MyMedR

Emerging problems of antibiotic resistance in community medicine

Parasakthi N

Malays J Pathol, 1996 Jun;18(1):9-13.

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.

Comparison of three different methods for the presumptive detection of ESBL production in ceftazidime-resistant strains of Klebsiella pneumoniae

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.

Evaluation of the use of Bactec anaerobic blood cultures in the detection of bacteraemia and fungaemia in children

Riley PA, Parasakthi N

Malays J Pathol, 1996 Jun;18(1):31-4.

PMID: 10879222

In an attempt to reduce costs, the role of Bactec anaerobic blood culture in the detection of bacteraemia and fungaemia in children was evaluated. Results from 3167 sets of aerobic and anaerobic blood cultures from children admitted to the University Hospital, Kuala Lumpur during a one year period, were analysed. Four hundred and eight (12.9%) sets of blood cultures were positive, of which 348 sets (11.0%) from 201 patients were clinically significant. Of the 348 significant positive sets, organisms were isolated on 177 (50.9%) occasions from both aerobic and anaerobic bottles, on 136 (39.1%) occasions from the aerobic bottle only and 35 (10.0%) occasions from the anaerobic bottle only. No strict anaerobes were isolated, but clinically significant isolates recovered from the anaerobic bottle only included Klebsiella pneumoniae, Salmonella species, Enterobacter cloacae, Staphylococcus aureus, coagulase negative staphylococci, Streptococcus pneumoniae and Group B streptococcus. Patients with bacteraemia diagnosed solely by anaerobic culture were distributed evenly across the various paediatric subspecialities. When results from the anaerobic bottles were excluded, the overall isolation rate was reduced from 11% to 9.9%. Potential financial savings resulting from omission of anaerobic cultures must be balanced against the small number of bacteraemic episodes that could be missed. Undiagnosed bacteraemia may result in increased morbidity and mortality with its own attendant financial implications.

Fulltext Characteristics of childhood diarrhea associated with enterotoxigenic Escherichia coli in Malaysia

Samuel S, Vadivelu J, Parasakthi N

Southeast Asian J. Trop. Med. Public Health, 1997 Mar;28(1):114-9.

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.

The bacteriology of brain abscess: a local experience in Malaysia

Puthucheary SD, Parasakthi N

Trans R Soc Trop Med Hyg, 1990 7 1;84(4):589-92.

PMID: 2091359

31 cases of intracranial abscess seen over a period of 10 years showed a peak incidence in the second and third decades of life with a male preponderance. Tetralogy of Fallot and other congenital cyanotic heart diseases were the predominant associated factors (32%). The commonest site of infection was the frontal lobe. Gram-stained smears of pus proved to be extremely useful. The majority of the organisms (82%) were either microaerophilic or anaerobic bacteria with Streptococcus milleri being the most frequent isolate. With the exception of Corynebacterium species, all isolates were susceptible to penicillin or chloramphenicol, most being susceptible to both.

Fulltext Susceptibility of 57 strains Ps. pseudomallei to some new B-lactams and other antibiotics

Puthucheary SD, Parasakthi N

Med J Malaysia, 1987 Dec;42(4):248-51.

PMID: 3454397

Fifty seven strains of Pseudomonas pseudomallei were tested for in vitro susceptibility to 15 antimicrobial agents. Amongst the generally recommended antibiotics for therapy of melioidosis, only 86%, 84% and 58% of the strains were found to be sensitive to trimethoprim-sulphamethoxazole, chloramphenicol and tetracycline respectively. Of the newer B-Iactams, in descending order of activity were, ceftazidime, ceftriaxone, cefotaxime, cefoperazone and cefuroxime. But on a weight for weight basis, ceftazidime was the most active agent and as such, may be considered in the therapy of acute septicaemic melioidosis."

Metronidazole resistance among Helicobacter pylori strains in Malaysia

Parasakthi N, Goh KL

Am J Gastroenterol, 1992 Jun;87(6):808.

PMID: 1590330

Primary and acquired resistance to clarithromycin among Helicobacter pylori strains in Malaysia

Parasakthi N, Goh KL

Am J Gastroenterol, 1995 Mar;90(3):519.

PMID: 7872306

The racial cohort phenomenon: seroepidemiology of Helicobacter pylori infection in a multiracial South-East Asian country

Goh KL, Parasakthi N

Eur J Gastroenterol Hepatol, 2001 Feb;13(2):177-83.

PMID: 11246618

BACKGROUND: Malaysia is a multiracial country where three major Asian races live together: Malay, Chinese and Indian. In addition, there are a number of native or indigenous races, particularly in East Malaysia. Differences in prevalence of gastric diseases between races have been noted, particularly with respect to peptic ulcer disease and gastric cancer. The aim of this study is to determine the prevalence rates and risk factors for Helicobacter pylori infection among various races in Malaysia.

METHODS: A large-scale prospective seroepidemiological study in West and East Malaysia using the HEL-p II commercial enzyme-linked immunosorbent assay kit (AMRAD, Melbourne, Australia) to detect H. pylori antibodies. Populations surveyed in West Malaysia were a rural community from Kuala Pilah, and blood donors from Kuala Lumpur and Kota Baru. Subjects studied in East Malaysia were volunteer blood donors from Kota Kinabalu, and blood donors and healthy volunteers from Sibu. Statistical analyses using multiple logistic regression analysis were carried out to identify independent risk factors for H. pylori infection

RESULTS: A total of 2,381 subjects were evaluated. H. pylori prevalence varied from different areas of study and ranged from a low of 26.4% in blood donors from Kota Baru to a high of 55.0% in Kota Kinabalu. The most striking differences, however, were noted in the prevalence rates among different racial groups. Prevalence rates among the Malays ranged from 11.9 to 29.2%, while the Chinese ranged from 26.7 to 57.5%, and those of Indians in two studies were 49.4 and 52.3%. In every location, Malays had a significantly lower prevalence compared with the other races. The highest prevalence rates were recorded among the indigenous races in Kota Kinabalu, East Malaysia. There was no difference between males and females in the studies. An increasing trend with age was noted in the majority of studies; however, no increase in prevalence rates was noted among the Malays.

CONCLUSIONS: The pattern of infection in a multiracial population in Malaysia points to a 'racial cohort' phenomenon. The infection appears to be confined to a racial group, with the Malays having consistently low prevalence rates. This observation may provide clues to the mode of transmission of infection.

Fulltext Colonisation factors amongst clinical isolates of enterotoxigenic Escherichia coli

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.

Comparison of susceptibility test methods to detect penicillin susceptibility in Streptococcus pneumoniae isolates

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.

Fulltext Bacterial infection of central venous catheters in short-term total parenteral nutrition

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.

Septicaemia in paediatric cancer patients: a 5-year surveillance study in university hospital, Kuala Lumpur, Malaysia

Ariffin H, Ariffin W, Peng LH, Parasakthi N

J Trop Pediatr, 1997 10;43(5):279-81.

PMID: 9364125 DOI: 10.1093/tropej/43.5.279

Infectious complications are the major cause of morbidity and mortality in children with malignancy. Empirical antimicrobial therapy in the management of fever of unknown origin should be tailored to local bacteriological data and antibiotic sensitivity patterns. Five-hundred-and-fifty-nine cases of culture-proven septicaemia occurring in pediatric cancer patients between 1990 and 1994 were retrospectively analysed and compared with a similar study done in our centre between 1976 and 1979. A wide spectrum of organisms was isolated. Staphylococcus epidermidis, Staphylococcus aureus, and Klebsiella pneumoniae were the most common and consistent bacteria isolated during the 5 year period. More than 70 per cent of the staphylococci were sensitive to methicillin and universally sensitive to vancomycin. However, a worrying trend of ceftazidime-resistance amongst gram-negative organisms was found. In these situations, the use of imipenem is recommended as resistance to this antimicrobial agent was exceedingly rare.

Fulltext Infective endocarditis amongst intravenous drug abusers seen at the University Hospital, Kuala Lumpur

Jayamalar R, Parasakthi N, Puthucheary SD

Med J Malaysia, 1987 Dec;42(4):264-8.

PMID: 3136302

Drug abuse is a major problem in Malaysia. Serious complications of intravenous drug addiction include septicaemia and infective endocarditis. We present nine cases of endocarditis occuring amongst drug abusers. The tricuspid valve was most frequently involved and the common aetiological organisms were S. aureus and Str. faecalis. There was a high mortality rate of 67% in our study, inspite of appropriate therapy. Early recognition of the disease and aggressive treatment is required to improve the associated mortality.

Human T- and B-lymphocyte populations in blood: local population studies

Pang T, Parasakthi N, Yap SF

Med J Malaysia, 1979 Mar;33(3):243-6.

PMID: 316496

Distribution of CBP genes in Streptococcus pneumoniae isolates in relation to vaccine types, penicillin susceptibility and clinical site

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.

Childhood invasive pneumococcal disease: a hospital-based study from Malaysia

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.

Extended-spectrum beta-lactam resistance due to AmpC hyperproduction and CMY-2 coupled with the loss of OMPK35 in Malaysian strains of Escherichia coli and Klebsiella pneumoniae

Palasubramaniam S, Subramaniam G, Muniandy S, Parasakthi N

Microb Drug Resist, 2007;13(3):186-90.

PMID: 17949305

In this report, we describe the detection of AmpC and CMY-2 beta-lactamases with the loss of OmpK35 porin among seven sporadic strains of ceftazidime-resistant Klebsiella pneumoniae and ceftazidime-resistant Escherichia coli. Cefoxitin, which was used as a marker of resistance toward 7-alpha-methoxy-cephalosporins, exhibited high minimum inhibitory concentration (MIC) values ranging between 128 microg/ml and >256 microg/ml in all the strains. The presence of hyperproducing AmpC enzymes was indicated by the positive three-dimensional test. Isoelectric focusing (IEF) study confirmed the presence of AmpC enzymes in all the strains. The ampC gene was detected by PCR in all the strains and confirmed by DNA sequencing. Large plasmids in all the strains, ranging from 60 kb to 150 kb in size, most likely encode the ampC gene. Two E. coli strains out of the seven strains showed positive amplification of the bla(CMY-2) gene, an AmpC variant, and was confirmed by DNA sequence analyses. DNA hybridization confirmed the bla(CMY-2) gene to be plasmid-mediated in both of these strains. However, one of these two strains also mediated a chromosomal CMY gene. All the strains showed an absence of OmpK35 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS/PAGE) and was confirmed by western blot analyses using raised polyclonal anti-OmpK35 antiserum. This suggests that, apart from CMY production, absence of OmpK35 porin also contributed to cefoxitin resistance resulting in extended-spectrum beta-lactam resistance among these isolates.

Invasive meningococcal disease in the University of Malaya Medical Centre, Kuala Lumpur, Malaysia

Raja NS, Parasakthi N, Puthucheary SD, Kamarulzaman A

J Postgrad Med, 2006 Jan-Mar;52(1):23-9; discussion 29.

PMID: 16534160

Neisseria meningitidis (N. meningitidis) remains the leading worldwide cause of acute bacterial meningitis and fatal sepsis in healthy individuals.

SHV-5 extended-spectrum beta-lactamase from Klebsiella pneumoniae associated with a nosocomial outbreak in a paediatric oncology unit in Malaysia

Palasubramaniam S, Subramaniam G, Muniandy S, Parasakthi N

Int J Infect Dis, 2005 May;9(3):170-2.

PMID: 15840458

Displaying publications 1 - 20 of 51 in total