MyMedR

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.

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."

Fulltext Serodiagnosis of melioidosis in Malaysia

Vadivelu J, Puthucheary SD, Gendeh GS, Parasakthi N

Singapore Med J, 1995 Jun;36(3):299-302.

PMID: 8553097

Current diagnosis of melioidosis is based on bacterial culture and/or serology which is becoming increasingly useful. An IgM-ELISA using heat-killed whole cells of Pseudomonas pseudomallei was developed and compared with an indirect haemagglutination technique (IHAT) and an indirect immunofluorescent technique(IFAT). The IgM-ELISA using a P:N ratio of > or = 2 had a sensitivity of 91% and a specificity of 96%. All 3 assays were further used in a seroepidemiological survey amongst different groups of patients and healthy individuals. It was found that the IFAT performed better than the IHAT, detecting antibodies to P. pseudomallei in 6% of diabetics, 5% of pyrexics, 8% of pregnant women and 3% of farmers. For the same groups the IgM-ELISA detected antibodies in 1% of pyrexics, 8% of pregnant women and a further 14% of farmers. The IgM-ELISA was found to be sensitive and useful for the serological diagnosis of acute melioidosis.

Detection of antibodies against Salmonella typhi outer membrane protein (OMP) preparation in typhoid fever patients

Verdugo-Rodriguez A, Gam LH, Devi S, Koh CL, Puthucheary SD, Calva E, et al.

Asian Pac J Allergy Immunol, 1993 Jun;11(1):45-52.

PMID: 8216558

An indirect ELISA was used to detect antibodies against outer membrane protein preparations (OMPs) from Salmonella typhi. Sera from patients with a definitive diagnosis of typhoid fever (TF) gave a mean absorbance reading, at 414 nm, of 1.52 +/- 0.23 as compared to 0.30 +/- 0.11 for sera from healthy individuals. This gave a positive to negative ratio of absorbance readings of approximately 5.1. Suspected TF patients (no isolation of S. typhi), with positive and negative Widal titers had mean absorbance readings of 1.282 +/00.46 and 0.25 +/- 0.19, respectively. Sera from patients with leptospirosis, rickettsial typhus, dengue fever, and other infections gave mean absorbances of 0.20 +/- 0.08, 0.24 +/- 0.08, 0.27 +/- 0.08, and 0.31 +/- 0.16, respectively. The sensitivity, specificity, positive and negative predictive values were 100%, 94%, 80% and 100%, respectively. The antibody response detected in the definitive TF cases was predominantly IgG in nature and no cross-reactivity was seen with OMP preparations extracted from E. coli. Variable reactivity was noted with OMP preparations obtained from other Salmonella spp. Three major OMPs are presented in the antigen preparation and strong binding of positive sera was detected to all three bands.

Genome size variation among recent human isolates of Salmonella typhi

Thong KL, Puthucheary SD, Pang T

Res. Microbiol., 1997 Mar-Apr;148(3):229-35.

PMID: 9765803

We performed genome size estimation of 17 recent human isolates of Salmonella typhi from geographically diverse regions using pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with restriction endonucleases XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3') and SpeI (5'-ACTAGT-3'), and summation of the sizes of restriction fragments obtained. All 17 isolates had circular chromosomes, and genome sizes differed by as much as 959 kb, ranging from 3,964 to 4,923 kb (mean genome size = 4,528 kb). The data obtained confirm the usefulness of PFGE in studies of bacterial genome size and are in agreement with recent results indicating considerable genetic diversity and genomic plasticity of S. typhi. The variation in genome sizes noted may be relevant to the observed biological properties of this important human pathogen, including its virulence.

Fulltext Acute respiratory failure in melioidosis

Puthucheary SD, Vadivelu J, Wong KT, Ong GS

Singapore Med J, 2001 Mar;42(3):117-21.

PMID: 11405563

In melioidosis caused by Burkholderia pseudomallei, although every organ in the body may be involved, the highest mortality of 73% occurs when the respiratory system is affected. These patients invariably die of acute respiratory failure. Most of them also have underlying predisposing factors like diabetes mellitus.

Salmonella meningitis and its complications in infants

Lee WS, Puthucheary SD, Omar A

J Paediatr Child Health, 1999 Aug;35(4):379-82.

PMID: 10457297

OBJECTIVE: To review the presenting features, complications and outcome of infants with Salmonella meningitis.

METHODOLOGY: Retrospective review of all cultures of cerebrospinal fluid positive for bacteria in children below 12 years of age, processed at the Department of Medical Microbiology, University of Malaya Medical Centre, Kuala Lumpur from 1973 to 1997. Records of all cases positive for Salmonella species were retrieved and studied.

RESULTS: Thirteen infants aged 3 days to 9 months with Salmonella meningitis were included. The median age of onset of symptoms was 4 months. The clinical and laboratory features were similar to other causes of bacterial meningitis. Salmonella enteritidis was the commonest serotype isolated. Nine infants developed fits, six of which were difficult to control. Other complications noted were hydrocephalus (five), subdural effusions (four), empyema (three), ventriculitis (two), intracranial haemorrhage and cerebral abscess (one each). The use of ampicillin and/or chloramphenicol and inadequate duration of therapy resulted in recrudescence or relapse in five infants. The overall mortality was 18%. The presence of empyema, intracerebral abscess, ventriculitis, hydrocephalus, and intracranial haemorrhage were associated with adverse neurodevelopmental sequelae or death. More than half of those who survived had normal long-term outcome.

CONCLUSION: Infants who developed neurological complications as a result of Salmonella meningitis had significant mortality and adverse long-term neurodevelopment outcome.

Exotoxin profiles of clinical isolates of Aeromonas hydrophila

Vadivelu J, Puthucheary SD, Navaratnam P

J Med Microbiol, 1991 Jun;34(6):363-7.

PMID: 2056519

Eighty-six clinical isolates of Aeromonas hydrophila were studied for their ability to produce four exotoxins: a haemolysin active against rabbit erythrocytes, cytotoxin and enterotoxin detectable with Vero cell cultures, and the cholera toxin-like factor detected by an enzyme-linked immunosorbent assay. At least one exotoxin was produced by 80% of enteric and 96% of non-enteric isolates. The exotoxin profiles of non-enteric isolates were more restricted than those of enteric isolates, with haemolysin and cytotoxin producers preponderant. Although haemolysin and cytotoxin were produced by isolates from all sources, the enterotoxin and cholera toxin-like factor were more common amongst enteric isolates. The production of haemolysin and cytotoxin were closely related but the association between the enterotoxin and the cholera toxin-like factor was not significant.

Fulltext Comparison of two assays for the detection of haemolysins of Aeromonas species

Vadivelu J, Puthucheary SD, Navaratnam P

Singapore Med J, 1992 Aug;33(4):375-7.

PMID: 1411668

The haemolysins produced by Aeromonas species were detected and compared by two assay methods--a modified blood agar plate assay and the rabbit erythrocyte haemolysin method. Both assays showed a high level of agreement (86%). The titres of the rabbit erythrocyte haemolysin assay correlated with the haemolytic zone diameter of the ox blood agar assay. In addition the agar haemolysin assay had simple media requirements, was easy to perform and results were well defined.

Fulltext Comparison of serum F2 isoprostane levels in diabetic patients and diabetic patients infected with Burkholderia pseudomallei

Puthucheary SD, Nathan SA

Singapore Med J, 2008 Feb;49(2):117-20.

PMID: 18301838

Oxidative stress can occur in sepsis and infection, when overproduction of free radicals is not countered by the host antioxidant system, leading to impairment of host cellular functions. Various disease states are accompanied by the accumulation of 15-F2t-IsoP in biological fluids. These isoprostanes are considered as markers of oxidative stress, and inflammation and inflammatory mediators.

Fulltext Comparison by electron microscopy of intracellular events and survival of Burkholderia pseudomallei in monocytes from normal subjects and patients with melioidosis

Puthucheary SD, Nathan SA

Singapore Med J, 2006 Aug;47(8):697-703.

PMID: 16865211

Burkholderia pseudomallei (B. pseudomallei) has been shown to persist intracellularly in patients with melioidosis, until reactivated by decreasing immunocompetence. We have previously demonstrated by transmission electron microscopy, the internalisation of B. pseudomallei by human macrophages and the occurrence of phagosome-lysosome fusion.

Fulltext Multiple-antigen ELISA for melioidosis--a novel approach to the improved serodiagnosis of melioidosis

Hara Y, Chin CY, Mohamed R, Puthucheary SD, Nathan S

BMC Infect Dis, 2013;13:165.

PMID: 23556548 DOI: 10.1186/1471-2334-13-165

Burkholderia pseudomallei, the causative agent of melioidosis, is endemic to Southeast Asia and northern Australia. Clinical manifestations of disease are diverse, ranging from chronic infection to acute septicaemia. The current gold standard of diagnosis involves bacterial culture and identification which is time consuming and often too late for early medical intervention. Hence, rapid diagnosis of melioidosis is crucial for the successful management of melioidosis.

Fulltext Global transcriptional analysis of Burkholderia pseudomallei high and low biofilm producers reveals insights into biofilm production and virulence

Chin CY, Hara Y, Ghazali AK, Yap SJ, Kong C, Wong YC, et al.

BMC Genomics, 2015;16:471.

PMID: 26092034 DOI: 10.1186/s12864-015-1692-0

Chronic bacterial infections occur as a result of the infecting pathogen's ability to live within a biofilm, hence escaping the detrimental effects of antibiotics and the immune defense system. Burkholderia pseudomallei, a gram-negative facultative pathogen, is distinctive in its ability to survive within phagocytic and non-phagocytic cells, to persist in vivo for many years and subsequently leading to relapse as well as the development of chronic disease. The capacity to persist has been attributed to the pathogen's ability to form biofilm. However, the underlying biology of B. pseudomallei biofilm development remains unresolved.

Fulltext Bacteraemic enteritis due to Campylobacter jejuni

Puthucheary SD, Lin HP

Med J Malaysia, 1982 Dec;37(4):378-80.

PMID: 7167093

Campylobacter Jejuni is being increasingly recognised as a cause of bacteraemia enteritis and two infants with this condition are described. Awareness of the organism. as a possible cause of septicaemia is important because it has special growth requirements and delay in the diagnosis can be detrimental in a disease which usually only responds to erythromycin, gentamicin and chloramphenicol.

Septicaemic melioidosis: a review of 50 cases from Malaysia

Puthucheary SD, Parasakthi N, Lee MK

Trans R Soc Trop Med Hyg, 1992 11 1;86(6):683-5.

PMID: 1287945

Fifty cases of septicaemic melioidosis were reviewed. There was a preponderance of disease among males (male:female ratio 3.2:1) and those aged over 30 years. The presenting clinical features were very varied and not pathognomonic, ranging from fever, cough and septicaemia to fulminant septicaemia and shock. Pulmonary involvement was recorded in 58% of the patients. Skin and soft tissue sepsis was seen in 24%, but many had signs and symptoms of multiorgan involvement. Associated underlying illness was identified in 76% of patients, diabetes mellitus being the commonest (38%), while 34% had more than one predisposing factor. The mortality of 65% in our series is a reflection of the less than satisfactory status of the diagnosis and therapy of septicaemic melioidosis. Only 24% of our patients received appropriate empirical antibiotic therapy. A high index of suspicion of melioidosis in endemic areas and the use of appropriate empirical antimicrobial therapy would be a step towards reducing the high mortality rate.

Fulltext Methicillin resistant Staphylococcus aureus--first case of bacteremia in the University Hospital, Kuala Lumpur

Puthucheary SD, Lim CT, Parasakthi N, Tan A, Lam KL

Singapore Med J, 1987 Oct;28(5):456-8.

PMID: 3433116

Fulltext In vitro activity of aminoglycosides, ureidopenicillins and cephalosporins against P. aeruginosa isolated in Kuala Lumpur

Ngeow YS, Puthucheary SD, Lai PS

Med J Malaysia, 1985 Sep;40(3):196-201.

PMID: 3939567

170 clinical isolates of Pseudomonas aeruginosa were tested for in vitro susceptibility to gentamicin, amikacin, tobramycin, netilmicin, kanamycin, streptomycin, cefotaxime, ceftriaxone, cefoperazone, ceftazidime, moxalactam, azlocillin, piperacillin and ticarcillin. Against 93 gentamicin-sensitive strains, the most active antibiotics were in descending order, ceftazidime, tobramycin, gentamicin, amikacin, and the ureidopenicillins. Against 77 gentamicin-resistant strains, only ceftazidime, amikacin and moxalactam had mode minimum inhibitory concentrations within achievable peak serum levels after standard therapeutic dosage. There was no correlation between cephalosporin resistance and aminoglycoside resistance except for cefoperazone, which, together with the ureidopenicillins and ticarcillin, showed marked decrease in activity against gentamicin-resistant strains.

Fulltext Exotoxin profiles of Campylobacters isolated in Malaysia

Tee TS, Devi S, Puthucheary SD, Kautner IM

Southeast Asian J. Trop. Med. Public Health, 1994 Sep;25(3):443-8.

PMID: 7777904

Approximately 57% of clinical and 33% of poultry isolates examined produced a cytotoxin. Cytotoxic activity was detected in 25 (50%) isolates of Campylobacter of which 12 were isolated from bloody diarrhea and 9 from watery stools. The cytotoxin titers were low, ranging from 2 to 16. The crude filtrates from 50 Campylobacter isolates showed no cytotoxic effect in Vero cells, no fluid accumulation in suckling mice and no hemolytic activity.

Detection of haemolytic activity of campylobacters by agarose haemolysis and microplate assay

Tay ST, Devi S, Puthucheary SD, Kautner IM

J Med Microbiol, 1995 Mar;42(3):175-80.

PMID: 7884798

There are several methods for the detection of haemolytic activity in campylobacters. However, we found the haemolytic effect of campylobacters on conventional blood agar plates to be variable, inconsistent and difficult to interpret. Blood agarose plates showed campylobacter haemolytic activity more clearly. The incubation conditions (temperature and gaseous) appear to be important for the expression of this activity. Ninety four percent of the Campylobacter isolates examined were found to be haemolytic by the microplate assay with minimal haemolytic units that ranged from 1 to 64. Haemolytic activity was detected only from live bacterial cultures and not from any of the 50 bacterial culture supernates, which suggests that campylobacters may possess a cell-associated haemolysin. The identification of such haemolytic activity in a large number of campylobacters (94%) suggests its potential role as a virulence factor in campylobacter gastroenteritis.

Fulltext Characterisation of Campylobacters from Malaysia

Tay ST, Puthucheary SD, Devi S, Kautner I

Singapore Med J, 1995 Jun;36(3):282-4.

PMID: 8553093

Eight-five clinical and 15 poultry isolates of Campylobacter species were characterised by biotyping, serotyping and by using a radiolabelled DNA probe. A total of 80% of the isolates from both sources were identified as C. jejuni. Also amongst the clinical strains were 5 c. jejuni subsp. doylei, 7 C. coli, 3 C. lari and 8 were untypable. The similarity in the distribution of C. jejuni in the clinical and poultry isolates adds credibility to published reports of chickens being the most common source of Campylobacter infections. Although the gold standard for identification of C. jejuni is the DNA probe, serotyping is more discriminating while biotyping is the most feasible method in most laboratories.

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.

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