In-vitro cytotoxicity and antimicrobial activities, against clinical isolates ofCampylobacterspecies andEntamoeba histolytica, of local medicinal plants from the Venda region, in South Africa
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In the quest for alternative treatments against Campylobacter jejuni and Entamoeba histolytica, which are both aetiological agents of diarrhoea world-wide, the in-vitro activities against the two pathogens of extracts of 18 South African medicinal plants have recently been assessed. Forty extracts from the 18 plant species were prepared and tested against 110 clinical isolates of Campylobacter spp. In addition, extracts from eight of the plant species were tested against a standard strain (HM-1:IMSS) of E. histolytica, and the cytotoxicity of each of 19 extracts from 15 of the plant species was explored using Vero cell cultures and microdilution assays. At least one extract of each plant species investigated was found to be active against some of the Campylobacter isolates. Extracts of Lippia javanica and Pterocarpus angolensis had the highest antibacterial activity, each giving a minimum inhibitory concentration (MIC) of 90 microg/ml. Of the extracts tested against E. histolytica, however, only those of P. angolensis and Syzigium cordatum were found to have anti-amoebic activity, with MIC of 1.2 and 7.5 mg/ml, respectively. Although most of the extracts showed little toxicity against Vero cells, with most of the median inhibitory concentrations (IC(50)) recorded exceeding 400 microg/ml, an extract of Bauhinia galpini was quite toxic, with an IC(50) of just 2.7 microg/ml. Acetone and methanol extracts of several of the plants show promise as templates for the design of new anti-diarrhoeal therapies.Entamoeba
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The study aimed to investigate the prevalence of Campylobacter spp. in different stages of poultry and pork processing in the Central region of Russia. A total of 47 Campylobacter isolates were obtained from 107 samples from poultry processing plants (40.2%): 87.2% were identified as Campylobacter jejuni, whereas 12.8% were identified as Campylobacter coli. The prevalence of Campylobacter was significantly (p <0.05) higher after evisceration in the poultry processing plant. Campylobacter spp.was detected in 62.7% of the equipment and environmental samples. From positive samples of Campylobacter spp., 84.3% of Campylobacter jejuni and 15.7% Campylobacter coli were observed. A total of nine Campylobacter isolates were obtained from 116 samples from pork processing plants (7.8%): 33.3% of them were identified as Campylobacter jejuni whereas 66.7% were identified as Campylobacter coli. Splitting and evisceration were also critical in Campylobacter contamination. Almost all pork carcasses were Campylobacter positive, and all of them were identified as Campylobacter coli. The prevalence of positive Campylobacter samples in poultry processing plants was significantly (p < 0.05) higher than in pork processing plants.
Campylobacter coli
Poultry farming
Evisceration (ophthalmology)
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ABSTRACT Effective diagnostic tools are essential in order to combat disease caused by the parasite Entamoeba histolytica . In this study, we compared the commercially available Ridascreen Entamoeba test (R-Biopharm) and the E. histolytica II test (Techlab), and we found that the E. histolytica II test detects E. histolytica infections more accurately.
Entamoeba
Amoebiasis
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Arecombinantly expressed protein, recEh-Pl, representing partofanimmunodominant surface antigen of pathogenic Entamoeba histolytica, wasusedforserodiagnosis ofinvasive amebiasis. Expression wasperformed underthecontrol ofaT7-RNApromoter byusing amodified procaryotic expression vector, designated pHisT7. Thisvector allowed high-yield expression ofrecEh-Pl fused toastretch ofsequence containing eight histidine residues, whichfacilitated purification bymetal chelate affinity chromatography onNi2+columns underhighly denatured conditions. Purified recEh-Pl wasfoundtobewatersoluble after prolonged dialysis andwasusedastheantigen forthedetection ofantiamebic serumantibodies byimmunoblotting and enzyme-linked immunosorbent assay. Inbothtests allseraofpatients withinvasive amebiasis reacted to recEh-Pl whereas noneofthose collected fromhealthy controls, including individuals withnoninvasive amebiasis, orfrompatients suffering frombacterial orprotozoan infections unrelated toE.histolytica didso. Theenteric protozoan parasite Entamoeba histolytica is thecausative agentofhumanamebiasis, infesting halfa billion people worldwide. In10%oftheinfected individuals, E.histolytica invades thetissues andcauses disease suchas hemorrhagic colitis orextraintestinal abscesses (16). Recent findings indicate thattwogenetically distinct formsofE. histolytica caninfect humansbutthatonlyoneofthemis abletoinvade tissues andcausedisease (1,3,11,12,15). Thusthenumerical difference between theoccurrence of infection andtheexpression ofmorbidity seemstobedueto theexistence ofthese twogenotypes, namedpathogenic and nonpathogenic E.histolytica. Thediagnosis ofamebiasis isbased onclinical symptoms, detection oftheparasite, histopathological results, andserological findings. Individuals withinvasive disease usually develop antiamebic serumantibodies. Since thedetection of E.histolytica inclinical specimens canbedifficult and sometimes fails, especially inpatients withextraintestinal abscesses, serodiagnostic assays suchascomplement fixation tests, latex agglutination tests, andenzyme-linked immunosorbent assays (ELISA) areimportant tools forthe diagnosis ofinvasive amebiasis. Ingeneral these assays are performed withE.histolytica whole-cell lysates asthe antigen. Thesecomplex antigen preparations havecertain disadvantages. Ontheonehand, theyarenotveryspecific andoccasionally areasource offalse-positive results, buton theother handtheyaredifficult tostandardize since various laboratories usedifferent E.histolytica isolates cultured underdifferent conditions. Toimprove serodiagnostic ability, astandardized testsystem applying defined antigens is necessary. We recently reported ontheidentification ofa partial cDNA designated cEh-Pl, specific forpathogenic E. histolytica (15). ThiscDNA wasfoundtobepartofthe coding sequence foranimmunodominant 125-kDa surface antigen (2). cEh-Pl wasobtained byscreening alambda gtll expression library derived frompathogenic E.histolytica withapoolofserafrompatients withamebicdiseases. In
Amoebiasis
Latex fixation test
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Entamoeba histolytica is a protozoan parasite responsible for invasive intestinal and extraintestinal amebiasis. The pathology of amebiasis is still poorly understood, which can be largely attributed to lack of molecular tools. Here we present the optimization of SNAP-tag technology via codon optimization specific for E. histolytica. The resultant SNAP protein is highly expressed in amebic trophozoites, and shows proper localization when tagged with an endoplasmic reticulum retention signal. We further demonstrate the capabilities of this system using super resolution microscopy, done for the first time in E. histolytica.
Entamoeba
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The protozoan intestinal parasite Entamoeba histolytica infects millions of people worldwide and is capable of causing amebic dysentery and amebic liver abscess. The closely related species Entamoeba dispar colonizes many more individuals, but this organism does not induce disease. To identify molecular differences between these two organisms that may account for their differential ability to cause disease in humans, we used two-dimensional gel-based (DIGE) proteomic analysis to compare whole cell lysates of E. histolytica and E. dispar. We observed 141 spots expressed at a substantially (>5-fold) higher level in E. histolytica HM-1∶IMSS than E. dispar and 189 spots showing the opposite pattern. Strikingly, 3 of 4 proteins consistently identified as different at a greater than 5-fold level between E. histolytica HM-1∶IMSS and E. dispar were identical to proteins recently identified as differentially expressed between E. histolytica HM-1∶IMSS and the reduced virulence strain E. histolytica Rahman. One of these was E. histolytica alcohol dehydrogenase 3 (EhADH3). We found that E. histolytica possesses a higher level of NADP-dependent alcohol dehydrogenase activity than E. dispar and that some EhADH3 can be localized to the surface of E. histolytica. Episomal overexpression of EhADH3 in E. histolytica trophozoites resulted in only subtle phenotypic differences in E. histolytica virulence in animal models of amebic colitis and amebic liver abscess, making it difficult to directly link EhADH3 levels to virulence differences between E. histolytica and less-pathogenic Entamoeba.
Dispar
Entamoeba
Amoebiasis
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Dispar
Entamoeba
Amoebiasis
Molecular Epidemiology
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Entamoeba
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Ethnobotany
Vernonia amygdalina
Combretaceae
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