids resembling bars, splinters of wood, and irregular masses. There was occasionally a glycogen vacuole. This ameba was identified as Entamoeba bovis.
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34
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[Oral protozoan diseases: experimental possibilities[]. ACTUALITES ODONTO-STOMATOLOGIQUES 1976:725-44. [PMID: 1020710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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35
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Ultrastructure of Entamoeba moshkovskii with particular regard to the presence of surface active lysosomes. Int J Parasitol 1974; 4:331-3. [PMID: 4855311 DOI: 10.1016/0020-7519(74)90089-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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36
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37
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The ultrastructure of cysts of Entamoeba invadens. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1973; 67:229-31. [PMID: 4722426 DOI: 10.1080/00034983.1973.11686882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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38
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The ultraviolet absorption spectra of chromatoid bodies of Entamoeba invadens in situ: an optical titration. Exp Cell Res 1973; 78:345-50. [PMID: 4698169 DOI: 10.1016/0014-4827(73)90078-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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39
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40
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Characteristics of ribosomes during differentiation from trophozoite to cyst in axenic Entamoeba sp. CELL DIFFERENTIATION 1972; 1:297-306. [PMID: 4677619 DOI: 10.1016/0045-6039(72)90005-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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41
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Comparison of trophozoite helical polysomes with cyst ribosomogen microcrystals in axenic Entamoeba sp. CELL DIFFERENTIATION 1972; 1:307-15. [PMID: 4677635 DOI: 10.1016/0045-6039(72)90006-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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42
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43
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Reconstruction of three-dimensional structures from sectioned helices by deconvolution of partial data. J Mol Biol 1972; 66:255-69. [PMID: 5038452 DOI: 10.1016/0022-2836(72)90477-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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44
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45
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Axenic mass cultivation of Entamoeba invadens and cell membrane isolation. THE JOURNAL OF PROTOZOOLOGY 1972; 19:102-7. [PMID: 5008843 DOI: 10.1111/j.1550-7408.1972.tb03422.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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46
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The nuclear structure of Entamoeba coli. Trans R Soc Trop Med Hyg 1972; 66:12. [PMID: 5048062 DOI: 10.1016/0035-9203(72)90021-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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47
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[Isolation of amoebae of the type "Hartmannella-Acanthamoeba" and "Naelgeria" from cold-blooded vertebrates]. ZEITSCHRIFT FUR PARASITENKUNDE (BERLIN, GERMANY) 1972; 40:139-50. [PMID: 4639181 DOI: 10.1007/bf00329149] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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48
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[Morphological study of pathogenic and potentially pathogenic amoebae of the types "Entamoeba" and "Hartmannella-Acanthamoeba" from reptiles]. ZEITSCHRIFT FUR PARASITENKUNDE (BERLIN, GERMANY) 1972; 40:107-29. [PMID: 4344750 DOI: 10.1007/bf00329147] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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49
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50
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[Microelectronic and microcinematographic investigations on the anti-amebic action of aminosidine]. PATHOLOGIE-BIOLOGIE 1969; 17:1031-8. [PMID: 4314015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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