Displaying publications 1 - 20 of 34 in total

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  1. Fulltext Curcumin effect on Acanthamoeba triangularis encystation under nutrient starvation
    Boonhok R, Sangkanu S, Phumjan S, Jongboonjua R, Sangnopparat N, Kwankaew P, et al.
    PeerJ, 2022;10:e13657.
    PMID: 35811814 DOI: 10.7717/peerj.13657
    BACKGROUND: Curcumin is an active compound derived from turmeric, Curcuma longa, and is known for its benefits to human health. The amoebicidal activity of curcumin against Acanthamoeba triangularis was recently discovered. However, a physiological change of intracellular pathways related to A. triangularis encystation mechanism, including autophagy in the surviving amoeba after curcumin treatment, has never been reported. This study aims to investigate the effect of curcumin on the survival of A. triangularis under nutrient starvation and nutrient-rich condition, as well as to evaluate the A. triangularis encystation and a physiological change of Acanthamoeba autophagy at the mRNA level.

    METHODS: In this study, A. triangularis amoebas were treated with a sublethal dose of curcumin under nutrient starvation and nutrient-rich condition and the surviving amoebas was investigated. Cysts formation and vacuolization were examined by microscopy and transcriptional expression of autophagy-related genes and other encystation-related genes were evaluated by real-time PCR.

    RESULTS: A. triangularis cysts were formed under nutrient starvation. However, in the presence of the autophagy inhibitor, 3-methyladenine (3-MA), the percentage of cysts was significantly reduced. Interestingly, in the presence of curcumin, most of the parasites remained in the trophozoite stage in both the starvation and nutrient-rich condition. In vacuolization analysis, the percentage of amoebas with enlarged vacuole was increased upon starvation. However, the percentage was significantly declined in the presence of curcumin and 3-MA. Molecular analysis of A. triangularis autophagy-related (ATG) genes showed that the mRNA expression of the ATG genes, ATG3, ATG8b, ATG12, ATG16, under the starvation with curcumin was at a basal level along the treatment. The results were similar to those of the curcumin-treated amoebas under a nutrient-rich condition, except AcATG16 which increased later. On the other hand, mRNA expression of encystation-related genes, cellulose synthase and serine proteinase, remained unchanged during the first 18 h, but significantly increased at 24 h post treatment.

    CONCLUSION: Curcumin inhibits cyst formation in surviving trophozoites, which may result from its effect on mRNA expression of key Acanthamoeba ATG-related genes. However, further investigation into the mechanism of curcumin in A. triangularis trophozoites arrest and its association with autophagy or other encystation-related pathways is needed to support the future use of curcumin.

    Matched MeSH terms: Amoeba*
  2. Molecular characterisation and potential pathogenicity analysis of Acanthamoeba isolated from recreational lakes in Peninsular Malaysia
    Abdul Halim R, Mohd Hussain RH, Aazmi S, Halim H, Ahmed Khan N, Siddiqui R, et al.
    J Water Health, 2023 Sep;21(9):1342-1356.
    PMID: 37756200 DOI: 10.2166/wh.2023.186
    The present study aims to identify the Acanthamoeba genotypes and their pathogenic potential in three recreational lakes in Malaysia. Thirty water samples were collected by purposive sampling between June and July 2022. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. The samples were vacuum filtered through nitrate filter, cultured onto non-nutrient agar and observed microscopically for amoebic growth. DNAs from positive samples were extracted and made to react with polymerase chain reaction using specific primers. Physiological tolerance tests were performed for all Acanthamoeba-positive samples. The presence of Acanthamoeba was found in 26 of 30 water samples by PCR. The highest rate in lake waters contaminated with amoeba was in Biru Lake (100%), followed by Titiwangsa Lake (80%) and Shah Alam Lake (80%). ORP, water temperature, pH and DO were found to be significantly correlated with the presence of Acanthamoeba. The most common genotype was T4. Temperature- and osmo-tolerance tests showed that 8 (30.8%) of the genotypes T4, T9 and T11 were highly pathogenic. The presence of genotype T4 in habitats related to human activities supports the relevance of this amoeba as a potential public health concern.
    Matched MeSH terms: Acanthamoeba*; Amoeba*
  3. Special issue on Free Living Amoebae (FLA): Recent advances presented at the XVIIth International Meeting on the Biology and Pathogenicity of Free-Living Amoebae (FLAM, 2017), Zarzis, Tunisia
    Lorenzo-Morales J, Sifaoui I, Reyes-Batlle M, Lares-Villa F, Lares-Jiménez LF, Omaña-Molina M, et al.
    Exp Parasitol, 2019 May;200:36.
    PMID: 30902622 DOI: 10.1016/j.exppara.2019.03.010
    Matched MeSH terms: Amoeba/pathogenicity*; Amoeba/physiology*
  4. Acanthamoeba keratitis in Malaysia
    Mohamed Kamel Abd Ghani, Irdawati Azhar, Haliza Abdul Mutalib, Anisah Nordin, Yusof Suboh, Noraina Ab Rahim, et al.
    Sains Malaysiana, 2018;47:1563-1569.
    Acanthamoeba spp. merupakan ameba hidup bebas yang tersebar luas di persekitaran. Ameba ini menyebabkan penyakit
    keratitis terutamanya kepada individu yang memakai kanta sentuh terkontaminasi atau mempunyai sejarah trauma
    pada mata. Tujuh puluh empat sampel kikisan kornea pesakit keratitis daripada 4 buah hospital di sekitar Lembah
    Kelang telah dikultur untuk menemukan Acanthamoeba spp. Keputusan kajian mendapati Acanthamoeba spp. berjaya
    dipencilkan daripada 14.87% sampel kikisan kornea pesakit keratitis. Berdasarkan kajian ini, kesemua pesakit keratitis
    Acanthamoeba adalah merupakan pemakai kanta sentuh yang majoritinya (90.9%) terdiri daripada kaum wanita. Kanta
    sentuh lembut terlibat dalam 90.9% kes manakala jenis kanta separa keras cuma satu kes 9.1%. Kesemua 11 pencilan
    Acanthamoeba yang dipencilkan adalah daripada kumpulan polyphagids yang biasanya patogenik kepada manusia dan
    menyebabkan jangkitan ini. Kegagalan pengguna kanta sentuh mengamalkan tahap kebersihan kanta sentuh yang baik
    merupakan faktor risiko yang penting dalam kejadian keratitis Acanthamoeba di Malaysia.
    Matched MeSH terms: Acanthamoeba; Amoeba; Acanthamoeba Keratitis
  5. Fulltext Temperature tolerance of Acanthemaoeba spp isolates from clinical and environmental specimens. [Ketahanan suhu Acanthamoeba spp. pencilan spesimen klinikal dan persekitaran.]
    Nurul Zarhana Jufri, Anisah Nordin, Mohamed Kamel Abd Ghani, Yusof Suboh, Noraina Abd Rahim
    Jurnal Sains Kesihatan Malaysia, 2010;8(2):1-3.
    MyJurnal
    Acanthamoeba is a free living protozoa that can cause keratitis and granulomatous amoebic encephalitis. Physiological characteristics of this amoeba are found to have a medical importance and related to the pathogenic potential of the organism. This study was carried out to investigate the physiological characteristic from the aspect of temperature tolerance. Six Acanthamoeba strains from three clinical isolates (HSB 1, HKL 48 and HKL 95) and three environmental isolates (PHS 2, PHS 11 and PHS 15) were used in this study. Test was done by culturing cysts at 30°C, 37°C and 42°C for two weeks and the ability of cysts to change to trophozoites were observed. The result showed all strain was able to change to trophozoites at 30°C and 37°C. However, no trophozoites were observed at 42°
    C. This indicate that there is a similarity in the physiological trait of strains from both isolates are the same and strains from the environment are able to show the pathogenic potential thus capable of causing infection to human.
    Keywords: Acanthamoeba; temperature tolerance; clinical; environmental isolates.
    Matched MeSH terms: Acanthamoeba; Amoeba; Acanthamoeba Keratitis
  6. Fulltext Pathogenic waterborne free-living amoebae: An update from selected Southeast Asian countries
    Abdul Majid MA, Mahboob T, Mong BG, Jaturas N, Richard RL, Tian-Chye T, et al.
    PLoS One, 2017;12(2):e0169448.
    PMID: 28212409 DOI: 10.1371/journal.pone.0169448
    Data on the distribution of free-living amoebae is still lacking especially in Southeast Asian region. The aquatic environment revealed a high occurrence of free-living amoebae (FLA) due to its suitable condition and availability of food source, which subsequently causes infection to humans. A total of 94 water samples consisted of both treated and untreated from Laos (31), Myanmar (42), and Singapore (21) were investigated for the presence of pathogenic FLA. Each water sample was filtered and cultured onto non-nutrient agar seeded with live suspension of Escherichia coli and incubated at room temperature. Morphological identification was conducted for both trophozoites and cysts via microscopic stains (Giemsa and immunofluorescence). The presence of Naegleria-like structures was the most frequently encountered in both treated and untreated water samples, followed by Acanthamoeba-like and Vermamoeba-like features. To identify the pathogenic isolates, species-specific primer sets were applied for molecular identification of Acanthamoeba, Naegleria, and Vermamoeba. The pathogenic species of Acanthamoeba lenticulata and A. triangularis were detected from untreated water samples, while Vermamoeba vermiformis was found in both treated and untreated water samples. Our results suggested that poor water quality as well as inadequate maintenance and treatment might be the cause of this alarming problem since chlorine disinfection is ineffective in eradicating these amoebas in treated water samples. Regular monitoring and examination of water qualities are necessary in order to control the growth, hence, further preventing the widespread of FLA infections among the public.
    Matched MeSH terms: Amoeba/classification; Amoeba/genetics; Amoeba/isolation & purification*
  7. Fulltext The immortal amoeba: a useful model to study cellular differentiation processes?
    Ahmed Khan N, Baqir H, Siddiqui R
    Pathog Glob Health, 2015;109(7):305-6.
    PMID: 26878933 DOI: 10.1080/20477724.2015.1103504
    Matched MeSH terms: Amoeba/cytology*
  8. Fulltext Systematic Review of Brain-Eating Amoeba: A Decade Update
    Ahmad Zamzuri M'I, Abd Majid FN, Mihat M, Ibrahim SS, Ismail M, Abd Aziz S, et al.
    Int J Environ Res Public Health, 2023 Feb 09;20(4).
    PMID: 36833715 DOI: 10.3390/ijerph20043021
    INTRODUCTION: Primary amoebic meningoencephalitis (PAM) is a rare but lethal infection of the brain caused by a eukaryote called Naegleria fowleri (N. fowleri). The aim of this review is to consolidate the recently published case reports of N. fowleri infection by describing its epidemiology and clinical features with the goal of ultimately disseminating this information to healthcare personnel.

    METHODS: A comprehensive literature search was carried out using PubMed, Web of Science, Scopus, and OVID databases until 31 December 2022 by two independent reviewers. All studies from the year 2013 were extracted, and quality assessments were carried out meticulously prior to their inclusion in the final analysis.

    RESULTS: A total of 21 studies were selected for qualitative analyses out of the 461 studies extracted. The cases were distributed globally, and 72.7% of the cases succumbed to mortality. The youngest case was an 11-day-old boy, while the eldest was a 75-year-old. Significant exposure to freshwater either from recreational activities or from a habit of irrigating the nostrils preceded onset. The symptoms at early presentation included fever, headache, and vomiting, while late sequalae showed neurological manifestation. An accurate diagnosis remains a challenge, as the symptoms mimic bacterial meningitis. Confirmatory tests include the direct visualisation of the amoeba or the use of the polymerase chain reaction method.

    CONCLUSIONS: N. fowleri infection is rare but leads to PAM. Its occurrence is worldwide with a significant risk of fatality. The suggested probable case definition based on the findings is the acute onset of fever, headache, and vomiting with meningeal symptoms following exposure to freshwater within the previous 14 days. Continuous health promotion and health education activities for the public can help to improve knowledge and awareness prior to engagement in freshwater activities.

    Matched MeSH terms: Amoeba*
  9. The amoebic complement fixation test
    WELLS R
    Med J Malaya, 1956 Dec;11(2):93-111.
    PMID: 13417932
    Matched MeSH terms: Amoeba*
  10. Fulltext Seroprevalence of anti-amoebic antibody among blood donors by indirect hemeagglutination assay
    Zeehaida M, Zairi NZ, Tan ZN, Wong WK, Lim BH
    Trop Biomed, 2009 Dec;26(3):366-8.
    PMID: 20237453
    The screening for anti-amoebic antibody among a group of donors was to obtain negative control serum samples for an on-going antigen development assay in diagnosis of amoebic liver abscess. Out of 200 samples, 125 (62.5%) were negative, whereas 44 (21.5%) had IHA titer of less than 1:128 and 31 (16.0%) of the samples had significant IHA titers of 1:128 or more, in which 2 serum samples gave titers of 1:4096.
    Matched MeSH terms: Amoeba/immunology*
  11. Occurrence of free-living amoebae (Acanthamoeba, Balamuthia, Naegleria) in water samples in Peninsular Malaysia
    Gabriel S, Khan NA, Siddiqui R
    J Water Health, 2019 Feb;17(1):160-171.
    PMID: 30758312 DOI: 10.2166/wh.2018.164
    The aim of this study was to determine the occurrence of free-living amoebae (FLA) in Peninsular Malaysia and to compare different methodologies to detect them from water samples. Water samples were collected from tap water, recreational places, water dispensers, filtered water, etc. and tested for FLA using both cultivation and polymerase chain reaction (PCR) via plating assays and centrifugation methods. Amoebae DNA was extracted using Instagene matrix and PCR was performed using genus-specific primers. Of 250 samples, 142 (56.8%) samples were positive for presence of amoebae, while 108 (43.2%) were negative. Recreational water showed higher prevalence of amoebae than tap water. PCR for the plating assays revealed the presence of Acanthamoeba in 91 (64%) samples and Naegleria in 99 (70%) of samples analysed. All samples tested were negative for B. mandrillaris. In contrast, the centrifugation method was less effective in detecting amoebae as only one sample revealed the presence of Acanthamoeba and 52 (29%) samples were positive for Naegleria. PCR assays were specific and sensitive, detecting as few as 10 cells. These findings show the vast distribution and presence of FLA in all 11 states of Peninsular Malaysia. Further studies could determine the possible presence of pathogenic species and strains of free-living amoebae in public water supplies in Malaysia.
    Matched MeSH terms: Acanthamoeba*; Amoeba*
  12. Anti-amoebic effects of synthetic acridine-9(10H)-one against brain-eating amoebae
    Ahmed U, Manzoor M, Qureshi S, Mazhar M, Fatima A, Aurangzeb S, et al.
    Acta Trop, 2023 Mar;239:106824.
    PMID: 36610529 DOI: 10.1016/j.actatropica.2023.106824
    Pathogenic A. castellanii and N. fowleri are opportunistic free-living amoebae. Acanthamoeba spp. are the causative agents of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK), whereas Naegleria fowleri causes a very rare but severe brain infection called primary amebic meningoencephalitis (PAM). Acridinone is an important heterocyclic scaffold and both synthetic and naturally occurring derivatives have shown various valuable biological properties. In the present study, ten synthetic Acridinone derivatives (I-X) were synthesized and assessed against both amoebae for anti-amoebic and cysticidal activities in vitro. In addition, excystation, encystation, cytotoxicity, host cell pathogenicity was also performed in-vitro. Furthermore, molecular docking studies of these compounds with three cathepsin B paralogous enzymes of N. fowleri were performed in order to predict the possible docking mode with pathogen. Compound VII showed potent anti-amoebic activity against A. castellanii with IC50 53.46 µg/mL, while compound IX showed strong activity against N. fowleri in vitro with IC50 72.41 µg/mL. Compounds II and VII showed a significant inhibition of phenotypic alteration of A. castellanii, while compound VIII significantly inhibited N. fowleri cysts. Cytotoxicity assessment showed that these compounds caused minimum damage to human keratinocyte cells (HaCaT cells) at 100 µg/mL, while also effectively reduced the cytopathogenicity of Acanthamoeba to HaCaT cells. Moreover, Cathepsin B protease was investigated in-silico as a new molecular therapeutic target for these compounds. All compounds showed potential interactions with the catalytic residues. These results showed that acridine-9(10H)-one derivatives, in particular compounds II, VII, VIII and IX hold promise in the development of therapeutic agents against these free-living amoebae.
    Matched MeSH terms: Acanthamoeba*; Amoeba*
  13. Natural Terpenes Inhibit the Cytopathogenicity of Naegleria fowleri Causing Primary Amoebic Meningoencephalitis in the Human Cell Line Model
    Rajendran K, Ahmed U, Meunier AC, Shaikh MF, Siddiqui R, Anwar A
    ACS Chem Neurosci, 2023 Dec 06;14(23):4105-4114.
    PMID: 37983556 DOI: 10.1021/acschemneuro.3c00258
    Naegleria fowleri is one of the free-living amoebae and is a causative agent of a lethal and rare central nervous system infection called primary amoebic meningoencephalitis. Despite the advancement in antimicrobial chemotherapy, the fatality rate in the reported cases is more than 95%. Most of the treatment drugs used against N. fowleri infection are repurposed drugs. Therefore, a large number of compounds have been tested against N. fowleri in vitro, but most of the compounds showed high toxicity. To overcome this, we evaluated the effectiveness of naturally occurring terpene compounds against N. fowleri. In this study, we evaluated the antiamoebic potential of natural compounds including Thymol, Borneol, Andrographolide, and Forskolin againstN. fowleri. Thymol showed the highest amoebicidal activity with IC50/24 h at 153.601 ± 19.6 μM. Two combinations of compounds Forskolin + Thymol and Forskolin + Borneol showed a higher effect on the viability of trophozoites as compared to compounds alone and hence showed a synergistic effect. The IC50 reported for Forskolin + Thymol was 81.30 ± 6.86 μM. Borneol showed maximum cysticidal activity with IC50/24 h at 192.605 ± 3.01 μM. Importantly, lactate dehydrogenase release testing revealed that all compounds displayed minimal cytotoxicity to human HaCaT, HeLa, and SH-SY5Y cell lines. The cytopathogenicity assay showed that Thymol and Borneol also significantly reduced the host cell cytotoxicity of pretreated amoeba toward the human HaCaT cell line. So, these terpene compounds hold potential as therapeutic agents against infections caused by N. fowleri and are potentially a step forward in drug development against this deadly pathogen as these compounds have also been reported to cross the blood-brain barrier. Therefore, an in vivo study using animal models is necessary to assess the efficacy of these compounds and the need for further research into the intranasal route of delivery for the treatment of these life-threatening infections.
    Matched MeSH terms: Amoeba*
  14. A proposed cascade of vascular events leading to granulomatous amoebic encephalitis
    Baig AM, Khan NA
    Microb Pathog, 2015 Nov;88:48-51.
    PMID: 26276705 DOI: 10.1016/j.micpath.2015.08.005
    Granulomatous amoebic encephalitis due to Acanthamoeba is a chronic disease that almost always results in death. Hematogenous spread is a pre-requisite followed by amoebae invasion of the blood-brain barrier to enter the central nervous system. Given the systemic nature of this infection, a significant latent period of several months before the appearance of clinical manifestations is puzzling. Based on reported cases, here we propose pathogenetic mechanisms that explain the above described latency of the disease.
    Matched MeSH terms: Acanthamoeba; Amoeba
  15. Fulltext Survivability of Acanthamoeba strains isolated from clinical and environmental specimens during axenization. [Kemandirian strain Acanthamoeba pencilan klinikal dan persekitaran semasa proses aksenisasi]
    Nurul Farhana Jufri, Anisah Nordin, Mohamed Kamel Abd. Ghani, Yusof Suboh, Noraina Abd. Rahim
    Jurnal Sains Kesihatan Malaysia, 2011;9(2):1-3.
    MyJurnal
    Acanthamoeba is a free living protozoa that can cause keratitis and granulomatous amoebic encephalitis. Physiological characteristics of this amoeba are found to have a medical importance in which it can be related to the pathogenicity potential of the organism. This study was carried out to investigate the physiological characteristics of survivability during axenization. Six Acanthamoeba strains from three clinical isolates (HSB 1, HKL 48 and HKL 95) and three environmental isolates (PHS 2, PHS 11 and PHS 15) were used in this study. Axenization test was done by treating cysts with hydrochloric acid (3%) and Page saline containing Gentamicin (100 μg/ml). Cysts were then cultured into PYG enrich media, incubated at 30oC and the presence and proliferation of trophozoites of Acanthamoeba were observed. This study showed that PHS 15, HSB 1, HKL 48 and HKL 95 could be axenized but they have poor proliferation rate in PYG enrich media. The result showed that the difference between both clinical and environmental isolates was observed in two strains; PHS 2 and PHS 11. This indicates that there is a possibility that the physiological traits of strains from both isolates are the same and strains from the environment are able to show the pathogenic potential and capable of causing infection to human.
    Keywords: Axenization, Survivability, Acanthamoeba, Clinical and environmental strains
    Matched MeSH terms: Acanthamoeba; Amoeba; Acanthamoeba Keratitis
  16. Synthetic nanoparticle-conjugated bisindoles and hydrazinyl arylthiazole as novel antiamoebic agents against brain-eating amoebae
    Kanwal, Mungroo MR, Anwar A, Ali F, Khan S, Abdullah MA, et al.
    Exp Parasitol, 2020 Nov;218:107979.
    PMID: 32866583 DOI: 10.1016/j.exppara.2020.107979
    Balamuthia mandrillaris and Naegleria fowleri are free-living amoebae that can cause life-threatening infections involving the central nervous system. The high mortality rates of these infections demonstrate an urgent need for novel treatment options against the amoebae. Considering that indole and thiazole compounds possess wide range of antiparasitic properties, novel bisindole and thiazole derivatives were synthesized and evaluated against the amoebae. The antiamoebic properties of four synthetic compounds i.e., two new bisindoles (2-Bromo-4-(di (1H-indol-3-yl)methyl)phenol (denoted as A1) and 2-Bromo-4-(di (1H-indol-3-yl)methyl)-6-methoxyphenol (A2)) and two known thiazole (4-(3-Nitrophenyl)-2-(2-(pyridin-3-ylmethylene)hydrazinyl)thiazole (A3) and 4-(Biphenyl-4-yl)-2-(2-(1-(pyridin-4-yl)ethylidene)hydrazinyl)thiazole (A4)) were evaluated against B. mandrillaris and N. fowleri. The ability of silver nanoparticle (AgNPs) conjugation to enrich antiamoebic activities of the compounds was also investigated. The synthetic heterocyclic compounds demonstrated up to 53% and 69% antiamoebic activities against B. mandrillaris and N. fowleri respectively, while resulting in up to 57% and 68% amoebistatic activities, respectively. Antiamoebic activities of the compounds were enhanced by up to 71% and 51% against B. mandrillaris and N. fowleri respectively, after conjugation with AgNPs. These compounds exhibited potential antiamoebic effects against B. mandrillaris and N. fowleri and conjugation of synthetic heterocyclic compounds with AgNPs enhanced their activity against the amoebae.
    Matched MeSH terms: Amoeba
  17. Fulltext Detection of Hartmannella sp, a free-living amoeba from Sungai Setiu, Terengganu
    Mat Amin N, Najmiah Mustaffa N, Md Arshad N
    Trop Biomed, 2004 Dec;21(2):77-80.
    PMID: 16493402
    Hartmannella sp is one of the free-living amoebae that have the ability to infect animal tissues because it has been found in human's nasal mucosa, dog's bronchial and turkey's intestine. Treatment for diseases inflicted by free-living amoebae is difficult because most of them infect and damage the host's tissues, so preventive measures are better to take rather than to cure the diseases. In this study, water taken from several stations namely Kampung Padang, Kampung Besut, Ibu Bekalan Setiu, Kampung Tasik, Kampung Guntung, Kampung Nyatoh, Kampung Penarik and Kampung Mangkok) along Sungai Setiu, Terengganu was examined for the presence of Hartmannella sp. The results of this study indicated that only Ibu Bekalan Setiu station was found positive to have the amoeba. Detail results on the water quality and nutrient contents measured in relation to the distribution of the amoeba at Ibu Bekalan Setiu station are presented and discussed.
    Matched MeSH terms: Amoeba
  18. Fulltext Kehadiran Acanthamoeba spp. pada bekas penyimpanan kanta sentuh pengguna asimptomatik
    Putri Noradyani Megat Hashim, Mohamed Kamel Abdul Ghani, Norhayati Moktar, Anisah Nordin, Yusof Suboh, Mimi Fazah Zainudin, et al.
    Jurnal Sains Kesihatan Malaysia, 2007;5(2):53-61.
    MyJurnal
    Keratitis Acanthamoeba merupakan sejenis inflamasi kornea yang dikaitkan dengan penggunaan kanta sentuh. la disebabkan oleh Acanthamoeba spp., ameba hidup bebas yang tersebar luas di pelbagai persekitaran manusia. Kontaminasi Acanthamoeba spp. pada bekas penyimpanan kanta sentuh merupakan faktor kehadiran ameba pada kanta seterusnya menjangkiti mata. Kajian ini bertujuan untuk melihat kehadiran Acanthamoeba spp. pada bekas penyimpanan kanta sentuh pengguna asimptomatik. Seramai 90 orang pengguna kanta sentuh asimptomatik terlibat dalam kajian ini. Sampel diambil secara swab pada bekas kanta sentuh dan dikulturkan ke atas agar bukan nutrien yang dilapisi Escherichia coli. Plat agar diperiksa setiap hart bagi mengesan kehadiran ameba. Kultur positif seterusnya disahkan di bawah 'Image Analysis with Video TesT 4.0'. Acanthamoeba spp. didapati positif pada lapan daripada 90 sampel (8. 7%) dan kesemua strain adalah kumpulan II (polyphagids). Penemuan ini membuktikan Acanthamoeba spp. boleh Nadir pada bekas penyimpanan kanta sentuh pengguna asimptomatik dan boleh menjadi risiko jangkitan keratitis Acanthamoeba.
    Matched MeSH terms: Acanthamoeba; Amoeba; Acanthamoeba Keratitis
  19. Fulltext Molecular detection of bacterial endosymbionts in acanthamoeba spp.: a preliminary study
    Faizah, M. H., Anisah, N., Yusof, S., Noraina, A. R., Adibah, M. R.
    Medicine & Health, 2017;12(2):286-292.
    MyJurnal
    Acanthamoeba spp. merupakan ameba hidup bebas yang biasa ditemui
    di persekitaran. Ia merupakan agen penyebab keratitis Acanthamoeba (AK)
    dan ensefalitis ameba bergranuloma (GAE). Ameba ini juga mampu menjadi
    perumah kepada pelbagai bakteria termasuklah yang bersifat patogenik seperti
    Mycobacterium, Legionella dan Staphylococcus aureus rintang metisilin (MRSA).
    Berdasarkan maklumat ini, satu kajian dijalankan untuk mengesan kehadiran tiga
    bakteria endosimbion berkepentingan perubatan di dalam Acanthamoeba spp. yang
    telah dipencilkan dari bolong penghawa dingin yang terdapat di wad and dewan
    bedah di Pusat Perubatan Universiti Kebangsaan Malaysia. Kehadiran bakteria
    endosimbion ini disaring menggunakan pasangan primer khusus bagi setiap genus
    menggunakan reaksi rantai polimerase (PCR) konvensional dan disahkan dengan
    analisis penjujukan. Dua puluh sembilan (80.56%) pencilan Acanthamoeba spp.
    didapati mengandungi bakteria endosimbion patogenik yang disasarkan dengan
    sekurang-kurangnya satu genus bakteria bagi setiap pencilan. Mycobacterium
    (82.76 %) adalah bakteria yang paling banyak dikesan, diikuti dengan Legionella sp.
    (65.52 %) dan Pseudomonas spp. (62.07 %). Tiada bakteria MRSA dikesan daripada
    mana-mana pencilan dalam kajian ini. Dua endosimbion Mycobacterium yang
    dikenalpasti telah dikelompokkan ke dalam strain Mycobacterium tuberculosis.
    Kami membuat kesimpulan bahawa, kebanyakan Acanthamoeba berpotensi untuk
    menjadi perumah bagi pelbagai bakteria patogenik, namun implikasi interaksi ini
    terhadap patogenisiti kedua-dua organisma masih kurang jelas dan memerlukan
    penyelidikan yang lebih lanjut.
    Matched MeSH terms: Acanthamoeba; Amoeba; Acanthamoeba Keratitis
  20. Brain-eating Amoebae Infection: Challenges and Opportunities in Chemotherapy
    Mungroo MR, Anwar A, Khan NA, Siddiqui R
    Mini Rev Med Chem, 2019;19(12):980-987.
    PMID: 30868950 DOI: 10.2174/1389557519666190313161854
    Pathogenic free-living amoeba are known to cause a devastating infection of the central nervous system and are often referred to as "brain-eating amoebae". The mortality rate of more than 90% and free-living nature of these amoebae is a cause for concern. It is distressing that the mortality rate has remained the same over the past few decades, highlighting the lack of interest by the pharmaceutical industry. With the threat of global warming and increased outdoor activities of public, there is a need for renewed interest in identifying potential anti-amoebic compounds for successful prognosis. Here, we discuss the available chemotherapeutic options and opportunities for potential strategies in the treatment and diagnosis of these life-threatening infections.
    Matched MeSH terms: Amoeba/drug effects*
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