Displaying publications 1 - 20 of 36 in total

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  1. Mohd Shah NA, Wan Abdul Wahab WN, Mohd Nawi SF, Mohd-Zain Z, Latif B, Suhaimi R
    Malays J Pathol, 2015 Dec;37(3):271-4.
    PMID: 26712674 MyJurnal
    Entamoeba histolytica, the causative agent for human amoebiasis, is among the most deadly parasites, accounting for the second highest mortality rate among parasitic diseases. Because this parasite dwells in low oxygen tension, for its cultivation, microaerophilic conditions are required to mimick the human gut environment. Several methods developed for optimal growth environment are commercially available and some are conventionally modified in-house which include the Anaerocult A and oil blocking preparation methods. This study was undertaken to compare the reliability of the Anaerocult A and the oil blocking methods in generating anaerobic environment for cultivation of E. histolytica. The trophozoites of E. histolytica HM1: IMSS strains were axenically cultivated in TYI-S-33 medium in culture incubated anaerobically by using Anaerocult A (Merck) and mineral oil blocking method. The outcomes of both methods were determined by the minimum inhibitory concentration (MIC) of metronidazole against E. histolytica by giving a score to the growth pattern of the trophozoites. The reliability of both methods was assessed based on susceptibility testing of E. histolytica to metronidazole. The MIC obtained by both anaerobic condition methods was 6.25 ug/ ml, thus showing that oil-blocking method is comparable to the Anaerocult A method and therefore, considered as a reliable method for generating an anaerobic environment for the cultivation of E. histolytica.
    Matched MeSH terms: Entamoeba histolytica*
  2. Wong WK, Tan ZN, Lim BH, Mohamed Z, Olivos-Garcia A, Noordin R
    Parasitol. Res., 2011 Feb;108(2):425-30.
    PMID: 20922423 DOI: 10.1007/s00436-010-2083-8
    Entamoeba histolytica is the etiologic agent for amoebiasis. The excretory-secretory (ES) products of the trophozoites contain virulence factors and antigens useful for diagnostic applications. Contaminants from serum supplements and dead trophozoites impede analysis of ES. Therefore, a protein-free medium that can sustain maximum viability of E. histolytica trophozoites for the longest time duration will enable collection of contaminant-free and higher yield of ES products. In the present study, we compared the efficacy of four types of media in maintaining ≥ 95% trophozoite viability namely Roswell Memorial Park Institute (RPMI-1640), Dulbecco's Modified Eagle Medium (DMEM), phosphate-buffered saline for amoeba (PBS-A), and Hank's balanced salt solution (HBSS). Concurrently, the effect of adding L: -cysteine and ascorbic acid (C&A) to each medium on the parasite viability was also compared. DMEM and RPMI 1640 showed higher viabilities as compared to PBS-A and HBSS. Only RPMI 1640 showed no statistical difference with the control medium for the first 4 h, however the ≥ 95% viability was only maintained for the first 2 h. The other protein-free media showed differences from the serum- and vitamin-free TYI-S-33 control media even after 1 h of incubation. When supplemented with C&A, all media were found to sustain higher trophozoite viabilities than those without the supplements. HBSS-C&A, DMEM-C&A, and RPMI 1640-C&A demonstrated no difference (P>0.05) in parasite viabilities when compared with the control medium throughout the 8-h incubation period. DMEM-C&A showed an eightfold increment in time duration of sustaining ≥ 95% parasite viability, i.e. 8 h, as compared to DMEM alone. Both RPMI 1640-C&A and HBSS-C&A revealed fourfold and threefold increments (i.e., 8 and 6 h, respectively), whereas PBS-A-C&A showed only one fold improvement (i.e., 2 h) as compared to the respective media without C&A. Thus, C&A-supplemented DMEM or RPMI are recommended for collection of ES products.
    Matched MeSH terms: Entamoeba histolytica/cytology; Entamoeba histolytica/drug effects*; Entamoeba histolytica/physiology
  3. Hartini Yusof, Mohamed Kamel Abd Ghani
    MyJurnal
    Infeksi Entamoeba histolytica adalah tersebar di seluruh dunia dengan prevalens infeksi yang lebih tinggi di kalangan masyarakat terpinggir termasuk Orang Asli yang tinggal di kawasan tropika dan subtropika. Seramai 71 orang kanak-kanak Orang Asli dari Pos Lenjang, Pahang telah terlibat di dalam kajian ini. Bagi kajian yang lebih terperinci, kumpulan kanak-kanak ini telah dibahagikan menurut jantina dan umur. Sampel feses dikumpul dan setiap sampel diperiksa bagi pengenalpastian Entamoeba histolytica dengan menggunakan 3 jenis teknik diagnostik yang berbeza iaitu teknik apusan langsung, konsentrasi formalin-eter dan perwarnaan trikrom. Prevalens infeksi protozoa usus Entamoeba histolytica di kalangan kanak-kanak Orang Asli di Pos Lenjang, Pahang adalah tinggi iaitu 22.5%. Dari segi jantina, prevalens infeksi lebih tinggi di kalangan kanak-kanak perempuan (32.5%) berbanding kanak-kanak lelaki (9.7%). Infeksi juga didapati lebih kerap berlaku di kalangan kanak-kanak yang bersekolah (32.4%) berbanding kanak-kanak prasekolah (11.8%). Prevalens infeksi Entamoeba histolytica yang tinggi di kalangan kanak-kanak Orang Asli di Pos Lenjang, Pahang adalah berhubung kait dengan pelbagai faktor termasuk status sosioekonomi yang rendah, budaya, kekurangan kemudahan asas dan tahap pengetahuan mengenai penjagaan kesihatan serta kebersihan diri yang rendah.
    Matched MeSH terms: Entamoeba histolytica
  4. Foo PC, Chan YY, See Too WC, Tan ZN, Wong WK, Lalitha P, et al.
    J. Med. Microbiol., 2012 Sep;61(Pt 9):1219-25.
    PMID: 22556327 DOI: 10.1099/jmm.0.044552-0
    Entamoeba histolytica is the only Entamoeba species that causes amoebiasis in humans. Approximately 50 million people are infected, with 100, 000 deaths annually in endemic countries. Molecular diagnosis of Entamoeba histolytica is important to differentiate it from the morphologically identical Entamoeba dispar to avoid unnecessary medication. Conventional molecular diagnostic tests require trained personnel, cold-chain transportation and/or are storage-dependent, which make them user-unfriendly. The aim of this study was to develop a thermostabilized, one-step, nested, tetraplex PCR assay for the detection of Entamoeba histolytica, Entamoeba dispar and Entamoeba species in cold-chain-free and ready-to-use form. The PCR test was designed based on the Entamoeba small subunit rRNA (SSU-rRNA) gene, which detects the presence of any Entamoeba species, and simultaneously can be used to differentiate Entamoeba histolytica from Entamoeba dispar. In addition, a pair of primers was designed to serve as an internal amplification control to help identify inhibitors in the samples. All PCR reagents together with the designed primers were thermostabilized by lyophilization and were stable at 24 °C for at least 6 months. The limit of detection of the tetraplex PCR was found to be 39 pg DNA or 1000 cells for Entamoeba histolytica and 78 pg DNA or 1000 cells for Entamoeba dispar, and the specificity was 100 %. In conclusion, this cold-chain-free, thermostabilized, one-step, nested, multiplex PCR assay was found to be efficacious in differentiating Entamoeba histolytica from other non-pathogenic Entamoeba species.
    Matched MeSH terms: Entamoeba histolytica/classification*; Entamoeba histolytica/genetics*; Entamoeba histolytica/isolation & purification
  5. Tan ZN, Wong WK, Nik Zairi Z, Abdullah B, Rahmah N, Zeehaida M, et al.
    Trop Biomed, 2010 Apr;27(1):79-88.
    PMID: 20562817 MyJurnal
    Entamoeba histolytica causes about 50 million infections worldwide with a death rate of over 100,000 annually. In endemic developing countries where resources are limited, microscopic examinations based on Wheatley trichrome staining is commonly used for diagnosis of intestinal amoebiasis. Other than being a time-consuming method, it must be performed promptly after stool collection as trophozoites disintegrate rapidly in faeces. The aim of this study was to compare the efficacies of Eosin-Y, Wheatley trichrome and Iodine stains in delineating the diagnostic features of the parasite, and subsequently to determine the suitable microscopy observation period for detection of erythrophagocytic and non-erythrophagocytic trophozoites spiked in semi-solid stool sample. Wheatley trichrome staining technique was performed using the standard method while the other two techniques were performed on the slides by mixing the respective staining solution with the spiked stool sample. One million of axenically cultured non-erythrophagocytic E. histolytica and erythrophagocytic E. histolytica were separately spiked into 2 g of fresh semisolid faeces. Percentage viability of the trophozoites in the spiked stool sample was determined at 30 minute intervals for eight hours using the 0.4% Trypan blue exclusion method. The results showed that Eosin-Y and Wheatley trichrome stained the karyosome and chromatin granules better as compared to Iodine stain. The percentage viability of non-erythrophagocytic trophozoites decreased faster than the erythrophagocytic form in the first 5 hours and both dropped to ~10% in the 6th hour spiked sample. In conclusion, Eosin-Y staining technique was found to be the easiest to perform, most rapid and as accurate as the commonly used Wheatley trichrome technique; Eosin-Y stained slide sealed with DPX could also be kept as a permanent record. A period not exceeding 6 hours after stool collection was found to be the most suitable in order to obtain good microscopy results of viable trophozoites.
    Matched MeSH terms: Entamoeba histolytica/cytology; Entamoeba histolytica/isolation & purification*
  6. Ning TZ, Kin WW, Mustafa S, Ahmed A, Noordin R, Cheong TG, et al.
    Asian Pac J Trop Biomed, 2012 Jan;2(1):61-5.
    PMID: 23569836 DOI: 10.1016/S2221-1691(11)60191-3
    To compare the efficacy of three different tissue stains, namely haematoxylin and eosin (H&E), periodic-acid Schiff (PAS) and immunohistochemical (IHC) stains for detection of Entamoeba histolytica (E. histolytica) trophozoites in abscessed liver tissues of hamster.
    Matched MeSH terms: Entamoeba histolytica/cytology; Entamoeba histolytica/isolation & purification*
  7. Wong WK, Tan ZN, Othman N, Lim BH, Mohamed Z, Olivos Garcia A, et al.
    Clin. Vaccine Immunol., 2011 Nov;18(11):1913-7.
    PMID: 21918120 DOI: 10.1128/CVI.05356-11
    Serodiagnosis of amoebiasis remains the preferred method for diagnosis of amoebic liver abscess (ALA). However, the commercially available kits are problematic in areas of endemicity due to the persistently high background antibody titers. Human serum samples (n = 38) from patients with ALA who live in areas of endemicity were collected from Hospital Universiti Sains Malaysia during the period of 2008 to 2010. Western blots using excretory-secretory antigen (ESA) collected from axenically grown Entamoeba histolytica were probed with the above serum samples. Seven antigenic proteins of ESA with various reactivities were identified, i.e., 152 kDa, 131 kDa, 123 kDa, 110 kDa, 100 kDa, 82 kDa, and 76 kDa. However, only the 152-kDa and 110-kDa proteins showed sensitivities above 80% in the Western blot analysis. All the antigenic proteins showed undetectable cross-reactivity when probed with healthy human serum samples (n = 30) and serum samples from other infections (n = 33). From the matrix-assisted laser desorption ionization-two-stage time of flight (MALDI-TOF/TOF) analysis, the proteins were identified as heavy subunits of E. histolytica lectin and E. histolytica pyruvate phosphate dikinase, respectively. Use of the E. histolytica lectin for diagnosis of ALA has been well reported by researchers and is being used in commercialized kits. However, this is the first report on the potential use of pyruvate phosphate dikinase for diagnosis of ALA; thus, this molecule merits further evaluation on its diagnostic value using a larger panel of serum samples.
    Matched MeSH terms: Entamoeba histolytica/immunology*; Entamoeba histolytica/chemistry*
  8. Saidin S, Yunus MH, Zakaria ND, Razak KA, Huat LB, Othman N, et al.
    BMC Infect. Dis., 2014;14:182.
    PMID: 24708664 DOI: 10.1186/1471-2334-14-182
    Amoebic liver abscess (ALA) is the most common clinical manifestation of extraintestinal amoebiasis especially in developing countries, causing up to 100 000 fatal cases annually. Accurate and early diagnosis is important to prevent the disease complications, however its diagnosis still poses many challenges due to the limitations of the available detection tools. Pyruvate phosphate dikinase (PPDK), an excretory-secretory protein of E. histolytica, has been reported as a potential diagnostic marker for ALA, hence it may be exploited in the development of a new test for ALA.
    Matched MeSH terms: Entamoeba histolytica/enzymology*; Entamoeba histolytica/genetics; Entamoeba histolytica/immunology
  9. Ray S, Khanra D, Saha M, Talukdar A
    Med. J. Malaysia, 2012 Oct;67(5):524-5.
    PMID: 23770872
    Amebic liver abscess is the most common extraintestinal manifestation of infection with Entamoeba histolytica. It is a common disease, especially in endemic areas, but it is a rare cause of inferior vena cava (IVC) obstruction, with only a few cases appearing in the literature. The authors describe a case of amebic liver abscess in a patient who developed a rare vascular complication of inferior vena cava thrombosis. The case responded to conservative treatment and radiological intervention.
    Matched MeSH terms: Entamoeba histolytica
  10. Farnaza A, Baha L
    Malays Fam Physician, 2010;5(3):148-150.
    PMID: 25606208 MyJurnal
    A 27-year-old man presented with a two-week history of central colicky abdominal pain associated with loose stools. Further history revealed that he had been exposed to contaminated waters. Stool investigation by direct wet stool smears revealed the presence of Entamoeba histolytica and Blastocystis hominis cysts. A diagnosis of amoebiasis secondary to E. histolytica and concurrent B. hominis infestation was made. We would like to emphasise the importance of clinical history including recent travel to endemic areas. Any suspicion of parasitic infection should prompt the clinician to investigate. Early diagnosis and management would prevent serious complications associated with E. Histolytica infection.
    Matched MeSH terms: Entamoeba histolytica
  11. Saidin S, Yunus MH, Othman N, Lim YA, Mohamed Z, Zakaria NZ, et al.
    Pathog Glob Health, 2017 May;111(3):128-136.
    PMID: 28335696 DOI: 10.1080/20477724.2017.1300421
    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 the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml-1. Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml-1. The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and real-time PCR were compared using 70 stool samples from patients infected with Entamoeba species (n = 45) and other intestinal pathogens (n = 25). When compared to real-time PCR, the diagnostic sensitivity of the dipstick for detection of E. histolytica was 65.4% (n = 17/26); while the diagnostic specificity when tested with stool samples containing other intestinal pathogens was 92% (23/25). In contrast, Techlab E. histolytica II ELISA detected 19.2% (5/26) of the E. histolytica-positive samples as compared to real-time PCR. The lateral flow dipstick test produced in this study enabled rapid detection of E. histolytica, thus it showed good potential to be further developed into a diagnostic tool for intestinal amoebiasis.
    Matched MeSH terms: Entamoeba histolytica/enzymology; Entamoeba histolytica/immunology*; Entamoeba histolytica/isolation & purification
  12. Mansharan Kaur Chaincel Singh
    MyJurnal
    Amoebiasis is a parasitic infection caused by the
    intestinal protozoan Entamoeba histolytica, most
    prevalent in developing countries. It results in 40,000 to
    100,000 deaths each year from amoebic colitis and extra
    intestinal infections. Amoebic liver abscess (ALA)
    is the most common extra intestinal site of infection
    with an incidence of between 3% and 9% of all cases of
    amoebiasis. Ultrasound which has a sensitivity of more
    than 90% for detecting ALA is highly recommended
    as an initial investigation followed by serological
    demonstration of circulating antibodies specific to
    Entamoeba histolytica.
    Matched MeSH terms: Entamoeba histolytica
  13. Yap FB, Lee BR
    Arch Dermatol, 2011 Jun;147(6):735-40.
    PMID: 21690541 DOI: 10.1001/archdermatol.2011.128-a
    Matched MeSH terms: Entamoeba histolytica/isolation & purification*
  14. Othman NH, Ismail AN
    Eur. J. Obstet. Gynecol. Reprod. Biol., 1993 Dec 15;52(2):135-7.
    PMID: 8157142
    A case of endometrial infection by Entamoeba histolytica is described in an elderly lady who presented with profuse vaginal discharge and was clinically misdiagnosed as endometrial carcinoma.
    Matched MeSH terms: Entamoeba histolytica*
  15. Noor Azian MY, Lokman Hakim S, Maslawaty MN
    Trop Biomed, 2006 Jun;23(1):31-6.
    PMID: 17041549 MyJurnal
    Amoebiasis is an infectious diseased caused by parasitic one-celled protozoan called Entamoeba histolytica. Numerous protozoa also can inhabit the gastro-intestinal tract of human. Majority of these protozoa are non-pathogenic commensals or only causes disease under certain circumstances. Morphologically, E. histolytica, the invasive form, share the same characteristic with the nonpathogenic form, E. dispar. Both strains can be distinguished by using DNA identification. Many previous researches in Malaysia only reported infection with E. histolytica infection. Therefore in this study we tried to classify infection among the aborigines in Cameron Highland as true E. histolytica or E. dispar by Nested Polymerase Chain Reaction (Nested PCR) and Restriction enzyme (RE) digestion. Results showed that 31 samples were positive by microscopic examination, however of these 28 (13.2%) samples were positive for E. histolytica and 12 (5.6%) samples were positive for E. dispar by molecular tools.
    Matched MeSH terms: Entamoeba histolytica/genetics*
  16. Thomas V, Sinniah B
    Ann Trop Med Parasitol, 1982 Apr;76(2):147-51.
    PMID: 6284074
    Matched MeSH terms: Entamoeba histolytica/immunology
  17. McClatchie S, Sambhi JS
    Ann Trop Med Parasitol, 1971 Jun;65(2):207-10.
    PMID: 4326239
    Matched MeSH terms: Entamoeba histolytica/isolation & purification
  18. Foo PC, Chan YY, Mohamed M, Wong WK, Nurul Najian AB, Lim BH
    Anal. Chim. Acta, 2017 May 08;966:71-80.
    PMID: 28372729 DOI: 10.1016/j.aca.2017.02.019
    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 chromatography control line that validated the functionality of the conjugated gold nanoparticles and membrane. The red lines on detection pad were generated when the gold nanoparticles conjugated antibody bound to the fluorescein labelled amplicons, and the capture agents bound to their specific hapten on the other 5' end of the double-stranded amplicon. The applicability of this DNA biosensor was demonstrated using amoebiasis-causing Entamoeba histolytica simultaneously with the non-pathogenic but morphologically identical Entamoeba dispar and Entamoeba moshkovskii. The biosensor detection limit was 10 E. histolytica trophozoites, and revealed 100% specificity when it was evaluated against 3 medically important Entamoeba species and 75 other pathogenic microorganisms. Heat stability test showed that the biosensor was stable for at least 181 days at ambient temperature. This ready-to-use and cold-chain-free biosensor facilitated the post-LAMP analysis based on visualisation of lines on strip instead of observation of amplicon patterns in agarose gel.
    Matched MeSH terms: Entamoeba histolytica/isolation & purification*
  19. Othman N, Mohamed Z, Verweij JJ, Huat LB, Olivos-García A, Yeng C, et al.
    Foodborne Pathog. Dis., 2010 Jun;7(6):637-41.
    PMID: 20132028 DOI: 10.1089/fpd.2009.0427
    Entamoeba histolytica is the second major cause of liver abscess disease in humans, particularly in developing countries. Recently, DNA molecular-based methods have been employed to enhance the detection of E. histolytica in either pus or stool specimens. In this study, the results of real-time polymerase chain reaction (PCR) to detect E. histolytica DNA in pus from liver abscess cases were compared with those of indirect hemagglutination assay on the corresponding serum samples. Bacterial cultures were also performed on the pus samples for the diagnosis of pyogenic liver abscess. The real-time PCR detected E. histolytica DNA in 23 of 30 (76.7%) pus samples, when compared with 14 of 30 (46.7%) serum samples in which anti-Entamoeba antibodies were detected by indirect hemagglutination assay and 4 of 30 (13.3%) pus samples that showed bacterial infection by culture. The use of real-time PCR is a promising detection method for diagnosis and epidemiology assessment of amoebic liver abscess.
    Matched MeSH terms: Entamoeba histolytica/classification; Entamoeba histolytica/genetics; Entamoeba histolytica/immunology; Entamoeba histolytica/isolation & purification*
  20. Angal L, Mahmud R, Samin S, Yap NJ, Ngui R, Amir A, et al.
    BMC Infect. Dis., 2015 Oct 29;15:467.
    PMID: 26511347 DOI: 10.1186/s12879-015-1178-3
    BACKGROUND: The prison management in Malaysia is proactively seeking to improve the health status of the prison inmates. Intestinal parasitic infections (IPIs) are widely distributed throughout the world and are still gaining great concern due to their significant morbidity and mortality among infected humans. In Malaysia, there is a paucity of information on IPIs among prison inmates. In order to further enhance the current health strategies employed, the present study aims to establish firm data on the prevalence and diversity of IPIs among HIV-infected and non-HIV-infected individuals in a prison, an area in which informed knowledge is still very limited.

    METHODS: Samples were subjected to microscopy examination and serological test (only for Strongyloides). Speciation for parasites on microscopy-positive samples and seropositive samples for Strongyloides were further determined via polymerase chain reaction. SPSS was used for statistical analysis.

    RESULTS: A total of 294 stool and blood samples each were successfully collected, involving 131 HIV positive and 163 HIV negative adult male inmates whose age ranged from 21 to 69-years-old. Overall prevalence showed 26.5% was positive for various IPIs. The IPIs detected included Blastocystis sp., Strongyloides stercoralis, Entamoeba spp., Cryptosporidium spp., Giardia spp., and Trichuris trichiura. Comparatively, the rate of IPIs was slightly higher among the HIV positive inmates (27.5%) than HIV negative inmates (25.8%). Interestingly, seropositivity for S. stercoralis was more predominant in HIV negative inmates (10.4%) compared to HIV-infected inmates (6.9%), however these findings were not statistically significant. Polymerase chain reaction (PCR) confirmed the presence of Blastocystis, Strongyloides, Entamoeba histolytica and E. dispar.

    CONCLUSIONS: These data will enable the health care providers and prison management staff to understand the trend and epidemiological situations in HIV/parasitic co-infections in a prison. This information will further assist in providing evidence-based guidance to improve prevention, control and management strategies of IPIs co-infections among both HIV positive and HIV negative inmates in a prison environment.

    Matched MeSH terms: Entamoeba histolytica/isolation & purification; Entamoeba histolytica/pathogenicity
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