Displaying publications 1 - 20 of 51 in total

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  1. Goh KL, Parasakthi N, Peh SC, Ong KK
    Med J Malaysia, 1995 Sep;50(3):208-11.
    PMID: 8926896
    Sixty-three breath samples were collected from patients who underwent a 14C-urea breath test. Following ingestion of a radiolabelled 14C-labelled urea solution, breath samples containing 14C-labelled carbon dioxide were trapped in a solution containing hyamine hydroxide. Samples were then counted in a liquid scintillation counter. Breath samples were collected at 2, 15, 20, 25 and 30 minutes following ingestion of the urea solution. The presence or absence of Helicobacter pylori (HP) infection was determined on the basis of endoscopic biopsy tests which included culture, histological examination, rapid urease test and a gram stain of a fresh tissue smear. Thirty-two HP positive and 31 HP negative samples were collected. The mean counts at 15, 20, 12 and 30 minutes time points were: 4413, 4458, 4109 and 3795 dpm respectively for the positive samples and 1275, 877, 690 and 565 dpm respectively for the negative samples. Based on a cutoff value (mean of the negative samples + 3 standard deviations) for every time point, HP positive and negative samples could be clearly differentiated giving a sensitivity and specificity of 100%. The 14C-urea breath test is a reliable and convenient diagnostic test for H. pylori.
  2. Lee WS, Puthucheary SD, Parasakthi N, Choo KE
    J Trop Pediatr, 2003 Feb;49(1):37-41.
    PMID: 12630719
    There is widespread resistance of Salmonella species to commonly prescribed antimicrobials the world over. We aimed to determine the antimicrobial susceptibility and serovar distribution of non-typhoidal Salmonella (NTS) isolated from blood cultures of Malaysian children. Positive isolates of NTS from blood cultures obtained from children admitted to the pediatric wards of University of Malaya Medical Center (UMMC), a large urban hospital from Kuala Lumpur (1991-2001), and Hospital Kota Bharu (HKB), from the predominantly rural state of Kelantan (1991-1999), Malaysia, were reviewed retrospectively. Serovar distribution and antimicrobial susceptibility were ascertained. A total of 64 and 55 isolates of NTS were obtained from blood cultures of children admitted to UMMC and HKB, respectively. The commonest serovar isolated was Salmonella enteritidis in both centers. The NTS isolated were highly sensitive to the antimicrobials tested: ampicillin 98 per cent, chloramphenicol 98 per cent, gentamicin 97 per cent, trimethoprim-sulfamethoxazole (TMP-SMX) 98 per cent, and ceftriaxone 100 per cent in UMMC; ampicillin 100 per cent, chloramphenicol 87 per cent, kanamycin 100 per cent, streptomycin 96 per cent, TMP-SMX 93 per cent, and tetracycline 89 per cent in HKB. There were only one and five multi-resistant isolates in UMMC and HKB, respectively. In conclusion, NTS isolated from blood cultures of Malaysian children from Kuala Lumpur and Kota Bharu were highly sensitive to commonly prescribed antibiotics. We speculate that this is due to the restriction of sales of antimicrobials in Malaysia except by prescription. Continuing vigilance and frequent antmicrobial surveillance is necessary.
  3. Chan L, Ngeow YF, Parasakthi N
    Med J Malaysia, 1998 Mar;53(1):10-5.
    PMID: 10968131
    Fourteen severely ill ventilated patients in an intensive care unit, requiring short-term total parenteral nutrition, were examined for catheter-related infection. Microbiological analysis using Maki's SQ technique was carried out on catheter exit site, catheter hub, proximal subcutaneous segment of catheter and catheter up. Qualitative cultures were carried out on total parenteral nutrition and peripheral blood samples. Twenty six of 29 catheters removed (90%) were culture positive but only 7 catheters were related to positive blood cultures, giving a catheter-related bacteremia (CRB) rate of 24%. Haematogenous seeding was strongly implicated in 7/29 (24%) of catheters. Patients' skin flora appeared to be the main source of catheter-related infection. The organisms isolated for patients with CRB included coagulase-negative staphylococci, Acinetobacter and Klebsiella. It is suggested that to control infective complications of central venous catheters, emphasis should be focused on specialised intravenous therapy teams and the use of strict protocols for insertion and care of central lines.
  4. Puthucheary SD, Parasakthi N, Liew ST, Chee YW
    Singapore Med J, 1994 Oct;35(5):453-6.
    PMID: 7701360
    One hundred and thirty-seven children with Campylobacter diarrhoea were reviewed. The predominant species was C. jejuni. Ninety-five percent of the children were below 5 years of age with 61% of these being 2-12 months old. A slight male preponderance was noted. About half the cases presented with fever and bloody diarrhoea; vomiting was seen in 28% and abdominal colic in only 8%. Moderate to severe diarrhoea was present in 48% of the children. Thirty-seven percent had a history of recent or concurrent illness. Other bacterial enteropathogens together with Campylobacter were isolated in 15% of the children. Erythromycin, the most useful drug, when indicated for Campylobacter infections, had an MIC90 of 2 mg/l with 96.2% of the strains being sensitive.
  5. Goh KL, Peh SC, Wong NW, Parasakthi N, Puthucheary SD
    J Gastroenterol Hepatol, 1990 5 1;5(3):277-80.
    PMID: 2103410
    Over a 15-month period, 399 patients with dyspepsia were investigated for the presence of Campylobacter pylori infection. Half of the patients (50.6%) had Campylobacter organisms in the antrum of the stomach. C. pylori was found in 96.1% of patients with histological changes of chronic active gastritis in the antrum. Of patients with duodenal and gastric ulcers, 87.8% and 87.5%, respectively, had Campylobacter organisms, as did 39.3% of patients with non-ulcer dyspepsia. C. pylori infection was most commonly found in Chinese and Indians. Although the prevalence of infection appeared to increase with age, there was an equal distribution amongst the sexes.
  6. Samuel S, Vadivelu J, Parasakthi N
    PMID: 9322293
    Amongst 107 diarrheal cases studied a bacterial agent was isolated from 71 (66%) cases of which 60 (85%) were due to a single agent and the remaining 11 (15%) were of mixed infections. Enterotoxigenic Escherichia coli (ETEC) was isolated from 65 cases. Other pathogens isolated included Salmonella spp, Shigella spp and rotavirus. There was a higher isolation rate of ETEC from females and rotavirus from males. The infection rate was found to higher for the 0-2 year age group as compared to the 3-5 year age group. Amongst the ETEC isolated the STa 2 toxotype was the predominant type.
  7. Lim LH, Lee WS, Parasakthi N
    J Paediatr Child Health, 2007 May;43(5):366-9.
    PMID: 17489826
    New conjugate vaccine for Streptococcus pneumoniae has been introduced in Malaysia recently. Information on infection due to S. pneumoniae in Malaysian children is scarce. We conducted a retrospective chart review of childhood invasive pneumococcal disease (IPD) presented to a single centre in Malaysia.
  8. Iyer L, Vadivelu J, Parasakthi N
    Singapore Med J, 1995 Oct;36(5):495-7.
    PMID: 8882532
    The production of heat-labile (LT) and heat-stable (ST) enterotoxins, colonisation factor antigens (CFAs) and haemagglutinins was investigated amongst 310 Escherichia coli (E. coli) isolates obtained from 62 children under the age of five, with diarrhoea. Twenty-one isolates were found to produce enterotoxins, of which fifteen (71%) isolates produced ST only, 2 (10%) produced LT only and 4 (19%) produced both LT and ST. However, none of the isolates demonstrated any of the common CFAs identified to date, but 8 out of the 21 isolates demonstrated haemagglutination with rabbit, sheep or human group A erythrocytes, suggesting the presence of putative CFAs, yet unidentified.
  9. Goh KL, Parasakthi N, Chuah SY, Toetsch M
    Eur J Gastroenterol Hepatol, 1997 Nov;9(11):1091-5.
    PMID: 9431900
    OBJECTIVES: To determine the efficacy of a three times daily (t.i.d.) versus a twice daily (b.i.d.) regimen of combination amoxycillin and metronidazole and famotidine in the eradication of Helicobacter pylori and the influence of metronidazole resistance on the outcome of treatment.

    PATIENTS: Patients selected had unequivocal evidence of H. pylori infection based on the urease test, culture and histology and had either peptic ulcer disease or non-ulcer dyspepsia.

    DESIGN: The study was a comparative and double-blind study and patients were randomized to receive either amoxycillin 750 mg t.i.d. and metronidazole 500 mg t.i.d. for 12 days or amoxycillin 1000 mg b.i.d. and metronidazole 500 mg b.i.d. for 12 days. Both groups also received famotidine 40 mg for 6 weeks.

    MAIN OUTCOME MEASURE: Patients were assessed for successful eradication, defined as absence of bacteria in all tests, at least 4 weeks after completion of antibiotic therapy by repeat gastroscopy.

    RESULTS: One hundred and twenty-nine patients were recruited for the study. Two patients defaulted follow-up, two patients were withdrawn from the study and six patients were found to be non-compliant with medications. The eradication rates of the t.i.d. regimen was higher than the b.i.d. regimen (per protocol (PP) analysis: 83.3% (50/60) vs. 76.3% (45/59), P=0.337; intention-to-treat (ITT) analysis: 78.5% (51/65) vs. 75.0% (48/64), P=0.642). Seventy-five patients had pre-treatment cultures checked for metronidazole resistance, 33 (44.0%) were found to be resistant. Acquired resistance occurred in 3/40 (7.5%) patients. Eradication rates of metronidazole-sensitive and metronidazole-resistant patients: t.i.d. regimen - 100% (17/17) and 88.2% (15/17), b.i.d. regimen - 19/21 (90.5%) and 11/15 (73.3%). Side effects were reported in up to 70% of patients but were mild and tolerable in the majority. Two patients were withdrawn from the study because of a fixed drug eruption in one and generalized macular rash in the other.

    CONCLUSION: Combination amoxycillin and metronidazole is effective in eradicating H. pylori. There was a tendency for the t.i.d. regimen to be better than the b.i.d. regimen and for metronidazole-resistant infections to be associated with a lower eradication rate but these differences did not reach statistical significance.

  10. Mohd Nasir MD, Parasakthi N
    Malays J Pathol, 2004 Jun;26(1):29-33.
    PMID: 16190104
    The increasing prevalence of penicillin-resistant Streptococuus pneumoniae urges for fast and accurate susceptibility testing methods. This study evaluated the comparability of three commonly used techniques; disk diffusion, E-test and agar dilution, to detect penicillin susceptibility in clinical isolates of S. pneumoniae. Fifty pneumococcal isolates, obtained from patients at the University of Malaya Medical Centre, were selected to include both penicillin-susceptible strains and those that had decreased susceptibility (resistant and intermediate) to penicillin. The minimum inhibitory concentration (MIC) values of penicillin to serve as the reference was determined by the agar dilution method in which, based on the MIC breakpoints recommended by the National Committee for Clinical Laboratory Standards (NCCLS), 27 strains had decreased susceptibility to penicillin with 17 strains resistant and 10 intermediate. Comparing to the agar dilution method, oxacillin disk diffusion test detected all strains with decreased penicillin susceptibility as such while E-test showed a close agreement of susceptibility (92%) of the isolates to penicillin. This confirmed that oxacillin is a good screening test for S. pneumoniae isolates with decreased susceptibility to penicillin while E-test is very reliable for rapid and accurate detection of penicillin susceptibility.
  11. Palasubramaniam S, Parasakthi N
    Malays J Pathol, 2001 Dec;23(2):73-8.
    PMID: 12166595
    Twenty-eight (28) strains of ceftazidime-resistant Klebsiella pneumoniae were isolated from blood cultures of in-patients from University Hospital, Kuala Lumpur between March 1995 and August 1996. Three methods were used to detect the production of ESBL enzymes by these strains. These three methods include the double-disc synergy test (DDST), inhibitor-potentiated disc-diffusion test (IPDD) and the E-test ESBL method. All strains could be identified as ESBL producers using the DDST method by a minimum of two beta-lactams and these included either a combination of ceftazidime and ceftriaxone with clavulanate respectively or cefotaxime and aztreonam with clavulanate respectively. Similarly using a combination of either cefotaxime and ceftriaxone with clavulanate or ceftriaxone and aztreonam with clavulanate respectively would have detected all strains as ESBL producers. The IPDD method could also detect for ESBL activity based on combinations of beta-lactam antibiotics with clavulanate respectively. All combinations of beta-lactam antibiotics could detect for ESBL activity in all the strains except a combination of either ceftazidime and aztreonam or cefotaxime and ceftriaxone with clavulanate respectively. The E-Test method using ceftazidime alone and in combination with clavulanate was found to be the most effective method in the presumptive identification of ESBL activity in all the strains.
  12. Goh KL, Parasakthi N, Chuah SY, Cheah PL, Lo YL, Chin SC
    Aliment Pharmacol Ther, 1997 Dec;11(6):1115-8.
    PMID: 9663838
    OBJECTIVES: To determine and compare the efficacy and tolerability of two 1-week regimen comprising omeprazole, clarithromycin and amoxycillin or metronidazole in the eradication of Helicobacter pylori, and to determine the influence of bacterial resistance to metronidazole and clarithromycin on the outcome of treatment.

    PATIENTS AND METHODS: Patients with unequivocal evidence of H. pylori infection based on culture, histology and rapid urease test of both antrum and corpus biopsies were recruited for the study. The study was a randomized, investigator-blind, comparative study. Patients received either omeprazole 20 mg o.m., clarithromycin 250 mg b.d. and amoxycillin 500 mg b.d. (OAC) or omeprazole 20 mg o.m., metronidazole 400 mg b.d. and clarithromycin 250 mg b.d. (OMC) for 1 week. Patients were assessed for successful eradication, which was defined as absence of bacteria in all tests (culture, histology and urease test on both antral and corpus biopsies), at least 4 weeks after completion of therapy.

    RESULTS: Eighty-two patients were recruited for the study. Eradication rates on intention-to-treat analysis were--OAC: 36/41 (87.8%, 95% CI: 73.8, 95.9); OMC: 33/41 (80.5%, 95% CI: 65.1, 91.2). On per protocol analysis were--OAC: 36/40 (90%, 95% CI: 76.3, 97.2); OMC: 32/38 (84.2%, 95% CI: 68.7, 94.0). All side-effects encountered were mild and no patient discontinued treatment because of intolerance to medications. The most common side-effects were altered taste (OAC 31.7%, OMC 53.7%) and lethargy (OAC 14.6%, OMC 19.5%). Pre-treatment metronidazole resistance was encountered in 34/63 (54.0%) patients. No bacterial strains were found with primary resistance to clarithromycin. Metronidazole resistance did not significantly affect eradication rates. Emergence of resistance to clarithromycin was not seen post-therapy.

    CONCLUSIONS: Both the OAC and the OMC regimens were convenient and well-tolerated treatments for H. pylori. However, eradication rates were lower than anticipated.

  13. Desa MN, Sekaran SD, Vadivelu J, Parasakthi N
    Epidemiol Infect, 2008 Jul;136(7):940-2.
    PMID: 17678563
    Choline-binding proteins (CBP) have been associated with the pathogenesis of Streptococcus pneumoniae. We screened, using PCR, for the presence of genes (cbpA, D, E, G) encoding these proteins in 34 isolates of pneumococci of known serotypes and penicillin susceptibility from invasive and non-invasive disease. All isolates harboured cbpD and cbpE whereas cbpA and cbpG were found in 47% and 59% respectively; the latter were more frequent in vaccine-associated types and together accounted for 77% of these isolates. No association was observed with penicillin susceptibility but 85% of non-invasive isolates were positive for these genes.
  14. Goh KL, Paramsothy M, Azian M, Parasakthi N, Peh SC, Bux S, et al.
    J Gastroenterol Hepatol, 1997 Dec;12(12):790-4.
    PMID: 9504887
    The objectives of the study were first, to determine if gastric emptying was altered in patients with functional dyspepsia with and without Helicobacter pylori infection compared with normal healthy volunteers; and second, to determine if there were further alterations in gastric emptying when the infection was eradicated. Gastric emptying was measured using a 99mtechnetium radiolabelled solid meal and gastric emptying time was measured as t1/2, viz. time taken for half the radiolabelled meal to be emptied from the stomach. The mean gastric emptying time for H. pylori-positive patients (n=20) was 56.4+/-24.8 min; H. pylori-negative patients (n=19) 67.8+/-31.8 min; and normal controls (n=20) 58.8+/-18.8min. No significant difference was obtained between the groups (ANOVA; P=0.348). Thirteen of 18 H. pylori-positive patients successfully eradicated the infection following treatment with omeprazole 40 mg o.m. and amoxycillin 500 mg t.d.s. for 2 weeks. The mean difference in the gastric emptying time before and after H. pylori eradication was 23.9+/-13.2 min (P= 0.556). There was no significant difference in the frequency of specific dyspeptic symptoms as well as the overall mean symptom score between the H. pylori-positive and -negative patients. Gastric emptying was not different between patients with functional dyspepsia and normal controls. Helicobacter pylori infection does not appear to affect gastric emptying in patients with functional dyspepsia.
  15. Goh K, Parasakthi N, Cheah P, Ranjeev C, Rosmawati M, Tan Y, et al.
    J Gastroenterol Hepatol, 2000 Aug;15(8):910-4.
    PMID: 11022833
    BACKGROUND: The aim of the present paper was to determine the efficacy and tolerability of a 1-week treatment regimen consisting of pantoprazole and two antibiotics: clarithromycin and amoxycillin, in the eradication of Helicobacter pylori.

    METHODS: The patients selected had unequivocal evidence of H. pylori infection based on urease test, culture and histology on antral and corpus biopsies obtained at endoscopy. Patients received pantoprazole 40 mg twice a day, clarithromycin 500 mg twice a day and amoxycillin 1 g twice a day for 1 week and were assessed for successful eradication at least 4 weeks after completion of therapy by repeat gastroscopy and gastric biopsies. Eradication was defined as absence of bacteria in both antral and corpus biopsies tested by culture, histology and urease test.

    RESULTS: One hundred and six patients were recruited for the study. The mean age was 48.0 years (range: 23-74 years). Four patients defaulted follow up and five patients were not compliant (taking less than 85%) with medications. Eradication rates on per-protocol analysis were: 88/97 (90.7%; 95% CI: 83.1-95.7); and on intention-to-treat analysis they were: 88/106 (83.0%; 95% CI: 75.9-90.2). Side-effects were in general mild and tolerable: 57 of 106 (53.7%) patients complained of a bitter taste; 15 (14.1%) complained of giddiness; 10 (9.4%) complained of increased abdominal pain; 11 (11.5%) complained of lethargy and 16 (15.1%) complained of loose motions. Pre-treatment metronidazole resistance was encountered in 57/74 strains (77.0%). Clarithromycin resistance was not encountered in any of the strains.

    CONCLUSIONS: The pantoprazole 1-week triple therapy with amoxycillin and clarithromycin is effective in H. pylori eradication. The treatment was well tolerated by patients. Metronidazole resistance was reported in a high percentage of strains isolated from patients. Clarithromycin resistance was, however, not detected in any of the strains.

  16. Parasakthi N
    Malays J Pathol, 1996 Jun;18(1):9-13.
    PMID: 10879217
    Emergence of antimicrobial resistance in bacteria associated with community acquired infections has made the choice of empirical therapy more difficult and more expensive. The problems due to possible spread of MRSA to the community, emergence of penicillin resistance in S. pneumoniae, ampicillin resistance in H. influenzae, and multiresistance among common enteric pathogens are highlighted. Bacteria have a remarkable ability to develop resistance to many of the newly synthesized antimicrobial agents but the appropriate use of antibiotics will delay and in many cases prevent the emergence of resistance.
  17. Vadivelu J, Feachem RG, Drasar BS, Harrison TJ, Parasakthi N, Thambypillai V, et al.
    Epidemiol Infect, 1989 Dec;103(3):497-511.
    PMID: 2691267
    The membrane-filter assay, GM1-ELISA, and DNA-DNA hybridization assay, were used to detect enterotoxigenic Escherichia coli (ETEC) in samples of water, weaning food, food preparation surface swabs, fingerprints of mothers, and the fingerprints and stools of children under 5 years of age, in 20 households in a Malaysian village. Weaning food and environmental samples were frequently contaminated by faecal coliforms, including ETEC. The membrane-filter assay detected and enumerated faecal coliforms and LT-ETEC in all types of water and weaning food samples. Highest concentrations of faecal coliforms and LT-ETEC were found in weaning food, followed by well-water, stored water and stored drinking water. The GM1-ELISA detected LT-ETEC in weaning food, food preparation surfaces, fingerprints and stool samples. The DNA-DNA hybridization assay detected a larger proportion of STa2-ETEC than the other toxotypes, either singly or in combination. All the assays in combination detected the presence of ETEC in all types of samples on at least one occasion in each household. It was not possible to classify households as consistently more or less contaminated with ETEC. On individual occasions it was possible to show a significant association of the presence of LT-ETEC between the fingerprints of children and their stools, fingerprints of mothers and children, and weaning food and the stools of the child consuming the food.
  18. Parasakthi N, Vadivelu J, Ariffin H, Iyer L, Palasubramaniam S, Arasu A
    Int J Infect Dis, 2000;4(3):123-8.
    PMID: 11179914
    OBJECTIVES: To describe the epidemiology, antimicrobial susceptibility, genomic profiles, and control of a nosocomial outbreak of multidrug-resistant Klebsiella pneumoniae (MRKP) that occurred in the pediatric oncology unit of the University of Malaya Medical Centre in Kuala Lumpur.

    MATERIALS AND METHODS: A prospective epidemiologic and microbiologic study was conducted of MRKP isolated from the blood and wound of a boy with necrotizing fasciitis after a 7-day course of ceftazidime and amikacin. In the following 2 weeks, phenotypically similar MRKP were isolated from the blood cultures of four other patients and rectal swabs of another three patients and two liquid soap samples located in the same ward.

    RESULTS: Antimicrobial profiles demonstrated that all the isolates were resistant to ceftazidime, sensitive to imipenem and ciprofloxacin, and confirmed to be extended-spectrum beta-lactamase producers. Plasmids of varying molecular weights were present in all isolates. In eight of these isolates, which included four from blood, there were common large molecular weight plasmids ranging from 80 kb to 100 kb. Pulsed-field gel electrophoresis analysis using XbaI demonstrated six different DNA profiles, A to F. Profile A was shared by two blood culture isolates and were related by 91%. Profile B was found in one rectal swab isolate and one isolate from liquid soap and were related by 94%. Profile C was shared by one blood isolate and one liquid soap isolate and showed 100% relatedness. Profiles D, E, and F each were demonstrated by one blood isolate and two rectal swab isolates, respectively. These showed only 65% relatedness.

    CONCLUSIONS: The MRKP strains in this outbreak were not clonal in origin. The decline of the outbreak after 4 weeks was attributed to the reemphasis of standard infection control procedures and the implementation of a program that addressed sites of environmental contamination.

  19. Goh KL, Cheah PL, Md N, Quek KF, Parasakthi N
    Am J Gastroenterol, 2007 Jan;102(1):40-5.
    PMID: 17100981
    To determine the risk factors for gastric cancer (GCA), with particular emphasis on ethnicity in our multiracial population.
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