Displaying publications 1 - 20 of 59 in total

Abstract:
Sort:
  1. Suresh K, Mak JW, Yong HS
    PMID: 1822869
    Thirty in vitro serial passages of Toxoplasman gondii cultures in Vero cell line performed once in every five days had a mean increase in parasite count of 74.4 +/- 14.8 times from that of initial counts. Long term cultures in Vero cell line did not alter the virulence of the parasite. The good correlation (r = 0.99) between the IFA titer and ELISA OD values using the parasite antigens from in vitro sources indicates that long term maintenance of T. gondii in culture does not affect significantly the ability to recognize antibodies to surface and soluble antigens. The results also show that soluble antigens containing host cells can be directly used for immunodiagnostic purposes without purification. The in vitro maintenance of T. gondii is safer and cheaper when compared to the in vivo method.
  2. Zuhaimy H, Leow SN, Vasudevan SK
    BMJ Case Rep, 2017 Aug 09;2017.
    PMID: 28794092 DOI: 10.1136/bcr-2017-221170
    We discuss the diagnostic challenge in an adult patient presented with purely ocular symptoms diagnosed with tuberculous meningitis (TBM). A 38-year-old woman presented with bilateral painless blurring of vision. There were bilateral sixth cranial nerve palsy and bilateral optic disc swelling. Optic nerve function tests were normal. Patient was lucid with no signs of meningism. Brain imaging were normal. She had a positive Mantoux test, high erythrocyte sedimentation rate but no clinical evidence of active pulmonary tuberculosis infection. Her Quantiferon-TB Gold in-tube test was negative. Cerebrospinal fluid analysis revealed a high opening pressure but no biochemical parameters to suggest TBM, hence she was treated as idiopathic intracranial hypertension. A diagnosis of TBM was finally made following a positive PCR for Mycobacterium tuberculosis Her vision improved with reduction in optic disc swelling following antituberculous treatment.
  3. Dhurga DB, Suresh K, Tan TC
    PLoS One, 2016;11(7):e0155390.
    PMID: 27471855 DOI: 10.1371/journal.pone.0155390
    The role and function of the granular life cycle stage in Blastocystis sp, remains uncertain despite suggestions being made that the granules are metabolic, reproductive and lipid in nature. This present study aims to understand granular formation by triggering apoptosis in Blastocystis sp. by treating them with metronidazole (MTZ). Blastocystis sp.cultures of 4 sub-types namely 1, 2, 3 and 5 when treated with 0.01 and 0.0001 mg/ml of metronidazole (MTZ) respectively showed many of the parasites to be both viable and apoptotic (VA). Treated subtype 3 isolates exhibited the highest number of granular forms i.e. 88% (p<0.001) (0.0001 mg/ml) and 69% (p<0.01) (0.01 mg/ml) respectively at the 72 h in in vitro culture compared to other subtypes. These VA forms showed distinct granules using acridine orange (AO) and 4',6-diamino-2-phenylindole (DAPI) staining with a mean per cell ranging from 5 in ST 5 to as high as 16 in ST 3. These forms showed intact mitochondria in both viable apoptotic (VA) and viable non-apoptotic (VNA) cells with a pattern of accumulation of lipid droplets corresponding to viable cells. Granular VA forms looked ultra-structurally different with prominent presence of mitochondria-like organelle (MLO) and a changed mitochondrial trans-membrane potential with thicker membrane and a highly convoluted inner membrane than the less dense non-viable apoptotic (NVA) cells. This suggests that granular formation during apoptosis is a self-regulatory mechanism to produce higher number of viable cells in response to treatment. This study directs the need to search novel chemotherapeutic approaches by incorporating these findings when developing drugs against the emerging Blastocystis sp. infections.
  4. Suresh K, Smith HV, Tan TC
    Appl Environ Microbiol, 2005 Sep;71(9):5619-20.
    PMID: 16151162
    Blastocystis cysts were detected in 38% (47/123) (37 Scottish, 17 Malaysian) of sewage treatment works. Fifty percent of influents (29% Scottish, 76% Malaysian) and 28% of effluents (9% Scottish, 60% Malaysian) contained viable cysts. Viable cysts, discharged in effluent, provide further evidence for the potential for waterborne transmission of Blastocystis.
  5. Aljabali AA, Hassan SS, Pabari RM, Shahcheraghi SH, Mishra V, Charbe NB, et al.
    Future Sci OA, 2021 Oct;7(9):FSO744.
    PMID: 34737885 DOI: 10.2144/fsoa-2021-0031
    The purpose of this review is to highlight recent scientific developments and provide an overview of virus self-assembly and viral particle dynamics. Viruses are organized supramolecular structures with distinct yet related features and functions. Plant viruses are extensively used in biotechnology, and virus-like particulate matter is generated by genetic modification. Both provide a material-based means for selective distribution and delivery of drug molecules. Through surface engineering of their capsids, virus-derived nanomaterials facilitate various potential applications for selective drug delivery. Viruses have significant implications in chemotherapy, gene transfer, vaccine production, immunotherapy and molecular imaging.
  6. Ismail NS, Subbiah SK, Taib NM
    Curr Pharm Biotechnol, 2020;21(14):1539-1550.
    PMID: 32598252 DOI: 10.2174/1389201021666200629145217
    BACKGROUND: This is the fastest work in obtaining the metabolic profiles of Pseudomonas aeruginosa in order to combat the infection diseases which leads to high morbidity and mortality rates. Pseudomonas aeruginosa is a high versatility of gram-negative bacteria that can undergo aerobic and anaerobic respiration. Capabilities in deploying different carbon sources, energy metabolism and regulatory system, ensure the survival of this microorganism in the diverse environment condition. Determination of differences in carbon sources utilization among biofilm and non-biofilm of Pseudomonas aeruginosa provides a platform in understanding the metabolic activity of the microorganism.

    METHODS: The study was carried out from September 2017 to February 2019. Four archive isolates forming strong and intermediate biofilm and non-biofilms producer were subcultured from archive isolates. ATCC 27853 P. aeruginosa was used as a negative control or non-biofilm producing microorganism. Biofilm formation was confirmed by Crystal Violet Assay (CVA) and Congo Red Agar (CRA). Metabolic profiles of the biofilm and non-biofilms isolates were determined by phenotype microarrays (Biolog Omnilog).

    RESULTS AND DISCUSSION: In this study, Pseudomonas aeruginosa biofilm isolates utilized uridine, L-threonine and L-serine while non-biofilm utilized adenosine, inosine, monomethyl, sorbic acid and succinamic acid.

    CONCLUSION: The outcome of this result will be used for future studies to improve detection or inhibit the growth of P. aeruginosa biofilm and non-biofilm respectively.

  7. Lee IL, Tan TC, Tan PC, Nanthiney DR, Biraj MK, Surendra KM, et al.
    Parasitol Res, 2012 Apr;110(4):1553-62.
    PMID: 22076050 DOI: 10.1007/s00436-011-2665-0
    Blastocystis sp. is a common intestinal parasite. To date, there have been sporadic and scanty studies on Blastocystis sp. carried out in rural communities in Nepal. We surveyed the prevalence of Blastocystis sp. and its possible associated risk factors, and reported the predominant Blastocystis sp. subtype in two rural communities, Bolde Phediche and Bahunipati, in Nepal. Human faecal samples were collected from 241 participants, cultured using in vitro cultivation and examined for Blastocystis sp. The presence of Blastocystis sp. in faecal samples was further confirmed by polymerase chain reaction (PCR) and subsequently genotyped using subtype-specific sequence tagged site (STS) primers. There were 26.1% (63/241) of the participants that were infected by Blastocystis sp. We detected 84.1% (53/63) of Blastocystis sp. subtype 4 infections in these rural communities. The unusually high prevalence of Blastocystis sp. subtype 4 can be attributed to the rearing of family-owned animals in barns built close to their houses. Eighty one percent (51/63) of the Blastocystis sp. infected participants drank not boiled or unfiltered water. The present study revealed that Blastocystis sp. could pose a health concern to the communities and travellers to the hilly area in Nepal. Infection may be transmitted through human-to-human, zoonotic and waterborne transmissions. We provide recommendations to ensure good public health practices.
  8. Tan TC, Ong SC, Suresh KG
    Parasitol Res, 2009 Oct;105(5):1283-6.
    PMID: 19603182 DOI: 10.1007/s00436-009-1551-5
    This represents the first study to determine the genetic diversity of Blastocystis sp. among cancer and HIV/AIDS patients. Forty Blastocystis sp. isolates obtained from 20 cancer and 20 HIV/AIDS patients were genotyped by PCR using seven pairs of known sequenced-tagged site primers. Out of the 40 isolates, 38 were identified as one of the known genotypes and two isolates were negative with all the STS primers. Blastocystis sp. subtype 3 which is reported to be associated with disease was found to be predominant among the study subjects.
  9. Tan TC, Suresh KG
    Parasitol Res, 2007 Nov;101(6):1521-5.
    PMID: 17701428
    Blastocystis hominis has been regarded as an enigmatic parasite as many aspects of its basic biology remain uncertain. Many reproductive processes have been suggested for the organism; however, to date, only the binary fission has been proven. Plasmotomy is one of the modes of reproduction previously suggested to be seen in in vitro cultures. The present study provides trichrome and acridine orange staining evidence for the existence of nucleic acid suggestive of division of nucleus into multinucleate forms with the respective cytoplasm dividing giving rise to two or three progeny B. hominis. Transmission electron micrographs further confirmed that these daughter cells had respective surrounding surface coat, mitochondria, and vacuoles.
  10. Tan TC, Suresh KG
    Parasitol Res, 2006 Nov;99(6):737-42.
    PMID: 16816959
    The amoeboid form of Blastocystis hominis has been reported infrequently, and its morphological descriptions have yielded conflicting and confusing reports. In the present study, we used the amoeboid forms seen predominantly in symptomatic patients infected with Blastocystis to provide detailed descriptions on the fine surface structure and intracellular morphology. Scanning electron microscopy revealed the irregular shape of the amoeboid form, with an intercalated fibrillar structure and a highly convoluted surface with deep indentations and projected pseudopodia. Transmission electron microscopy showed the existence of two types of amoeboid forms of B. hominis in in vitro culture, one with a large central vacuole containing tiny electron-dense particles while the other contains multiple small vacuoles in the cytoplasm. A surface coat with varying thickness surrounded the amoeboid form, which also showed prominent, extended pseudopodia of varying shape. Irregularly shaped mitochondrion-like organelles with prominent cristae, lipid inclusions, and multiple vacuoles were frequently seen in close proximity with the pseudopodia. The characteristic nucleus with a crescentic band of electron-dense chromatin material was also seen.
  11. Tan TC, Suresh KG
    Parasitol Res, 2006 Feb;98(3):189-93.
    PMID: 16323025
    Blastocystis hominis is one of the most common human parasites that inhabit the intestinal tract. Conflicting reports continue to exist regarding the existence and the functional role of the amoeboid forms in the life cycle of the parasite. The present study investigates the presence of these forms in 20 isolates obtained from ten symptomatic and asymptomatic patients respectively. A total of 10,000 parasite cells per ml from each isolate were inoculated into three culture tubes each containing 3 ml of Jones' medium supplemented with 10% horse serum, incubated at 37 degrees C. The contents were examined daily for 10 days. Irregular and polymorphic amoeboid forms with multiple extended pseudopodia were observed in all isolates from symptomatic patients, while none of the isolates from asymptomatic patients showed the presence of the amoeboid forms. The amoeboid forms were initially noted on day 2 and the percentages increased from 2% to 28%, with peak percentages from day 3 to day 6. Transmission electron microscopy revealed two types of amoeboid forms; one containing a large central vacuole completely filled with tiny electron-dense granules, and the other which revealed multiple small vacuoles within the central body. The cytoplasm contained strands of electron-dense granules resembling rough endoplasmatic reticulum, which is suggestive of active protein synthesis. The surface coat of the amoeboid form surrounding the parasite showed uneven thickness. Acridine orange stained the central body yellow and the periphery orange, indicating activity at the level of nucleic acids. The amoeboid form could either be an indicator of pathogenicity of B. hominis, or the form likely to contribute to pathogenicity and be responsible for the symptoms seen in patients.
  12. Afzan MY, Suresh K
    Parasitol Res, 2012 Jul;111(1):371-81.
    PMID: 22398830 DOI: 10.1007/s00436-012-2848-3
    Trichomonas vaginalis, a flagellated protozoan parasite causes a variety of adverse health consequences in both men and women. The parasite exists in the trophozoite and the pseudocystic stage. The study reports for the first time that pseudocyst forms of T. vaginalis isolated from cervical neoplasia (CN) patients demonstrated distinct, different and significant in vitro growth profiles when grown in vitro cultures from day 1 up to day 5 (p<0.05, Mann-Whitney test) when compared with the same life cycle stages isolated from non-cervical neoplasia but symptomatic patients (NCN). Pseudocysts from CN and NCN isolates remained viable in distilled water until 3 h 10 min and 2 h 10 min, respectively. The nucleus of pseudocysts in CN isolates using acridine orange and DAPI showed more intense staining revealing higher nuclear content. The FITC-labeled Concanavalin A stained stronger green fluorescence with surface of pseudocysts in CN isolates showing more rough and creased surface with higher numbers of deep micropores with larger numbers of chromatin masses, vacuoles, and hydrogenosomes. The study confirms that pseudocystic stage from CN, despite the uniformity in appearance of being rounded and showing no motility without a true cyst wall under light microscopy, demonstrated different biochemical, surface, and ultrastructural properties. The study provides evidence that phenotypic variant forms of pseudocysts does exist and possibly does play a role in exacerbating cervical cancer.
  13. Afzan MY, Sivanandam S, Suresh K
    J Appl Microbiol, 2012 Jan;112(1):132-7.
    PMID: 22040369 DOI: 10.1111/j.1365-2672.2011.05185.x
    We previously reported that Modified Field Stain (MF) can be used as a rapid stain for diagnosis. In the present study we extend the observation to include the stain as an alternative method to assess viability of the cells.
  14. Mak JW, Lam PL, Choong MF, Suresh K
    J. Helminthol., 1990 Jun;64(2):96-9.
    PMID: 2387979
    The known filaricides, suramin and diethylcarbamazine citrate, were tested against subperiodic Brugia malayi infection in the leaf-monkey, Presbytis cristata. As expected, intravenous suramin at 10 mg/kg daily x 5 days or 17 mg/kg weekly x 5 weeks, did not show any microfilaricidal activity, but substantially reduced the recovery of live adult worms to 50.6% and 13.6% of controls respectively. Oral diethylcarbamazine citrate at 6 mg/kg daily x 6 or 10 days reduced final microfilarial counts to 30% of initial counts four weeks post-treatment and adult worm recovery was reduced to 4.5% and 0% of controls respectively. Although the antifilarial activity of these drugs against the infection in this non-human primate model appears to be similar to that seen in man, these results have to be confirmed using larger groups of animals.
  15. Mak JW, Lam PL, Rain AN, Suresh K
    Parasitol Res, 1988;74(4):383-5.
    PMID: 3387410
    Ivermectin at single doses of 0.2-1.0 mg/kg body weight reduced the microfilarial counts of subperiodic Brugia malayi in Presbytis cristata by 59.9%-89.6% of initial counts, 4 weeks after treatment. Adult filaricidal activity was poor, live adult worms being recovered from all animals at autopsy. There was no serious side effect at these doses.
  16. Raman S, Samuel D, Suresh K
    Aust N Z J Obstet Gynaecol, 1991 Aug;31(3):217-20.
    PMID: 1804081
    In this study 24 patients who had conventional erect lateral X-ray pelvimetry had a CT pelvimetry done after delivery to complete the pelvimetry views. The erect lateral pelvimetry was read independently by a Consultant Radiologist, Consultant Obstetrician and a Medical Officer training in Obstetrics and Gynaecology. Using CT pelvimetry as the 'gold standard' (as the error of measurement was known with the machine used) the 3 readings were compared. There was no statistical difference in the values suggesting that X-ray pelvimetry is comparable to CT pelvimetry. However CT pelvimetry is preferred, if available, because of the lower dose of radiation involved, more comfort for the patient and shorter time in performing the procedure. Measurements done are easily read directly from the CT console.
  17. Mak JW, Choong MF, Lam PL, Suresh K
    Acta Trop, 1990 May;47(4):223-6.
    PMID: 1973024
    The leaf-monkeys, Presbytis cristata and Presbytis melalophos, experimentally infected with subperiodic Brugia malayi, have been used for studies on the pathoimmunology of the infection and the screening of potential filaricides during the last 6-8 years, and considerable information on the pattern of microfilaraemia and adult worm recoveries have been obtained. The prepatent periods in 97 P. cristata and 45 P. melalophos, each infected with about 200 infective larvae, were similar, these being approximately 70 and 68 days respectively. Although all infected animals became microfilaraemic, the peak geometric mean count was much higher in P. cristata than in P. melalophos, this being 182.0 and 65.8 per ml blood respectively. Mean adult worm recovery expressed as the percentage of the infective dose was 4.7% and 2.5%, respectively. Most worms were recovered from the sacral nodes/thoracic duct or inguinal lymph nodes in these animals. In view of the higher worm recovery and the higher peak microfilaraemia attained, it is concluded that P. cristata is a better model for the infection than P. melalophos.
  18. Mak JW, Lam PL, Rain AN, Suresh K
    J. Helminthol., 1987 Dec;61(4):311-4.
    PMID: 3437112
    Four Presbytis cristata were treated with oral ivermectin at the same time as the subcutaneous inoculation of 100 infective larvae monthly for three months. Two animals given 0.2 mg/kg monthly and two others given 0.3 mg/kg monthly as well as three control animals became patent for microfilaraemia. However, only 1% of the infective dose was recovered as adult worms from animals in the higher drug dosage group compared to 8.2% and 6.2% in the lower dosage and control groups respectively.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links