MyMedR

Fulltext Antibiotic susceptibility of community-acquired Staphylococcus aureus

Tan HS, Ngeow YF, Jamal F

Med J Malaysia, 1986 Mar;41(1):24-9.

55% of a sample of patients in a rural
community, and 76% of a sample of patients and
staff in the local district hospital were found to
be nasal carriers for Staphylococcus aureus. The
in vitro antibiotic susceptibility patterns of 46
strains of S. aureus isolated in nasal carriers as
well as of 43 strains in community-acquired skin
infections were characterised. High levels of
resistance were expressed to penicillin (73%),
cephalexin (64%) and tetracycline (46%).
Resistance to erythromycin (18%) was moderate.
A few strains showed resistance to methicillin
(5 isolates), vancomycin (4), [usidic acid (3),
cotrimoxazole (1), and none to gentamicin.
Penicillin can no longer be recommended for
treating community-acquired S. aureus infections.

Fulltext Plasmids in penicillinase-producing Neisseria gonorrhoeae in Peninsular Malaysia

Koh CL, Kalaimathee KK, Ngeow YF

Med J Malaysia, 1984 Dec;39(4):269-71.

PMID: 6443581

The plasmid profiles of 66 strains of penicillinase-producing Neisseria gonorrhoeae (PPNG), isolated in Peninsular Malaysia, were determined by agarose gel electrophoresis. All the isolates harboured two common plasmid species, a 4.4 x 10 6 Far-East type R plasmid associated with beta-lactamase production and a 2.6 x 106 plasmid of unknown function. In addition to these two plasmids, 51 (77%) PPNG isolates also carried a 24.5 x 106 conjugative plasmid.

Heat inactivation of serum potentiates anti-cardiolipin antibody binding in ELISA

Cheng HM, Ngeow YF, Sam CK

J Immunol Methods, 1989 Nov 30;124(2):235-8.

PMID: 2600427

Heat treatment of sera at 56 degrees C for 30 min results in positive ELISA reactions for anti-cardiolipin antibody (aCL) in sera that had undetectable or low levels of aCL before heat inactivation. The positive, potentiated reactivity of the heated sera in the aCL ELISA could be inhibited with the cardiolipin antigen and was abolished by prior IgG depletion using staphylococcal protein A. The heat-potentiating effect of aCL binding in ELISA was evident in both normal human sera and clinical sera including sera from patients with systemic lupus erythematosus and syphilis.

Gonococcal vulvovaginitis among female children in Malaysia

Ismail R, Toh CK, Ngeow YF

Sex Transm Dis, 1985 7 1;12(3):114-6.

PMID: 4035521

In this retrospective review of 16 children with vulvovaginitis due to Neisseria gonorrhoeae, the authors attempt to estimate the incidence of this infection and to ascertain the routes of transmission. From January 1977 to December 1982, 422 cases of gonococcal vulvovaginitis in women of all age groups were encountered at the University Hospital, Kuala Lumpur, Malaysia. Of these, 406 cases (96.2%) occurred in adults, and 16 cases (3.8%) occurred in children younger than 12 years of age. Penicillinase-producing N. gonorrhoeae (PPNG) strains were isolated from five (31%) of the 16 girls; all five cases were subsequently treated with cefuroxime and probenecid. The rest responded to intramuscular procaine penicillin. Although all patients appeared to be cured, only ten of 11 (two with PPNG) had test-of-cure cultures performed after treatment. Although interviewing the parents revealed no history of sexual contact in these children, nine of the girls were linked to culture-positive adult(s).

Plasmid profiles of Neisseria gonorrhoeae in Peninsular Malaysia

Kalaimathee KK, Koh CL, Ngeow YF

Microbiol. Immunol., 1985;29(10):921-6.

PMID: 3935906

The plasmid profiles of 160 strains of Neisseria gonorrhoeae isolated in Peninsular Malaysia, comprising 80 penicillinase-producing (PPNG) and 80 non-penicillinase-producing (non-PPNG) isolates, were determined. The 80 PPNG isolates were divided into two plasmid groups. All of them harbored two common plasmid species, a 4.4 megadalton (Md) R plasmid previously associated with beta-lactamase production in PPNG strains from the Far East and a 2.6 Md multicopy plasmid of unknown function. In addition to these two plasmids, 60 (75%) PPNG isolates also carried a large 24.5 Md conjugative plasmid. In contrast, the 80 non-PPNG strains were divided into three plasmid groups. All of them possessed the 2.6 Md cryptic plasmid, and 35 (44%) isolates also harbored the 24.5 Md transfer plasmid. Besides these two plasmids, one non-PPNG isolate carried an additional 7.8 Md cryptic plasmid.

Screening for gonorrhea in a prenatal clinic in Southeast Asia

Goh TH, Ngeow YF, Teoh SK

Sex Transm Dis, 1981 4 1;8(2):67-9.

PMID: 7256495

Screening by culture of endocervical specimens revealed four cases of gonorrhea among 744 pregnant women attending the prenatal clinic at the University Hospital in Kuala Lumpur, Malaysia. The observed prevalence of gonorrhea (0.54%) in pregnant women is similar to that in Great Britain (0.2-0.7%), but lower than the prevalences reported for North America (2.5-7.5%) and Thailand (11.9%). The results indicate that routine screening of pregnant women attending prenatal clinics in Malaysia would aid in the control of gonorrhea in that country.

Treatment of gonorrhea with sulbactam/ampicillin

Ngeow YF, Ramachandran S, Cheong YM

Sex Transm Dis, 1991 7 1;18(3):192-4.

PMID: 1948519

Between January and August, 1989, 36 men and 28 women with uncomplicated lower genital tract infections by Neisseria gonorrhoeae were given single intramuscular injections of sulbactam (500 mg)/ampicillin (1000 mg) together with 1 g oral probenecid. Cure rates that were obtained were 100% for women, 97.2% for men, 100% for patients with penicillinase-producing Neisseria gonorrhoeae (PPNG), and 98.4% for patients with non-PPNG. No serious side effects were encountered, and patient acceptance of the drug was good. A high proportion of patients had concurrent chlamydial infection. Sulbactam/ampicillin was found to be effective against gonococcal urethritis and cervicitis by both PPNG and non-PPNG but have little effect on concomitant chlamydial infections, especially in women.

Ethnic distribution of Chlamydophila pneumoniae antibodies in a Malaysian population and possible correlation with coronary heart disease

Naidu BR, Ngeow YF, Pang T

Eur J Epidemiol, 2003;18(2):135-7.

PMID: 12733835

Chlamydophila pneumoniae, an important respiratory pathogen causing lower respiratory tract infections, has also been implicated in coronary heart disease (CHD). This study reports a cross-sectional, demographic, serological analysis of the prevalence of Chlamydophila pneumoniae antibodies in a multiracial Malaysian population. Generally, Malaysian Indians had the highest degree of seropositivity (58%) followed by the Chinese (54%) and the Malays (32%), results which were statistically significant (CI: 95%; p < 0.01). Interestingly, this trend was also reflected in the study group consisting of patients with acute myocardial infarctions (AMI) and chronic CHD. Again, the Indians were more frequently seropositive (65%), with more than 50% having IgG titres > or = 128. Comparatively, the Chinese and Malays showed 51 and 17% seropositivity respectively. These results were also statistically significant (CI: 95%; p < 0.01). Malaysian Indians are more commonly afflicted with CHD. A variety of factors have been suggested to explain this prevalence including diet, social habits, genetics and the possible role of infectious agents. This study notes an interesting association between this pattern of racial prevalence and the possible role of C. pneumoniae infections as a contributory/predisposing factor in the development of cardiovascular disease.

Emergence of Klebsiella pneumoniae producing dual carbapenemases (NDM-1 and OXA-232) and 16S rRNA methylase (armA) isolated from a Malaysian patient returning from India

Al-Marzooq F, Ngeow YF, Tay ST

Int J Antimicrob Agents, 2015 Apr;45(4):445-6.

PMID: 25631676 DOI: 10.1016/j.ijantimicag.2014.12.013

Community-acquired vancomycin-resistant Enterococcus faecium: a case report from Malaysia

Raja NS, Karunakaran R, Ngeow YF, Awang R

J Med Microbiol, 2005 Sep;54(Pt 9):901-903.

PMID: 16091445 DOI: 10.1099/jmm.0.46169-0

Vancomycin-resistant enterococci (VRE) are formidable organisms renowned for their ability to cause infections with limited treatment options and their potential for transferring resistance genes to other Gram-positive bacteria. Usually associated with nosocomial infections, VRE are rarely reported as a cause of community-acquired infection. Presented here is a case of community-acquired infection due to vancomycin-resistant Enterococcus faecium. The patient had been applying herbal leaves topically to his cheek to treat a buccal space abscess, resulting in a burn of the overlying skin. From pus aspirated via the skin a pure culture of E. faecium was grown that was resistant to vancomycin with a MIC of >256 microg ml-1 by the E test and resistant to teicoplanin by disc diffusion, consistent with the VanA phenotype. The organism was suspected of contaminating the leaf and infecting the patient via the burnt skin. This case highlights the need for further studies on the community prevalence of VRE among humans and animals to define unrecognized silent reservoirs for VRE, which may pose a threat to public health.

Prevalence of chlamydial antibody in Malaysians

Ngeow YF, Rachagan SP, Ramachandran S

J Clin Pathol, 1990 May;43(5):400-2.

PMID: 2196283

A single antigen indirect immunofluorescence test was used to screen for chlamydial antibody among Malaysian infants, children, sexually active adults and prostitutes. Of 794 serum samples tested, 361 (45.5%) were positive. Seropositivity increased with age and sexual activity and ranged from 10 to 16% among children under 10 years old to 94.4% among prostitutes. Pregnant women and female adolescents showed a higher antibody prevalence than nonpregnant and older women. Six (13%) infants under 6 months of age were positive for chlamydial IgM.

Fulltext Antibiotic resistance in Mycobacterium Abscessus and Mycobacterium Fortuitum isolates from Malaysian patients

Jayasingam SD, Zin T, Ngeow YF

Int J Mycobacteriol, 2017 11 25;6(4):387-390.

PMID: 29171453 DOI: 10.4103/ijmy.ijmy_152_17

BACKGROUND: Rapidly growing mycobacterial species (RGM) are increasingly being recognized as the cause of various superficial and deep infections in humans. Two of the species most frequently isolated from clinical specimens are Mycobacterium abscessus and Mycobacterium fortuitum. Both species are associated with antibiotic resistances that may complicate therapy. This paper describes the pattern of resistance to five antibiotics commonly prescribed for RGM infections, in M. abscessus and M. fortuitum isolated from Malaysian patients.

METHODS: The bacterial strains studied were examined with Etest strips to determine their minimum inhibitory concentrations (MICs) toward amikacin, ciprofloxacin, clarithromycin, imipenem, and linezolid.

RESULTS: Among 51 M. abscessus isolates examined by the Etest, the overall MICs of ciprofloxacin, imipenem, amikacin, clarithromycin, and linezolid showed resistance rates of 33.3%, 31.4%, 2.0%, 5.9%, and 21.6%, to the five antibiotics, respectively. M. abscessus subspecies abscessus was more resistant than M. abscessus subsp. massilience to ciprofloxacin, imipenem, and linezolid but was more susceptible to clarithromycin and amikacin. M. fortuitum isolates were significantly less resistant than M. abscessus to ciprofloxacin (3.6%) and imipenem (7.1%) but more resistant to clarithromycin (42.9%) and linezolid (39.3%).

CONCLUSION: A suitable combination therapy for Malaysian patients would be amikacin plus clarithromycin and ciprofloxacin, to cover infections by all three M. abscessus subspecies and M. fortuitum.

Fulltext Atypical pneumonia due to Chlamydia pneumoniae: a case report

Cheong YM, Wong WK, Ngeow YF

Singapore Med J, 1993 Aug;34(4):352-3.

PMID: 8266214

A first case of Chlamydia pneumoniae pneumonia in Malaysia is reported. The diagnosis was made by a significant change in C. pneumoniae antibody titre. The infection responded well to a course of erythromycin.

Fulltext The association between VSX1 exon3 gene variants and keratoconus in Malaysian patients

Deva JP, Ngeow YF, Zin T

Indian J Ophthalmol, 2023 Jun;71(6):2443-2447.

PMID: 37322657 DOI: 10.4103/IJO.IJO_2894_22

PURPOSE: This case-control study aims to examine possible associations of VSX1 exon3 gene variants with the development of keratoconus (KC) in Malaysian patients.

METHODS: A case-control study was done on 42 keratoconus cases, 127 family member controls, and 96 normal controls.

RESULTS: Three gene variants, p.A182A, p.P237P, and p.R217H showed significant associations with keratoconus (P < 0.05). While p.A182A and p.P227P were more prevalent than in the family and normal controls (OR 3.14-4.05), the reverse was observed with p.R217H (OR 0.086-1.59). With Haploview analysis, p.A182A and p.P237P were shown to be in linkage disequilibrium (LD) (LOD (logarithm of the odds score) score of 2.0, r2 of 0.957, and 95% confidence interval (CI) of 0.96-1.00).

CONCLUSION: The study results suggest that the p.A182A and p.P237P variants could have contributed to the development of keratoconus in some Malaysians and that these two variants are likely to be co-inherited. In contrast, the p.R217H variant appeared to confer some protection against the development of keratoconus.

Incidence and distribution of vaginal yeasts in Malaysian women

Ngeow YF, Soo-Hoo TS

Mycoses, 1989 Nov;32(11):563-7.

PMID: 2615779

A total of 2,153 high vaginal swabs were processed for the presence of yeasts. The specimens were obtained from pregnant and non-pregnant Malaysian women with and without vaginitis. The yeast species most commonly isolated were Candida albicans, C. glabrata, C. famata and C. parapsilosis. C. albicans was isolated from 27% of pregnant women with vaginitis, 14% of pregnant women with no overt vaginitis, 15% of non-pregnant women with vaginitis, and 3% of non-pregnant women with no vaginitis. The significant difference of the isolation rates from women with and without vaginitis indicates that C. albicans is likely to be a vaginal pathogen.

Fulltext Molecular typing of Mycobacterium abscessus based on tandem-repeat polymorphism

Wong YL, Ong CS, Ngeow YF

J Clin Microbiol, 2012 Sep;50(9):3084-8.

PMID: 22760048 DOI: 10.1128/JCM.00753-12

A variable-number tandem-repeat (VNTR) typing assay for the differentiation of Mycobacterium abscessus strains was developed. This assay showed complete reproducibility, locus stability, and a discriminatory power (Hunter-Gaston discriminatory index [HGDI] of 0.9563) that is superior to that of multilocus sequencing. It is a promising tool for the investigation of Mycobacterium abscessus epidemiology and nosocomial outbreaks.

Fulltext Support from Phylogenomic Networks and Subspecies Signatures for Separation of Mycobacterium massiliense from Mycobacterium bolletii

Tan JL, Ngeow YF, Choo SW

J Clin Microbiol, 2015 Sep;53(9):3042-6.

PMID: 26157149 DOI: 10.1128/JCM.00541-15

Mycobacterium abscessus subspecies classification has important clinical implications. We used phylogenomic network and amino acid analyses to provide evidence for the separation of Mycobacterium bolletii and Mycobacterium massiliense into two distinct subspecies which can potentially be differentiated rapidly by their protein signatures.

The positive impact of Streptococcus mutans on the growth of Candida albicans within mixed-species biofilms and implications to dental health

Wang X, Yap SF, Ngeow YF

Malays J Pathol, 2024 Aug;46(2):295-298.

PMID: 39207006

INTRODUCTION: Candida albicans and Streptococcus mutans co-exist in biofilms in the oral cavity. In this study, the impact of S. mutans on the growth of C. albicans within a mixed-species biofilm was examined.

MATERIALS AND METHODS: Single species C. albicans biofilms and mixed species biofilms containing C. albicans and S. mutans at 1:3 and 1:10 ratios were constructed in 6-well microtiter plates. After 24 hours of incubation, the density of resuspended biofilm cells was determined as CFU/ml and used to compare the growth of C. albicans in single species and mixed species biofilms.

RESULTS: The CFU/ml of C. albicans in mixed-species biofilms was found to be higher than that in single-species biofilms.

CONCLUSION: S. mutans promotes the growth of C. albicans in a co-inhabited biofilm.

Fulltext Mycobacterium abscessus - to treat or not to treat

Pang YK, Ngeow YF, Wong YL, Liam CK

Respirol Case Rep, 2013 Dec;1(2):31-3.

PMID: 25473536 DOI: 10.1002/rcr2.17

A patient with Mycobacterium abscessus lung disease was mistaken to have pulmonary tuberculosis with airway colonization by the non-tuberculous mycobacterium. Appropriate antibiotics were only given when the patient's signs and symptoms worsened while on anti-tuberculosis therapy. Despite treatment with a combination of antibiotics showing in vitro susceptibility, the pathogen persisted in the respiratory secretions for longer than 6 months and the patient suffered a spontaneous pneumothorax 14 months into treatment. This case illustrates the chronic course of M. abscessus lung infection, the tendency for flare-ups, the inadequacy of current treatment regimens, and the necessity for prolonged patient follow-up.

Fulltext A phylogenomic approach to bacterial subspecies classification: proof of concept in Mycobacterium abscessus

Tan JL, Khang TF, Ngeow YF, Choo SW

BMC Genomics, 2013;14:879.

PMID: 24330254 DOI: 10.1186/1471-2164-14-879

Mycobacterium abscessus is a rapidly growing mycobacterium that is often associated with human infections. The taxonomy of this species has undergone several revisions and is still being debated. In this study, we sequenced the genomes of 12 M. abscessus strains and used phylogenomic analysis to perform subspecies classification.

Displaying publications 21 - 40 of 124 in total