Publications

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the effects of phosphanegold(i) thiolates on the biological properties of acanthamoeba castellanii belonging to the t4 genotype.gold compounds have shown promise in the treatment of non-communicable diseases such as rheumatoid arthritis and cancer, and are considered of value as anti-microbial agents against gram-negative and gram-positive bacteria, and have anti-parasitic properties against schistosoma mansoni, trypanosoma brucei, plasmodium falciparum, leishmania infantinum, giardia lamblia, and entamoeba histolytica. they are known to affect enzymatic activities that are required for the cellular respiration processes ...201728366172
diagnosis of intestinal parasites in a rural community of venezuela: advantages and disadvantages of using microscopy or rt-pcr.a cross-sectional study was carried out to determine the prevalence and diagnostic performance of microscopy and real time pcr (rt-pcr) for 14 intestinal parasites in a venezuelan rural community with a long history of persistent intestinal parasitic infections despite the implementation of regular anthelminthic treatments. a total of 228 participants were included in this study. a multiplex rt-pcr was used for the detection of dientamoeba fragilis, giardia intestinalis, cryptosporidium sp. and ...201728007484
geospatial distribution of intestinal parasitic infections in rio de janeiro (brazil) and its association with social determinants.intestinal parasitic infections remain among the most common infectious diseases worldwide. this study aimed to estimate their prevalence and provide a detailed analysis of geographical distribution of intestinal parasites in the metropolitan region of rio de janeiro, considering demographic, socio-economic, and epidemiological contextual factors.201728273080
epidemiology of soil-transmitted helminth and intestinal protozoan infections in preschool-aged children in the amhara region of ethiopia.intestinal parasites are important contributors to global morbidity and mortality and are the second most common cause of outpatient morbidity in ethiopia. this cross-sectional survey describes the prevalence of soil-transmitted helminths and intestinal protozoa in preschool children 0-5 years of age in seven communities in the amhara region of ethiopia, and investigates associations between infection, household water and sanitation characteristics, and child growth. stool samples were collected ...201728167597
prevalence and seasonal variation of human intestinal parasites in patients attending hospital with abdominal symptoms in northern jordan.this study was carried out to determine the prevalence of intestinal parasites and their seasonal variation in northern jordan. a total of 21 906 stool samples were collected over a period of 4 years (2009- 2013) from 5 government hospitals in 3 cities. samples were processed and examined microscopically and by concentration methods. parasitic infection was found in 9611 samples (44%). giardia lamblia was the most prevalent parasite (41%) followed by entamoeba histolytica (31%) and ent. coli (13 ...201728134428
seroprevalence of five parasitic pathogens in pregnant women in ten caribbean countries.to date, published epidemiological studies of parasitic infections in humans in the caribbean region are very limited. here, we report the seroprevalence of five parasitic pathogens, including ascaris lumbricoides, entamoeba histolytica, giardia lamblia, schistosoma mansoni, and toxocara canis in 435 serum samples collected between 2008 and 2011 from pregnant women in ten caribbean islands. we tested the serum samples for igg antibodies against the five parasites by enzyme-linked immunosorbent a ...201727778108
human parasites in the roman world: health consequences of conquering an empire.the archaeological evidence for parasites in the roman era is presented in order to demonstrate the species present at that time, and highlight the health consequences for people living under roman rule. despite their large multi-seat public latrines with washing facilities, sewer systems, sanitation legislation, fountains and piped drinking water from aqueducts, we see the widespread presence of whipworm (trichuris trichiura), roundworm (ascaris lumbricoides) and entamoeba histolytica that caus ...201726741568
occurrence of blastocystis spp. in uberaba, minas gerais, brazil.intestinal parasites are a problem for public health all over the world. the infection with blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. in this study, the occurrence of intestinal parasites, with emphasis on blastocystis, in patients at the universidade federal do triângulo mineiro was investigated in uberaba (mg) through microscopy of direct smears and fecal concentrates using ritchie's method. feces of 1,323 patients were examined from ap ...201726200960
synthesis and biological evaluation of newer 1,3,4-oxadiazoles incorporated with benzothiazepine and benzodiazepine moieties.a series of thiazepines and diazepines having 1,3,4-oxadiazole moiety were synthesized, and they were analyzed for their in vitro antimicrobial activity against several bacteria (staphylococcus aureus, staphylococcus pyogenes, escherichia coli, and pseudomonas aeruginosa) and fungi (candida albicans, aspergillus niger, and aspergillus clavatus) and protozoa (entamoeba histolytica, giardia lamblia, trypanosoma cruzi and leishmania mexicana). few of the selected compounds were tested for their ant ...201728182579
prevalence of intestinal parasites among food handlers of sari, northern iran.parasitic infection is highly prevalent throughout the developing countries of the world. food handlers are a potential source of infection for many intestinal parasites and other enteropathogenic infections as well. the aim of this study was to determine the prevalence of intestinal parasite carriers among food handlers attending the public health center laboratory in sari, northern iran for annual check-up. the study was performed from august 2011 through february 2012. stool samples were coll ...201725923893
association between enteric protozoan parasites and gastrointestinal illness among hiv- and tuberculosis-infected individuals in the chowke district, southern mozambique.human immune deficiency virus (hiv) and tuberculosis (tb) infections remain major public health issues globally, particularly in sub-saharan africa. impairment of both cell-mediated and humoral immunity by hiv and/or tb infections may limit the host's defences against other pathogens, including the diarrheagenic protozoan cryptosporidium spp., giardia intestinalis, and entamoeba histolytica. during september-december 2015 a cross-sectional study was conducted to assess the prevalence and molecul ...201728302528
reprofiled drug targets ancient protozoans: drug discovery for parasitic diarrheal diseases.recently, we developed a novel automated, high throughput screening (hts) methodology for the anaerobic intestinal parasite entamoeba histolytica. we validated this hts platform by screening a chemical library containing us food and drug administration (fda)-approved drugs and bioactive compounds. we identified an fda-approved drug, auranofin, as most active against e. histolytica both in vitro and in vivo. our cell culture and animal studies indicated that thioredoxin reductase, an enzyme invol ...201723137963
pattern of co-infection by enteric pathogenic parasites among hiv sero-positive individuals in a tertiary care hospital, mumbai, india.one of the major medical concerns in people living with hiv/aids (plha) is management of diarrhea that can lead to severe morbidity and mortality. such clinical scenario warrants an analysis of intestinal parasites, which are important opportunistic pathogens in plha. owing to the scarcity of recent pattern of intestinal opportunistic infections from this region, the study was designed to determine the opportunistic parasites causing diarrhea in plha; and to find out whether there is any signifi ...201726392653
triage and protocol recommendations for the parasitology laboratory based on an epidemiological investigation of parasite diagnostics in ontario laboratories.a study was performed using a subset of ontario laboratory parasitology data, with three objectives: to describe parasitic infections in ontario; to identify risk factors for acquiring a parasitic infection using routinely collected information; and to use this information to assess current protocols for parasite testing in laboratories and, in turn, to propose alternatives to optimize the allocation of laboratory resources.201725587292
occurrence of giardia, cryptosporidium, and entamoeba in wild rhesus macaques (macaca mulatta) living in urban and semi-rural north-west india.giardia duodenalis, cryptosporidium spp., and entamoeba spp. are intestinal protozoa capable of infecting a range of host species, and are important causes of human morbidity and mortality. understanding their epidemiology is important, both for public health and for the health of the animals they infect. this study investigated the occurrence of these protozoans in rhesus macaques (macaca mulatta) in india, with the aim of providing preliminary information on the potential for transmission of t ...201728229045
detection and differentiation of entamoeba histolytica and entamoeba dispar in clinical samples through pcr-denaturing gradient gel electrophoresis.amebiasis is one of the twenty major causes of disease in mexico; however, the diagnosis is difficult due to limitations of conventional microscopy-based techniques. in this study, we analyzed stool samples using polymerase chain reaction-denaturing gradient gel electrophoresis (pcr-dgge) to differentiate between entamoeba histolytica (pathogenic) and e. dispar (non-pathogenic). the target for the pcr amplification was a small region (228 bp) of the adh112 gene selected to increase the sensitivi ...201728380216
development of a thermostabilised triplex lamp assay with dry-reagent four target lateral flow dipstick for detection of entamoeba histolytica and non-pathogenic entamoeba spp.this study highlighted the development of a four target nitrocellulose-based nucleic acid lateral flow immunoassay biosensor in a dry-reagent strip format for interpretation of double-labelled double-stranded amplicons from thermostabilised triplex loop-mediated isothermal amplification assay. the dna biosensor contained two test lines which captured biotin and texas red labelled amplicons; a lamp internal amplification control line that captured digoxigenin labelled amplicon; and a chromatograp ...201728372729
molecular diagnosis of entamoeba spp. versus microscopy in the great cairo.amoebiasis is a human disease produced by entamoeba histolytica which causes widespread mortality and morbidity worldwide through diarrheal disease and abscess establishment in parenchymal tissues such as liver, lung, and brain. the true prevalence of infection is unknown for most areas of the world due to the difficulty to characterise entamoeba histolytica versus other non-pathogenic amoebas with identical morphology, as entamoeba dispar, and entamoeba moshkovskii. to overcome microscopy misid ...201728030342
gene migration for re-emerging amebiasis in iran's northwest-iraq borders: a microevolutionary scale for reflecting epidemiological drift of entamoeba histolytica metapopulations.in the microevolutionary scales of entamoeba isolates, the gene migration shows how entamoeba spp. has epidemiologically drifted among border countries. five hundred fecal samples were taken from patients suffering gastrointestinal disorders, abdominal pain, and diarrhea at saggez, northwest iran located within the border iraq country. following parasitological techniques, dna samples were extracted and amplified by polymerase chain reaction (pcr) of 18s rrna region to identify entamoeba infecti ...201727761718
application of multiplex pcr for detection and differentiation of entamoeba histolytica, entamoeba dispar and entamoeba moshkovskii.entamoeba moshkovskii and e. dispar are impossible to differentiate microscopically from the pathogenic species e. histolytica. multiplex polymerase chain reaction (multiplex pcr) is a widespread molecular biology technique for amplification of multiple targets in a single pcr experiment.201725759727
entamoeba dispar: could it be pathogenic.amebiasis is a disease caused by the protozoan parasite entamoeba histolytica. this ameba can colonize the human intestine and persist as a commensal parasite, similar to entamoeba dispar, an ameba considered to be non-pathogenic. the similarities between e. histolytica and e. dispar make the latter an attractive model for studies aimed at clarifying the pathogenesis of amebiasis. however, in addition to being an interesting experimental model, this relative of e. histolytica remains poorly unde ...201725709947
spontaneous resolution of a hepatogastric fistula. 201728345399
development and initial evaluation of a lateral flow dipstick test for antigen detection of entamoeba histolytica in stool sample.entamoeba histolytica infection remains a public health concern in developing countries. early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rppdk) and e. histolytica excretory-secretory antigens to produce polyclonal antibodies. a rapid dipstick test was produced using anti-rppdk pab lined on t ...201728335696
structural and functional studies of a noncanonical dicer from entamoeba histolytica.rnaseiii proteins are dsrna-specific endonucleases involved in many important biological processes, such as small rna processing and maturation in eukaryotes. various small rnas have been identified in a protozoan parasite entamoeba histolytica. ehrnaseiii is the only rnaseiii endonuclease domain (riiid)-containing protein in e. histolytica. here, we present three crystal structures that reveal several unique structural features of ehrnaseiii, especially the interactions between the two helixes ...201728317870
the tudor staphylococcal nuclease protein of entamoeba histolytica participates in transcription regulation and stress response.entamoeba histolytica is the protozoa parasite responsible of human amoebiasis, disease that causes from 40,000 to 100,000 deaths annually worldwide. however, few are known about the expression regulation of molecules involved in its pathogenicity. transcription of some virulence-related genes is positively controlled by the cis-regulatory element named ure1. previously we identified the transcription factor that binds to ure1, which displayed a nuclear and cytoplasmic localization. this protein ...201728293543
behavior of dna-lacking mitochondria in entamoeba histolytica revealed by organelle transplant.the anaerobic protozoan parasite entamoeba histolytica has mitosomes that are mitochondria lacking some canonical functions and organelle dna. mitosomes play an important role in the life cycle of the parasite. the distribution of proteins in mitosomes is not uniform, and how mitosomes are maintained and retained is unknown. to answer these questions, we developed a transplant method for mitosomes with hemagglutinin-tagged protein into recipient cells containing mitosomes with myc-tagged protein ...201728287148
role of eosinophils and tumor necrosis factor alpha in interleukin-25-mediated protection from amebic colitis.the parasite entamoeba histolytica is a cause of diarrhea in infants in low-income countries. previously, it was shown that tumor necrosis factor alpha (tnf-α) production was associated with increased risk of e. histolytica diarrhea in children. interleukin-25 (il-25) is a cytokine that is produced by intestinal epithelial cells that has a role in maintenance of gut barrier function and inhibition of tnf-α production. il-25 expression was decreased in humans and in the mouse model of amebic coli ...201728246365
antiprotozoal, antimycobacterial, and anti-inflammatory evaluation of cnidoscolus chayamansa (mc vaugh) extract and the isolated compounds.cnidoscolus chayamansa is a medicinal and edible plant known as chaya, is commonly used as an anti-inflammatory, antiprotozoal, antibacterial agent and as a remedy for respiratory illness, gastrointestinal disorders, and vaginal infections related with the inflammation process. in this paper, we describe the plant's phytochemical analysis and biological activities (antimycobacterial, antibacterial, antiprotozoal, and anti-inflammatory properties) of the chcl3:meoh (1:1) leaves extract and isolat ...201728222400
antiprotozoal constituents from annona cherimola miller, a plant used in mexican traditional medicine for the treatment of diarrhea and dysentery.annona cherimola miller (annonaceae) is a medicinal plant frequently recommended in mexican traditional medicine for the treatment of gastrointestinal disorders such as diarrhea and dysentery.201728216899
entamoeba histolytica-encoded homolog of macrophage migration inhibitory factor contributes to mucosal inflammation during amebic colitis. 201728186296
[ambiguous hepatic mass and fever after stay in turkey].we report the case of a 76-year old female patient with a hepatic mass after staying in eastern turkey. there were no indices for malignancy or an infection with echinococcus or entamoeba histolytica. finally we diagnosed a fascioliasis (liver fluke) and cured the patient successfully.201728180910
first molecular epidemiology of entamoeba histolytica, e. dispar and e. moshkovskii infections in yemen: different species-specific associated risk factors.to investigate the molecular epidemiology of entamoeba histolytica, e. dispar and e. moshkovskii infections among rural communities in yemen.201728151567
sine polymorphism reveals distinct strains of entamoeba histolytica from north india.entamoeba histolytica is an intestinal parasite causing significant morbidity and mortality in the developing world. more tools are needed to understand the epidemiology and molecular pathogenesis of amebiasis. virulence pattern of e. histolytica could be linked with the genotype of a strain. several loci showing insertion polymorphism of retrotransposable short interspersed nuclear elements ehsine1 and ehsine2 have been reported among laboratory strains of e. histolytica. the present study was ...201728131659
investigating the mechanism of adp-forming acetyl-coa synthetase from the protozoan parasite entamoeba histolytica.adp-forming acetyl-coa synthetase (acd) catalyzes the interconversion of acetyl-coa and acetate. the related succinyl-coa synthetase follows a three-step mechanism involving a single phosphoenzyme, but a novel four-step mechanism with two phosphoenzyme intermediates was proposed for pyrococcus acd. characterization of enzyme variants of entamoeba acd in which the two proposed phosphorylated his residues were individually altered revealed that only his252 is essential for enzymatic activity. anal ...201728129670
the monomeric gtpase rab35 regulates phagocytic cup formation and phagosomal maturation in entamoeba histolytica.one of the hallmarks of amoebic colitis is the detection of entamoeba histolytica (eh) trophozoites with ingested erythrocytes. therefore, erythrophagocytosis is traditionally considered as one of the most important criteria to identify the pathogenic behavior of the amoebic trophozoites. phagocytosis is an essential process for the proliferation and virulence of this parasite. phagocytic cargo, upon internalization, follows a defined trafficking route to amoebic lysosomal degradation machinery. ...201728126902
iron responsive-like elements in the parasite entamoeba histolytica.in entamoeba histolytica, iron modulates virulence and gene expression via unknown regulatory mechanisms. the existence of a posttranscriptional iron regulatory system parallel to the ire/irp (iron-responsive element/iron regulatory protein) system in the protozoan trichomonas vaginalis has recently been reported. due to their evolutionary closeness and the importance of iron for growth and virulence in these protozoa, we hypothesized the existence of an ire/irp-like mechanism in e. histolytica. ...201728100304
nanoformulation of synergistic tlr ligands to enhance vaccination against entamoeba histolytica.diarrheal infectious diseases represent a major cause of global morbidity and mortality. there is an urgent need for vaccines against diarrheal pathogens, especially parasites. modern subunit vaccines rely on combining a highly purified antigen with an adjuvant to increase their efficacy. in the present study, we evaluated the ability of a nanoliposome adjuvant system to trigger a strong mucosal immune response to the entamoeba histolytica gal/galnac lectin leca antigen. cba/j mice were immunize ...201728089548
molecular prevalence of entamoeba histolytica/dispar infection among patients attending four health centres in north-west ethiopia.the prevalence of amoebiasis is often overestimated owing to its epidemiological overlap with the non-pathogenic entamoeba dispar to provide evidence for this conjecture, a cross-sectional study was conducted from november 2013 to january 2015. a range of 180-200 µg of semi-solid and formed stools and 200 µl of diarrhoeic stool samples were used for dna extraction from microscopically e. histolytica/dispar positive samples using the qiaamp® dna stool mini kit according to manufacturers' instruct ...201726834117
employing binol-phosphoroselenoyl chloride for selective inositol phosphorylation and chemical synthesis of glycosyl inositol phospholipid from entamoeba histolytica.here we describe the chemical synthesis of glycosyl inositol phospholipids from entamoeba histolytica. the key feature of this synthesis is a regioselective phosphorylation reaction that occurs via desymmetrization of a myo-inositol derivative with phosphoroselenoyl chloride. we also developed a new protecting group strategy that utilizes allyl and alloc groups to synthesize complex glycolipids bearing unsaturated lipids. these developments provided an efficient synthetic route for various compl ...201728390155
corrigendum: n-acetyl ornithine deacetylase is a moonlighting protein and is involved in the adaptation of entamoeba histolytica to nitrosative stress. 201728378758
stem loop-mediated isothermal amplification test: comparative analysis with classical lamp and pcr in detection of entamoeba histolytica in kenya.entamoeba histolytica, the causative agent for amoebiasis is a considerable burden to population in the developing countries where it accounts for over 50 million infections. the tools for detection of amoebiasis are inadequate and diagnosis relies on microscopy which means a significant percent of cases remain undiagnosed. moreover, tests formats that can be rapidly applied in rural endemic areas are not available.201728359328
cytosine dna methylation at promoter of non ltr retrotransposon and heat shock protein gene (hsp70) of entamoeba histolytica and lack of correlation with transcription status.non ltr retrotransposons (ehlines and ehsines) occupy 11% of the entamoeba histolytica genome. since promoter dna methylation at cytosines has been correlated with transcriptional silencing of transposable elements in model organisms we checked whether this was the case in ehline1. we located promoter activity in a 841bp fragment at 5'-end of this element by luciferase reporter assay. from rnaseq and rt-pcr analyses we selected a transcriptionally active and silent copy to study cytosine dna met ...201728082182
prevalence and risk factors for intestinal parasitic infection in schoolchildren in battambang, cambodia.most intestinal parasitic infections (ipis), commonly endemic in tropical resource-poor developing countries, are neglected tropical diseases. parasitic infections and malnutrition are most commonly found in children. we determined the prevalence of ipis and the risk factors in battambang province, northwestern cambodia, from august to september 2015. this study collected 308 valid questionnaires and specimens from dontri (173, 56.2%) and kon kaêk (135, 43.8%) primary schools. all stool samples ...201728070012
muc2 mucin and butyrate contribute to the synthesis of the antimicrobial peptide cathelicidin in response to entamoeba histolytica- and dextran sodium sulfate-induced colitis.embedded in the colonic mucus are cathelicidins, small cationic peptides secreted by colonic epithelial cells. humans and mice have one cathelicidin-related antimicrobial peptide (cramp) each, ll-37/hcap-18 and cramp, respectively, with related structure and functions. altered production of muc2 mucin and antimicrobial peptides is characteristic of intestinal amebiasis. the interactions between muc2 mucin and cathelicidins in conferring innate immunity against entamoeba histolytica are not well ...201728069814
amoebic liver abscess in northern sri lanka: first report of immunological and molecular confirmation of aetiology.since 1985, amoebic liver abscess (ala) has been a public health problem in northern sri lanka. clinicians arrive at a diagnosis based on clinical and ultrasonographic findings, which cannot differentiate pyogenic liver abscess (pla) from ala. as the treatment and outcome of the ala and pla differs, determining the etiological agent is crucial.201728061872
new antiprotozoal agents: synthesis and biological evaluation of different 4-(7-chloroquinolin-4-yl) piperazin-1-yl)pyrrolidin-2-yl)methanone derivatives.in an endeavor to develop efficacious antiprotozoal agents 4-(7-chloroquinolin-4-yl) piperazin-1-yl)pyrrolidin-2-yl)methanone derivatives (5-14) were synthesized, characterized and biologically evaluated for antiprotozoal activity. the compounds were screened in vitro against the hm1: imss strain of entamoeba histolytica and nf54 chloroquine-sensitive strain of plasmodium falciparum. among the synthesized compounds six exhibited promising antiamoebic activity with ic50 values (0.14-1.26μm) lower ...201728027871
data on rad51 amino acid sequences from higher and lower eukaryotic model organisms and parasites.this paper contains data related to the research article titled "characterization of the recombination activities of the entamoeba histolytica rad51 recombinase" (kelso et al., in press) [1]. the known and putative amino acid sequence of rad51, the central enzyme of homologous recombination, from nineteen different higher and lower eukaryotic organisms was analyzed. here, we show amino acid conservation using a multiple sequence alignment, overall sequence identities using a percent identity mat ...201728018950
(1)h, (13)c and (15)n nmr assignments of an unusual ca(2+)-binding protein from entamoeba histolytica in its apo form.we report almost complete sequence specific (1)h, (13)c and (15)n nmr assignments of an unusual ca(2+)-binding protein from entamoeba histolytica (ehcabp6) in its apo form as a prelude to its structural and functional characterization.201727990612
functionally conserved rna-binding and protein-protein interaction properties of line-orf1p in an ancient clade of non-ltr retrotransposons of entamoeba histolytica.retrotransposons are mobile genetic elements found in most organisms. their origin and evolution is not very well understood. retrotransposons that lack long terminal repeats (non-ltr) have been classified based on their reverse transcriptase (rt) and endonuclease sequences into groups, of which r2 is the most ancient. its members contain a single open reading frame (orf) while there are two orfs in the other groups, of which orf2 contains the rt and endonuclease sequences. it is thought that or ...201727894878
study of infections among human immunodeficiency virus/acquired immunodeficiency syndrome patients in shadan hospital, telangana, india.human immunodeficiency virus (hiv) pandemicity is a major concern today as it causes greater loss of productivity than any other disease. hiv infection leads to profound immune deficiency and patients become highly susceptible to opportunistic infections (ois). hiv epidemic in india is heterogeneous in nature, both in terms of routes of transmission as well as geographical spread.201727890948
antioxidant defense of nrf2 vs pro-inflammatory system of nf-κb during the amoebic liver infection in hamster.entamoeba histolytica is the causative agent of amoebic liver abscess (ala), which course with an uncontrolled inflammation and nitro-oxidative stresses, although it is well known that amoeba has an effective defence mechanisms against this toxic environment, the underlying molecular factors responsible for progression of tissue damage remain largely unknown. the purpose of the present study was to determine during the acute stage of ala in hamsters, the involvement of nuclear factor (erythroid- ...201727876112
improved anticancer and antiparasitic activity of new lawsone mannich bases.substituted lawsone mannich bases 2a-e, 3a-e and 4a-e were prepared and tested for their biological activities. the new fatty alkyl substituted compounds 2a-c exhibited strong and selective growth inhibitory activities in the low one-digit micromolar and sub-micromolar range against a panel of human cancer cell lines associated with ros formation. in addition, compounds 2a-c revealed sub-micromolar anti-trypanosomal activities against parasitic trypanosoma brucei brucei cells via deformation of ...201727912173
lateral gene transfer of p-cresol- and indole-producing enzymes from environmental bacteria to mastigamoeba balamuthi.p-cresol and indole are volatile biologically active products of the bacterial degradation of tyrosine and tryptophan respectively. they are typically produced by bacteria in animal intestines, soil and various sediments. here, we demonstrate that the free-living eukaryote mastigamoeba balamuthi and its pathogenic relative entamoeba histolytica produce significant amounts of indole via tryptophanase activity. unexpectedly, m. balamuthi also produces p-cresol in concentrations that are bacteriost ...201727902886
underestimated amoebic appendicitis among hiv-1-infected individuals in japan.entamoeba histolytica is not a common causative agent of acute appendicitis. however, amoebic appendicitis can sometimes be severe and life threatening, mainly due to a lack of awareness. also, its frequency, clinical features, and pathogenesis remain unclear. the study subjects were hiv-1-infected individuals who presented with acute appendicitis and later underwent appendectomy at our hospital between 1996 and 2014. formalin-fixed paraffin-embedded preserved appendix specimens were reexamined ...201727847377
phase i clinical trial results of auranofin, a novel antiparasitic agent.under an nih priority to identify new drugs to treat class b parasitic agents, we performed high-throughput screens, which identified the activity of auranofin (ridaura) against entamoeba histolytica and giardia intestinalis, major causes of water- and foodborne outbreaks. auranofin, an orally administered, gold (au)-containing compound that was approved by the fda in 1985 for treatment of rheumatoid arthritis, was effective in vitro and in vivo against e. histolytica and both metronidazole-sens ...201727821451
the intestinal bacterial microbiome and e. histolytica infection.entamoeba histolytica, the etiological agent of amebiasis, is a significant cause of pediatric diarrhea in south asia and sub-saharan africa. the clinical outcome of an e. histolytica exposure varies enormously and can present as diarrhea, dysentery, or amebic liver abscess. host and parasite factors likely contribute to the outcome of infection with the parasite, but do not explain the wide variation in presentation of disease. this suggests that other environmental factors affect disease. an e ...201727525214
characterization of the recombination activities of the entamoeba histolytica rad51 recombinase.the protozoan parasite responsible for human amoebiasis is entamoeba histolytica. an important facet of the life cycle of e. histolytica involves the conversion of the mature trophozoite to a cyst. this transition is thought to involve homologous recombination (hr), which is dependent upon the rad51 recombinase. here, a biochemical characterization of highly purified ehrad51 protein is presented. the ehrad51 protein preferentially binds ssdna, forms a presynaptic filament and possesses atp hydro ...201727678398
heterodimerization of the entamoeba histolytica ehcpadh virulence complex through molecular dynamics and protein-protein docking.ehcpadh is a protein complex involved in the virulence of entamoeba histolytica, the protozoan responsible for human amebiasis. it is formed by the ehcp112 cysteine protease and the ehadh adhesin. to explore the molecular basis of the complex formation, three-dimensional models were built for both proteins and molecular dynamics simulations (mds) and docking calculations were performed. results predicted that the pehcp112 proenzyme and the mehcp112 mature enzyme were globular and peripheral memb ...201726861050
seroprevalence of entamoeba histolytica from a tertiary care hospital, south india.amebiasis is the third leading cause of death after malaria and schistosomiasis. diagnosis is based on microscopy, culture, isoenzyme analysis, and serology-based techniques. in resource-limited nation such as india where polymerase chain reaction cannot be employed, serology is considered to be the reliable diagnostic tool. to find the seroprevalence of entamoeba histolytica igg antibody by enzyme-linked immunosorbent assay (elisa) among the liver abscess cases and healthy controls.201726998437
phenolic acid composition and anti-parasitic effects of four peucedanum species on entamoeba histolytica trophozoites.the aim of this study was to determine phenolic acid composition and anti-parasitic effects of peucedanum caucasicum, p. palimbioides, p. longibracteolatum and p. chryseum on entamoeba histolytica.201726622297
possible hematological changes associated with acute gastroenteritis among kindergarten children in gaza.gastroenteritis is considered one of the leading causes of morbidity and mortality in children especially in developing countries. it is a major childhood problem in gaza and one of the most common etiologic agents of iron deficiency anemia (ida).201726229719
inhibition of amebic lysosomal acidification blocks amebic trogocytosis and cell killing.entamoeba histolytica ingests fragments of live host cells in a nibbling-like process termed amebic trogocytosis. amebic trogocytosis is required for cell killing and contributes to tissue invasion, which is a hallmark of invasive amebic colitis. work done prior to the discovery of amebic trogocytosis showed that acid vesicles are required for amebic cytotoxicity. in the present study, we show that acidified lysosomes are required for amebic trogocytosis and cell killing. interference with lysos ...201728851845
synthetic analogs of an entamoeba histolytica glycolipid designed to combat intracellular leishmania infection.intracellular pathogens belonging to the genus leishmania have developed effective strategies that enable them to survive within host immune cells. immunostimulatory compounds that counteract such immunological escape mechanisms represent promising treatment options for diseases. here, we demonstrate that a lipopeptidephosphoglycan (lppg) isolated from the membrane of a protozoan parasite, entamoeba histolytica (eh), shows considerable immunostimulatory effects targeted against leishmania (l.) m ...201728842620
the macrophage cytoskeleton acts as a contact sensor upon interaction with entamoeba histolytica to trigger il-1β secretion.entamoeba histolytica (eh) is the causative agent of amebiasis, one of the major causes of dysentery-related morbidity worldwide. recent studies have underlined the importance of the intercellular junction between eh and host cells as a determinant in the pathogenesis of amebiasis. despite the fact that direct contact and ligation between eh surface gal-lectin and ehcp-a5 with macrophage α5β1 integrin are absolute requirements for nlrp3 inflammasome activation and il-1β release, many other undef ...201728837696
bioflow: a non-invasive, image-based method to measure speed, pressure and forces inside living cells.cell motility is governed by a complex molecular machinery that converts physico-chemical cues into whole-cell movement. understanding the underlying biophysical mechanisms requires the ability to measure physical quantities inside the cell in a simple, reproducible and preferably non-invasive manner. to this end, we developed bioflow, a computational mechano-imaging method and associated software able to extract intracellular measurements including pressure, forces and velocity everywhere insid ...201728835648
in vitro testing of potential entamoeba histolytica pyruvate phosphate dikinase inhibitors.adverse effects and resistance to metronidazole have motivated the search for new antiamoebic agents against entamoeba histolytica. control of amoeba growth may be achieved by inhibiting the function of the glycolytic enzyme and pyruvate phosphate dikinase (ppdk). in this study, we screened 10 compounds using an in vitro ppdk enzyme assay. these compounds were selected from a virtual screening of compounds in the national cancer institute database. the antiamoebic activity of the selected compou ...201728820699
microbiome-mediated neutrophil recruitment via cxcr2 and protection from amebic colitis.the disease severity of entamoeba histolytica infection ranges from asymptomatic to life-threatening. recent human and animal data implicate the gut microbiome as a modifier of e. histolytica virulence. here we have explored the association of the microbiome with susceptibility to amebiasis in infants and in the mouse model of amebic colitis. dysbiosis occurred symptomatic e. histolytica infection in children, as evidenced by a lower shannon diversity index of the gut microbiota. to test if dysb ...201728817707
outbreak of intestinal amoebiasis among men who have sex with men, barcelona (spain), october 2016 and january 2017.entamoeba histolytica has been recently recognised as an emerging sexually transmissible pathogen in men who have sex with men (msm), causing sporadic outbreaks in countries where it is not endemic. here we report two closed clusters of invasive amoebiasis occurring in barcelona, spain, in october 2016 (four cases) and in january 2017 (four cases).201728797327
different behavior of myeloperoxidase in two rodent amoebic liver abscess models.the protozoan entamoeba histolytica is the etiological agent of amoebiasis, which can spread to the liver and form amoebic liver abscesses. histological studies conducted with resistant and susceptible models of amoebic liver abscesses (alas) have established that neutrophils are the first cells to contact invasive amoebae at the lesion site. myeloperoxidase is the most abundant enzyme secreted by neutrophils. it uses hydrogen peroxide secreted by the same cells to oxidize chloride ions and prod ...201728796788
larrea tridentata: a novel source for anti-parasitic agents active against entamoeba histolytica, giardia lamblia and naegleria fowleri.protozoan parasites infect and kill millions of people worldwide every year, particularly in developing countries where access to clean fresh water is limited. among the most common are intestinal parasites, including giardia lamblia and entamoeba histolytica. these parasites wreak havoc on the epithelium lining the small intestines (g. lamblia) and colon (e. histolytica) causing giardiasis and amebiasis, respectively. in addition, there are less common but far more deadly pathogens such as naeg ...201728793307
crystal structure of the peg-bound sh3 domain of myosin ib from entamoeba histolytica reveals its mode of ligand recognition.the versatility in the recognition of various interacting proteins by the sh3 domain drives a variety of cellular functions. here, the crystal structure of the c-terminal sh3 domain of myosin ib from entamoeba histolytica (ehmysh3) is reported at a resolution of 1.7 å in native and peg-bound states. comparisons with other structures indicated that the peg molecules occupy protein-protein interaction pockets similar to those occupied by the peptides in other peptide-bound sh3-domain structures. a ...201728777082
a unique case of empyema secondary to amoebic liver abscess.an amoebic liver abscess is an extraintestinal manifestation of amoebiasis that can present with complaints such as right upper quadrant pain and fever. it might not necessarily be associated with abdominal complaints and can have many other atypical presentations. it may present with lung diseases, cardiac diseases, or brain abscesses. we present a case of a patient with empyema secondary to amoebic liver abscess whose diagnosis was delayed due to an unusual presentation. a combination of radio ...201728775917
differential expression of pathogenic genes of entamoeba histolytica vs e. dispar in a model of infection using human liver tissue explants.we sought to establish an ex vivo model for examining the interaction of e. histolytica with human tissue, using precision-cut liver slices (pcls) from donated organs. e. histolytica- or e. dispar-infected pcls were analyzed at different post-infection times (0, 1, 3, 24 and 48 h) to evaluate the relation between tissue damage and the expression of genes associated with three factors: a) parasite survival (peroxiredoxin, superoxide dismutase and 70 kda heat shock protein), b) parasite virulence ...201728771523
agc family kinase 1 participates in trogocytosis but not in phagocytosis in entamoeba histolytica.the protozoan parasite entamoeba histolytica is the aetiologic agent of amoebiasis, an endemic infection in developing countries with considerable morbidity and mortality. recently, trogocytosis has been recognized as the key step in amoebic cytolysis and invasion, a paradigm shift in understanding pathogenicity of this organism. here we report that agc family kinase 1 is specifically involved in trogocytosis of live human cells and does not participate in phagocytosis of dead cells. live imagin ...201728740237
investigation of pyrophosphate versus atp substrate selection in the entamoeba histolytica acetate kinase.acetate kinase (ack; e.c. 2.7.2.1), which catalyzes the interconversion of acetate and acetyl phosphate, is nearly ubiquitous in bacteria but is present only in one genus of archaea and certain eukaryotic microbes. all acks utilize atp/adp as the phosphoryl donor/acceptor in the respective directions of the reaction (acetate + atp [formula: see text] acetyl phosphate + adp), with the exception of the entamoeba histolytica ack (ehack) which uses pyrophosphate (ppi)/inorganic phosphate (pi) (acety ...201728724909
occult amoebic liver abscess as cause of extensive inferior vena cava and hepatic vein thrombosis.the most common extraintestinal complication of entamoeba histolytica is amoebic liver abscess (ala). hepatic vein and inferior vena cava (ivc) thrombosis are rare but well-documented complications of ala, typically attributed to mechanical compression and inflammation associated with a large abscess. we present a case of a previously healthy 43-year-old canadian man presenting with constitutional symptoms and right upper quadrant abdominal pain. he was found to have thrombophlebitis of the ivc, ...201728722597
case report: endemic amebiasis in australia: implications for residents, travelers, and clinicians.entamoeba histolytica is considered endemic in australia; however, cases are rare, occurring almost exclusively in high-risk individuals. we describe a series of locally acquired, complicated cases in low-risk individuals from far north queensland in whom the diagnosis was delayed. amebiasis may pose a greater local threat than is currently recognized.201728719303
x-ray snapshots of a pyridoxal enzyme: a catalytic mechanism involving concerted [1,5]-hydrogen sigmatropy in methionine γ-lyase.pyridoxal 5'-phosphate (plp)-enzymes are essentially involved in amino acid and amine metabolism of a wide variety of organisms. despite their extensive biochemical studies, there are little evidence and structural data to comprehensively elaborate the catalytic mechanism. we obtained x-ray snapshots of l-methionine γ-lyase from entamoeba histolytica (ehmgl), a plp-enzyme catalyzing the γ-elimination reaction of methionine. here, we suggest a catalytic mechanism of ehmgl by using the x-ray snaps ...201728687762
in-silico prediction and modeling of the entamoeba histolytica proteins: serine-rich entamoeba histolytica protein and 29 kda cysteine-rich protease.amoebiasis is the third most common parasitic cause of morbidity and mortality, particularly in countries with poor hygienic settings. there exists an ambiguity in the diagnosis of amoebiasis, and hence there arises a necessity for a better diagnostic approach. serine-rich entamoeba histolyticaprotein (srehp), peroxiredoxin and gal/galnac lectin are pivotal in e. histolyticavirulence and are extensively studied as diagnostic and vaccine targets. for elucidating the cellular function of these pro ...201728674640
adherens junctions and desmosomes are damaged by entamoeba histolytica: participation of ehcpadh complex and ehcp112 protease.entamoeba histolytica trophozoites adhere to epithelium at the cell-cell contact and perturb tight junctions disturbing the transepithelial electrical resistance. behind tight junctions are the adherens junctions (ajs) that reinforce them and the desmosomes (dsms) that maintain the epithelium integrity. the damage produced to ajs and dmss by this parasite is unknown. here, we studied the effect of the trophozoites, the ehcpadh complex, and the ehcp112 recombinant enzyme (rehcp112) on aj and dsm ...201728656597
multiplex pcr gastro-intestinal panels for the management of traveller's diarrhea : are they accurate and useful?until recently, the search for enteropathogens causing travellers' diarrhea was based on stool culture (campylobacter spp., salmonella spp. and shigella spp.), direct microscopy with (cryptosporidium spp.) or without specific staining (giardia lamblia, entamoeba histolytica) or specific antigen detection (giardia lamblia, entamoeba histolytica). molecular analyses are progressively replacing traditional diagnostic methods but their clinical usefulness remains to be better defined. this article a ...201728627855
enteric multiplex pcr panels: a new diagnostic tool for amoebic liver abscess?invasive amoebiasis is a life-threatening infection requiring immediate detection and treatment. however, diagnosis is challenging because conventional methods such as light microscopy and serology are unreliable. molecular techniques are therefore considered the new diagnostic reference standard, but most of the developed assays are research tools and not widely available. recently commercial multiplex pcr panels have been introduced which permit the simultaneous detection of multiple enteric p ...201728626584
antiamoebic activity of petiveria alliacea leaves and their main component, isoarborinol.petiveria alliacea l. (phytolacaceae) is a medicinal plant with a broad range of traditional therapeutic properties, including the treatment of dysentery and intestinal infections caused by protozoan parasites. however, its effects against entamoeba histolytica have not been reported yet. we investigated the antiamoebic activity present in the leaves of p. alliacea antiamoebic activity was evaluated in methanolic and aqueous extracts, as well as in the hexanic, methanolic, and etoac fractions. t ...201728621111
intestinal parasitic infestation among paediatric diarrhoea patients attending hospitals in port blair, andaman and nicobar islands.acute childhood diarrhoea remains one of the leading causes of childhood morbidity and mortality in developing countries. the present study was conducted to estimate the prevalence of various intestinal parasitic infestation among children aged 5 years and less suffering from acute diarrhoea disease attending hospitals in andaman islands. during the period from january 2012 to december 2013, a total of 675 acute diarrhoea patients were included in the study. among these samples, 476 (70.5, 95 % ...201728615884
heavy subunit of cell surface gal/galnac lectin (hgl) undergoes degradation via endo-lysosomal compartments in entamoeba histolytica.the human gut parasite entamoeba histolytica uses a multifunctional virulence factor, hgl, a cell surface transmembrane receptor subunit of gal/galnac lectin that contributes to adhesion, invasion, cytotoxicity and immune response in the host. at present, the physiologic importance of hgl receptor is mostly known for pathogenicity of e. histolytica. however, the molecular mechanisms of hgl trafficking events and their association with the intracellular membrane transport machinery are largely un ...201728613117
entamoeba histolytica infection in female sex workers: a matched case-control study in durango, mexico.infection with entamoeba histolytica (e. histolytica) can be potentially transmitted by sexual contact. the seroepidemiology of e. histolytica in female sex workers has not been studied. the aim of the study was to determine whether e. histolytica is associated with the occupation of female sex work. in addition, the correlates of e. histolytica seroprevalence in female sex workers were also investigated.201728611864
investigation of a food-borne outbreak of gastroenteritis in a school canteen revealed a variant of sapovirus genogroup v not detected by standard pcr, sollentuna, sweden, 2016.a food-borne outbreak of gastroenteritis with more than 650 suspected cases occurred in april 2016 in sollentuna, sweden. it originated in a school kitchen serving a total of 2,700 meals daily. initial microbiological testing (for campylobacter, salmonella, shigella, yersinia, giardia, cryptosporidium, entamoeba histolytica, adeno-, astro-, noro-, rota- and sapovirus) of stool samples from 15 symptomatic cases was negative, despite a clinical presentation suggestive of calicivirus. analyses of t ...201728602163
synthesis, antiprotozoal activity, and chemoinformatic analysis of 2-(methylthio)-1h-benzimidazole-5-carboxamide derivatives: identification of new selective giardicidal and trichomonicidal compounds.a series of twelve new 2-(methylthio)-1h-benzimidazole-5-carboxamide derivatives (1-12) were synthesized and their antiparasitic activity was tested in vitro against giardia intestinalis, trichomonas vaginalis and entamoeba histolytica. experimental evaluations showed ic50 values within the nanomolar range for all tested compounds, some showing higher activity than metronidazole and albendazole. a chemoinformatic study was used to compare the structure-activity relationship of the synthesized ca ...201728595066
identification of s-nitrosylated (sno) proteins in entamoeba histolytica adapted to nitrosative stress: insights into the role of sno actin and in vitro virulence.we have recently reported that entamoeba histolytica trophozoites can adapt to toxic levels of the nitric oxide (no) donor, s-nitrosoglutathione (gsno). even if the consequences of this adaptation on the modulation of gene expression in no-adapted trophozoites (nat) have been previously explored, insight on s-nitrosylated (sno) proteins in nat is missing. our study aims to fill this knowledge gap by performing a screening of sno proteins in nat. employing sno resin-assisted capture (rac), we ide ...201728589096
antiprotozoal activities of tiliroside and other compounds from sphaeralcea angustifolia (cav.) g. don.sphaeralcea angustifolia (malvaceae) is extensively used in mexican traditional medicine for the treatment of gastrointestinal disorders such as diarrhea and dysentery.201728539736
parallel elisas using crude soluble antigen and excretory-secretory antigen for improved serodiagnosis of amoebic liver abscess.crude soluble antigen (csa) produced from entamoeba histolytica trophozoite is conventionally used for serodiagnosis of invasive amoebiasis. however, high background seropositivities by csa-assay in endemic areas complicate the interpretation of positive result in clinical settings. instead, incorporating a second assay which indicates active or recent infection into the routine amoebic serology could possibly complement the limitations of csa-assay. hence, the present study aimed to evaluate th ...201728506795
structure of ca2+-binding protein-6 from entamoeba histolytica and its involvement in trophozoite proliferation regulation.cell cycle of entamoeba histolytica, the etiological agent of amoebiasis, follows a novel pathway, which includes nuclear division without the nuclear membrane disassembly. we report a nuclear localized ca2+-binding protein from e. histolytica (abbreviated hereafter as ehcabp6), which is associated with microtubules. we determined the 3d solution nmr structure of ehcabp6, and identified one unusual, one canonical and two non-canonical cryptic ef-hand motifs. the cryptic ef-ii and ef-iv pair with ...201728505197
crystal structure of the entamoeba histolytica rna lariat debranching enzyme ehdbr1 reveals a catalytic zn(2+) /mn(2+) heterobinucleation.the rna lariat debranching enzyme, dbr1, is a metallophosphoesterase that cleaves 2'-5' phosphodiester bonds within intronic lariats. previous reports have indicated that dbr1 enzymatic activity is supported by diverse metal ions including ni(2+) , mn(2+) , mg(2+) , fe(2+) , and zn(2+) . while in initial structures of the entamoeba histolytica dbr1 only one of the two catalytic metal-binding sites were observed to be occupied (with a mn(2+) ion), recent structures determined a zn(2+) /fe(2+) het ...201728504306
multiplex pcr detection of cryptosporidium sp, giardia lamblia and entamoeba histolytica directly from dried stool samples from guinea-bissauan children with diarrhoea.in developing countries, diarrhoea is the most common cause of death for children under five years of age, with giardia lamblia, cryptosporidium and entamoeba histolytica as the most frequent pathogenic parasites. traditional microscopy for stool parasites has poor sensitivity and specificity, while new molecular methods may provide more accurate diagnostics. in poor regions with sample storage hampered by uncertain electricity supply, research would benefit from a method capable of analysing dr ...201728446068
intestinal parasitic infections: current status and associated risk factors among school aged children in an archetypal african urban slum in nigeria.intestinal parasitic infections (ipis) among school aged children (sac) in nigeria remains endemic, hence the need for regular surveillance to attract the attention of policy makers. this cross-sectional study investigated the current prevalence and factors associated with intestinal parasitic infections among school aged children in an urban slum of lagos city, nigeria.201728711437
antiprotozoal, antibacterial and antidiarrheal properties from the flowers of chiranthodendron pentadactylon and isolated flavonoids.chiranthodendron pentadactylon larreat. (sterculiaceae) is a mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea.201728539715
profile of intestinal parasitosis among school-aged children in kiliba (eastern dr congo).this study of feces sought to determine the prevalence of human intestinal parasites in the kiliba area of the eastern dr congo. feces of 602 school children aged from 9 to 20 years were collected from april to june 2014 and examined. direct analyses were supplemented with the kato and ritchie methods. the global prevalence of intestinal parasitosis in school-aged children in the kiliba area was 91.4 % [95 % ci: 87.6-94.3%]. the frequency of helminthiasis was high at 73.8 % (95 % ci: 68.4-78.6%) ...201728655684
gastrointestinal parasites in captive and free-ranging cebus albifrons in the western amazon, ecuador.currently, there is a lack of surveys that report the occurrence of gastrointestinal parasites in the white-headed capuchin monkey (cebus albifrons). we therefore assessed the presence and richness (= number of different parasite genera) of parasites in c. albifrons in wildlife refuges (n = 11) and in a free-ranging group near a human village (n = 15) in the ecuadorian amazon. in the 78 samples collected (median of 3 samples per animal), we identified a total of 6 genera of gastrointestinal para ...201728808619
an integrated study of human and animal infectious disease in the lake victoria crescent small-holder crop-livestock production system, kenya.the neglected zoonotic diseases (nzd) are an understudied group that are a major cause of illness throughout the developing world. in general, little is known about the prevalence and burden of nzds in affected communities, particularly in relation to other infectious diseases with which they are often co-endemic. we describe the design and descriptive epidemiological outputs from an integrated study of human and animal zoonotic and non-zoonotic disease in a rural farming community in western ke ...201728666412
hookworm infection is associated with decreased cd4+ t cell counts in hiv-infected adult ugandans.most studies evaluating epidemiologic relationships between helminths and hiv have been conducted in the pre-art era, and evidence of the impact of helminth infections on hiv disease progression remains conflicting. less is known about helminth infection and clinical outcomes in hiv-infected adults receiving antiretroviral therapy (art). we sampled hiv-infected adults for eight gastrointestinal parasites and correlated parasitic infection with demographic predictors, and clinical and immunologic ...201728542260
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