Displaying publications 1 - 20 of 59 in total

Abstract:
Sort:
  1. Weng PL, Ramli R, Hamat RA
    PMID: 31533204 DOI: 10.3390/ijerph16183439
    Enterococci are commonly found in humans, animals and environments. Their highly adaptive mechanisms are related to several virulent determinants and their ability to resist antibiotics. Data on the relationship between the esp gene, biofilm formation and antibiotic susceptibility profiles may differ between countries. This cross-sectional study was conducted to determine the proportion of esp gene and biofilm formation among Enterococcus faecalis and Enterococcus faecium clinical isolates. We also investigated the possible association between the esp gene with antibiotic susceptibility patterns and biofilm formation. The isolates were collected from clinical samples and identified using biochemical tests and 16SRNA. Antibiotic susceptibility patterns and a biofilm assay were conducted according to the established guidelines. Molecular detection by PCR was used to identify the esp gene using established primers. In total, 52 and 28 of E. faecalis and E. faecium were identified, respectively. E. faecium exhibited higher resistance rates compared to E. faecalis as follows: piperacillin/tazobactam (100% versus 1.9%), ampicillin (92.8% versus 1.9%), high-level gentamicin resistance (HLGR) (89.3% versus 25.0%) and penicillin (82.1% versus 7.7%). E. faecium produced more biofilms than E. faecalis (59.3% versus 49.0%). E. faecium acquired the esp gene more frequently than E. faecalis (78.6% versus 46.2%). Interestingly, the associations between ampicillin and tazobactam/piperacillin resistance with the esp gene were statistically significant (X2 = 4.581, p = 0.027; and X2 = 6.276, p = 0.012, respectively). Our results demonstrate that E. faecium exhibits high rates of antimicrobial resistance, esp gene acquisition and biofilm formation. These peculiar traits of E. faecium may have implications for the management of enterococcal infections in hospitals. Thus, concerted efforts by all parties in establishing appropriate treatment and effective control measures are warranted in future.
  2. Shueh CS, Neela V, Hussin S, Hamat RA
    J Microbiol Methods, 2013 Aug;94(2):141-143.
    PMID: 23756145 DOI: 10.1016/j.mimet.2013.06.001
    We developed a time-saving and cost-efficient Pulsed Field Gel Electrophoresis (PFGE) method for the typing of Stenotrophomonas maltophilia by modifying the conventional procedures. Our modifications related to the cell suspension preparation, lysis of bacterial cells in plugs, washing steps, and consumption of restriction enzyme. Although few rapid PFGE protocols on Gram-negative bacteria are available, the use of comparatively large amounts of costly reagents prompted us to look for other alternative. Hence, by considering the speed, simplicity, and relatively low cost, the modified protocol may be of more practical value than other established protocols in investigating S. maltophilia nosocomial outbreaks.
  3. Ahmadi SH, Neela V, Hamat RA, Goh BL, Syafinaz AN
    Trop Biomed, 2013 Dec;30(4):602-7.
    PMID: 24522129 MyJurnal
    Peritonitis still remains a serious complication with high rate of morbidity and mortality in patients on CAPD. Rapid and accurate identification of pathogens causing peritonitis in a CAPD patient is essential for early and optimal treatment. The aim of this study was to use 16S rRNA and ITS gene sequencing to identify common bacterial and fungal pathogens directly from the peritoneal fluid without culturing. Ninety one peritoneal fluids obtained from 91 different patients on CAPD suspected for peritonitis were investigated for etiological agents by 16S rRNA and ITS gene sequencing. Data obtained by molecular method was compared with the results obtained by culture method. Among the 45 patients confirmed for peritonitis based on international society of peritoneal dialysis (ISPD) guidelines, the etiological agents were identified in 37(82.2%) samples by culture method, while molecular method identified the etiological agents in 40(88.9%) samples. Despite the high potential application of the 16S rRNA and ITS gene sequencing in comparison to culture method to detect the vast majority of etiological agents directly from peritoneal fluids; it could not be used as a standalone test as it lacks sensitivity to identify some bacterial species due to high genetic similarity in some cases and inadequate database in Gene Bank. However, it could be used as a supplementary test to the culture method especially in the diagnosis of culture negative peritonitis.
  4. Ghasemzadeh-Moghaddam H, van Wamel W, van Belkum A, Hamat RA, Neela VK
    Eur J Clin Microbiol Infect Dis, 2017 Mar;36(3):451-458.
    PMID: 27815779 DOI: 10.1007/s10096-016-2817-3
    The humoral immune response against 43 staphylococcal antigens was compared among hospitalized patients where none of them had any staphylococcal infection on the day of admission with or without nasal Staphylococcus aureus carriage. Fifty-nine carriers and 59 matched non-carriers were studied. The carriers harbored S. aureus of 35 different spa types, including three t037/ST239 methicillin-resistant S. aureus (MRSA) (5.1%). Among the 118 patients, 31 acquired S. aureus during hospitalization. In colonized and non-colonized patients, unique patterns of S. aureus-specific immune responses were observed. The mean fluorescence indices (MFIs) of antibodies against 36/43 (83.7%) antigens were seen to be elevated among carriers. The MFI among carriers with acquisition was significantly higher for staphylococcal superantigen-like protein 5 (SSL5, p = 0.028) when compared to carriers without acquisition. High antibody levels against staphylococcal enterotoxin A (SEA) among carriers illustrate its role as a superantigen in both infection and colonization. We also report a dynamic immune response in S. aureus-carrying patients against the recently reported formyl peptide receptor-like inhibitory (FLIPr)-like protein. In the current study, the dynamics of antibodies against staphylococcal antigens among carrier patients seem quite similar to non-carrier patients. To better understand the dynamic immunogenicity during S. aureus infection and colonization, artificial colonization studies and investigation of the changes in the levels of antibodies against other staphylococcal antigens are recommended.
  5. Moussa AA, Md Nordin AF, Hamat RA, Jasni AS
    Infect Drug Resist, 2019;12:3269-3274.
    PMID: 31695445 DOI: 10.2147/IDR.S219544
    Background: Enterococcus faecium and Enterococcus faecalis are among the predominant species causing hospital-acquired infections. Currently, enterococcal infections are treated using combination therapy of an aminoglycoside with cell-wall active agents, which led to high level aminoglycoside resistance (HLAR) and vancomycin resistance (VRE) among enterococci. The aim of this study was to determine the prevalence of HLAR and the distribution of the resistance genes among clinical E. faecalis and E. faecium isolates in Malaysia.

    Materials and methods: Seventy-five enterococci isolates recovered from different clinical sources were re-identified by subculturing on selective medium, Gram staining, biochemical profiling (API 20 Strep), and 16s rRNA sequencing. Antimicrobial susceptibility testing (AST) was performed using Kirby-Bauer disc diffusion, E-test, and broth microdilution methods. PCR amplification was used to detect the presence of aminoglycoside modifying enzyme (AME) genes [aac(6')-Ie-aph(2")-Ia, aph(2")-Ib, aph(2")-Ic, aph(2")-Id, aph(3')-IIIa]. Descriptive data analysis was used to analyze the antibiotic susceptibility profiles and the distribution of HLAR genes.

    Results: The majority of the isolates recovered from the clinical samples are E. faecalis (66.7%), with the highest recovery from the pus. The prevalence of HLGR (51%) is higher when compared to HLSR (45-49%). Analysis of the resistance genes showed that bifunctional genes aac(6')-Ie-aph(2")-Ia and aph(3')-IIIa contributed to the HLAR E. faecalis and E. faecium. The other AME genes [aph(2")-Ib, aph(2")-Ic, aph(2")-Id] were not detected in this study.

    Conclusion: This study provides the first prevalence data on HLAR and the distribution of the AME genes among E. faecalis and E. faecium isolates from Malaysia. These highlight the need for continued antibiotic surveillance to minimize its emergence and further dissemination.

  6. Mohd Khairul IO, Nurzam SCH, Hamat RA
    Med J Malaysia, 2022 Jan;77(1):110-112.
    PMID: 35087008
    Although Corynebacterium urealyticum has rarely been isolated in diagnostic laboratories, this bacterium can be a significant uropathogen causing significant complications. It causes cystitis and alkaline encrusted cystitis, commonly involved in patients who need prolonged hospitalization and bladder catheterisation. We report here a case of a 19-yearold young man who was diagnosed with N-Methyl Daspartate receptor (NMDAR) encephalitis that requires hospitalization for optimization of rehabilitation treatment in Hospital Kuala Lumpur, Malaysia. His urine culture isolated slow growing gram-positive pleomorphic rods subsequently identified as C. urealyticum. Based on the risk factors, the isolation of C. urealyticum could not be simply dismissed as contaminants. The patient was treated successfully with vancomycin for two weeks.
  7. Ghafourian A, Ghafourian S, Sadeghifard N, Mohebi R, Shokoohini Y, Nezamoleslami S, et al.
    Int J Immunopathol Pharmacol, 2015 1 13;27(4):485-9.
    PMID: 25572727
    Vitiligo is an acquired cutaneous disorder of pigmentation, with an incidence of 0.5% to 2% worldwide. There are three major hypotheses for the pathogenesis of vitiligo that are not exclusive of each other: biochemical/cytotoxic, neural and autoimmune. Recent data provide strong evidence supporting an autoimmune pathogenesis of vitiligo. As vitiligo can have a major effect on quality of life, treatment can be considered and should preferably begin early when then disease is active. Current treatment modalities are directed towards stopping progression of the disease and achieving repigmentation. Therapies include corticosteroids, topical immunomodulators, photo(chemo)therapy, surgery, combination therapies and depigmentation of normally pigmented skin. It seems that traditional Chinese medicine could be more effective than the current treatment for vitligo.
  8. Kalidasan V, Joseph N, Kumar S, Hamat RA, Neela VK
    Indian J Microbiol, 2018 Sep;58(3):257-267.
    PMID: 30013269 DOI: 10.1007/s12088-018-0740-2
    Iron is an essential nutrient for all living organisms with critical roles in many biological processes. The mammalian host maintains the iron requirements by dietary intake, while the invading pathogenic bacteria compete with the host to obtain those absorbed irons. In order to limit the iron uptake by the bacteria, the human host employs numerous iron binding proteins and withholding defense mechanisms that capture iron from the microbial invaders. To counteract, the bacteria cope with the iron limitation imposed by the host by expressing various iron acquisition systems, allowing them to achieve effective iron homeostasis. The armamentarium used by the human host and invading bacteria, leads to the dilemma of who wins the ultimate war for iron.
  9. Soheili S, Ghafourian S, Sekawi Z, Neela V, Sadeghifard N, Ramli R, et al.
    ScientificWorldJournal, 2014;2014:623174.
    PMID: 25147855 DOI: 10.1155/2014/623174
    Enterococcus, a Gram-positive facultative anaerobic cocci belonging to the lactic acid bacteria of the phylum Firmicutes, is known to be able to resist a wide range of hostile conditions such as different pH levels, high concentration of NaCl (6.5%), and the extended temperatures between 5(°)C and 65(°)C. Despite being the third most common nosocomial pathogen, our understanding on its virulence factors is still poorly understood. The current study was aimed to determine the prevalence of different virulence genes in Enterococcus faecalis and Enterococcus faecium. For this purpose, 79 clinical isolates of Malaysian enterococci were evaluated for the presence of virulence genes. pilB, fms8, efaAfm, and sgrA genes are prevalent in all clinical isolates. In conclusion, the pathogenicity of E. faecalis and E. faecium could be associated with different virulence factors and these genes are widely distributed among the enterococcal species.
  10. Ghasemzadeh-Moghaddam H, van Belkum A, Hamat RA, van Wamel W, Neela V
    Microb Drug Resist, 2014 Oct;20(5):472-7.
    PMID: 24841796 DOI: 10.1089/mdr.2013.0222
    The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.
  11. Weng PL, Ramli R, Shamsudin MN, Cheah YK, Hamat RA
    Biomed Res Int, 2013;2013:938937.
    PMID: 23819125 DOI: 10.1155/2013/938937
    Little is known on the genetic relatedness and potential dissemination of particular enterococcal clones in Malaysia. We studied the antibiotic susceptibility profiles of Enterococcus faecium and Enterococcus faecalis and subjected them to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). E. faecium and E. faecalis displayed 27 and 30 pulsotypes, respectively, and 10 representative E. faecium and E. faecalis isolates (five each) yielded few different sequence types (STs): ST17 (2 isolates), ST78, ST203, and ST601 for E. faecium, and ST6, ST16, ST28, ST179, and ST399 for E. faecalis. Resistance to tazobactam-piperacillin and ampicillin amongst E. faecium isolates was highly observed as compared to E. faecalis isolates. All of the isolates were sensitive to vancomycin and teicoplanin. The presence of epidemic and nosocomial strains of selected E. faecium STs: 17, 78, and 203 and E. faecalis ST6 as well as high rates of resistance to multiple antibiotics amongst E. faecium isolates is of a particular concern.
  12. Syafinaz AN, Hamat RA, Malina O, Siti NM, Niazlin MT, Jamal F
    Med J Malaysia, 2011 Aug;66(3):259-60.
    PMID: 22111454 MyJurnal
    A case of hymenolepiasis in a renal transplant recipient. Issues discussed include the benefit of anti-parasitic agents as well as the preventive measures.
  13. Hamat RA, Rahman AA, Osman M, Unyah NZ, Abdullah WO, Isa NH
    Trans R Soc Trop Med Hyg, 2010 Feb;104(2):170-2.
    PMID: 19732927 DOI: 10.1016/j.trstmh.2009.07.019
    Cutaneous larva migrans is a common parasitic skin disease that can be easily prevented by wearing 'protective' footwear. However, this has been under-emphasized in terms of what constitutes the protective footwear. Even though the disease resolves spontaneously, the significant duration of the disease along with severity of pruritus make treatment unavoidable. Here, we present a very long-standing creeping eruption, which puzzled many attending clinicians handling the case, and the possibility of long socks as a causal effect on the development of cutaneous larva migrans infection.
  14. Liew YK, Neela V, Hamat RA, Nordin SA, Chong PP
    Electrophoresis, 2013 Feb;34(3):397-400.
    PMID: 23161123 DOI: 10.1002/elps.201200380
    The typical concentration of protein loaded varies from 0.13 to 1.40 μg/μL for a classical silver staining method in 2DE gel. Here, we present a simple modified classical silver staining method by modifying the silver impregnation and development reaction steps. This modified method detects the protein spots at extremely low loaded concentrations, ranging from 0.0048 to 0.0480 μg/μL. We recommend this modified silver staining as an excellent method for the limited biological samples used for silver-stained 2DE analysis. Altogether, the protocol takes close to two days from first dimension separation to second dimension separation, followed by silver staining, scanning, and analysis.
  15. Eskandarian N, Neela V, Ismail Z, Puzi SM, Hamat RA, Desa MN, et al.
    Int J Infect Dis, 2013 Sep;17(9):e777-80.
    PMID: 23453715 DOI: 10.1016/j.ijid.2013.01.011
    Group B Streptococcus (GBS) is a leading cause of infections such as meningitis and septicemia in neonates and pregnant women; however the significance of invasive GBS disease has not been clearly defined in non-pregnant adults.
  16. Alreshidi MA, Alsalamah AA, Hamat RA, Neela V, Alshrari AS, Atshan SS, et al.
    Eur J Clin Microbiol Infect Dis, 2013 Jun;32(6):755-61.
    PMID: 23318757 DOI: 10.1007/s10096-012-1801-9
    One hundred and twenty methicillin-resistant Staphylococcus aureus (MRSA) isolated from cancer and non-cancer patients in Saudi Arabia were investigated for antibiotic resistance, virulence determinants and genotypes. The majority of MRSA isolates from cancer (n = 44, 73.3 %) and non-cancer patients (n = 34, 56.7 %) were multi-resistant to more than four classes of antibiotics. Virulence gene profiling showed that all strains were commonly positive for adhesin genes, except ebps and bbp genes, which were not detected in any isolate. Although the presence of adhesin genes varied slightly among MRSA isolates from cancer and non-cancer patients, these variations were not found to be statistically significant. In contrast, the presence of the toxin genes seb, sec, seg and sei was significantly elevated in MRSA strains isolated from cancer patients. Multilocus sequence typing (MLST) detected six and nine sequence types (STs) among isolates from cancer and non-cancer patients, respectively. Using spa typing, 12 and 25 types were detected, including four new types. The ability of different MRSA clones to become multi-resistant and their ability to acquire different virulence factors may contribute to their success as pathogens in individual groups of patients.
  17. Sukeri S, Zahiruddin WM, Shafei MN, Hamat RA, Osman M, Jamaluddin TZMT, et al.
    PMID: 32882876 DOI: 10.3390/ijerph17176362
    BACKGROUND: Perceived severity and susceptibility refers to one's belief of the seriousness and the risk of contracting a specific disease. It is an essential study in public health as it assists in the understanding of the motivating factors towards disease prevention. This qualitative study aimed to explore perceived severity and susceptibility towards leptospirosis infection among respondents in two states of Malaysia.

    METHODS: Focus group discussions using the phenomenology approach was conducted involving 72 respondents in Selangor and Kelantan. Data were examined using content analysis.

    RESULTS: Respondents perceived leptospirosis infection as severe due to its poor disease prognosis and complications. However, some rated it less severe when compared with other chronic diseases such as cancer and AIDS. Their perceptions were influenced by their knowledge about the disease, media portrayal and frequency of health campaigns by the government. All respondents believed they were not susceptible to the disease.

    CONCLUSION: The low perceived susceptibility of leptospirosis infection is a matter of concern as it may contribute to respondents' lack of motivation towards preventing the disease. The study findings may provide the basis for health promotional activities designed to heighten public perceived threat towards leptospirosis infection and thereby improving preventive health behaviors for avoiding leptospirosis.

  18. Hamzah SNA, Mohd Desa MN, Jasni AS, Mohd Taib N, Masri SN, Hamat RA
    Med J Malaysia, 2021 03;76(2):164-170.
    PMID: 33742623
    BACKGROUND: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterisation, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterise the molecular epidemiology by emm typing and MLST methods.

    MATERIALS AND METHODS: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA, speB, speJ, ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Phylogenetic tree branches were constructed from sequence analysis utilised by neighbour joining method generated from seven housekeeping genes using MEGA X software.

    RESULTS: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied.

    CONCLUSION: The present study showed that group A streptococcci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterising a heterogeneous population of GAS in hospitals.

Filters
Contact Us

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

External Links