Displaying all 16 publications

Abstract:
Sort:
  1. Koay AS, Tay ST, Cheong YM, Yasin RM
    PMID: 8629074
    An IgM dot-immunobinding assay (IgM-DIA) was developed for the diagnosis of scrub typhus infection. The whole cell antigens of Karp, Kato and Gilliam strains of Rickettsia tsutsugamushi were immobilized onto nitrocellulose paper and reacted with patients sera. The presence of IgM R. tsutsugamushi specific antibody in the patient sera could be detected by the observation of a visible brown dot on the nitrocellulose paper. The IgM-DIA has a sensitivity of 90.4% and specificity of 81.4% as compared to the indirect immunoperoxidase test. The IgM-DIA is rapid, simple, cost-effective, does not require microscope or incubator. It is recommended as a rapid screening test for the diagnosis of scrub typhus infection in the field or rural area within the hyperendemic region.
  2. Thong KL, Hoe SL, Puthucheary SD, Yasin R
    BMC Infect Dis, 2005 Feb 14;5:8.
    PMID: 15707504
    In Malaysia, Shigella spp. was reported to be the third commonest bacterial agent responsible for childhood diarrhoea. Currently, isolation of the bacterium and confirmation of the disease by microbiological and biochemical methods remain as the "gold standard". This study aimed to detect the prevalence of four Shigella virulence genes present concurrently, in randomly selected Malaysian strains via a rapid multiplex PCR (mPCR) assay.
  3. Yasin RM, Jegathesan MM, Tiew CC
    PMID: 10050191
    From January 1983 to December 1992 a total of 20,874 salmonella were serotyped in the Bacteriology Division IMR, which showed an increase of 100% compared to the previous ten-years. There were 97 serotypes which belonged to 22 Kauffmann-white groups. Twenty two serotypes hitherto were seen in this study period. S. typhi was the commonest serotype isolated. Overall there was a rise in the isolation of non-typhoidal salmonella particularly S. enteritidis which increased by 760% and S. blockley which increased by 720%. However there is a drop in the isolation of S typhimurium by 223% and S. paratyphi B by 319%.
    Publication year=1996-1997
  4. Hoe CH, Yasin RM, Koh YT, Thong KL
    J Appl Microbiol, 2005;99(1):133-40.
    PMID: 15960673
    Antimicrobial resistance of Shigella sonnei from Malaysia was determined and subtyping was carried by pulsed-field gel electrophoresis (PFGE) to assess the extent of genetic diversity of these strains.
  5. Bakeri SA, Yasin RM, Koh YT, Puthucheary SD, Thong KL
    J Appl Microbiol, 2003;95(4):773-80.
    PMID: 12969291
    The study was undertaken to determine clonal relationship and genetic diversity of the human strains of Salmonella enterica serovar Enteritidis isolated from 1995 to 2002 from different parts of Malaysia.
  6. Goh YL, Yasin R, Puthucheary SD, Koh YT, Lim VK, Taib Z, et al.
    J Appl Microbiol, 2003;95(5):1134-42.
    PMID: 14633043
    DNA fingerprinting of Salmonella enterica serotype Paratyphi B isolated in Malaysia during 1982-83, 1992 and 1996-2002 was carried out by pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility tests and D-tartrate utilization tests to assess the extent of genetic diversity of these isolates in Malaysia.
  7. Lim KT, Yeo CC, Md Yasin R, Balan G, Thong KL
    J Med Microbiol, 2009 Nov;58(Pt 11):1463-1469.
    PMID: 19589908 DOI: 10.1099/jmm.0.011114-0
    The emergence of multidrug-resistant (MDR) and extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae poses a serious antibiotic management problem as resistance genes are easily transferred from one organism to another. Fifty-one strains of K. pneumoniae isolated from sporadic cases in various hospitals throughout Malaysia were analysed by antimicrobial susceptibility testing, PCR detection of ESBL-encoding genes and DNA fingerprinting. Although 27 of the 51 K. pneumoniae strains were MDR (i.e. resistant to three or more classes of antibiotics), the majority of the strains (98 %) were sensitive to imipenem. PCR detection using ESBL gene-specific primers showed that 46 of the K. pneumoniae strains harboured bla(SHV), 19 harboured bla(CTX-M), 5 harboured bla(OXA-1) and 4 harboured bla(TEM-1). Class 1 integron-encoded intI1 integrase was detected in 21 of the 51 K. pneumoniae strains and amplification of the integron 5'CS region showed the presence of several known antibiotic resistance gene cassettes of various sizes. Results of conjugation and transformation experiments indicated that some of the ESBL-encoding genes (i.e. bla(SHV), bla(CTX-M) and bla(TEM-1)) were transmissible and were likely plasmid-encoded. DNA fingerprinting using PFGE and PCR-based methods indicated that the 51 K. pneumoniae strains were genetically diverse and heterogeneous.
  8. Lim KT, Yasin R, Yeo CC, Puthucheary S, Thong KL
    J Biomed Biotechnol, 2009;2009:165637.
    PMID: 19672454 DOI: 10.1155/2009/165637
    The emergence of Escherichia coli that produce extended spectrum beta-lactamases (ESBLs) and are multidrug resistant (MDR) poses antibiotic management problems. Forty-seven E. coli isolates from various public hospitals in Malaysia were studied. All isolates were sensitive to imipenem whereas 36 were MDR (resistant to 2 or more classes of antibiotics). PCR detection using gene-specific primers showed that 87.5% of the ESBL-producing E. coli harbored the blaTEM gene. Other ESBL-encoding genes detected were blaOXA, blaSHV, and blaCTX-M. Integron-encoded integrases were detected in 55.3% of isolates, with class 1 integron-encoded intI1 integrase being the majority. Amplification and sequence analysis of the 5'CS region of the integrons showed known antibiotic resistance-encoding gene cassettes of various sizes that were inserted within the respective integrons. Conjugation and transformation experiments indicated that some of the antibiotic resistance genes were likely plasmid-encoded and transmissible. All 47 isolates were subtyped by PFGE and PCR-based fingerprinting using random amplified polymorphic DNA (RAPD), repetitive extragenic palindromes (REPs), and enterobacterial repetitive intergenic consensus (ERIC). These isolates were very diverse and heterogeneous. PFGE, ERIC, and REP-PCR methods were more discriminative than RAPD in subtyping the E. coli isolates.
  9. Thong KL, Goh YL, Radu S, Noorzaleha S, Yasin R, Koh YT, et al.
    J Clin Microbiol, 2002 Jul;40(7):2498-503.
    PMID: 12089269
    The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.
  10. Jeevajothi Nathan J, Mohd Desa MN, Thong KL, Clarke SC, Masri SN, Md Yasin R, et al.
    Infect Genet Evol, 2014 Jan;21:391-4.
    PMID: 24342879 DOI: 10.1016/j.meegid.2013.11.026
    Streptococcus pneumoniae is an epidemiologically important bacterial pathogen. Recently, we reported the antibiotic susceptibility patterns of a limited collection of pneumococcal isolates in Malaysia with a high prevalence of erythromycin resistant strains. In the present study, 55 of the pneumococcal isolates of serotype 19F were further analysed by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The generated genotypic patterns were then correlated with the antibiograms previously reported. Forty-seven different PFGE profiles (PTs) were obtained, showing that the isolates were genetically diverse. MLST identified 16 sequence types (STs) with ST-236 being predominant (58.2%), followed by ST-81 (10.3%). Among the ST-236 isolates, 22 were erythromycin resistant S. pneumoniae (ERSP) and 15 were trimethoprim/sulfamethoxazole (TMP/SMX) resistant, while among ST-81, four isolates were ERSP and two were TMP/SMX resistant. The high prevalence of erythromycin resistant serotype 19F isolates of ST-236 in this study has also been reported in other North and South East Asian countries.
  11. Yasin RM, Suan KA, Meng CY
    Sex Transm Dis, 1997 May;24(5):257-60.
    PMID: 9153733
    BACKGROUND AND OBJECTIVES: The antimicrobial susceptibility pattern of Neisseria gonorrhoeae varies from one country to another and may also change with time. To monitor these variations and changes, it is desirable to have a method that is simple and reproducible. This study was undertaken to determine the in vitro susceptibility of N. gonorrhoeae to azithromycin and to assess the reliability of results obtained using E-test methodology for determination of the minimum inhibitory concentration (MIC) of azithromycin.

    STUDY DESIGN: The MICs for 135 clinical isolates of N. gonorrhoeae were determined by a modified Kirby-Bauer method recommended by the National Committee for Clinical Laboratory Standards against penicillin, cefuroxime, ceftriaxone, norfloxacin, tetracycline, kanamycin, spectinomycin, and azithromycin. The MIC of azithromycin was determined by both the E-test and agar dilution method. All tests were done simultaneously.

    RESULTS: The MIC of azithromycin to all 135 isolates ranged from 0.078 to 0.25 microgram/ml with the agar dilution method and from 0.016 to 0.50 microgram/ml with the E-test. The MIC50 and MIC90 of azithromycin were 0.064 microgram/ml and 0.125 microgram/ml, respectively, by the agar dilution method, whereas they are slightly higher by the E-test method. Seventy-six of the isolates were beta-lactamase producers and 69 were high-level tetracycline-resistant N. gonorrhoeae. There was no difference in the MIC50 and MIC90 of azithromycin in these groups of isolates. The percentage agreement within the acceptable +/-1 log2 dilution difference between MICs obtained by E-test and those obtained by the agar dilution method was 97.8%.

    CONCLUSIONS: Azithromycin has a very good in vitro antigonococcal activity, and the E-test is a reliable method to determine the MIC of azithromycin against N. gonorrhoeae.

  12. Jeevajothi Nathan J, Mohd Taib N, Mohd Desa MN, Masri SN, Md Yasin R, Jamal F, et al.
    Med J Malaysia, 2013 Apr;68(2):119-24.
    PMID: 23629556 MyJurnal
    The in vitro activities of 6 antimicrobial agents against clinical isolates of Streptococcus pneumoniae (pneumococci) were investigated and the erythromycin minimum inhibitory concentrations (MICs) were correlated with the two major macrolide resistance determinants, mef(A) and erm(B). MICs of commonly used antibiotics as well as the presence of macrolide resistance determinant genes in all isolates were tested. Seventy one pneumococcal isolates collected at Institute for Medical Research (IMR) were included in this study. Phenotypic characterization, MIC determination using E-test strips and polymerase chain reactions for antibiotic resistance determination were included. Among the isolates, 25 (35.2%) isolates were erythromycin susceptible, 3 (4.2%) were intermediate and 42 (60.6%) were resistant. Fifty three isolates (74.7%) were found with mef(A) alone, 15 (21.1%) isolates with erm(B) + mef(A) combination and 3 (4.2%) isolates with none of the two genes. The in vitro activity of penicillin, amoxicillin clavulanic acid, ceftriaxone and cefotaxime is superior to trimethoprim-sulfamethoxazole and erythromycin. In conclusion, pneumococcal isolates in this study were highly susceptible to penicillin with very low MICs. However, a very high prevalence rate of erythromycin resistance was observed. Erythromycin resistant S. pneumoniae isolates with both mef(A) and erm(B) showed very high MICs ≥256 μg/mL.
  13. Radu S, Ho YK, Lihan S, Yuherman, Rusul G, Yasin RM, et al.
    Epidemiol Infect, 1999 Oct;123(2):225-32.
    PMID: 10579441
    A total of 31 strains of Vibrio cholerae O1 (10 from outbreak cases and 7 from surface water) and non-O1 (4 from clinical and 10 from surface water sources) isolated between 1993 and 1997 were examined with respect to presence of cholera enterotoxin (CT) gene by PCR-based assays, resistance to antibiotics, plasmid profiles and random amplified polymorphic DNA (RAPD) analysis. All were resistant to 9 or more of the 17 antibiotics tested. Identical antibiotic resistance patterns of the isolates may indicate that they share a common mode of developing antibiotic resistance. Furthermore, the multiple antibiotic resistance indexing showed that all strains tested originated from high risk contamination. Plasmid profile analysis by agarose gel electrophoresis showed the presence of small plasmids in 12 (7 non-O1 and 5 O1 serotypes) with sizes ranging 1.3-4.6 MDa. The CT gene was detected in all clinical isolates but was present in only 14 (6 O1 serotype and 8 non-O1 serotype) isolates from environmental waters. The genetic relatedness of the clinical and environmental Vibrio cholerae O1 and non-O1 strains was investigated by RAPD fingerprinting with four primers. The four primers generated polymorphisms in all 31 strains of Vibrio cholerae tested, producing bands ranging from < 250 to 4500 bp. The RAPD profiles revealed a wide variability and no correlation with the source of isolation. This study provides evidence that Vibrio cholerae O1 and non-O1 have significant public health implications.
  14. Tee TS, Kamalanathan M, Suan KA, Chun SS, Ming HT, Yasin RM, et al.
    Am J Trop Med Hyg, 1999 Jul;61(1):73-7.
    PMID: 10432060
    The seroprevalence of Orientia tsutsugamushi, Rickettsia typhi, and TT118 spotted fever group (SFG) rickettsiae in 300 rubber estate workers in Slim River, Malaysia was determined in December 1996 and March 1997. In December, which was the wet season, 23.3%, 3.0%, and 57.3% of the population had antibodies detected against the three rickettsiae, respectively. The highest seropositive rate of 40% was detected for single infection with SFG rickettsiae, followed by a rate of 15.3% for both O. tsutsugamushi and SFG rickettsiae among the rubber estate workers. Subjects less than 21 years old had a lower seroprevalence of SFG rickettsiae compared with the other age groups. Indians had a higher seroprevalence of O. tsutsugamushi compared with other ethnic groups. Rubber tappers had a higher seroprevalence of SFG rickettsiae compared with other occupational groups. During the dry season in March 1997, there was a significant increase in the seroprevalence of R. typhi. The seroconversion rates for IgM against O. tsutsugamushi, R. typhi, and SFG rickettsiae were 5.7%, 12.3%, and 15.1%, respectively, during the four-month period. Significant variations of antibody titers towards the three rickettsiae was noted among subjects who were bled twice. This suggests a significant and continual exposure of rubber estate workers to the three rickettsiae.
  15. Yasin R, Muntham D, Chirakalwasan N
    Sleep Breath, 2016 Dec;20(4):1137-1144.
    PMID: 27535070 DOI: 10.1007/s11325-016-1380-6
    PURPOSE: Sleepiness and tiredness are common complaints among young doctors. Sleep deprivation is believed to be the main culprit. However, we believe that there may be other sleep disorders which may contribute to these symptoms such as occult obstructive sleep apnea (OSA).

    METHODS: A prospective cross-sectional study was performed among young doctors less than 40 years old, working at King Chulalongkorn Memorial Hospital, Bangkok, Thailand, and Hospital Kuala Lumpur, Kuala Lumpur, Malaysia, using questionnaires and home sleep apnea testing (Apnealink™Plus). The primary objective of this study was to evaluate the prevalence of OSA (apnea-hypopnea index (AHI) ≥5). The secondary objectives were to evaluate the prevalence of obstructive sleep apnea syndrome (OSAS) defined by AHI ≥5 + excessive daytime sleepiness (EDS), sleep deprivation (the difference of weekend (non-workdays) and weekday (workdays) wake-up time of at least 2 h), EDS (Epworth Sleepiness Scale score ≥10), tiredness, and perception of inadequate sleep as well as to identify their predictors.

    RESULTS: Total of 52 subjects completed the study. Mean age and mean body mass index (BMI) were 31.3 ± 4 and 23.3 ± 3.6, respectively. The prevalence of OSA and OSAS were 40.4 and 5.8 %, respectively. One third of OSA subjects were at least moderate OSA. Prevalence of sleep deprivation, EDS, tiredness, and perception of inadequate sleep were 44.2, 15.4, 65.4, and 61.5 %, respectively. History of snoring, being male, and perception of inadequate sleep were significant predictors for OSA with the odds ratio of 34.5 (p = 0.016, 95 % CI = 1.92-619.15), 18.8 (p = 0.001, 95 % CI = 3.10-113.41), and 7.4 (p = 0.037, 95 % CI = 1.13-48.30), respectively. Only observed apnea was a significant predictor for OSAS with odds ratio of 30.7 (p = 0.012, 95 % CI = 2.12-442.6). Number of naps per week was a significant predictor for EDS with the odds ratio of 1.78 (p = 0.007, 95 % CI = 1.17-2.71). OSA and total number of call days per month were significant predictors for tiredness with the odds ratio of 4.8 (p = 0.036, 95 % CI = 1.11-20.72) and 1.3 (p = 0.050, 95 % CI = 1.0004-1.61), respectively. OSA was the only significant predictor for perception of inadequate sleep with the odd ratios of 4.5 (p = 0.022, 95 % CI = 1.24-16.59).

    CONCLUSIONS: Our results demonstrated relatively high prevalence of OSA and OSAS among young doctors. Snoring, being male, and perception of inadequate sleep were significant predictors for OSA. Observed apnea was a significant predictor for OSAS. OSA was a significant predictor for tiredness and perception of inadequate sleep.

  16. Mohd Khalid MK, Yakob Y, Md Yasin R, Wee Teik K, Siew CG, Rahmat J, et al.
    Mol Vis, 2015;21:1185-90.
    PMID: 26539030
    The availability of molecular genetic testing for retinoblastoma (RB) in Malaysia has enabled patients with a heritable predisposition to the disease to be identified, which thus improves the clinical management of these patients and their families. In this paper, we presented our strategy for performing molecular genetic testing of the RB1 gene and the findings from our first 2 years of starting this service.
Related Terms
Filters
Contact Us

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

External Links