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Y M Cheong

Publications and source records attributed to Y M Cheong.

At least 37 records · Page 2Linked to original sources
PubMed1995

Disinfection: gaps between recommended and actual practice.

Basic practices on disinfection was surveyed in 6 hospitals using an observation and interview checklist. Two surveys were done, one pre-(first survey) and one post-intervention (second survey). The disinfection and sterilization policy of the Ministry of Health was not available in 66 (70.2%) and 12 (13%) of the units in the first and second survey respectively. In the second survey, staff in all the units washed disinfectant containers before refilling compared with 41.5% of the units in the first survey. Dilution of disinfectants not recommended was found to be used in the first survey. Storing cleaned and sterile items in disinfectants, using disinfectant as a substitute for sterilization of autoclavable items and not decontaminating spillages were some of the wrong practices observed. Considerable improvements were made in the second survey. Improper usage of disinfectants was also indicated by failure of the in-use test. Rate of failure of disinfectants in-use decreased from 11.6% in the first survey to 5.0% in the second survey. To ensure proper disinfection practices, a comprehensive training program on disinfection is required for nurses and attendants.

Data Collection↗
PubMed1994

Molecular epidemiologic analysis of Vibrio cholerae O1 isolates by pulsed-field gel electrophoresis.

Isolates of Vibrio cholerae O1 El Tor from two well-defined cholera outbreaks in Malaysia were analyzed by using pulsed-field gel electrophoresis (PFGE). Isolates from sporadic cases occurring during the same time period were also studied. Digestion of chromosomal DNA from these isolates of V. cholerae O1 with restriction endonucleases NotI (5'-GCGGCCGC-3') and SfiI (5'-GGCCNNNN-3'), followed by PFGE, produced restriction endonuclease analysis (REA) patterns consisting of 13 to 24 bands (ranging in size from 46 to 398 kbp). Analysis of the REA patterns generated by PFGE after digestion with NotI and SfiI suggested the clonal nature and close genetic identity of the isolates obtained during each of the two outbreaks (Dice coefficient, 0.93 to 1.0). Although they had very similar REA patterns, the two outbreak clones were not identical. Isolates of V. cholerae O1 from sporadic cases, on the other hand, appeared to be much more heterogeneous (five different REA patterns detected in the five isolates tested; Dice coefficient, 0.31 to 0.81) than those obtained during the two outbreaks. We conclude that PFGE of V. cholerae O1 chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for molecular typing of V. cholerae isolates for epidemiological purposes.

Bacterial Typing Techniques↗
PubMed1994

Epidemiologic analysis of sporadic Salmonella typhi isolates and those from outbreaks by pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis (PFGE) was used to compare and analyze 158 isolates of Salmonella typhi from five well-defined outbreaks of typhoid fever in Malaysia and also isolates involved in sporadic cases of typhoid fever occurring during the same period. Digestion of chromosomal DNAs from these S. typhi isolates with the restriction endonucleases XbaI (5'-TCTAGA-3'), SpeI (5'-ACTAGT-3'), and AvrII (5'-CCTAGG-3') and then PFGE produced restriction endonuclease analysis (REA) patterns consisting of 11 to 24 DNA fragments ranging in size from 20 to 630 kbp. Analysis of the REA patterns generated by PFGE after digestion with XbaI and SpeI indicated that the S. typhi isolates obtained from sporadic cases of infection were much more heterogeneous (at least 13 different REA patterns were detected; Dice coefficient, between 0.73 and 1.0) than those obtained during outbreaks of typhoid fever. The clonal nature and the close genetic identities of isolates from outbreaks in Alor Setar, Penang, Kota Kinabalu, Johor Bahru, and Kota Bahru were suggested by the fact that only a limited number of REA patterns, which mostly differed by only a single band, were detected (one to four patterns; Dice coefficient, between 0.82 and 1.0), although a different pattern was associated with each of these outbreaks. Comparison of REA patterns with ribotyping for 18 S. typhi isolates involved in sporadic cases of infection showed a good correlation, in that 72% of the isolates were in the same group. There was no clear correlation of phage types with a specific REA pattern. We conclude that PFGE of s. typhi chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for comparing and differentiating S. typhi isolates for epidemiological purposes.

Base Sequence↗
PubMed1994

Isolation of Moraxella catarrhalis from sputum specimens of Malaysian patients.

Moraxella catarrhalis has gained reputation as a pathogen in the lower respiratory tract especially in patients with underlying chronic lung diseases. It is considered significant when isolated from sputum specimens of adults with respiratory tract infections. A study was carried out to determine the prevalence of Moraxella catarrhalis isolated in sputum specimens and beta-lactamase production of these isolates. Sputum specimens sent to the Bacteriology division, Institute for Medical Research from April 1990 until April 1993 were screened for Moraxella catarrhalis. A total of 1678 sputum specimens were processed and Moraxella catarrhalis was isolated from 15 (0.89%) of the sputum specimens. Six out of 15 (40%) were isolated from patients with chronic lung disease. Eight out of 15 (47%) were beta-lactamase producers. Moraxella catarrhalis isolated in good-quality sputum must not be disregarded and should be looked for especially in patients with chronic obstructive pulmonary disease. Beta-lactamase production should be tested on all isolates so that appropriate treatment can be given. All the isolates in this study were sensitive to cotrimoxazole.

Adolescent↗
PubMed1994

The use of surgical antibiotic prophylaxis in seven Malaysian hospitals.

A survey on the use of antibiotics in surgical prophylaxis was carried out in seven Malaysian hospitals. Details of antibiotic prescriptions were obtained through questionnaires completed by the prescriber. A total of 430 such prescriptions was analysed. A large number of different antibiotic regimens were used for a variety of surgical procedures. The majority of prescriptions (70%) were issued for procedures where such prophylaxis was probably not necessary. Antibiotics were also often prescribed for durations that were longer than necessary. There is an urgent need to educate surgeons and standardize surgical prophylactic regimens in order to reduce cost and combat the emergence of antibiotic resistance.

Anti-Bacterial Agents↗
PubMed1994

Antimicrobial resistance in 6 Malaysian general hospitals.

Knowledge of local antimicrobial resistance patterns of bacteria is a valuable guide to empirical antimicrobial therapy. This paper reports the resistance patterns of more than 36,000 bacteria isolated between August 1991 and July 1992 in six Malaysian hospitals and discusses the implications of the results. A customized menu driven software programme was developed to analyse the results. Generally, resistance to the commonly used antibiotics like ampicillin, cloxacillin, cephalosporins, gentamicin, cotrimoxazole and tetracycline was high. Some differences in resistance rate amongst the six hospitals were also noted. Continuous surveillance of antimicrobial resistance in hospitals is encouraged for the effective control of the emergence of antimicrobial resistance.

Drug Resistance, Microbial↗
PubMed1994

Incidence of Listeria spp. in vegetables in Kuala Lumpur.

From April 1992 to September 1992, 280 samples of 10 different fresh vegetables, bought from four different market outlets in Kuala Lumpur were examined for the presence of Listeria spp. Most of the market produce were locally grown with the exception of carrots. The isolation procedure was based on the Food & Drug Administration method (modified) used for the detection of Listeria spp. Isolation media used were Listeria Selective medium and LiCl- phenylethanol-Moxalactam agars. The identification of isolates was by means of conventional biochemical tests and API Listeria identification system. Five out of the 280 samples showed Listeria contamination, Listeria monocytogenes was isolated in lettuce, sengkuang (Pachyrrhizus erosus) and selom Oenanthe javanica) and Listeria innocua was isolated from sengkuang (Pachyrrhizus erosus) and pegaga (Hydrocotyle asiatica).

Food Handling↗
PubMed1993

Epitope mapping of the Sta58 major outer membrane protein of Rickettsia tsutsugamushi.

Binding studies of 160 overlapping, synthetic octapeptides from the hydrophilic regions of the Sta58 major outer membrane protein of Rickettsia tsutsugamushi with sera from patients with scrub typhus revealed 15 immunodominant peptides which are recognized by all the sera tested. Further analysis of the specificity of peptide binding with five of these peptides indicated that the peptides showed significantly stronger binding to scrub typhus patients' sera than they did to sera from patients with other febrile illnesses common in the region, i.e., malaria, dengue fever, typhoid fever, and leptospirosis. The main antibody class binding to these peptides appears to be immunoglobulin M, and there appears to be little correlation between reactivity with peptides and antibody titers measured by the indirect immunoperoxidase test.

Amino Acid Sequence↗
PubMed1993

Pattern of antibiotic usage in hospitals in Malaysia.

A prospective survey of antibiotic prescribing patterns in six Ministry of Health general hospitals in Malaysia was undertaken. Information on antibiotic prescriptions including the types of antibiotics used and the purposes for prescription was obtained through the use of questionnaires. A total of 1,918 antibiotic prescriptions were available for analysis. About two-thirds of prescriptions were for therapeutic purposes. The most common infections treated were lower respiratory infection (31%), followed by skin and soft tissue infection (17%), and urinary tract infection (8%). Only 20% of the therapeutic prescriptions were based on microbiological test results. Prophylactic prescriptions were issued for a variety of indications, the most common being toilet and suture of wounds. Only 5% of prophylactic prescriptions were of less than 3 days duration. There was great diversity in antibiotics and antibiotic regimens employed. It was evident that there was a lack of compliance with guidelines on antibiotic use issued by the Ministry of Health.

Anti-Bacterial Agents↗
PubMed1993

Preliminary evaluation of the INDX DIP-S-TICKS with positive rickettsial samples in Malaysia.

Forty-four serum samples of various reactivities to rickettsial antigens demonstrated by the indirect immunoperoxidase technique were tested with INDX Dip-S-Ticks (INDX Integrated Diagnostics Inc., USA) Kit for the detection of tick borne diseases. The kit utilised Rickettsia rickettsii the causative agent of Rocky Mountain spotted fever (RMSF) as antigens. The samples positive for endemic typhus were also tested against R. typhi, the agent for endemic typhus by the same method. The aim of this study was to determine the extent of cross-reactivity of R. rickettsii with rickettsial infections in Malaysia. Nine out of 12 tick typhus, 4 out of 10 scrub typhus and 4 out of 12 endemic typhus samples cross reacted with R. rickettsii. Ten out of 12 endemic samples were positive with R. typhi by the same method. From the study, we concluded that the INDX Dip-S-Ticks Kit can be used as a rapid screening test to detect endemic and tick-borne rickettsial infections in Malaysia but a second serological test is strongly recommended on all weakly reactive cases.

Animals↗
PubMed1992

Development and evaluation of dot-immunobinding assay for detection of scrub typhus infection in Leptotrombidium fletcheri (Acari: Trombiculidae).

A dot-immunobinding assay (DIBA) was compared with a direct fluorescent antibody technique (DFAT) for the detection of Rickettsia tsutsugamushi infection in Leptotrombidium fletcheri (Womersley & Heaslip). Laboratory colonies of infected and noninfected chiggers were examined. The relative proportions of positive, negative, and indeterminate results were significantly different between DIBA and DFAT for infected but not for noninfected chiggers. DIBA was more sensitive and had a better negative predictive value and a lower false negative percentage than DFAT. It was concluded that DIBA is a suitable alternative to DFAT for detecting scrub typhus infection in chiggers.

Animals↗
PubMed1992

A microbiological study of vaginal discharge in women attending a Malaysian gynaecological clinic.

Vaginal discharge is a common complaint of women attending gynaecological clinics. The purpose of this study was to compare the occurrence of commonly implicated microorganisms in vaginal discharge amongst women with or without the complaint, attending a gynaecological and family planning clinic. The association of Gardnerella vaginalis with bacterial vaginosis was also studied. It was found that there were no significant differences between the cases and controls in the isolation rate of Gardnerella vaginalis, Torulopsis glabrata, Ureaplasma urealyticum, Mycoplasma ssp and Group B streptococcus (p greater than 0.05). Only the isolation rate of Candida albicans was significantly higher in the cases than controls (p less than 0.01). However, there was a significant association of G. vaginalis with bacterial vaginosis.

Adolescent↗
PubMed1992

Bacteriology turnaround time in seven Malaysian general hospitals.

A turnaround time study was conducted for bacteriological culture tests in seven Malaysian general hospitals. The turnaround times were determined using a specially designed form that was completed by the ward staff. Doctors at these hospitals were also polled to find out whether they were satisfied with the promptness of bacteriological test reporting in their hospitals. The turnaround times obtained from this survey were found to be satisfactory taking into account the constraints of laboratory methods employed. Nevertheless only about a third of doctors expressed satisfaction with the timeliness of the bacteriological test reporting. Doctors and microbiologists should get together and agree on acceptable standards of turnaround times that are practical and reasonable.

Bacteriological Techniques↗
PubMed1991

A microbiological study of genital ulcers in Kuala Lumpur.

The microbial aetiology of genital ulcers was studied in 249 patients (241 men and 8 women) attending a Sexually Transmitted Disease Clinic in Kuala Lumpur, Malaysia. Herpes simplex virus type 2 was isolated in 48 (19.2%) patients, Haemophilus ducreyi from 22 (8.8%), Neisseria gonorrhoeae from seven (2.8%) and Chlamydia trachomatis from four (1.6%). Syphilis was diagnosed in 18 (7.2%) patients on the basis of dark field microscopy. Two (0.8%) patients were found to have both chancroid and syphilis and one (0.5%) had both gonorrhoea and syphilis. No organism was isolated in the remaining 151 (61.5%) patients. Overall, the accuracy of clinical diagnosis was 58% for single infection, 67% for herpes, 63% for syphilis, 47% for chancroid and 0% for lymphogranuloma venereum. Therefore, our study confirms the need for laboratory tests to diagnose accurately the aetiology of genital ulcer disease.

Adolescent↗
PubMed1990

Detection of Helicobacter pylori from endoscopic biopsies and the biochemical characteristics of these isolates.

Helicobacter pylori (formerly Campylobacter pylori) has been recently described as a gastritis-associated bacterium. We examined endoscopic biopsies of 100 patients with dyspepsia and found H. pylori in the gastric antrum of 34 (34%) by either culture, urease tests and/or histology. Thirty-one out of 41 patients (75.6%) confirmed to have chronic active gastritis histologically had H. pylori in their gastric antrum compared to 3 out of 59 patients (5.1%) with dyspepsia but normal histology (p less than 0.01). Histological examination, using gram stain and the Warthin-Starry Silver stain, detected 29 of the 34 positive cases (85.3%); urease test, 26 cases (76.5%) and culture, 22 cases (64.7%). A combination of histological examination and urease test increased the detection rate to 97.1%. Therefore we felt that for the detection of H. pylori in endoscopic biopsies, culture, which is time consuming and expensive, is not necessary in routine diagnosis as it did not improve the diagnostic rate over a combination of histology and urease test. A comparative study on three media (blood agar, chocolate agar and Skirrow's agar) used in the isolation of the organism showed that non-selective blood agar and chocolate agar were superior to Skirrow's agar. The strains isolated appeared to be homogeneous in their morphological and biochemical characteristics.

Biopsy↗