Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
label-free electrochemical detection of an entamoeba histolytica antigen using cell-free yeast-scfv probes.inexpensive, simple and quick detection of pathogen antigens in human samples is a key global health objective. limiting factors include the cost and complexity of diagnostic tests that utilize antibody probes. herein, we present a method for label-free electrochemical detection of a protein from the enteric pathogen entamoeba histolytica using cell-free yeast-embedded antibody-like fragments (yeast-scfv) as novel affinity reagents.201323329132
prevalence of intestinal parasites among hiv patients in baringo, kenya.hiv patients have reduced immune response which makes them more susceptible to different infections. this cross-sectional study was carried out to document the prevalence of intestinal parasites among hiv patients in baringo county, kenya.201223330028
[comparison of individual differences in the direct microscopic examination in the diagnosis of intestinal parasites].the aim is to emphasise the importance for intestinal parasites' diagnosis by direct microscopic examination and the discrepancies among results from different microscopists.201223339941
catalysis by n-acetyl-d-glucosaminylphosphatidylinositol de-n-acetylase (pig-l) from entamoeba histolytica: new roles for conserved residues.we showed previously that entamoeba histolytica pig-l exhibits a novel metal-independent albeit metal-stimulated activity. using mutational and biochemical analysis, here we identify asp-46 and his-140 of the enzyme as being important for catalysis. we show that these mutations neither affect the global conformational of the enzyme nor alter its metal binding affinity. the defect in catalysis, due to the mutations, is specifically due to an effect on v(max) and not due to altered substrate affin ...201323341455
small rna pyrosequencing in the protozoan parasite entamoeba histolytica reveals strain-specific small rnas that target virulence genes.small rna mediated gene silencing is a well-conserved regulatory pathway. in the parasite entamoeba histolytica an endogenous rnai pathway exists, however, the depth and diversity of the small rna population remains unknown.201323347563
novel tpr-containing subunit of tom complex functions as cytosolic receptor for entamoeba mitosomal transport.under anaerobic environments, the mitochondria have undergone remarkable reduction and transformation into highly reduced structures, referred as mitochondrion-related organelles (mros), which include mitosomes and hydrogenosomes. in agreement with the concept of reductive evolution, mitosomes of entamoeba histolytica lack most of the components of the tom (translocase of the outer mitochondrial membrane) complex, which is required for the targeting and membrane translocation of preproteins into ...201323350036
prevalence and genetic diversity of entamoeba species infecting macaques in southwest china.many colonies of macaques (macaca fascicularis and macaca mulatta) are maintained in china, especially in guangxi and guizhou. a total of 803 fresh stool samples infected with entamoeba were obtained from three big colonies of macaques located in southwest china. the samples were examined for the presence of five entamoeba species using pcr. entamoeba nuttalli, entamoeba dispar, entamoeba coli, and entamoeba chattoni infections were detected, but entamoeba histolytica infection was not. this stu ...201323354942
entamoeba histolytica exacerbates epithelial tight junction permeability and proinflammatory responses in muc2(-/-) mice.human mucin-2 (muc-2) is the first line of innate host defense in preventing pathogen-induced epithelial injury. entamoeba histolytica (eh) colonizes the mucus layer by binding of the parasite's surface galactose lectin to galactose and n-acetyl-d-galactosamine residues on colonic muc-2, preventing parasite contact-dependent cytolysis of epithelial cells. we quantified early innate responses to eh in wild-type and muc-2-deficient mice (muc2(-/-)) using closed colonic loops. eh infection in wild- ...201323357502
evaluation of formalin-ether sedimentation and trichrome staining techniques: its effectiveness in detecting entamoeba histolytica/dispar/moshkovskii in stool samples.this study was conducted to evaluate two routinely microscopic diagnostic methods in comparison with single-round pcr assay as the reference technique to detect entamoeba histolytica/dispar/moshkovskii. examination was performed on 500 stool samples obtained from orang asli communities in different states of malaysia using formalin-ether sedimentation, trichrome staining and single-round pcr techniques. ninety-three stool samples were detected e. histolytica/dispar/moshkovskii positive by routin ...201323361047
prevalence of entamoeba nuttalli infection in wild rhesus macaques in nepal and characterization of the parasite isolates.we have recently resurrected the name entamoeba nuttalli castellani, 1908 for a potentially virulent ameba isolate, p19-061405, obtained from a rhesus macaque in kathmandu, nepal. the ameba was morphologically indistinguishable from entamoeba histolytica/entamoeba dispar/entamoeba moshkovskii, but located phylogenetically between e. histolytica and e. dispar. to evaluate the prevalence of e. nuttalli infection in wild rhesus macaques, 112 fecal samples were collected in four locations of the kat ...201323370534
the α-helical regions of kerp1 are important in entamoeba histolytica adherence to human cells.the lysine and glutamic acid rich protein kerp1 is a unique surface adhesion factor associated with virulence in the human pathogen entamoeba histolytica. both the function and structure of this protein remain unknown to this date. here, we used circular dichroism, analytical ultracentrifugation and bioinformatics modeling to characterize the structure of kerp1. our findings revealed that it is an α-helical rich protein organized as a trimer, endowed with a very high thermal stability (tm = 89.6 ...201323378906
experimental amoebic liver abscess in hamsters caused by trophozoites of a brazilian strain of entamoeba dispar.it has been claimed that amoebic molecules such as amoebapore, galactose/n-acetyl galactosamine inhibitable lectin, and cysteine proteases are responsible for host tissue destruction and are present in both pathogenic entamoeba histolytica and non-pathogenic entamoeba dispar. some reports have provided evidence that after infection with e. dispar, pathological changes may occur in some humans. the aim of this study was to evaluate e. dispar pathogenicity by comparing it to the pathogenicity of e ...201323380037
the incidence of feco-oral parasites in street-food vendors in buea, south-west region cameroon.the street-food industry lacks legal recognition, it operates in unstable and precarious conditions, involving women and men with minimal or no knowledge of hygienic food handling practices. infective eggs, bacteria, toxins and cysts of faecal orally transmissible parasites are common agents responsible for food contamination in developing countries.201223382755
profile of catering staff at a tertiary care hospital in mumbai.food borne illnesses, even today, continue to be a major public health problem in both developing and developed nations. food handlers play an important role in ensuring food safety throughout the chain of production, processing, storage and preparation.health of food handlers is of great importance for maintaining hygienic quality of food prepared and served by them. thus, the present study was conducted to study socio-demographic characteristics, morbidity pattern and immunization status of ca ...201123390464
[investigation of norovirus infection incidence among 0-5 years old children with acute gastroenteritis admitted to two different hospitals in ankara, turkey].norovirus causes severe gastroenteritis requiring hospitalization especially in children less than five years of age both in developed and developing countries. therefore, we aimed to investigate the incidence of norovirus (nov) in 0-5 years old children with acute gastroenteritis in two large hospitals in ankara, turkey. stool samples were obtained from 1000 (413 female, 587 male) children between 0-5 years old with acute gastroenteritis who attended to the department of paediatrics, ministry o ...201323390907
entamoeba histolytica: identification of thioredoxin-targeted proteins and analysis of serine acetyltransferase-1 as a prototype example.entamoeba histolytica, the causative agent of amoebiasis, possesses the dithiol-containing redox proteins trx (thioredoxin) and trxr (trx reductase). both proteins were found to be covalently modified and inactivated by metronidazole, a 5-nitroimidazole drug that is commonly used to treat infections with microaerophilic protozoan parasites in humans. currently, very little is known about enzymes and other proteins participating in the trx-dependent redox network of the parasite that could be ind ...201323398389
the small gtpase ehrabb of entamoeba histolytica is differentially expressed during phagocytosis.it has been described that the pathogenicity of entamoeba histolytica is influenced by environmental conditions and that transcription profile changes occur during invasion, suggesting that gene expression may be involved in the virulence of this parasite. however, the molecular mechanisms that are implicated in the control of gene expression in this microorganism are poorly understood. here, we showed that the expression of the ehrabb protein, a small gtpase involved in phagocytosis, is modifie ...201323400794
intestinal parasitic and candida infection associated with hiv infection in cameroon.hiv causes progressive impairment of the cellular immune system leading to increased susceptibility to infectious agents. parasitic infestations are common in hiv-infected patients and usually lead to diarrhoea. few studies have addressed the issue of intestinal parasites among hiv-infected persons in cameroon.  this investigation was conducted in douala, cameroon, to assess the prevalence of gastrointestinal parasites in hiv-infected patients, taking into account their immune status and treatme ...201323416660
prevalence of intestinal parasitic infections among highland and lowland dwellers in gamo area, south ethiopia.epidemiological information on the prevalence of intestinal parasitic infections in different regions is a prerequisite to develop appropriate control strategies. therefore, this present study was conducted to assess the magnitude and pattern of intestinal parasitism in highland and lowland dwellers in gamo area, south ethiopia.201323419037
testosterone increases susceptibility to amebic liver abscess in mice and mediates inhibition of ifnγ secretion in natural killer t cells.amebic liver abscess (ala), a parasitic disease due to infection with the protozoan entamoeba histolytica, occurs age and gender dependent with strong preferences for adult males. using a mouse model for ala with a similar male bias for the disease, we have investigated the role of female and male sexual hormones and provide evidence for a strong contribution of testosterone. removal of testosterone by orchiectomy significantly reduced sizes of abscesses in male mice, while substitution of testo ...201323424637
effect of the leptin receptor q223r polymorphism on the host transcriptome following infection with entamoeba histolytica.resistance to amebiasis is associated with a polymorphism in the leptin receptor. previous studies demonstrated that humans with the ancestral q223 leptin receptor allele were nearly four times less likely to be infected with entamoeba histolytica than those carrying the mutant r223 allele. we hypothesized that the q223 allele protected against e. histolytica via stat3-mediated transcription of genes required for mucosal immunity. to test this, mice containing the humanized lepr q or r allele at ...201323429533
single residue mutation in active site of serine acetyltransferase isoform 3 from entamoeba histolytica assists in partial regaining of feedback inhibition by cysteine.the cysteine biosynthetic pathway is essential for survival of the protist pathogen entamoeba histolytica, and functions by producing cysteine for countering oxidative attack during infection in human hosts. serine acetyltransferase (sat) and o-acetylserine sulfhydrylase (oass) are involved in cysteine biosynthesis and are present in three isoforms each. while ehsat1 and ehsat2 are feedback inhibited by end product cysteine, ehsat3 is nearly insensitive to such inhibition. the active site residu ...201323437075
[second national survey of intestinal parasitic infections in cuba, 2009].the intestinal parasitic infections are still endemic in cuba, with a higher frequency in rural and mountain regions. twenty five years after the last national survey, it deemed necessary to carry out a new national survey in order to know the prevalence of intestinal parasitic infections and to compare the obtained results between both studies. that knowledge would be valuable to work out strategies of health and to design a control program for intestinal parasitic infections in cuba.201223444621
epidemiological analysis of eosinophilia and elevation of immunoglobulin e as a predictable and relative risk of enteroparasitosis.among the intestinal parasites, the helminthiasis occupies a prominent position in brazil, since it worsens malnutrition and the gives rise to neurovegetative disorders. helminths like ascaris lumbricoides, enterobius vermicularis, hookworm, trichuris trichiura and strongyloides stercoralis stand out due to several factors that modulate the immune response of individuals. among the protozoa are giardia lamblia, entamoeba histolytica. e. dispar. parasitic helminth antigens are important to stimul ...201223444622
intestinal parasitic infections in hiv infected and non-infected patients in a low hiv prevalence region, west-cameroon.the magnitude of intestinal parasitic infection in acquired immunodeficiency syndrome patients requires careful consideration in the developing world where poor nutrition is associated with poor hygiene and several tropical diseases. however, there have been very few studies addressing this issue in cameroon. this study was conducted to determine the prevalence of intestinal parasitosis in hiv/aids patients in dschang -cameroon. stool and blood specimens from hiv/aids patients and control group ...201323451283
resolution of refractory thrombotic thrombocytopenic purpura (ttp) after successful treatment of a fulminant colitis due to entamoeba histolytica. 201323453561
false-negative serologies in amebic liver abscess: report of two cases.amebiasis, the parasitic disease caused by entamoeba histolytica, may result in extra-intestinal diseases among which liver abscess is the most common manifestation. we report two cases of amebic liver abscess illustrating the inequal sensitivity of serologic tests detecting anti-amebic antibodies.201323464723
entamoeba histolytica induces cell death of ht29 colonic epithelial cells via nox1-derived ros.entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. however, signaling mechanisms of colon cell death induced by e. histolytica are not fully elucidated. in this study, we investigated the signaling role of nox in cell death of ht29 colonic epithelial cells induced by e. histolytica. incubation of ht29 cells with amoebic trophozoites resulted in dna fragmentation that is a hallmark of apoptotic cell death. in addition, ...201323467460
prevalence of opportunistic intestinal parasitic infection among hiv infected patients who are taking antiretroviral treatment at jimma health center, jimma, ethiopia.one of the major health problems among hiv sero-positive patients are superimposed infections due to the deficient immunity. furthermore, intestinal parasitic (ip) infections, which are also one of the basic health problems in tropical regions, are common in these patients. infection by opportunistic pathogens, including various forms of intestinal parasites has been the hall mark of hiv since the beginning of the epidemic.201323467951
toll-like receptor signaling activation by entamoeba histolytica induces beta defensin 2 in human colonic epithelial cells: its possible role as an element of the innate immune response.entamoeba histolytica, a protozoan parasite of humans, produces dysenteric diarrhea, intestinal mucosa damage and extraintestinal infection. it has been proposed that the intestinal microbiota composition could be an important regulatory factor of amebic virulence and tissue invasion, particularly if pathogenic bacteria are present. recent in vitro studies have shown that entamoeba histolytica trophozoites induced human colonic caco2 cells to synthesize tlr-2 and tlr-4 and proinflammatory cytoki ...201323469306
proteases from entamoeba spp. and pathogenic free-living amoebae as virulence factors.the standard reference for pathogenic and nonpathogenic amoebae is the human parasite entamoeba histolytica; a direct correlation between virulence and protease expression has been demonstrated for this amoeba. traditionally, proteases are considered virulence factors, including those that produce cytopathic effects in the host or that have been implicated in manipulating the immune response. here, we expand the scope to other amoebae, including less-pathogenic entamoeba species and highly patho ...201323476670
silencing of entamoeba histolytica glucosamine 6-phosphate isomerase by rna interference inhibits the formation of cyst-like structures.encystment is an essential process in the biological cycle of the human parasite entamoeba histolytica. in the present study, we evaluated the participation of e. histolytica gln6pi in the formation of amoeba cyst-like structures by rna interference assay. amoeba trophozoites transfected with two gln6pi sirnas reduced the expression of the enzyme in 85%, which was confirmed by western blot using an anti-gln6pi antibody. the e. histolytica gln6pi knockdown with the mix of both sirnas resulted in ...201323484154
a coprological survey for assessing intensity of parasitic infection in school children: cross-sectional study.intestinal parasitic infections (ipis) are endemic worldwide and have been the cause of illness and disease worldwide.201123507633
intestinal parasitic infestation among children in a semi-urban indian population.survey on the prevalence of various intestinal parasitic infestations in different geographic regions is a prerequisite to obtain an accurate understanding of the burden and cause of intestinal parasitic infestations in a particular area. the aim of the present study was to determine the intestinal parasitic infestation among children in a semi-urban area.201123508675
a novel, multi-parallel, real-time polymerase chain reaction approach for eight gastrointestinal parasites provides improved diagnostic capabilities to resource-limited at-risk populations.diagnosis of gastrointestinal parasites has traditionally relied on stool microscopy, which has low diagnostic sensitivity and specificity. we have developed a novel, rapid, high-throughput quantitative multi-parallel real-time polymerase chain reaction (qpcr) platform. species-specific primers/probes were used for eight common gastrointestinal parasite pathogens: ascaris lumbricoides, necator americanus, ancylostoma duodenale, giardia lamblia, cryptosporidium spp., entamoeba histolytica, trichu ...201323509117
cysteine protease-binding protein family 6 mediates the trafficking of amylases to phagosomes in the enteric protozoan entamoeba histolytica.phagocytosis plays a pivotal role in nutrient acquisition and evasion from the host defense systems in entamoeba histolytica, the intestinal protozoan parasite that causes amoebiasis. we previously reported that e. histolytica possesses a unique class of a hydrolase receptor family, designated the cysteine protease-binding protein family (cpbf), that is involved in trafficking of hydrolases to lysosomes and phagosomes, and we have also reported that cpbf1 and cpbf8 bind to cysteine proteases or ...201323509141
nested pcr reveals elevated over-diagnosis of e. histolytica in barcelona, venezuela.the aim of this study was to identify the presence of entamoeba histolytica and e. dispar by nested pcr in children attending the "dr. luis razetti" hospital, barcelona, anzoátegui state. of the 1,141 fecal samples coproparasitologically evaluated by conventional microscopy, 150 were diagnosed positive for e. histolytica in 0-10 year-old-children, of both sexes. the signs, symptoms and a full coproparasitological report were obtained from all of these and nested pcr was performed to identify e. ...201223513487
evaluation of entamoeba histolytica recombinant phosphoglucomutase protein for serodiagnosis of amoebic liver abscess.amoebic liver abscess (ala) is the most frequent clinical presentation of extra-intestinal amoebiasis. the diagnosis of ala is typically based on the developing clinical symptoms, characteristic changes on radiological imaging and serology. numerous serological tests have been introduced for the diagnosis of ala, either detecting circulating amoebic antigens or antibodies. however those tests show some pitfalls in their efficacy and/or the preparation of the tests are costly and tedious. the com ...201323514636
g protein signaling in the parasite entamoeba histolytica.the parasite entamoeba histolytica causes amebic colitis and systemic amebiasis. among the known amebic factors contributing to pathogenesis are signaling pathways involving heterotrimeric and ras superfamily g proteins. here, we review the current knowledge of the roles of heterotrimeric g protein subunits, ras, rho and rab gtpase families in e. histolytica pathogenesis, as well as of their downstream signaling effectors and nucleotide cycle regulators. heterotrimeric g protein signaling likely ...201323519208
metastatic abscess formation in a preexisting chest wall tumor: a rare initial presentation of klebsiella pneumoniae liver abscess.the common infectious agents in the chest wall include mycobacterium tuberculosis, actinomyces, fungi, nocardia, entamoeba histolytica, and other aerobes and anaerobes. klebsiella pneumoniae is an uncommon etiological agent. we describe a case of ankylosing spondylitis in a 45-year-old man, who had exhibited a painless lump in the left posterior chest wall for 3 months and who presented with acute-onset pain, erythematous change, and fever in the 2 weeks before admission. cultures of the blood a ...201323526295
overexpression of specific cysteine peptidases confers pathogenicity to a nonpathogenic entamoeba histolytica clone.cysteine peptidases (cps) of entamoeba histolytica are considered to be important pathogenicity factors. previous studies have found that under standard axenic culture conditions, only four (ehcp-a1, ehcp-a2, ehcp-a5, and ehcp-a7) out of 35 papain-like ehcp genes present in the e. histolytica genome are expressed at high levels. little is known about the expression of cps in e. histolytica during amoebic liver abscess (ala) formation. in the current study, a quantitative real-time pcr assay was ...201323532975
webuye health and demographic surveillance systems baseline survey of soil-transmitted helminths and intestinal protozoa among children up to five years.background. the intestinal parasitic infections (ipis) are globally endemic, and they constitute the greatest cause of illness and disease worldwide. transmission of ipis occurs as a result of inadequate sanitation, inaccessibility to potable water, and poor living conditions. objectives. to determine a baseline prevalence of ipis among children of five years and below at webuye health and demographic surveillance (hdss) area in western kenya. methods. cross-sectional survey was used to collect ...201323533444
discovery of entamoeba histolytica hexokinase 1 inhibitors through homology modeling and virtual screening.entamoeba histolytica, the parasite which causes amebiasis is responsible for 110,000 deaths a year. entamoeba histolytica depends on glycolysis to obtain atp for cellular work. according to metabolic flux studies, hexokinase exerts the highest flux control of this metabolic pathway; therefore, it is an excellent target in the search of new antiamebic drugs. to this end, a tridimensional model of e. histolytica hexokinase 1 (ehhk1) was constructed and validated by homology modeling. after virtua ...201423534932
localization of phosphatidylinositol 4,5-bisphosphate to lipid rafts and uroids in the human protozoan parasite entamoeba histolytica.entamoeba histolytica is an intestinal protozoan parasite and is the causative agent of amoebiasis. during invasive infection, highly motile amoebae destroy the colonic epithelium, enter the blood circulation, and disseminate to other organs such as liver, causing liver abscess. motility is a key factor in e. histolytica pathogenesis, and this process relies on a dynamic actomyosin cytoskeleton. in other systems, phosphatidylinositol 4,5-bisphosphate [pi(4,5)p2] is known to regulate a wide varie ...201323545298
site-specific o-glycosylation on the muc2 mucin protein inhibits cleavage by the porphyromonas gingivalis secreted cysteine protease (rgpb).the colonic epithelial surface is protected by an inner mucus layer that the commensal microflora cannot penetrate. we previously demonstrated that entamoeba histolytica secretes a protease capable of dissolving this layer that is required for parasite penetration. here, we asked whether there are bacteria that can secrete similar proteases. we screened bacterial culture supernatants for such activity using recombinant fragments of the muc2 mucin, the major structural component, and the only gel ...201323546879
prevalence of intestinal parasitic infections in certified food-handlers working in food establishments in the city of nairobi, kenya.most intestinal parasites are cosmopolitan with the highest prevalence in the tropics and subtopics. rural-to-urban migration rapidly increases the number of food eating places in towns and their environs. some of these eating estabishments have poor sanitation and are overcrowded, facilitating disease transmission, especially through food-handling. our investigations in nairobi, therefore, were set to determine the presence of intestinal parasites in food-handlers with valid medical certificate ...201223554735
prevalence of intestinal parasitic infections and risk factors among schoolchildren at the university of gondar community school, northwest ethiopia: a cross-sectional study.intestinal parasitic infections are among the major public health problems in sub-saharan africa. their distribution is mainly associated with poor personal hygiene, environmental sanitation and limited access to clean water. indeed, epidemiological information on the prevalence of various intestinal parasitic infections in different localities is a prerequisite to develop appropriate control measures. therefore, the aim of this study was to assess the prevalence of intestinal parasitic infectio ...201323560704
[prevalence of intestinal parasites in the maxakali indigenous community in minas gerais, brazil, 2009].a prevalence survey using the tf-test technique to identify intestinal parasites was conducted in the maxakali indigenous villages in minas gerais state, brazil. stool samples were collected on three alternating days, in separate tubes, containing 10% formalin, and unified in a laboratory by double filtering centrifugation. samples of sediment aliquot were prepared in triplicate and examined by microscope (10x and 40x) for eggs, cysts, and larvae. prevalence of parasites (89.5%) and polyparasiti ...201323568298
polyunsaturated fatty acids induce polarized submembranous f-actin aggregates and kill entamoeba histolytica.we have recently identified a novel galacto-glycerolipid (ggl) from the plant oxalis corniculata that killed the human pathogen entamoeba histolytica. in this study, we show that the anti-amoebic activity of ggl was due to the polyunsaturated fatty acid α-linolenic acid (c18:3 ) side chain. treatment of α-linolenic acid to e. histolytica trophozoites disrupted the cytoskeletal network and led to polarization of f-actin at one end of the cells with prominent filopodial extensions. in addition, cl ...201323568815
detection of entamoeba histolytica in experimentally induced amoebic liver abscess: comparison of three staining methods.to compare the efficacy of three different tissue stains, namely haematoxylin and eosin (h&e), periodic-acid schiff (pas) and immunohistochemical (ihc) stains for detection of entamoeba histolytica (e. histolytica) trophozoites in abscessed liver tissues of hamster.201223569836
unexpected properties of nadp-dependent secondary alcohol dehydrogenase (adh-1) in trichomonas vaginalis and other microaerophilic parasites.our previous observation that nadp-dependent secondary alcohol dehydrogenase (adh-1) is down-regulated in metronidazole-resistant trichomonas vaginalis isolates prompted us to further characterise the enzyme. in addition to its canonical enzyme activity as a secondary alcohol dehydrogenase, a pronounced, so far unknown, background nadph-oxidising activity in absence of any added substrate was observed when the recombinant enzyme or t. vaginalis extract were used. this activity was strongly enhan ...201323578856
entamoeba histolytica. 201323589427
nif-type iron-sulfur cluster assembly system is duplicated and distributed in the mitochondria and cytosol of mastigamoeba balamuthi.in most eukaryotes, the mitochondrion is the main organelle for the formation of iron-sulfur (fes) clusters. this function is mediated through the iron-sulfur cluster assembly machinery, which was inherited from the α-proteobacterial ancestor of mitochondria. in archamoebae, including pathogenic entamoeba histolytica and free-living mastigamoeba balamuthi, the complex iron-sulfur cluster machinery has been replaced by an ε-proteobacterial nitrogen fixation (nif) system consisting of two componen ...201323589868
synthesis and evaluation of 7-chloro-4-(piperazin-1-yl)quinoline-sulfonamide as hybrid antiprotozoal agents.a new series of 4-aminochloroquinoline based sulfonamides were synthesized and evaluated for antiamoebic and antimalarial activities. out of the eleven compounds evaluated (f1-f11), two of them (f3 and f10) showed good activity against entamoeba histolytica (ic50 <5 μm). three of the compounds (f5, f7 and f8) also displayed antimalarial activity against the chloroquine-resistant (fcr-3) strain of plasmodium falciparum with ic50 values of 2 μm. compound f7, whose crystal structure was also determ ...201323602620
systematic application of multiplex pcr enhances the detection of bacteria, parasites, and viruses in stool samples.to determine whether systematic testing of faecal samples with a broad range multiplex pcr increases the diagnostic yield in patients with diarrhoea compared with conventional methods and a clinician initiated testing strategy.201323603249
primary pathogenicity analysis of a chinese entamoeba histolytica isolate.this study is the first to isolate an entamoeba histolytica strain from chinese amoebic patients and to conduct a detailed examination of its virulence. a fecal sample that contains cysts of e. histolytica was obtained from guangxi province. the sample was cultured axenically and then cloned by limiting dilution, and named as xlac. in vitro and in vivo tests were conducted to evaluate the virulence of the entamoeba isolate. the e. histolytica strain xlac was successfully cloned and cultured axen ...201323612076
worldwide genealogy of entamoeba histolytica: an overview to understand haplotype distribution and infection outcome.although entamoeba histolytica is one of the most prevalent intestinal parasites, how the different strains of this species are distributed all over the world and how different genotypes are associated with the infection outcome are yet to be fully understood. recently, the use of a number of molecular markers has made the characterization of several genotypes in those regions with high incidence of amoebiasis possible. this work proposes the first genealogy of e. histolytica, with an haplotype ...201323624203
prevalence of intestinal protozoa in communities along the lake victoria region of uganda.the objective of this study was to assess water-borne parasite point prevalence in communities in close proximity to lake victoria in uganda prior to the implementation of a clean water intervention, and to investigate possible associations of water source and latrine access with protozoan prevalence. utilizing a rapid antigen test, parasite prevalence for giardia lamblia and entamoeba histolytica/dispar was determined from stool samples of individuals living in six ugandan communities. stool sa ...201323642567
intestinal parasitic infections among expatriate workers in al-madina al-munawarah, kingdom of saudi arabia.al madinah al munawarah, kingdom of saudi arabia (ksa) has one of the largest number of expatriate workers. most of them are from sri-lanka, indonesia, philippines, india and bangladesh. these countries are considered as endemic areas for intestinal parasites. a total of 2732 stool samples were screened for intestinal parasites. positive cases were recorded among 407 stool samples (14.9%). the common parasitic infections were encountered among 20-29 age groups (18.5%) while, the lowest infection ...201323665711
pcr amplification and dna sequence analysis of parasitic intestinal protozoa in specimens stained with chlorazol black e.chlorazol black e (cbe) stain has been used for the detection and identification of intestinal parasitic protozoa. in recent years, genotyping of protozoa has been performed to examine pathogenicity and for epidemiologic analysis. in this study, protozoan dna was amplified from preserved human fecal specimens stained with cbe that were positive for giardia intestinalis (syn. g. lamblia and g. duodenalis), chilomastix mesnili, pentatrichomonas hominis, and entamoeba histolytica. dna was amplified ...201323666647
differential detection of entamoeba histolytica, entamoeba dispar and entamoeba moshkovskii in fecal samples by nested pcr in the united arab emirates (uae).amoebiasis is one of the most important infectious diseases afflicting mainly tropical and subtropical countries. this study was carried out in the sharjah emirate, uae in order to accurately detect and differentiate entamoeba histolytica, entamoeba dispar and e. moshkovskii in fecal samples collected from the sharjah municipality public health clinic by elisa and nested polymerase chain reaction (pcr). one hundred and twenty specimens were examined and the pcr was positive for e. histolytica, e ...201323666654
entamoeba histolytica antigenic protein detected in pus aspirates from patients with amoebic liver abscess.entamoeba histolytica is a causative agent of amoebic liver abscess (ala) and is endemic in many underdeveloped countries. we investigated antigenic e. histolytica proteins in liver abscess aspirates using proteomics approach. pus samples were first tested by real-time pcr to confirm the presence of e. histolytica dna and the corresponding serum samples tested for e. histolytica-specific igg by a commercial elisa. proteins were extracted from three and one pool(s) of pus samples from ala and pla ...201323680184
intestinal parasitic infections in children presenting with diarrhoea in outpatient and inpatient settings in an informal settlement of nairobi, kenya.the distribution of and factors associated with intestinal parasitic infections are poorly defined in high risk vulnerable populations such as urban slums in tropical sub-saharan africa.201323705776
different clinical outcomes of entamoeba histolytica in malaysia: does genetic diversity exist?the present study was conducted to investigate the clinical outcomes of entamoeba histolytica infection in symptomatic and asymptomatic orang asli (aborigine) communities in malaysia. examination was performed on 500 stool samples obtained from orang asli communities in 3 different states using formalin-ether concentration, trichrome staining, and single-round pcr techniques. out of 500 stool samples, single infection of e. histolytica, entamoeba dispar, and entamoeba moshkovskii was identified ...201323710093
development of loop-mediated isothermal amplification for rapid detection of entamoeba histolytica.to develop a loop-mediated isothermal amplification (lamp) assay for the detection of entamoeba histolytica e. histolytica, the causative agent of amebiasis.201323711706
seroprevalence of entamoeba histolytica infection among chinese men who have sex with men.men who have sex with men (msm) were found to be one of the high-risk populations for entamoeba histolytica (e. histolytica) infection. accompanied by the prevalence of human immunodeficiency virus (hiv) among msm, invasive amebiasis caused by e. histolytica has been paid attention to as an opportunistic parasitic infection. however, the status of e. histolytica infection among msm has been barely studied in mainland china.201323717699
sialic acid-dependent attachment of mucins from three mouse strains to entamoeba histolytica.mouse strain-specific differences in the carbohydrate composition of intestinal mucins were hypothesized to account for strain-dependent susceptibility to entamoeba histolytica. to test this hypothesis, intestinal mucins from susceptible and resistant inbred strains of mice were analyzed for their o-glycan content and for their ability to inhibit amoebic adherence to (galnac)12-27-hsa neo-glycoproteins. the results showed that the colorectal mucin o-glycan of susceptible cba mice was lower in si ...201323726913
synthesis and antiprotozoal activity of novel 2-{[2-(1h-imidazol-1-yl)ethyl]sulfanyl}-1h-benzimidazole derivatives.a series of 19 new 2-{[2-(1h-imidazol-1-yl)ethyl]sulfanyl}-1h-benzimidazole derivatives was synthesized starting from the properly substituted 1,2-phenylendiamine. these compounds have hydrogen or methyl at position 1; while hydrogen, chlorine, ethoxy or methoxycarbonyl group is at position 5 and/or 6. the novel compounds were tested against protozoa trichomonas vaginalis, giardia intestinalis and entamoeba histolytica. experimental evaluations revealed strong activity for all tested compounds, ...201323731944
intestinal parasites in a quilombola community of the northern state of espírito santo, brazil.the aim of this study was to determine the occurrence of intestinal parasites in a quilombola community from the northern espírito santo, brazil. descendants of slaves who arrived in brazil in the sixteenth century, this population settled in the municipality of são mateus in 1858. fresh fecal samples from 82 individuals who agreed to participate in the study were collected between august 2009 and july 2010, and immediately sent to the clinical laboratory of the centro universitário norte do esp ...201323740008
high occurrence of entamoeba histolytica in the municipalities of ariquemes and monte negro, state of rondônia, western amazonia, brazil.entamoeba histolytica infections were investigated in residents of the ariquemes and monte negro municipalities in rondônia state, brazil.201323740019
molecular basis of ligand recognition by oass from e. histolytica: insights from structural and molecular dynamics simulation studies.o-acetyl serine sulfhydrylase (oass) is a pyridoxal phosphate (plp) dependent enzyme catalyzing the last step of the cysteine biosynthetic pathway. here we analyze and investigate the factors responsible for recognition and different conformational changes accompanying the binding of various ligands to oass.201323747298
chemo-informatic design of antibiotic geldenamycin analogs to target stress proteins hsp90 of pathogenic protozoan parasites.stress proteins hsp90 (heat shock proteins) are essential molecular chaperones involved in signal transduction, cell cycle control, stress management, folding and degradation of proteins. hsp90 have been found in a variety of organisms including pathogens suggesting that they are ancient and conserved proteins. here, using molecular modeling and docking protocols, antibiotic geldenamycin and its analog are targeted to the hsp90 homolog proteins of pathogenic protozoans plasmodium falciparum, lei ...201323750075
intestinal parasite prevalence in an area of ethiopia after implementing the safe strategy, enhanced outreach services, and health extension program.the safe strategy aims to reduce transmission of chlamydia trachomatis through antibiotics, improved hygiene, and sanitation. we integrated assessment of intestinal parasites into large-scale trachoma impact surveys to determine whether documented environmental improvements promoted by a trachoma program had collateral impact on intestinal parasites.201323755308
drug repurposing: mining protozoan proteomes for targets of known bioactive compounds.to identify potential opportunities for drug repurposing by developing an automated approach to pre-screen the predicted proteomes of any organism against databases of known drug targets using only freely available resources.201623757409
the ehcpadh112 complex of entamoeba histolytica interacts with tight junction proteins occludin and claudin-1 to produce epithelial damage.entamoeba histolytica, the protozoan responsible for human amoebiasis, causes between 30,000 and 100,000 deaths per year worldwide. amoebiasis is characterized by intestinal epithelial damage provoking severe diarrhea. however, the molecular mechanisms by which this protozoan causes epithelial damage are poorly understood. here, we studied the initial molecular interactions between the e. histolytica ehcpadh112 virulence complex and epithelial mdck and caco-2 cells. by confocal microscopy, we di ...201323762290
giant liver abscess with bilateral pleural effusion: an unfamiliar association.amoebic liver abscess is a common problem in tropical countries. however, its protean manifestations sometimes pose diagnostic dilemma leading to delay in starting appropriate therapy. we report here one interesting case of an amoebic liver abscess where the patient developed some uncommon features like bilateral pedal edema and bilateral pleural effusion. although unilateral effusion is well known in such patients, the cause of bilateral involvement of pleura in this patient remained largely un ...201223767022
amebic liver abscess complicated by inferior vena cava thrombosis: a case report.amebic liver abscess is the most common extraintestinal manifestation of infection with entamoeba histolytica. it is a common disease, especially in endemic areas, but it is a rare cause of inferior vena cava (ivc) obstruction, with only a few cases appearing in the literature. the authors describe a case of amebic liver abscess in a patient who developed a rare vascular complication of inferior vena cava thrombosis. the case responded to conservative treatment and radiological intervention.201223770872
comparison of clinical and laboratory characteristics of intestinal amebiasis with shigellosis among patients visiting a large urban diarrheal disease hospital in bangladesh.between 1993 and 2011, a total of 371 intestinal amebiasis (ia), caused by entamoeba histolytica cases were compared with 1,113 shigellosis (randomly selected) patients of icddr,b, excluding co-infections (rotavirus and vibrio cholerae) in two age stratums: 0-14 years of age and ≥ 15 years of age. the number of ia and shigellosis cases gradually reduced over the study period. in multivariate analysis, individuals 0-14 years of age, slum dwellers (odds ratio [or] 3.51; 95% confidence interval [ci ...201323775017
drug resistance in natural isolates of leishmania donovani s.l. promastigotes is dependent of pgp170 expression.resistance of pathogens to drugs is a growing concern regarding many diseases. parasites like leishmania, plasmodium and entamoeba histolytica; and neoplastic cells, present the multidrug-resistant phenotype rendering chemotherapy ineffective. the acquired resistance of leishmania to antimony has generated intense research on the mechanisms involved but the question has not yet been resolved. to test the hypothesis that drug efflux in leishmania, as measured by flow cytometry using the fluoresce ...201323776486
determination of an unstable pentapeptide, monocyte locomotion inhibitory factor, in dog blood by lc-ms/ms: application to a pharmacokinetic study.a liquid chromatography-tandem mass spectrometry (lc-ms/ms) method has been developed and established for the quantitative determination of monocyte locomotion inhibitory factor, a pentapeptide (met-gln-cys-asn-ser) produced by entamoeba histolytica in axenic culture, in dog blood. the main challenge was the chemical and enzymatic instability of the peptide which was successfully overcome. after a simple protein precipitation, mlif was separated from as-5 (met-gln-gly-asn-ser), acted as an inter ...201323777619
functional manipulation of a calcium-binding protein from entamoeba histolytica guided by paramagnetic nmr.ehcabp1, one of the calcium-binding proteins from entamoeba histolytica, is a two-domain ef-hand protein. the two domains of ehcabp1 are structurally and functionally different from each other. however, both domains are required for structural stability and a full range of functional diversity. analysis of sequence and structure of ehcabp1 and other cabps indicates that the c-terminal domain of ehcabp1 possesses a unique structure compared with other family members. this had been attributed to t ...201323782698
intestinal parasites in hiv-seropositive patients in the continental region of equatorial guinea: its relation with socio-demographic, health and immune systems factors.prevalence of intestinal parasitic infections in hiv-positive people and its association with clinical and socioeconomic factors has been investigated on the mainland of equatorial guinea, in order to define the precise measures for improvement of their quality of life.201323783759
identification and analysis of putative homologues of mechanosensitive channels in pathogenic protozoa.mechanosensitive channels play important roles in the physiology of many organisms, and their dysfunction can affect cell survival. this suggests that they might be therapeutic targets in pathogenic organisms. pathogenic protozoa lead to diseases such as malaria, dysentery, leishmaniasis and trypanosomiasis that are responsible for millions of deaths each year worldwide. we analyzed the genomes of pathogenic protozoa and show the existence within them of genes encoding putative homologues of mec ...201323785469
synthesis and in vitro evaluation of new ethyl and methyl quinoxaline-7-carboxylate 1,4-di-n-oxide against entamoeba histolytica.in our search for new antiamoebic agents, a new series of ethyl and methyl quinoxaline-7-carboxylate 1,4-di-n-oxide derivatives have been synthesized using the beirut reaction. all compounds were characterized by spectroscopic techniques and elemental analysis. antiamoebic activity was evaluated in vitro against entamoeba histolytica strain hm1:imss by the microdilution method, and the structure-activity relationship was analyzed. we found that eleven quinoxaline derivatives showed greater activ ...201323787289
[colonic amoebiasis simulating a cecal tumor: case report].colonic ameboma is a rare inflammatory pseudo-tumor of the colon that can mimic cancer development. this case was located in the cecum and appeared malignant from a macroscopic view. accordingly a right hemicolectomy was performed, followed by an end-to-side ileocolic anastomosis. the pathology study enabled us to correct the diagnosis and affirm its amebic origin.201623797923
identification of calcium-transporting atpases of entamoeba histolytica and cellular localization of the putative serca.calcium has an important role on signaling of different cellular processes in the protozoa parasite entamoeba histolytica, including development and pathogenesis. however, the systems that control calcium responses in this parasite are incompletely understood. calcium-atpases (ca(2+)-atpases) are proteins that play an important role in calcium homeostasis by catalyzing the active efflux of this ion from cytoplasm and are essential to the correct functioning of the cell machinery. here, we report ...201323800535
genomic distribution of sines in entamoeba histolytica strains: implication for genotyping.the major clinical manifestations of entamoeba histolytica infection include amebic colitis and liver abscess. however the majority of infections remain asymptomatic. earlier reports have shown that some e. histolytica isolates are more virulent than others, suggesting that virulence may be linked to genotype. here we have looked at the genomic distribution of the retrotransposable short interspersed nuclear elements ehsine1 and ehsine2. due to their mobile nature, some ehsine copies may occupy ...201323815468
intestinal parasitic infections in suburban government schools, lak hok subdistrict, muang pathum thani, thailand.to provide baseline information of parasitic infections in 3 suburban government schools, lakhok subdistrict of muang pathum thani, thailand.201323827146
expression, purification, and evaluation of recombinant leca as a candidate for an amebic colitis vaccine.entamoeba histolytica, which causes amebic colitis and liver abscess, is considered a major enteric pathogen in residents and travelers to developing countries where the disease is endemic. interaction of this protozoan parasite with the intestine is mediated through the binding of the trophozoite stage to intestinal mucin and epithelium via a galactose and n-acetyl-d-galactosamine (gal/galnac) lectin comprised of a disulfide linked heavy (ca. 180 kda) and light chain (ca. 35 kda) and a noncoval ...201423827311
entamoeba histolytica brain abscess.brain abscess due to entamoeba histolytica is most commonly seen in a small percentage of patients who also have an amebic liver abscess. the typical patient is a young man who after treatment for liver abscess with apparent improvement develops symptoms and signs of central nervous system involvement. the average age of the patient is 30 years, and common presentations include headache, vomiting, and altered mental status. signs of amebic brain abscess include most commonly meningeal signs, fac ...201323829905
effects of hygiene and defecation behavior on helminths and intestinal protozoa infections in taabo, côte d'ivoire.more than 1 billion people are currently infected with soil-transmitted helminths and schistosomes. the global strategy to control helminthiases is the regular administration of anthelmintic drugs to at-risk populations. however, rapid re-infection occurs in areas where hygiene, access to clean water, and sanitation are inadequate.201323840358
the 25 kda subunit of cleavage factor im is a rna-binding protein that interacts with the poly(a) polymerase in entamoeba histolytica.in eukaryotes, polyadenylation of pre-mrna 3' end is essential for mrna export, stability and translation. taking advantage of the knowledge of genomic sequences of entamoeba histolytica, the protozoan responsible for human amoebiasis, we previously reported the putative polyadenylation machinery of this parasite. here, we focused on the predicted protein that has the molecular features of the 25 kda subunit of the cleavage factor im (cfim25) from other organisms, including the nudix (nucleoside ...201323840799
the calcium binding protein ehcabp6 is a microtubular-end binding protein in entamoeba histolytica.the genome of entamoeba histolytica encodes several calcium binding proteins and those characterized thus far have been shown to participate predominantly in phagocytosis and endocytosis. our study showed that ehcabp6 has two ef-hand domains efi and efiii; it can bind ca(2+) in vitro and undergoes conformational transition on binding ca(2+) suggesting that it can serve as a calcium signal sensor. ehcabp6 is localized in the nucleus, cytoplasm and plasma membrane and is sensitive to heat stress. ...201323848346
evaluation of luminex xtag gastrointestinal pathogen analyte-specific reagents for high-throughput, simultaneous detection of bacteria, viruses, and parasites of clinical and public health importance.acute diarrheal disease (add) can be caused by a range of pathogens, including bacteria, viruses, and parasites. conventional diagnostic methods, such as culture, microscopy, biochemical assays, and enzyme-linked immunosorbent assays (elisa), are laborious and time-consuming and lack sensitivity. combined, the array of tests performed on a single specimen can increase the turnaround time (tat) significantly. we validated a 19plex laboratory-developed gastrointestinal pathogen panel (gpp) using l ...201323850948
cytokine and chemokine responses to helminth and protozoan parasites and to fungus and mite allergens in neonates, children, adults, and the elderly.in rural sub-saharan africa, endemic populations are often infected concurrently with several intestinal and intravascular helminth and protozoan parasites. a specific, balanced and, to an extent, protective immunity will develop over time in response to repeated parasite encounters, with immune responses initially being poorly adapted and non-protective. the cellular production of pro-inflammatory and regulatory cytokines and chemokines in response to helminth, protozoan antigens and ubiquitous ...201323855879
investigation of intestinal parasites in dialysis patients.to search for the opportunistic and other pathogenic intestinal parasites in dialysis patients, and to compare the methods used for diagnosis.201323860891
identification and characterization of micrornas from entamoeba histolytica hm1-imss.entamoeba histolytica is the causative agent of amebiasis, a disease that is a major source of morbidity and mortality in the developing world. micrornas (mirnas) are a large group of non-coding rnas that play important roles in regulating gene expression and protein translation in animals. genome-wide identification of mirnas is a critical step to facilitating our understanding of genome organization, genome biology, evolution, and post-transcriptional regulation.201323874540
the genome and transcriptome of the enteric parasite entamoeba invadens, a model for encystation.several eukaryotic parasites form cysts that transmit infection. the process is found in diverse organisms such as toxoplasma, giardia, and nematodes. in entamoeba histolytica this process cannot be induced in vitro, making it difficult to study. in entamoeba invadens, stage conversion can be induced, but its utility as a model system to study developmental biology has been limited by a lack of genomic resources. we carried out genome and transcriptome sequencing of e. invadens to identify molec ...201323889909
need for species-specific detection for the diagnosis of amoebiasis in a non-endemic setting.the diagnosis of amoebiasis caused by entamoeba histolytica is traditionally based on microscopy. however, the specificity of this method may be questioned, especially in areas where infections by e. histolytica are rare. in the present study, a species-specific real-time pcr was used for the identification of the morphologically similar species e. histolytica and entamoeba dispar. out of 15 microscopy-positive stool samples, all were negative for e. histolytica and positive for e. dispar. in 2 ...201323902585
[infectious etiology of acute idiopathic intussusception in children].the intussusception (iia) is an invagination of the immediate part of the intestine. she is responsible for a syndrome with an occlusive venous compression and swelling that can rapidly progress to intestinal necrosis. most cases occur in children aged 6 to 18 months and occur more frequently in boys than girls. there are two types of iia: the iia idiopathic representing 90-95% of invaginations of the child and the iia secondary to local injury of the gastrointestinal tract or occurring in a par ...201323906565
Displaying items 6401 - 6500 of 7191