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Iron-saturated lactoferrin and pathogenic protozoa: could this protein be an iron source for their parasitic style of life?Iron is an essential nutrient for the survival of pathogens inside a host. As a general strategy against microbes, mammals have evolved complex iron-withholding systems for efficiently decreasing the iron accessible to invaders. Pathogens that inhabit the respiratory, intestinal and genitourinary tracts encounter an iron-deficient environment on the mucosal surface, where ferric iron is chelated by lactoferrin, an extracellular glycoprotein of the innate immune system. However, parasitic protozo ...201222191452
Evaluation of the efficacy of a recombinant Entamoeba histolytica cysteine proteinase gene (EhCP5) antigen in Minipig.Entamoeba histolytica cysteine proteinase gene 5(EhCP5) is one of the major proteinase genes of all EhCP-transcripts. The amebiasis cysteine proteinase gene encoding an antigen from E. histolytica, as well as the recombinant EhCP5, obtained by cloning and expression of the EhCP5 gene in heterologous host Escherichia coli BL-21 (DE3), were used to evaluate their ability to induce immune protective responses in Minipig against challenge infection in a minipig-E. histolytica model. There was a 52.2 ...201122202181
Towards the establishment of a porcine model to study human amebiasis.Entamoeba histolytica is an important parasite of the human intestine. Its life cycle is monoxenous with two stages: (i) the trophozoite, growing in the intestine and (ii) the cyst corresponding to the dissemination stage. The trophozoite in the intestine can live as a commensal leading to asymptomatic infection or as a tissue invasive form producing mucosal ulcers and liver abscesses. There is no animal model mimicking the whole disease cycle. Most of the biological information on E. histolytic ...201122205970
evaluation of amoebicidal potential of paneth cell cryptdin-2 against entamoeba histolytica.background: amoebiasis is a major public health problem in tropical and subtropical countries. currently, metronidazole is the gold choice medication for the treatment of this disease. however, reports have indicated towards the possibility of development of metronidazole-resistance in entamoeba strains in near future. in view of the emergence of this possibility, in addition to the associated side effects and mutagenic ability of the currently available anti-amoebic drugs, there is a need to ex ...201122206022
direct detection of the acetate-forming activity of the enzyme acetate kinase.acetate kinase, a member of the acetate and sugar kinase-hsp70-actin (askha) enzyme superfamily(1-5), is responsible for the reversible phosphorylation of acetate to acetyl phosphate utilizing atp as a substrate. acetate kinases are ubiquitous in the bacteria, found in one genus of archaea, and are also present in microbes of the eukarya(6). the most well characterized acetate kinase is that from the methane-producing archaeon methanosarcina thermophila(7-14). an acetate kinase which can only ut ...201122214984
amoebicidal activity of the rhizomes and aerial parts of allium sivasicum on entamoeba histolytica.amebiasis is a severe illness caused by entamoebachistolytica. the aim of this study is to evaluate the in vitro amebicidal activity of the rhizomes and aerial parts of allium sivasicum, an endemic plant species from the flora of turkey. both extracts showed a time- and dose-dependent amebicidal action on the trophozoites. among the extracts tested, rhizomes of a. sivasicum showed the strongest amebicidal effect on the trophozoites. in the presence of the rhizome extract at 2.0 mg/ml concentrati ...201222215196
a parasitological survey of natural water springs and inhabitants of a tourist city in southeastern brazil.abstract the goals of this study were to investigate the occurrence of cryptosporidium oocysts and giardia cysts in main springs of campos do jordão, an important tourist city, in brazil and to gather the largest amount of parasitological data from autochthonous population that live in rural areas of this city. the membrane filtration technique followed by direct immunofluorescence assay was employed for concentration and visualization of waterborne protozoa. in the period between june 2003 an ...201222217166
newly visualized fibrillar collagen scaffolds dictate entamoeba histolytica invasion route in the human colon.the extracellular matrix (ecm) and its role in the outcome of infectious diseases have been poorly investigated. in this study, we determined the impact of the collagen fibres architecture on the invasive process of the enteric parasite entamoeba histolytica. the behaviour of e. histolytica wild-type and silenced for the cysteine protease a5 (cp-a5) were compared on a three-dimensional collagen matrix and within human colon fragments for fibrillar collagen cleavage and migration. the interstitia ...201222233454
probing the antiamoebic and cytotoxicity potency of novel tetrazole and triazine derivatives.a series of compounds bearing a tetrazole and triazine ring motif conjugated with a so(2)nh function were synthesized and investigated for their antiamoebic potency. cytotoxicity of the compounds was checked on human hepatocellular carcinoma cell line hepg2. incorporation of triazine ring in place of tetrazole resulted in a precipitous increase in the antiamoebic activity of the compounds. antiamoebic activity of the investigated compounds was found to be position and substituent dependent. in v ...201122236470
in silico analysis of ubiquitin/ubiquitin-like modifiers and their conjugating enzymes in entamoeba species.covalent modification of proteins by ubiquitin (ub) and ubiquitin-like modifiers (ubls) regulates many cellular functions in eukaryotes. these modifications are likely to be associated with pathogenesis, growth, and development of many protozoan parasites but molecular details about this pathway are unavailable for most protozoa. this study presents an analysis of the ub pathway in three members of the entamoeba species. using bioinformatics tools we have identified all ub and ubl genes along wi ...201222246365
trends and prevalence of intestinal parasites at a tertiary care center in lebanon over a decade.intestinal parasitic infections or infestation are amongst the most prevalent infections worldwide. this study aimed at revealing the changing trends over a decade duration of intestinal parasites identified at a major tertiary care center in lebanon between 1997-1998 and 2007-2008. the total number of specimens tested were 14,771 for 1997-1998 vs 7477 for 2007-2008. the positive findings for parasites were 2077 (14%) vs 1047 (14%), respectively. the majority of recovered parasites in both study ...201122259902
evaluation of an immunochromatographic dip strip test for simultaneous detection of cryptosporidium spp, giardia duodenalis, and entamoeba histolytica antigens in human faecal samples.immunochromatographic (ic) tests may play an important role in the future diagnosis of parasitic diseases because of their speed and simplicity of use. a recently developed test to detect cryptosporidium spp, giardia duodenalis and entamoeba histolytica was evaluated. microscopy and pcr were the "gold standard" reference techniques and the results of this ic test were compared with those obtained with elisa and ic single test for the three parasites. one hundred sixty stool samples were assayed. ...201222262367
human milk oligosaccharides reduce entamoeba histolytica attachment and cytotoxicity in vitro.human milk oligosaccharides (hmo), complex sugars that are highly abundant in breast milk, block viral and bacterial attachment to the infant's intestinal epithelium and lower the risk of infections. we hypothesised that hmo also prevent infections with the protozoan parasite entamoeba histolytica, as its major virulence factor is a lectin that facilitates parasite attachment and cytotoxicity and binds galactose (gal) and n-acetyl-galactosamine. hmo contain gal, are only minimally digested in th ...201222264879
obtaining of three recombinant antigens of entamoeba histolytica and evaluation of their immunogenic ability without adjuvant in a hamster model of immunoprotection.a 30-kda surface collagen binding protein peroxiredoxin of entamoeba histolytica (ehcbp30) was evaluated either alone or fused to the chaperone (chp) or atpase (atp) domains of heat shock protein 70 of trypanosoma cruzi (tchsp70) as a vaccine candidate in a hamster model of experimental amoebic liver abscess (ala) development. three constructs were produced containing the ehcbp30 dna sequence, one expressing ehcbp30 and two expressing ehcbp30 fused to either chp or atp domains of tchsp70. high p ...201222266120
the patient presenting with acute dysentery - a systematic review.objectives: the etiologies, clinical presentations and diagnosis of acute pathogen-specific dysentery in children and adults in industrialized and developing regions is described to help develop recommendations for therapy. methods: we conducted a systematic review of literature published between january 2000 and june 2011 to determine the frequency of occurrence of pathogen-specific dysentery. results: shigella, salmonella, and campylobacter remain the most frequent bacterial causes of dysenter ...201222266388
differences in cap formation between invasive entamoeba histolytica and non-invasive entamoeba dispar.the rapid redistribution of surface antigen-antibody complexes in trophozoites of the human protozoan parasite entamoeba histolytica, in a process known as capping, has been considered as a means of the parasite to evade the host immune response. so far, capping has been documented in the invasive e. histolytica, whereas the mobility of surface components in the non-invasive entamoeba dispar is not known. e. dispar does not induce liver lesions in rodent experimental models, in contrast to the l ...201222278728
porcine colon explants in the study of innate immune response to entamoeba histolytica.human amebiasis is caused by the protozoan entamoeba histolytica. this protozoan is responsible for muco-hemorrhagic diarrhoea and liver abscess in affected populations. e. histolytica can be asymptomatic commensally confined to the intestinal lumen or can result in invasion of the colonic mucosa leading to ulceration and/or liver abscesses. recently, human colonic explants have been identified as valuable in the study of host-parasite interactions. here we investigated the potential of porcine ...201222297149
profiles of entamoeba histolytica-specific immunoglobulins in human sera.to determine the profiles of anti-entamoeba histolytica (e. histolytica) iga, igg, and igm in sera of diarrheic and non-diarrheic individuals and partially characterize target antigens.201222305791
gastrointestinal parasites of captive and free-roaming primates at the afi mountain primate conservation area in calabar, nigeria and their zoonotic implications.a study on the gastrointestinal parasites among free-living and captive primates at the afi mountain, primate conservation area in calabar, nigeria was undertaken for the first time to ascertain their zoonotic implications. faecal samples were subjected to direct smear, floatation, quantitative estimation of helminth eggs (epg) and oocysts (opg), larval isolation and identification by modified baerman's technique and oocyst sporulation for specie identification. out of the 108 primates examined, ...201122308652
synthesis, characterization and antiamoebic activity of some hydrazone and azole derivatives bearing pyridyl moiety as a promising heterocyclic scaffold.in an effort to develop effective antiamoebic agents, some hydrazones and azoles containing pyridyl moiety were synthesized and screened for in vitro antiamoebic activity against hm1:imss strain of entamoeba histolytica. among all the compounds, only five compounds (1, 3, 5, 9 and 11) were found to be better inhibitors of growth of e. histolytica than the reference drug metronidazole. the cytotoxic studies of these compounds on human breast cancer mcf-7 cell line revealed that all the compounds ...201222309914
a comparative study of the tf-test®, kato-katz, hoffman-pons-janer, willis and baermann-moraes coprologic methods for the detection of human parasitosis.this study compares the diagnostic accuracy of the tf-test(®) (tft) for human parasitosis with results obtained using the traditional kato-katz (kk), hoffman-pons-janer (hpj), willis and baermann-moraes (bm) techniques. overall, four stool samples were taken from each individual; three alternate-day tft stool samples and another sample that was collected in a universal container. stool samples were taken from 331 inhabitants of the community of quilombola santa cruz. the gold standard (gs) for p ...201222310539
quantification of diarrhea risk related to wastewater contact in thailand.wastewater reuse contributes to closing the nutrient recycling loop as a sustainable way of managing water resources. bangkok has over a thousand man-made drainage and irrigation canals for such purposes. its use for agricultural and recreational purposes has a long tradition in rural and peri-urban areas. however, the continuation of these practices is increasingly questioned since potential health risks are an issue if such practices are not appropriately managed. the microbial and chemical qu ...201222311100
evaluation of the intestinal microbial diversity in miniature pig after orally infected with entamoeba histolytica.the objective of this study was to analyze the difference in intestinal microbial diversity between healthy and (entamoeba histolytica) orally infected minipig. enterobacterial repetitive intergenic consensus (eric)-pcr was applied to analyze this diversity and dynamic change, including the duodenum, jejunum, ileum, cecum, and rectum from healthy and orally infected minipig at different time points. the results showed that the intestinal microbial community of the control minipigs was stable and ...201222314784
establishment of a transient transfection system and expression of firefly luciferase in entamoeba invadens.entamoeba invadens is used as a model system to study trophozoite to cyst differentiation since entamoeba histolytica, the causative agent of amoebiasis cannot encyst in culture. however, a system for introduction of cloned genes in e. invadens is not available. here we report an electroporation-based method for transfection of e. invadens tophozoites and demonstrate the expression of firefly luciferase reporter gene driven from the e. invadens ribosomal protein l3 promoter. the efficiency of lu ...201222321531
cloning, expression and evaluation of the efficacy of a recombinant entamoeba histolytica cysteine proteinase (ehcp4) antigen in minipig.cysteine proteinases 4 (ehcp4) of entamoeba histolytica are considered important for ameba pathogenicity. the recombinant gene was obtained by cloning and expression of the ehcp4 gene in heterologous host escherichia coli bl-21 (de3), were used to evaluate their ability to induce immune protective responses in minipig against challenge infection in a minipig-e. histolytica model. there was a 53.16% reduction (p<0.001) in the group of recovery of challenged e. histolytica compared with that in th ...201222326593
leptin protects host cells from entamoeba histolytica cytotoxicity by a stat3-dependent mechanism.the adipocytokine leptin links nutritional status to immune function. leptin signaling protects from amebiasis, but the molecular mechanism is not understood. we developed an in vitro model of ameba-host cell interaction to test the hypothesis that leptin prevents ameba-induced apoptosis in host epithelial cells. we demonstrated that activation of mammalian leptin signaling increased cellular resistance to amebic cytotoxicity, including caspase-3 activation. exogenous expression of the leptin re ...201222331430
effect of bovine lactoferrin in a therapeutic hamster model of hepatic amoebiasis.entamoeba histolytica is the causative agent of amoebiasis, a disease that produces dysentery as a result of the perforation of the large intestine. this parasite often invades other organs, primarily the liver, leading to an amoebic liver abscess (ala), which can cause death. metronidazole is the drug of choice for the treatment of ala; however, it produces toxic side effects in patients. lactoferrin (lf) is a glycoprotein of the innate immune response that sequesters iron in the mucosae. lf po ...201222332957
prevalence of gastrointestinal infection among international travellers returning to canada.to describe the prevalence of parasitic and bacterial gastrointestinal infection (excluding enterotoxigenic escherichia coli) among international travellers attending the international travel clinic at the university of calgary.199322346439
prevalence of intestinal parasitic infections among mentally disabled children and adults of urmia, iran.the prevalence of intestinal parasites infection in institutions for mental retardation of urmia city, west azerbaijan province, iran was investigated.201022347245
virtual screening, identification and in vitro testing of novel inhibitors of o-acetyl-l-serine sulfhydrylase of entamoeba histolytica.the explosive epidemicity of amoebiasis caused by the facultative gastrointestinal protozoan parasite entamoeba histolytica is a major public health problem in developing countries. multidrug resistance and side effects of various available antiamoebic drugs necessitate the design of novel antiamobeic agents. the cysteine biosynthetic pathway is the critical target for drug design due to its significance in the growth, survival and other cellular activities of e. histolytica. here, we have scree ...201222355310
leptin signaling protects the gut from entamoeba histolytica infection.the role of the adipose-derived hormone leptin, and leptin receptors, in signaling satiety to the central nervous system and regulating energy balance is well recognized. but leptin also acts on peripheral tissues such as skeletal muscles, adipose tissues, pancreas, liver, intestine and the immune system. the existence of different splice variants of leptin receptor and the numerous intracellular signaling pathways triggered by leptin make this a truly versatile system. two recent studies explor ...201422356851
finding the smoking gun: protein tyrosine phosphatases as tools and targets of unicellular microorganisms and viruses.protein tyrosine phosphatases (ptps) are increasingly recognized as important effectors of host-pathogen interactions. since guan and dixon reported in 1990 that phosphatase yoph serves as an essential virulence determinant of yersinia, the field shifted significantly forward, and dozens of ptps were identified in various microorganisms and even in viruses. the discovery of extensive tyrosine signaling networks in non-metazoan organisms refuted the moth-eaten paradigm claiming that these organis ...201222360485
prevalence of intestinal parasites among patients of a tertiary hospital in benin city, nigeria.intestinal parasitic infections have been described as constituting the greatest single worldwide cause of illness and disease.201122363084
toward low-cost affinity reagents: lyophilized yeast-scfv probes specific for pathogen antigens.the generation of affinity reagents, usually monoclonal antibodies, remains a critical bottleneck in biomedical research and diagnostic test development. recombinant antibody-like proteins such as scfv have yet to replace traditional monoclonal antibodies in antigen detection applications, in large part because of poor performance of scfv in solution. to address this limitation, we have developed assays that use whole yeast cells expressing scfv on their surfaces (yeast-scfv) in place of soluble ...201222363793
status of intestinal parasitosis among hospital visiting patients in deukhury valley, dang, nepal.intestinal parasitosis is highly prevalent among the general population in nepal. this study aimed to assess the status of intestinal parasitosis among patients attending deukhury community hospital, lamahi, dang, situated in the mid western region of nepal. a total of 210 stool samples examined by direct smear technique were reported. the overall prevalence of intestinal parasitic infection was found to be 21.4% (m = 23.5% vs f = 19.3%). children < 15 yrs age were infected more often as compare ...201122364091
multisite performance evaluation of an enzyme-linked immunosorbent assay for detection of giardia, cryptosporidium, and entamoeba histolytica antigens in human stool.a novel fecal antigen detection assay for fresh and frozen human samples that detects but does not differentiate giardia spp, cryptosporidium spp, and entamoeba histolytica, the tri-combo parasite screen, was compared to three established enzyme-linked immunosorbent assays (elisas) at three international sites. it exhibited 97.9% sensitivity and 97.0% specificity, with positive and negative predictive values of 93.4% and 99.1%, respectively. the tri-combo test proved a reliable means to limit th ...201222378909
novel transmembrane receptor involved in phagosome transport of lysozymes and β-hexosaminidase in the enteric protozoan entamoeba histolytica.lysozymes and hexosaminidases are ubiquitous hydrolases in bacteria and eukaryotes. in phagocytic lower eukaryotes and professional phagocytes from higher eukaryotes, they are involved in the degradation of ingested bacteria in phagosomes. in entamoeba histolytica, which is the intestinal protozoan parasite that causes amoebiasis, phagocytosis plays a pivotal role in the nutrient acquisition and the evasion from the host defense systems. while the content of phagosomes and biochemical and physio ...201222383874
endoplasmic reticulum stress-sensing mechanism is activated in entamoeba histolytica upon treatment with nitric oxide.the endoplasmic reticulum stores calcium and is a site of protein synthesis and modification. changes in er homeostasis lead to stress responses with an activation of the unfolded protein response (upr). the entamoeba histolytica endomembrane system is simple compared to those of higher eukaryotes, as a canonical er is not observed. during amoebiasis, an infection of the human intestine and liver by e. histolytica, nitric oxide (no) triggers an apoptotic-like event preceded by an impairment of e ...201222384074
novel protein-protein interactions between entamoeba histolyticad-phosphoglycerate dehydrogenase and phosphoserine aminotransferase.physical interactions between d-phosphoglycerate dehydrogenase (ehpgdh) and phosphoserine aminotransferase (ehpsat) from an enteric human parasite entamoeba histolytica was observed by pull-down assay, gel filtration chromatography, chemical cross-linking, emission anisotropy, molecular docking and molecular dynamic simulations. the protein-protein complex had a 1:1 stochiometry with a dissociation constant of 3.453 × 10(-7) m. ionic interactions play a significant role in complex formation and ...201222386871
biochemical, mutational and in silico structural evidence for a functional dimeric form of the ornithine decarboxylase from entamoeba histolytica.entamoeba histolytica is responsible for causing amoebiasis. polyamine biosynthesis pathway enzymes are potential drug targets in parasitic protozoan diseases. the first and rate-limiting step of this pathway is catalyzed by ornithine decarboxylase (odc). odc enzyme functions as an obligate dimer. however, partially purified odc from e. histolytica (ehodc) is reported to exist in a pentameric state.201222389745
self-circularizing 5'-ets rnas accumulate along with unprocessed pre ribosomal rnas in growth-stressed entamoeba histolytica.the primary transcript of rrna genes is a large pre rrna which is precisely processed to release the mature rrnas. the 5'-external transcribed spacer (ets) of rrna genes contains important sites for pre rrna processing. once the processing is accomplished the ets is rapidly degraded. we show that in growth-stressed cells of the human parasitic protist entamoeba histolytica the a'-a(0) sub-fragment of the 5'-ets accumulates to high levels as a family of rna molecules of size 666 to 912 nt. these ...201222396851
programmed cell death in giardia.programmed cell death (pcd) has been observed in many unicellular eukaryotes; however, in very few cases have the pathways been described. recently the early divergent amitochondrial eukaryote giardia has been included in this group. in this paper we investigate the processes of pcd in giardia. we performed a bioinformatics survey of giardia genomes to identify genes associated with pcd alongside traditional methods for studying apoptosis and autophagy. analysis of giardia genomes failed to high ...201222405231
efficacy of a gal-lectin subunit vaccine against experimental entamoeba histolytica infection and colitis in baboons (papio sp.).to determine the efficacy of a gal-lectin based intranasal synthetic peptide vaccine, we developed a new experimental primate model of entamoeba histolytica intestinal infection. release of xenic e. histolytica trophozoites (5×10(6)) into the small bowel of baboons (papio sp.) resulted in a rapid intestinal anti-amebic antibody response and a brief infection; however, release of trophozoites directly into the cecum (5 baboons) elicited a sustained e. histolytica infection, as determined by quant ...201222406457
stable transfection and continuous expression of heterologous genes in entamoeba invadens.amoebiasis is spread by the ingestion of dormant entamoeba histolytica cysts. intervention of encystation could break the transmission cycle, thereby reducing disease burden. the model system used to study trophozoite to cyst differentiation is entamoeba invadens. here we describe an electroporation-based method for stable transfection of e. invadens with a plasmid peineo-luc containing the neomycin phosphotransferase gene under the control of e. invadens ribosomal protein gene s10 promoter. the ...201222426570
thiosemicarbazone fragment embedded within 1,2,4-triazole ring as inhibitors of entamoeba histolytica.a series of 1,2,4-triazole derivatives containing thiosemicarbazone linkage was synthesized and evaluated for their in vitro antiamoebic activity against hm1:imss strain of entamoeba histolytica. all the compounds were capable of inhibiting the growth of e. histolytica out of which four compounds (ic(50)=0.28-1.38 μm) were found to have better efficacy than the standard drug metronidazole (ic(50)=1.8 μm). cytotoxicity of the active compounds was assessed by mtt assay using human breast cancer mc ...201222444681
evidence for a link between locus r-r sequence type and outcome of infection with entamoeba histolytica.the results of entamoeba histolytica infections range from asymptomatic colonization to variable disease outcomes. however, markers that may predict infection outcomes are not known. here, we investigated sequence types of a non-coding trna-linked locus r-r to identify surrogate markers that may show association with infection outcomes. among 112 clinical samples--21 asymptomatic, 20 diarrhoea/dysentery and 71 liver abscesses--we identified 11 sequence types. sequence type 5rr was mostly associa ...201222448930
[five year surveillance of entamoeba histolytica and giardia antigen of stool samples by elisa method].the aim of this study is to show the ratio of detection of distribution of e. histolytica ve giardia in the fecal samples of the patients with diarrhoea complaints admitted to the hospitals and medical centers of our instution between june 2004 and june 2009.201222450915
[the distribution of intestinal parasites detected in the uludag university medical faculty hospital between 2009-2010].intestinal parasite infection is still an important public health problem. in this study, patients with various gastrointestinal system complaints presenting at various clinics of the uludag university medical faculty, between 2009-2010 were investigated for intestinal parasites.201222450916
control of entamoeba histolytica adherence involves metallosurface protease 1, an m8 family surface metalloprotease with homology to leishmanolysin.invasive amebiasis due to entamoeba histolytica infection is an important cause of morbidity in developing countries. the e. histolytica genome contains two homologues to the metalloprotease leishmanolysin gene, entamoeba histolytica msp-1 (ehmsp-1) and ehmsp-2, while the commensal ameba entamoeba dispar has lost ehmsp-1. in this study, we sought to characterize e. histolytica metallosurface protease 1 (ehmsp-1). using immunoprecipitation and a model substrate, we found that ehmsp-1 was a functi ...201222451519
opportunistic parasites among immunosuppressed children in minia district, egypt.a total of 450 stool samples were collected from inpatient and outpatient clinics of pediatric department, minia university hospital, minia district, egypt. two groups of patients were studied, including 200 immunosuppressed and 250 immunocompetent children. stool samples were subjected to wet saline and iodine mounts. a concentration technique (formol-ether sedimentation method) was carried out for stool samples diagnosed negative by wet saline and iodine mounts. samples were stained by 2 diffe ...201222451735
lipids induce expression of serum-responsive transmembrane kinase ehtmkb1-9 in an early branching eukaryote entamoeba histolytica.mechanisms underlying the initiation of proliferative response are known only for a few organisms, and are not understood for the medically important organisms including entamoeba histolytica. the trans membrane kinase ehtmkb1-9 of e. histolytica is one of the early indicators of proliferation and its' expression is regulated by serum, one of the components necessary for cellular proliferation in vitro. in this study we show that bovine serum albumin (bsa) can induce ehtmkb1-9 expression in plac ...201222451862
oral lactoferrin treatment resolves amoebic intracecal infection in c3h/hej mice.entamoeba histolytica is a protozoan parasite that causes amoebiasis, an illness that affects many people around the world. we have previously reported that lactoferrin is able to kill e. histolytica in in vitro cultures. the aim of the present study was to evaluate the therapeutic effect of orally administered bovine lactoferrin in the control of intestinal amoebiasis of susceptible c3h/hej mice. the results showed that 20 mg lactoferrin/kg orally administered each day for 1 week was able to el ...201222452668
purification and cellular localization of the entamoeba histolytica transcarboxylase.genome analysis of entamoeba histolytica predicts the presence of acetyl-coa carboxylase. using western blot, histochemistry, and confocal microscopy, we demonstrated the presence of a biotin-containing protein in the cytoplasm of e. histolytica, with a molecular weight of 136 kda and biotin-carboxylase activity. this protein probably corresponds to a transcarboxylase that catalyzes the rate-limiting reaction leading to fatty acid elongation.201222453500
entamoeba histolytica cell surface calreticulin binds human c1q and functions in amebic phagocytosis of host cells.phagocytosis of host cells is characteristic of tissue invasion by the intestinal ameba entamoeba histolytica, which causes amebic dysentery and liver abscesses. entamoeba histolytica induces host cell apoptosis and uses ligands, including c1q, on apoptotic cells to engulf them. two mass spectrometry analyses identified calreticulin in amebic phagosome preparations, and, in addition to its function as an endoplasmic reticulum chaperone, calreticulin is believed to be the macrophage receptor for ...201222473608
a novel class of cysteine protease receptors that mediate lysosomal transport.the transport of lysosomal proteins is, in general, mediated by mannose 6-phosphate receptors via carbohydrate modifications. here, we describe a novel class of receptors that regulate the transport of lysosomal hydrolases in the enteric protozoan entamoeba histolytica, which is a good model organism to investigate membrane traffic. a novel 110 kda cysteine protease (cp) receptor (cp-binding protein family 1, cpbf1) was initially discovered by affinity co-precipitation of the major cp (ehcp-a5), ...201222486861
ehadh112 is a bro1 domain-containing protein involved in the entamoeba histolytica multivesicular bodies pathway.ehadh112 is an entamoeba histolytica bro1 domain-containing protein, structurally related to mammalian alix and yeast bro1, both involved in the endosomal sorting complexes required for transport (escrt)-mediated multivesicular bodies (mvb) biogenesis. here, we investigated an alternative role for ehadh112 in the mvb protein trafficking pathway by overexpressing 166 amino acids of its n-terminal bro1 domain in trophozoites. trophozoites displayed diminished phagocytosis rates and accumulated exo ...201222500103
exposure to host ligands correlates with colocalization of gal/galnac lectin subunits in lipid rafts and phosphatidylinositol (4,5)-bisphosphate signaling in entamoeba histolytica.entamoeba histolytica is an intestinal parasite that causes dysentery and liver abscess. parasite cell surface receptors, such as the gal/galnac lectin, facilitate attachment to host cells and extracellular matrix. the gal/galnac lectin binds to galactose or n-acetylgalactosamine residues on host components and is composed of heavy (hgl), intermediate (igl), and light (lgl) subunits. although igl is constitutively localized to lipid rafts (cholesterol-rich membrane domains), hgl and lgl transien ...201222505337
diagnosis of soil-transmitted helminthiasis in an amazonic community of peru using multiple diagnostic techniques.an observational descriptive study was conducted in a shipibo-conibo/ese'eja community of the rainforest in peru to compare the kato-katz method and the spontaneous sedimentation in tube technique (sstt) for the diagnosis of intestinal parasites as well as to report the prevalence of soil-transmitted helminth (sth) infections in this area. a total of 73 stool samples were collected and analysed by several parasitological techniques, including kato-katz, sstt, modified baermann technique (mbt), a ...201222515992
evaluation of the efficacy of a recombinant entamoeba histolytica cysteine proteinase (ehcp112) antigen in minipig.cysteine proteinases 112 (ehcp112) of entamoeba histolytica are considered important for ameba pathogenicity. the recombinant gene was obtained by cloning and expression of the ehcp112 gene in heterologous host escherichia coli bl-21 (de3), were used to evaluate their ability to induce immune protective responses in minipig against challenge infection in a minipig-e. histolytica model. there was a 46.29% reduction (p<0.001) in the group of recovery of challenged e. histolytica compared with that ...201222521909
withdrawn: use of a recombinant entamoeba histolytica cysteine proteinase antigen to evaluation of the efficacy of immune protective responses in miniature pigs.this article has been withdrawn at the request of the author(s) and/or editor. the publisher apologizes for any inconvenience this may cause. the full elsevier policy on article withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.201222522180
prevalence of intestinal parasites and bacteria among food handlers in a tertiary care hospital.the aim of this work is to determine the prevalence of intestinal parasites and bacteria among the food handlers.201122529512
nonutility of routine testing of stool for ova and parasites in a tertiary care canadian centre.in many clinical situations, stool examinations for ova and parasites (o&p) are routine in the work-up of patients with acute or chronic diarrhea. frequently, these tests are found to be negative for pathogens. the purpose of this study was to examine the diagnostic yield of routine stool testing for o&p in a canadian tertiary care centre and to estimate the potential clinical benefit of a positive result.201222540249
development of a thermostabilized, one-step, nested, tetraplex pcr assay for simultaneous identification and differentiation of entamoeba species, entamoeba histolytica and entamoeba dispar from stool samples.entamoeba histolytica is the only entamoeba species that causes amoebiasis in humans. approximately 50 million people are infected, with 100, 000 deaths annually in endemic countries. molecular diagnosis of entamoeba histolytica is important to differentiate it from the morphologically identical entamoeba dispar to avoid unnecessary medication. conventional molecular diagnostic tests require trained personnel, cold-chain transportation and/or are storage-dependent, which make them user-unfriendl ...201222556327
clinical studies on amoebiasis and giardiasis evaluating the efficacy of kutaja (holarrhena antidysenterica) in entamoeba histolytica cyst passers.the clinical study records the clinical presentations of forty cases with amoebias and / or giardiasis including the efficacy of kutaja (holarrhena antidysenterica) in intestinal amoebiasis. e. h. cyst passers also have symptoms like loose motions, constipation, flatulence, abdominal cramping, diminished appetite and mucus in stools. patients with giardiasis have more tendency to diarrhoea and flatulence with no mucus in stools. 70 per cent good response was observed in e. h. cyst passers when t ...198622557529
transient and stable transfection in the protozoan parasite entamoeba invadens.entamoeba histolytica is an important human pathogen and a major health problem worldwide. many aspects of parasite biology can be studied with the exception of stage conversion, which cannot be reproduced adequately in e. histolytica. the reptile parasite entamoeba invadens is a vital model system for studying stage conversion since it can be induced to undergo both encystation and excystation with high efficiency in vitro. however, functional studies using e. invadens have been limited by the ...201222561071
intestinal microbial community diversity between healthy and orally infected rabbit with entamoeba histolytica by eric-pcr.enterobacterial repetitive intergenic consensus (eric)-pcr was applied to analyze the difference of intestinal microbial community diversity between healthy and orally infected rabbits with entamoeba histolytica. the dynamic changes in different parts of digestive system including the duodenum, jejunum, ileum, caecum, and rectum in healthy and infected rabbits at different time points were also tested. the intestinal microbial community of the control healthy rabbits was steady, and the total nu ...201222562215
unique short tandem repeat nucleotide sequences in entamoeba histolytica isolates from china.a few pcr-based dna typing methods using repetitive elements contained within both protein-coding genes and noncoding dnas have been reported for entamoeba histolytica over the years. the serine-rich e. histolytica protein and trna-linked short tandem repeats (strs) are most commonly used to investigate the relationship between parasite genotype and e. histolytica infection outcome. many e. histolytica infections in china have been reported; however, little genome information has been provided. ...201222562237
structure-function relationships of human milk oligosaccharides.human milk contains more than a hundred structurally distinct oligosaccharides. in this review, we provide examples of how the structural characteristics of these human milk oligosaccharides (hmo) determine functionality. specific α1-2-fucosylated hmo have been shown to serve as antiadhesive antimicrobials to protect the breast-fed infant against infections with campylobacter jejuni, one of the most common causes of bacterial diarrhea. in contrast, α1-2-fucosylation may abolish the beneficial ef ...201222585916
prevalence of intestinal parasites in hiv-positive/aids patients.the aim of this study was to assess the prevalence of intestinal parasites among hiv-positive/aids patients. a control group comprising 30 apparently healthy hiv-negative individuals was included. of the 60 samples collected from the patients and examined, 34 (56.7%) presented with diarrhoea, while 26 (43.3%) had no reported cases of diarrhoea at the time of study. seventeen (50%) of the parasites detected in the 34 patients (those with history of diarrhoea) were diarrhoea-related causative agen ...200622589594
proteomic analysis of the cyst stage of entamoeba histolytica.the category b agent of bioterrorism, entamoeba histolytica has a two-stage life cycle: an infective cyst stage, and an invasive trophozoite stage. due to our inability to effectively induce encystation in vitro, our knowledge about the cyst form remains limited. this also hampers our ability to develop cyst-specific diagnostic tools.201222590659
a high-throughput drug screen for entamoeba histolytica identifies a new lead and target.entamoeba histolytica, a protozoan intestinal parasite, is the causative agent of human amebiasis. amebiasis is the fourth leading cause of death and the third leading cause of morbidity due to protozoan infections worldwide(1), resulting in ~70,000 deaths annually. e. histolytica has been listed by the national institutes of health as a category b priority biodefense pathogen in the united states. treatment relies on metronidazole(2), which has adverse effects(3), and potential resistance of e. ...201222610278
recombinant sines are formed at high frequency during induced retrotransposition in vivo.non-long terminal repeat retrotransposons are referred to as long interspersed nuclear elements (lines) and their non-autonomous partners are short interspersed nuclear elements (sines). it is believed that an active sine copy, upon retrotransposition, generates near identical copies of itself, which subsequently accumulate mutations resulting in sequence polymorphism. here we show that when a retrotransposition-competent cell line of the parasitic protist entamoeba histolytica, transfected with ...201222617294
common pathways for receptor-mediated ingestion of escherichia coli and ldl cholesterol by entamoeba histolytica regulated in part by transmembrane kinase 39.the single-celled parasite, entamoeba histolytica, is an enteric pathogen that ingests bacteria and host cells. inhibition of phagocytosis renders the parasite avirulent. the ligand/receptor interactions that allow e. histolytica to phagocytose are not well understood. we hypothesised that e. histolytica trophozoites might accomplish ingestion through the utilisation of a scavenger receptor for cholesterol. here we show that acetylated low density lipoprotein cholesterol was phagocytosed by amoe ...201222619755
genomic diversity of the human intestinal parasite entamoeba histolytica.entamoeba histolytica is a significant cause of disease worldwide. however, little is known about the genetic diversity of the parasite. we re-sequenced the genomes of ten laboratory cultured lines of the eukaryotic pathogen entamoeba histolytica in order to develop a picture of genetic diversity across the genome.201222630046
ccr9+ t cells contribute to the resolution of the inflammatory response in a mouse model of intestinal amoebiasis.analysis of the mechanisms underlying the inflammatory response in amoebiasis is important to understand the immunopathology of the disease. mucosal associated effector and regulatory t cells may play a role in regulating the inflammatory immune response associated to entamoeba histolytica infection in the colon. a subpopulation of regulatory t cells has recently been identified and is characterized by the expression of the chemokine receptor ccr9. in this report, we used ccr9 deficient (ccr9(-/ ...201222633147
clostridium difficile and entamoeba histolytica infections in patients with colitis in the philippines.amoebiasis is a common cause of non-specific colitis in the philippines. the prevalence of clostridium difficile infection with colitis is unknown. empiric use of metronidazole for colitis treatment is widely practiced. we investigated the association of c. difficile or entamoeba histolytica infection with endoscopically/histopathologically proven colitis among adults in the philippines. two hundred and ten patients undergoing colonoscopy were enrolled. demographic and clinical data were reviewe ...201222657531
synthesis and in vitro evaluation of novel tetrazole embedded 1,3,5-trisubstituted pyrazoline derivatives as entamoeba histolytica growth inhibitors.a series of pyrazoline derivatives (1a-15a) was synthesized by cyclization of chalcones (1-15) with 2-[5-(4-methoxyphenyl)-1h-tetrazol-1-yl]acetohydrazide under basic conditions and were screened in vitro, to find out effect on the growth of hm1: imss strain of entamoeba histolytica. the compounds 3a, 4a, 11a, 13a and 14a showed encouraging results with ic(50) value in the range of 0.86-1.28 μm. however compound 13a showed most promising results with ic(50) = 0.86 μm which is half of the metroni ...201222658085
cockroaches and flies in mechanical transmission of medical important parasites in khaldyia village, el-fayoum, governorate, egypt.the role of non-blood sucking insects in dissemination of human parasites was investigated in khaldyia village, al-fayoum governorate over during the summer of 2011. a total of 278 american cockroach (periplaneta americana), and 508 house flies musca domestica var. vicina were collected. the insects were collected indoors and outdoors. flies were abundant in defecation areas and around houses. the recovered zoonotic parasites identified were cysts of entamoeba histolytica cryptosporidium parvum ...201222662605
entamoeba histolytica: a snapshot of current research and methods for genetic analysis.entamoeba histolytica represents one of the leading causes of parasitic death worldwide. although identified as the causative agent of amebiasis since 1875, the molecular mechanisms by which the parasite causes disease are still not fully understood. studying entamoeba reveals insights into a eukaryotic cell that differs in many ways from better-studied model organisms. thus, much can be learned from this protozoan parasite on evolution, cell biology, and rna biology. in this review we discuss s ...201222664276
evaluation of a rapid point-of-care fecal antigen detection test for entamoeba histolytica.amebiasis is a major cause of morbidity and mortality in the developing world. a reliable point-of-care test would help to improve diagnosis and early treatment. we evaluated a novel rapid fecal antigen detection test for e. histolytica (e. histolytica quik chek; techlab, inc., blacksburg, va), in a cohort of children in bangladesh where amebiasis is endemic. this point-of-care test had a sensitivity of 100% and a specificity of 100% when compared with enzyme-linked immunosorbent assay antigen d ...201222665604
risk of underdiagnosing amebic dysentery due to false-negative entamoeba histolytica antigen detection.entamoeba histolytica antigen assays on stool are widely used to diagnose amebiasis. we report a case of confirmed amebic colitis with a false-negative antigen detection that became positive after treatment. our results indicate that these assays may underdiagnose acute amebic infection when used alone and should be used cautiously.201222683092
virulence and virulence factors in entamoeba histolytica, the agent of human amoebiasis.human infections with entamoeba histolytica sporadically become pathogenic, unknown triggers converting the parasite to its invasive phenotype. parasite virulence results from complex host-parasite interactions implicating multiple amoebic and host factors, eliciting host defence responses and parasite resistance to stress caused by the host reactions and changing environments during tissue invasion.201222710276
development of a multiplex pcr assay to detect gastroenteric pathogens in the feces of mexican children.acute gastroenteritis (age) is a major cause of childhood morbidity and mortality worldwide; the etiology of age includes viruses, bacteria, and parasites. a multiplex pcr assay to simultaneously identify human astrovirus (hastv), calicivirus (hucvs), entamoeba histolytica (e. histolytica), and enteroinvasive escherichia coli (eiec) in stool samples is described. a total of 103 samples were individually analyzed by elisa (enzyme-linked immunosorbent assays) and rt-pcr/pcr. hastv and hucvs were d ...201222711331
maximising the potential of voluntary counselling and testing for hiv: sexually transmitted infections and hiv epidemiology in a population testing for hiv and its implications for practice.this study aimed to describe the epidemiology of hiv infection and sexually transmitted infections (stis) among persons who attended voluntary counselling and testing (vct) service for hiv and to assess whether the vct programme reached the right population at risk in taiwan.201222717470
potential cytotoxic and amoebicide activity of first row transition metal compounds with 2,9-bis-(2',5'-diazahexanyl)-1,1-phenanthroline (l1).a new synthetic pathway was reported to obtain n6 donor ligand 2,9-bis-(2',5'-diazahexanyl)-1,10-phenanthroline (l1) and its coordination compounds of essential divalent metal ions mn, fe, co, ni, cu and zn. complete characterization of all compounds was done with the conventional techniques. crystal structures of [nil1](pf(6))(2) and [znl1](pf(6))(2)·h(2)o were also reported. electrochemical studies have shown an active participation of the aromatic moiety of the ligand in redox reactions. the ...201222722265
entamoeba moshkovskii is associated with diarrhea in infants and causes diarrhea and colitis in mice.entamoeba moshkovskii is prevalent in developing countries and morphologically indistinguishable from pathogenic entamoeba histolytica and nonpathogenic entamoeba dispar. it is not known if e. moshkovskii is pathogenic.201222723640
determining the prevalence of intestinal parasites in three orang asli (aborigines) communities in perak, malaysia.this study was conducted to determine the prevalence of intestinal parasites among children and adult orang aslis (aborigines) from different locations in perak. faecal samples were collected and analyzed using the direct smear and formal ether sedimentation technique. some of the faecal samples were stained using the modified acid fast stain for cryptosporidium. nail clippings of the respondents and the soil around their habitat were also analyzed. of the 77 stool samples examined, 39 (50.6%) w ...201222735840
structure analysis of entamoeba histolytica dnmt2 (ehmeth).in eukaryotes, dna methylation is an important epigenetic modification that is generally involved in gene regulation. methyltransferases (mtases) of the dnmt2 family have been shown to have a dual substrate specificity acting on dna as well as on three specific trnas (trna(asp), trna(val), trna(gly)). entamoeba histolytica is a major human pathogen, and expresses a single dna mtase (ehmeth) that belongs to the dnmt2 family and shows high homology to the human enzyme as well as to the bacterial d ...201222737219
amoebic cervicitis mimicking posterior wall fibroid: a rare presentation.amoebiasis of the uterine cervix is an extremely rare entity, and presentation as fibroid uterus has not been reported, to the best of our knowledge in our extensive search of the english literature. it can clinically simulate cervical malignancy by virtue of surface papillomatous and overall ulcerated and necrotic appearance. we present a case of amoebic infection of the cervix in a 45-year-old female which was suspected to be a posterior wall fibroid with degeneration until a histopathological ...201422743593
an amebic anti-inflammatory peptide down-regulates ex vivo il-1β expression in patients with rheumatoid arthritis.the monocyte locomotion inhibitory factor (mlif) is a heat-stable pentapeptide produced by entamoeba histolytica in culture. this factor displays several anti-inflammatory properties (i.e., inhibition of locomotion and respiratory burst in monocytes, reduction of skin hypersensitivity and delay of mononuclear cells in human rebuck skin windows) with inhibition of adhesion molecules, chemokines, and other genes including interleukin-1β (il-1β). in animal models, it reduces carragenin-induced infl ...201522749729
autophosphorylation of ser428 of ehc2pk plays a critical role in regulating erythrophagocytosis in the parasite entamoeba histolytica.the protozoan parasite entamoeba histolytica can invade both intestinal and extra intestinal tissues resulting in amoebiasis. during the process of invasion e. histolytica ingests red blood and host cells using phagocytic processes. though phagocytosis is considered to be a key virulence determinant, the mechanism is not very well understood in e. histolytica. we have recently demonstrated that a novel c2 domain-containing protein kinase, ehc2pk is involved in the initiation of erythrophagocytos ...201222753771
blastocystis spp., cryptosporidium spp., and entamoeba histolytica exhibit similar symptomatic and epidemiological patterns in healthcare-seeking patients in karachi.in this study, we collected data on the incidence of enteric parasites in healthcare-seeking individuals along with their symptoms to quantify the potential roles of factors such as age, sex, and seasonality in infection. we performed analysis to identify factors which could help differentiate parasitic infection from other causes of gastrointestinal illness in a community. the size of the patient population (n = 339), patient selection methodology, collection methods, and statistical analysis f ...201222763702
antiamoebic properties of the actinomycete metabolites echinomycin a and tirandamycin a.entamoeba histolytica infects 50 million people per year, causing 100,000 deaths worldwide. the primary treatment for amoebiasis is metronidazole. however, increased pathogen resistance combined with the drug's toxic side effects encourages a search for alternative therapeutic agents. secondary metabolites from marine bacteria are a promising resource for antiprotozoan drug discovery. in this study, extracts from a collection of marine-derived actinomycetes were screened for antiamoebic properti ...201222763704
seroprevalence of entamoeba histolytica infection in china.the seroprevalence of entamoeba histolytica infection in the residents of seven provinces in china was examined by using an enzyme-linked immunosorbent assay with a crude antigen and a recombinant surface antigen, c-igl, of the parasites. a total of 1,312 serum samples were investigated. the positivity rates for these two antigens were 11.05% and 6.25%, respectively. there was no significant difference in the seropositivity to e. histolytica between men and women. we used a logistic regression m ...201222764298
prevalence of intestinal parasites in hiv-positive patients on the island of bioko, equatorial guinea: its relation to sanitary conditions and socioeconomic factors.the prevalence of intestinal parasitic diseases and their associated factors has been investigated in hiv populations from the island of bioko, equatorial guinea. the feces of 310 participants from the island of bioko (260 hiv-positive and 50 hiv-negative) were analyzed by microscopic observation. immunochromatography was also used to diagnose giardia, entamoeba histolytica and cryptosporidium spp. in addition, patients were asked for sociodemographic, economic and academic status, and cd4+ t ce ...201222771815
infantile amoebiasis: a case report.amoebiasis continues to be a major cause of morbidity and mortality in children in developing countries. entamoeba histolytica infections are commonly observed in tropical and subtropical regions of the world including iran. in developed countries entamoeba histolytica infections are commonly seen in travelers, recent immigrants, homosexual men, and inmates of institutions. the disease is more severe in the two extremes of life. this paper paper describes a four-month-old male infant with entamo ...201222779016
high-level parasitic contamination of soil sampled in ibadan metropolis.soil transmitted helminthes infections are common chronic human infections worldwide, this has been recognized as an important health problem, particularly in developing countries. the study was conducted within ibadan metropolis in oyo state, south western nigeria between september 2008 and march 2009 to determine the prevalence of intestinal parasite in soil samples within the city. a total of 102 soil samples were collected from different sources from five local government areas ranging from ...201122783681
a detoxifying oxygen reductase in the anaerobic protozoan entamoeba histolytica.we report the characterization of a bacterial-type oxygen reductase abundant in the cytoplasm of the anaerobic protozoan parasite entamoeba histolytica. upon host infection, e. histolytica is confronted with various oxygen tensions in the host intestine, as well as increased reactive oxygen and nitrogen species at the site of local tissue inflammation. resistance to oxygen-derived stress thus plays an important role in the pathogenic potential of e. histolytica. the genome of e. histolytica has ...201222798391
benign ulcer of the right colon clinically misdiagnosed as carcinoma: an additional case.benign solitary ulcer of the colon is an uncommon lesion that was originally described by cruveilhier in 1832. its aetiology remains unknown, and there are no pathognomonic lesions or symptoms. diagnosis is made by exclusion; in fact, diseases such as specific infections (cytomegalovirus, campylobacter jejuni, entamoeba histolytica), common clinical conditions (acute appendicitis, diverticulitis, intestinal obstruction, inflammatory bowel disease), pharmacotherapy (non-steroidal anti-inflammator ...201222799054
[the distribution of intestinal parasites in people admitted to the yüzüncü yıl university parasitology laboratory of health research and training hospital, in 2009].this study was performed to present the distribution of intestinal parasites in parients admitted to the parasitology laboratory of the health research and training hospital of yüzüncü yıl university in 2009.201222801916
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