<i>Entamoeba histolytica</i> is an anaerobic parasitic protozoan and well known as a human pathogen, while its close relative, <i>Entamoeba dispar</i>, also possesses similar characteristics as...<i>Entamoeba histolytica</i> is an anaerobic parasitic protozoan and well known as a human pathogen, while its close relative, <i>Entamoeba dispar</i>, also possesses similar characteristics as an infectious agent. These microorganisms are generally transmitted in fecal-contaminated water. However, <i>E. dispar</i> present in industrial wastewater is also capable of creating biofilms that can cause adverse impacts in piping networks. Therefore, it is important to detect both of these protozoan species in water and to find a cost-effective technique for inactivation or management control. This review article summarizes the available detection methods in water and wastewater matrices along with feasible disinfection techniques.展开更多
Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.hist...Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.展开更多
Objective:To compare the efficacy of three different tissue stains,namely haematoxylin and eosin(H&E),periodic-acid Schiff(PAS)and immunohistochemical(1HC)stains for detection of Entamoeba histolytica(E.histolytic...Objective:To compare the efficacy of three different tissue stains,namely haematoxylin and eosin(H&E),periodic-acid Schiff(PAS)and immunohistochemical(1HC)stains for detection of Entamoeba histolytica(E.histolytica)trophozoites in abscessed liver tissues of hamster.Methods:Amoebic liver abscess was experimentally induced in a hamster by injecting 1×10~6of axenically cultured virulent E.histolytica trophozoites(HM1-IMSS strain)into the portal vein.After a week post-inoculation,the hamster was sacrificed and the liver tissue sections were stained with H&E,PAS and IHC stains to delect the amoebic trophozoite.Results:The three stains revealed tissue necrosis and amoebic trophozoites,but with varying clarity.H&E and PAS stained the trophozoites pink and magenta,respectively,however it was difficult to differentiate the stained trophozoites from the macrophages because of their similarity in size and morphology.On the other hand,IHC stain revealed distinct brown appearance of the trophozoites in the infected liver tissues.Conclusions:It can be concluded that out of the three stains.IHC is the best for identification of E.histolytica trophozoites in tissue sections.展开更多
Amebic liver abscesses(ALAs)are the most commonly encountered extraintestinal manifestation of human invasive amebiasis,which results from Entamoeba histolytica(E.histolytica)spreading extraintestinally.Amebiasis can ...Amebic liver abscesses(ALAs)are the most commonly encountered extraintestinal manifestation of human invasive amebiasis,which results from Entamoeba histolytica(E.histolytica)spreading extraintestinally.Amebiasis can be complicated by liver abscess in 9%of cases,and ALAs led to almost 50000 fatalities worldwide in 2010.Although there have been fewer and fewer cases in the past several years,ALAs remain an important public health problem in endemic areas.E.histolytica causes both amebic colitis and liver abscess by breaching the host’s innate defenses and invading the intestinal mucosa.Trophozoites often enter the circulatory system,where they are filtered in the liver and produce abscesses,and develop into severe invasive diseases such as ALAs.The clinical presentation can appear to be colitis,including upper-right abdominal pain accompanied by a fever in ALA cases.Proper diagnosis requires nonspecific liver imaging as well as detecting anti-E.histolytica antibodies;however,these antibodies cannot be used to distinguish between a previous infection and an acute infection.Therefore,diagnostics primarily aim to use PCR or enzyme-linked immunosorbent assay to detect E.histolytica.ALAs can be treated medically,and percutaneous catheter drainage is only necessary in approximately 15%of cases.The indicated treatment is to administer an amebicidal drug(such as tinidazole or metronidazole)and paromomycin or other luminal cysticidal agent for clinical disease.Prognosis is good with almost universal recovery.Establishing which diagnostic methods are most efficacious will necessitate further analysis of similar clinical cases.展开更多
AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk ...AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro.METHODS:Samples of human milk were collected from 5 healthy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained.RESULTS:The lethal effect of E. histolytica on the medium supplemented with different concentrations of both colostrum and mature human milk was significant during the first 30min. We also detected that the results of colostrum and mature human milk were similar. No statistically significant differences were found between same concentrations of colostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk have significant lethal effect on E. histolytica and protect against its infection in breast fed children.展开更多
Objective:To characterize the Entamoeba histolytica(E.histolytica)antigen(s)recognized by moribound amoebic liver abscess hamsters.Methods:Crude soluble antigen of E.histolytica was probed with sera of moribund hamste...Objective:To characterize the Entamoeba histolytica(E.histolytica)antigen(s)recognized by moribound amoebic liver abscess hamsters.Methods:Crude soluble antigen of E.histolytica was probed with sera of moribund hamsters in 1D-and 2D-Westem blot analyses.The antigenic protein was then sent for tandem mass spectrometry analysis.The corresponding gene was cloned and expressed in Escherichia coli BL21-AI to produce the recombinant E.histolytica ADP-forming acetyl-CoA synthetase(EhACS)protein.A customised ELISA was developed to evaluate the sensitivity and specificity of the recombinant protein.Results:A^75 kDa protein band with a pl value of 5.91-6.5 was found to be antigenic;and not detected by sera of hamsters in the control group.Tandem mass spectrometry analysis revealed the protein to be the 77 kDa E.histolytica ADP-forming acetyl-CoA synthetase(EhACS).The customised ELISA results revealed 100%sensitivity and 100%specificity when tested against infected(n=31)and control group hamsters(n=5)serum samples,respectively.Conclusions:This rinding suggested the significant role of EhACS as a biomarker for moribund hamsters with acute amoebic liver abscess(ALA)infection.It is deemed pertinent that future studies explore the potential roles of EhACS in better understanding the pathogenesis of ALA;and in the development of vaccine and diagnostic tests to control ALA in human populations.展开更多
Objective:To determine the profdes of anti-Entamoeba histolytica(E.histolytica) IgA.IgC. and IgM in sera of diarrheic and non-diarrheic individuals and partially characterize target antigens.Methods:Serum samples from...Objective:To determine the profdes of anti-Entamoeba histolytica(E.histolytica) IgA.IgC. and IgM in sera of diarrheic and non-diarrheic individuals and partially characterize target antigens.Methods:Serum samples from thirty diarrheic and thirty non-diarrheic individuals were subjected to IgA,IgG,and IgM profiling through enzyme-linked immunosorbent assay (EI.ISA),flow cytometry,and immunoblot.Results:ELBA titer results showed that both diarrheic and non-diarrheic individuals possess high levels of E.histolytica-specific IgG compared to IgA and IgM.How cytometry data showed that diarrheic serum samples had higher mean reaction percentages against E.histolytica cells compared to non-diarrheic samples.Immunoreactive E.histolytica proteins with molecular weights ranging belween 7 kDa and 292 kDa were recognized by diarrheic serum IgG,and 170 kDa and 250 kDa by non-diarrheic serum IgG. Conclusions:Our findings suggest that serum anti-E.histolytica IgG,compared with serum anti-E.histolytica IgA and IgM responses,was generally high in both diarrheic and nondiarrheic sera,indicating a past exposure to the organism both in symptomatic patients as well as in asymptomatic carriers,respectively.In addition,serum IgG from diarrheic and non-diarrheic patients were able to detect immunogenic E.histolytica proteins.展开更多
AIM:The effects of cobalt,copper,cadmium and barium ions on the cysts of Entamoeba histolyt/ca (E,histolytica), an amebic dysentery agent,cultured in Robinson medium were investigated. METHODS:E.histolytica cysts and ...AIM:The effects of cobalt,copper,cadmium and barium ions on the cysts of Entamoeba histolyt/ca (E,histolytica), an amebic dysentery agent,cultured in Robinson medium were investigated. METHODS:E.histolytica cysts and trophozoites isolated from a patient with amebiasis were cultivated in the medium, incubated at 37℃ for a period of 4 days and 40×10~4/ml amebic cysts were then transferred to a fresh medium.At the second stage,0.05,0.1 and 0.2 mM of selected metal ions were added to the medium,and the effects of these ions on parasitic reproduction compared with the control group were observed. RESULTS:It was determined that the number of living parasites in all the groups containing metal ions decreased significantly starting from 30 minutes (P<0.01).CuCl_2 showed the highest lethal effect on E.histolytica cysts,whereas the lowest lethal effect was observed with CoCl_2.It was also seen that the number of living cells was decreased as the ion concentration and exposure time were increased,and that there were no living parasites in the medium at the end of 24 h (P<0.01). CONCLUSION:It may be stated that the effect of ever- increasing contamination of the environment with metal waste materials on parasites should be investigated further.展开更多
A large number of microbial pathogens bind to heparan sulphate on eukaryotic cell surfaces. Heparan Sulphate Binding Proteins (HSBPs) from Entamoeba histolytica culture lysates were obtained by sequential ammonium sul...A large number of microbial pathogens bind to heparan sulphate on eukaryotic cell surfaces. Heparan Sulphate Binding Proteins (HSBPs) from Entamoeba histolytica culture lysates were obtained by sequential ammonium sulphate precipitation and Protein purify. SDS-PAGE and immunoblotting experiments indicated the presence of two major extracellular proteins in E. histolytica (51.2 kDa and 61.0 kDa). Characterization of HSBPs by 2D Gel electrophoresis of 40% (NH4)2SO4 precipitated lysate of E. histolytica revealed that the isoelectric point of 51.2 kDa HSBP was at pH3.0. The protein of 61.0 kDa HSBP showed three spots in 40% (NH4)2SO4 lysate which had isoelectric point between pH 4.0 - 7.0. While in 80% (NH4)2SO4 precipitated lysate, 51.2 kDa HSBP showed only one spot which had isoelectric point at pH 3. However, 61.0 kDa HSBP revealed 2 spots which had isoelectric point between pH 4 and 5. The result showed that this parasite has proteins which interact with heparan sulphate whose molecular formula is C14H23NO21S-23. These proteins may have a role in binding of parasite to heparan sulphate on host cells. Further characterization by MALDI-TOF analysis of HSBPs from E. histolytica demonstrated HSBPs to be novel protein in this parasite which has been isolated, purified and characterized first time by our group in the present study.展开更多
AIM To study the sensitivity and antioxidant enzyme response in two clinical isolates of Entamoeba histolytica(E. histolytica) during treatment with antiamoebic drugs,auranofin and metronidazole. METHODS E. histolytic...AIM To study the sensitivity and antioxidant enzyme response in two clinical isolates of Entamoeba histolytica(E. histolytica) during treatment with antiamoebic drugs,auranofin and metronidazole. METHODS E. histolytica were isolated from stool samples and maintained in Robinson's biphasic culture medium. Clinial isolates were maintained in xenic culture medium,and harvested for determination of minimum inhibitory concentrations to the two antiamoebic drugs,Metronidazole and Auranofin using microtiter plate tests. The percent survival of the two isolates were determined using the trypan blue cell count. Isolate 980 was treated with 70 μmol/L and 2 μmol/L while isolate 989 was treated with 20 μmol/L and 0.5 μmol/L of metronidazole and auranofin respectively for 24 h. Fifty thousand cells of each isolate were harvested after 24 h of treatment for analysis of the mRNA expressions of the antioxidant enzymes,thioredoxin reductase,peroxiredoxin and FeSOD using the specific primers. Cell lysate was used for determination of enzyme activity of thioredoxin reductase by measuring DTNB reduction spectrophotometrically at412 nm.RESULTS Minimum inhibitory concentration of the clinical isolates 980 and 989 for auranofin was 3 μmol/L and 1 μmol/L respectively while that for metronidazole was 80 μmol/L and 30 μmol/L respectively. Thioredoxin reductase,peroxiredoxin and FeSOD expression levels were significantly reduced in the isolate 980 when treated with Auranofin. Metronidazole treatment showed a down regulation of thioredoxin reductase. Though not significant both at the mRNA and the enzyme activity levels. Peroxiredoxin and FeSOD however remained unchanged. Auranofin treatment of isolate 989,showed an upregulation in expression of thioredoxin reductase while Peroxiredoxin and FeSOD did not show any change in expression. Upon treatment with metronidazole,isolate 989 showed an increase in thioredoxin reductase expression. Peroxiredoxin and FeSOD expressions however remain unchanged both at mRNA and enzyme activity level.CONCLUSION Clinical isolates from New Delhi NCR region show different sensitivities to antiamoebic drugs. Auranofin is effective against isolate showing higher tolerance to metronidazole as shown by its inhibition in thioredoxin reductase activity.展开更多
The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP...The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP) of a total 780 patients (children and adults) admitted to Samarra General Hospital were assessed. Samples of fresh feces were collected in normal physiological saline and examined using Olympic microscopes. The frequency of the parasite E. histolytica was 12.8% (46.3% male and 53.6% female). The highest frequency of infection of E. histolytica (13.8%) was found at age group (1 - 5 years old) followed by <1 year old children while the lowest (7.4%) was at ages (>41 years old). The highest rate of infection (33.9%) was found in September and the lowest (2.2%) in January. Similarly, the general infection frequency of the parasite G. lamblia was 3.9% with the highest rate at ages 1 - 20 years old and the lowest rate was 7.3% for >50 years old. The monthly, highest rate of infection (5.2%) was in August and least (2.2%) in January (2.2%). The frequency of total protein (TPD) in the blood relevant to the presence of parasite E. histolytica and G. lamblia was 4.6% and 1%, respectively. It is concluded that the above two parasites are the most common gastrointestinal parasite in Iraq whose pathogenesis to be which is likely to escalate during the summer seasons and at low hygienic services environment. There has been an irrelevance neither to anemia nor total protein deficiency. It is recommended that Ministry of Health in Iraq should not share the global idea of defining the giardiasis as a neglected disease.展开更多
The protozoan parasites Entamoeba histolytica and Blastocystis hominis are responsible for causing human amebiasis and hominis infections,respectively.These infections are highly prevalent and are often linked to wate...The protozoan parasites Entamoeba histolytica and Blastocystis hominis are responsible for causing human amebiasis and hominis infections,respectively.These infections are highly prevalent and are often linked to waterborne diseases.Due to the absence of regulations for monitoring these protozoa at the discharge points of wastewater treatment plants(WWTPs),the effluents reaching surface waters contribute to waterborne transmission.This underscores the significance of the removal capacities of WWTPs in reducing the spread of these infectious parasites.Therefore,this study examined five different types of WWTPs in Ankara,Turkey,over a year to assess their capacities to remove E.histolytica and B.hominis.The seasonal abundances of genes specific to these protozoa in both the influents and effluents of each WWTP were measured using a quantitative polymerase chain reaction.The reduction in the number of protozoan rDNA copies between the influent and effluent samples was evaluated as the removal capacity,expressed in log10 reduction(LRV)values.The results elucidated that the removal of E.histolytica and B.hominis was highly affected by the process used.Membrane bioreactor systems displayed the highest removal capacity with LRV>3.Therefore,discharges of WWTPs with other processes could need further monitoring to minimize the potential risk for public health.展开更多
In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to ty...In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eu- karyotes, Entamoeba and several other amitochondrial pro- tozoans have been recognized as ancient pre-mitochondriate eukaryotes and named “archezoa”, the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acqui- sition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies re- vealed that Entamoeba contained an organelle, “crypton” or “mitosome”, which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mi- tochondrion in Entamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status of En- tamoeba is discussed.展开更多
文摘<i>Entamoeba histolytica</i> is an anaerobic parasitic protozoan and well known as a human pathogen, while its close relative, <i>Entamoeba dispar</i>, also possesses similar characteristics as an infectious agent. These microorganisms are generally transmitted in fecal-contaminated water. However, <i>E. dispar</i> present in industrial wastewater is also capable of creating biofilms that can cause adverse impacts in piping networks. Therefore, it is important to detect both of these protozoan species in water and to find a cost-effective technique for inactivation or management control. This review article summarizes the available detection methods in water and wastewater matrices along with feasible disinfection techniques.
基金supported financially by a research grant from the Natural Sciences Research Institute,University of the Philippines ) BIO 1 l-l-05) to W.L.R.
文摘Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.
基金Supported by a grant from Universiti Sains Malaysia(grant No.1001/PPSK/813009)received financial support through the USM Fellowship
文摘Objective:To compare the efficacy of three different tissue stains,namely haematoxylin and eosin(H&E),periodic-acid Schiff(PAS)and immunohistochemical(1HC)stains for detection of Entamoeba histolytica(E.histolytica)trophozoites in abscessed liver tissues of hamster.Methods:Amoebic liver abscess was experimentally induced in a hamster by injecting 1×10~6of axenically cultured virulent E.histolytica trophozoites(HM1-IMSS strain)into the portal vein.After a week post-inoculation,the hamster was sacrificed and the liver tissue sections were stained with H&E,PAS and IHC stains to delect the amoebic trophozoite.Results:The three stains revealed tissue necrosis and amoebic trophozoites,but with varying clarity.H&E and PAS stained the trophozoites pink and magenta,respectively,however it was difficult to differentiate the stained trophozoites from the macrophages because of their similarity in size and morphology.On the other hand,IHC stain revealed distinct brown appearance of the trophozoites in the infected liver tissues.Conclusions:It can be concluded that out of the three stains.IHC is the best for identification of E.histolytica trophozoites in tissue sections.
文摘Amebic liver abscesses(ALAs)are the most commonly encountered extraintestinal manifestation of human invasive amebiasis,which results from Entamoeba histolytica(E.histolytica)spreading extraintestinally.Amebiasis can be complicated by liver abscess in 9%of cases,and ALAs led to almost 50000 fatalities worldwide in 2010.Although there have been fewer and fewer cases in the past several years,ALAs remain an important public health problem in endemic areas.E.histolytica causes both amebic colitis and liver abscess by breaching the host’s innate defenses and invading the intestinal mucosa.Trophozoites often enter the circulatory system,where they are filtered in the liver and produce abscesses,and develop into severe invasive diseases such as ALAs.The clinical presentation can appear to be colitis,including upper-right abdominal pain accompanied by a fever in ALA cases.Proper diagnosis requires nonspecific liver imaging as well as detecting anti-E.histolytica antibodies;however,these antibodies cannot be used to distinguish between a previous infection and an acute infection.Therefore,diagnostics primarily aim to use PCR or enzyme-linked immunosorbent assay to detect E.histolytica.ALAs can be treated medically,and percutaneous catheter drainage is only necessary in approximately 15%of cases.The indicated treatment is to administer an amebicidal drug(such as tinidazole or metronidazole)and paromomycin or other luminal cysticidal agent for clinical disease.Prognosis is good with almost universal recovery.Establishing which diagnostic methods are most efficacious will necessitate further analysis of similar clinical cases.
文摘AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro.METHODS:Samples of human milk were collected from 5 healthy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained.RESULTS:The lethal effect of E. histolytica on the medium supplemented with different concentrations of both colostrum and mature human milk was significant during the first 30min. We also detected that the results of colostrum and mature human milk were similar. No statistically significant differences were found between same concentrations of colostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk have significant lethal effect on E. histolytica and protect against its infection in breast fed children.
基金Supported by Malaysia Ministry of Education Long-Term Research Grant Scheme(LRGS)No.203/PSK/6722002
文摘Objective:To characterize the Entamoeba histolytica(E.histolytica)antigen(s)recognized by moribound amoebic liver abscess hamsters.Methods:Crude soluble antigen of E.histolytica was probed with sera of moribund hamsters in 1D-and 2D-Westem blot analyses.The antigenic protein was then sent for tandem mass spectrometry analysis.The corresponding gene was cloned and expressed in Escherichia coli BL21-AI to produce the recombinant E.histolytica ADP-forming acetyl-CoA synthetase(EhACS)protein.A customised ELISA was developed to evaluate the sensitivity and specificity of the recombinant protein.Results:A^75 kDa protein band with a pl value of 5.91-6.5 was found to be antigenic;and not detected by sera of hamsters in the control group.Tandem mass spectrometry analysis revealed the protein to be the 77 kDa E.histolytica ADP-forming acetyl-CoA synthetase(EhACS).The customised ELISA results revealed 100%sensitivity and 100%specificity when tested against infected(n=31)and control group hamsters(n=5)serum samples,respectively.Conclusions:This rinding suggested the significant role of EhACS as a biomarker for moribund hamsters with acute amoebic liver abscess(ALA)infection.It is deemed pertinent that future studies explore the potential roles of EhACS in better understanding the pathogenesis of ALA;and in the development of vaccine and diagnostic tests to control ALA in human populations.
基金supported by a research grant from the Natural Sciences Research Institute of the University of the Philippines(B10-09-2-03) to W.L.R.
文摘Objective:To determine the profdes of anti-Entamoeba histolytica(E.histolytica) IgA.IgC. and IgM in sera of diarrheic and non-diarrheic individuals and partially characterize target antigens.Methods:Serum samples from thirty diarrheic and thirty non-diarrheic individuals were subjected to IgA,IgG,and IgM profiling through enzyme-linked immunosorbent assay (EI.ISA),flow cytometry,and immunoblot.Results:ELBA titer results showed that both diarrheic and non-diarrheic individuals possess high levels of E.histolytica-specific IgG compared to IgA and IgM.How cytometry data showed that diarrheic serum samples had higher mean reaction percentages against E.histolytica cells compared to non-diarrheic samples.Immunoreactive E.histolytica proteins with molecular weights ranging belween 7 kDa and 292 kDa were recognized by diarrheic serum IgG,and 170 kDa and 250 kDa by non-diarrheic serum IgG. Conclusions:Our findings suggest that serum anti-E.histolytica IgG,compared with serum anti-E.histolytica IgA and IgM responses,was generally high in both diarrheic and nondiarrheic sera,indicating a past exposure to the organism both in symptomatic patients as well as in asymptomatic carriers,respectively.In addition,serum IgG from diarrheic and non-diarrheic patients were able to detect immunogenic E.histolytica proteins.
文摘AIM:The effects of cobalt,copper,cadmium and barium ions on the cysts of Entamoeba histolyt/ca (E,histolytica), an amebic dysentery agent,cultured in Robinson medium were investigated. METHODS:E.histolytica cysts and trophozoites isolated from a patient with amebiasis were cultivated in the medium, incubated at 37℃ for a period of 4 days and 40×10~4/ml amebic cysts were then transferred to a fresh medium.At the second stage,0.05,0.1 and 0.2 mM of selected metal ions were added to the medium,and the effects of these ions on parasitic reproduction compared with the control group were observed. RESULTS:It was determined that the number of living parasites in all the groups containing metal ions decreased significantly starting from 30 minutes (P<0.01).CuCl_2 showed the highest lethal effect on E.histolytica cysts,whereas the lowest lethal effect was observed with CoCl_2.It was also seen that the number of living cells was decreased as the ion concentration and exposure time were increased,and that there were no living parasites in the medium at the end of 24 h (P<0.01). CONCLUSION:It may be stated that the effect of ever- increasing contamination of the environment with metal waste materials on parasites should be investigated further.
文摘A large number of microbial pathogens bind to heparan sulphate on eukaryotic cell surfaces. Heparan Sulphate Binding Proteins (HSBPs) from Entamoeba histolytica culture lysates were obtained by sequential ammonium sulphate precipitation and Protein purify. SDS-PAGE and immunoblotting experiments indicated the presence of two major extracellular proteins in E. histolytica (51.2 kDa and 61.0 kDa). Characterization of HSBPs by 2D Gel electrophoresis of 40% (NH4)2SO4 precipitated lysate of E. histolytica revealed that the isoelectric point of 51.2 kDa HSBP was at pH3.0. The protein of 61.0 kDa HSBP showed three spots in 40% (NH4)2SO4 lysate which had isoelectric point between pH 4.0 - 7.0. While in 80% (NH4)2SO4 precipitated lysate, 51.2 kDa HSBP showed only one spot which had isoelectric point at pH 3. However, 61.0 kDa HSBP revealed 2 spots which had isoelectric point between pH 4 and 5. The result showed that this parasite has proteins which interact with heparan sulphate whose molecular formula is C14H23NO21S-23. These proteins may have a role in binding of parasite to heparan sulphate on host cells. Further characterization by MALDI-TOF analysis of HSBPs from E. histolytica demonstrated HSBPs to be novel protein in this parasite which has been isolated, purified and characterized first time by our group in the present study.
基金Supported by WOS-A grant from Department of Science and Technology,New Delhi,Government of India to Iyer LR,No.SR/WOS-A/LS-98/2007"Programme support on molecular parasitology",Department of Biotechnology,New Delhi,India to Paul J,No.BT/01/CEIB/11/v/08
文摘AIM To study the sensitivity and antioxidant enzyme response in two clinical isolates of Entamoeba histolytica(E. histolytica) during treatment with antiamoebic drugs,auranofin and metronidazole. METHODS E. histolytica were isolated from stool samples and maintained in Robinson's biphasic culture medium. Clinial isolates were maintained in xenic culture medium,and harvested for determination of minimum inhibitory concentrations to the two antiamoebic drugs,Metronidazole and Auranofin using microtiter plate tests. The percent survival of the two isolates were determined using the trypan blue cell count. Isolate 980 was treated with 70 μmol/L and 2 μmol/L while isolate 989 was treated with 20 μmol/L and 0.5 μmol/L of metronidazole and auranofin respectively for 24 h. Fifty thousand cells of each isolate were harvested after 24 h of treatment for analysis of the mRNA expressions of the antioxidant enzymes,thioredoxin reductase,peroxiredoxin and FeSOD using the specific primers. Cell lysate was used for determination of enzyme activity of thioredoxin reductase by measuring DTNB reduction spectrophotometrically at412 nm.RESULTS Minimum inhibitory concentration of the clinical isolates 980 and 989 for auranofin was 3 μmol/L and 1 μmol/L respectively while that for metronidazole was 80 μmol/L and 30 μmol/L respectively. Thioredoxin reductase,peroxiredoxin and FeSOD expression levels were significantly reduced in the isolate 980 when treated with Auranofin. Metronidazole treatment showed a down regulation of thioredoxin reductase. Though not significant both at the mRNA and the enzyme activity levels. Peroxiredoxin and FeSOD however remained unchanged. Auranofin treatment of isolate 989,showed an upregulation in expression of thioredoxin reductase while Peroxiredoxin and FeSOD did not show any change in expression. Upon treatment with metronidazole,isolate 989 showed an increase in thioredoxin reductase expression. Peroxiredoxin and FeSOD expressions however remain unchanged both at mRNA and enzyme activity level.CONCLUSION Clinical isolates from New Delhi NCR region show different sensitivities to antiamoebic drugs. Auranofin is effective against isolate showing higher tolerance to metronidazole as shown by its inhibition in thioredoxin reductase activity.
文摘The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP) of a total 780 patients (children and adults) admitted to Samarra General Hospital were assessed. Samples of fresh feces were collected in normal physiological saline and examined using Olympic microscopes. The frequency of the parasite E. histolytica was 12.8% (46.3% male and 53.6% female). The highest frequency of infection of E. histolytica (13.8%) was found at age group (1 - 5 years old) followed by <1 year old children while the lowest (7.4%) was at ages (>41 years old). The highest rate of infection (33.9%) was found in September and the lowest (2.2%) in January. Similarly, the general infection frequency of the parasite G. lamblia was 3.9% with the highest rate at ages 1 - 20 years old and the lowest rate was 7.3% for >50 years old. The monthly, highest rate of infection (5.2%) was in August and least (2.2%) in January (2.2%). The frequency of total protein (TPD) in the blood relevant to the presence of parasite E. histolytica and G. lamblia was 4.6% and 1%, respectively. It is concluded that the above two parasites are the most common gastrointestinal parasite in Iraq whose pathogenesis to be which is likely to escalate during the summer seasons and at low hygienic services environment. There has been an irrelevance neither to anemia nor total protein deficiency. It is recommended that Ministry of Health in Iraq should not share the global idea of defining the giardiasis as a neglected disease.
文摘The protozoan parasites Entamoeba histolytica and Blastocystis hominis are responsible for causing human amebiasis and hominis infections,respectively.These infections are highly prevalent and are often linked to waterborne diseases.Due to the absence of regulations for monitoring these protozoa at the discharge points of wastewater treatment plants(WWTPs),the effluents reaching surface waters contribute to waterborne transmission.This underscores the significance of the removal capacities of WWTPs in reducing the spread of these infectious parasites.Therefore,this study examined five different types of WWTPs in Ankara,Turkey,over a year to assess their capacities to remove E.histolytica and B.hominis.The seasonal abundances of genes specific to these protozoa in both the influents and effluents of each WWTP were measured using a quantitative polymerase chain reaction.The reduction in the number of protozoan rDNA copies between the influent and effluent samples was evaluated as the removal capacity,expressed in log10 reduction(LRV)values.The results elucidated that the removal of E.histolytica and B.hominis was highly affected by the process used.Membrane bioreactor systems displayed the highest removal capacity with LRV>3.Therefore,discharges of WWTPs with other processes could need further monitoring to minimize the potential risk for public health.
文摘In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eu- karyotes, Entamoeba and several other amitochondrial pro- tozoans have been recognized as ancient pre-mitochondriate eukaryotes and named “archezoa”, the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acqui- sition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies re- vealed that Entamoeba contained an organelle, “crypton” or “mitosome”, which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mi- tochondrion in Entamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status of En- tamoeba is discussed.
