Displaying publications 1 - 20 of 56 in total

Abstract:
Sort:
  1. Fulltext Physician's Perspectives on Factors Influencing Antibiotic Resistance: A Qualitative Study in Vietnam
    Di KN, Tay ST, Sri La Sri Ponnampalavanar S, Pham DT, Wong LP
    Healthcare (Basel), 2022 Dec 31;11(1).
    PMID: 36611587 DOI: 10.3390/healthcare11010126
    (1) Background: The antibiotic resistance (ABR) rates are escalating to seriously high levels worldwide. This study was conducted to determine physicians' perspectives on factors influencing ABR in Vietnam. (2) Methods: Focus group discussion (FGD) was conducted through in-depth interviews on ABR perspectives with 5-6 physicians from different geographical locations and hospitals in Vietnam between March and June 2020. The research questions were focused on three main themes of (a) knowledge deficiency on ABR and hospital-acquired infection, (b) antibiotic prescribing practice among clinicians in the healthcare setting, and (c) regulations and hospital policies on antibiotic use. The descriptive analysis was performed using QRS NVivo software. (3) Results: A total of six FGDs were conducted among 34 physicians (18 males, 16 females) aged 26-53 years old from six public and six private hospitals in Vietnam. Most of the participants were attending physicians (85.3%) and had 5-10 years of experience in surgical wards (55.9%). For theme (a), a majority of participants agreed that they had adequate information updates on how ABR develops in their clinical setting; and were well aware of hospital-acquired infections. For theme (b), the participants agreed that WHO guidelines and Vietnam national guidelines were two important reference documents in guiding physicians in antibiotic use. For theme (c), the FGD study revealed awareness of ABR, hospital antibiotic policies, and procedures for administrators on antibiotic use that were updated and complied with. (4) Conclusions: While different levels of control measures against ABR are ongoing in Vietnam, several weaknesses in the current antibiotic prescribing strategies in the hospital and clinical setting management policies have been identified in the healthcare system. The research findings will be helpful for policymakers to have better plans of action against ABR in Vietnam.
  2. Knowledge, attitude and practice in relation to catheter-associated urinary tract infection (CAUTI) prevention: A cross-sectional study
    Mong I, Ramoo V, Ponnampalavanar S, Chong MC, Wan Nawawi WNF
    J Clin Nurs, 2022 Jan;31(1-2):209-219.
    PMID: 34105196 DOI: 10.1111/jocn.15899
    BACKGROUND: Healthcare-associated infection (HAI) is one of the major threats to patients' safety besides being among the principal causes of patient morbidity and mortality. Catheter-associated urinary tract infection (CAUTI) is reported to be the most common HAI worldwide. CAUTI can be prevented with appropriate practice and care by healthcare personnel, especially nurses, who play the main role in urinary catheter care. Nurses' knowledge and attitude are considered to be important factors that influence their practice.

    OBJECTIVES: To assess nurses' level of knowledge, attitude and perceived practice regarding CAUTI and its preventive measures.

    METHODS: A cross-sectional design was adopted, and a self-administered questionnaire was used to collect data. Nurses from the medical and surgical inpatient wards of a tertiary teaching hospital in Malaysia were recruited in two stages using the stratified and simple random sampling methods. A total of 301 nurses participated. Descriptive analysis, an independent t test, ANOVA and hierarchical multiple regression were employed to analyse the data using SPSS software version 25. In addition, a STROBE checklist was used to report the results of this study.

    RESULTS: Nurses were found to have good knowledge, a positive attitude and good perceived practice regarding CAUTI prevention. Nurses aged above 30 and who had more than ten years of experience reported higher knowledge levels. Knowledge was found to be positively correlated with attitude and perceived practice; however, attitude explained a higher variance in perceived practice of CAUTI prevention compared with knowledge.

    CONCLUSION: Attitude was found to have a higher significant influence on perceived practice in this study. Educators need to emphasise the inculcation of a positive attitude among nurses rather than just knowledge for CAUTI prevention. Since this study assessed perceived practice, examining nurses' actual practice and its impact on patient outcomes is recommended in future studies.

  3. Fulltext Genomic comparison and phenotypic profiling of small colony variants of Burkholderia pseudomallei
    Zulkefli NJ, Teh CSJ, Mariappan V, Ngoi ST, Vadivelu J, Ponnampalavanar S, et al.
    PLoS One, 2021;16(12):e0261382.
    PMID: 34910764 DOI: 10.1371/journal.pone.0261382
    Burkholderia pseudomallei (B. pseudomallei) is an intracellular pathogen that causes melioidosis, a life-threatening infection in humans. The bacterium is able to form small colony variants (SCVs) as part of the adaptive features in response to environmental stress. In this study, we characterize the genomic characteristics, antimicrobial resistance (AMR), and metabolic phenotypes of B. pseudomallei SCV and wild type (WT) strains. Whole-genome sequence analysis was performed to characterize the genomic features of two SCVs (CS and OS) and their respective parental WT strains (CB and OB). Phylogenetic relationship between the four draft genomes in this study and 19 publicly available genomes from various countries was determined. The four draft genomes showed a close phylogenetic relationship with other genomes from Southeast Asia. Broth microdilution and phenotype microarray were conducted to determine the AMR profiles and metabolic features (carbon utilization, osmolytes sensitivity, and pH conditions) of all strains. The SCV strains exhibited identical AMR phenotype with their parental WT strains. A limited number of AMR-conferring genes were identified in the B. pseudomallei genomes. The SCVs and their respective parental WT strains generally shared similar carbon-utilization profiles, except for D,L-carnitine (CS), g-hydroxybutyric acid (OS), and succinamic acid (OS) which were utilized by the SCVs only. No difference was observed in the osmolytes sensitivity of all strains. In comparison, WT strains were more resistant to alkaline condition, while SCVs showed variable growth responses at higher acidity. Overall, the genomes of the colony morphology variants of B. pseudomallei were largely identical, and the phenotypic variations observed among the different morphotypes were strain-specific.
  4. Overview of the distribution of Burkholderia pseudomallei Sequence Types and the Emergence of Sequence Type 1342 in Malaysia
    Teh CSJ, Yap PSX, Zulkefli NJ, Subramaniam P, Sit PS, Kong ZX, et al.
    Transbound Emerg Dis, 2021 Jan 27.
    PMID: 33506647 DOI: 10.1111/tbed.14005
    Burkholderia pseudomallei, a Gram-negative bacterial pathogen that causes melioidosis, is of public health importance in endemic areas including Malaysia. An investigation of the molecular epidemiology links of B. pseudomallei would contribute to better understanding of the clonal relationships, transmission dynamics and evolutionary change. Multi-locus sequence typing (MLST) of 45 clinical B. pseudomallei isolates collected from sporadic meliodosis cases in Malaysia was performed. In addition, a total of 449 B. pseudomallei Malaysian strains submitted to the MLST database from 1964 until 2019 were included in the temporal analysis to determine the endemic sequence types (STs), emergence and re-emergence of ST(s). In addition, strain-specific distribution was evaluated using BURST tool. Genotyping of 45 clinical strains were resolved into 12 STs and the majority were affiliated with ST46 (n=11) and ST1342 (n=7). Concomitantly, ST46 was the most prevalent ST in Malaysia which first reported in 1964. All the Malaysian B. pseudomallei strains were resolved into 76 different STs with 36 of them uniquely present only in Malaysia. ST1342 was most closely related to ST1034, in which both STs were unique to Malaysia and first isolated from soil samples in Pahang, a state in Malaysia. The present study revealed a high diversity of B. pseudomallei in Malaysia. Localised evolution giving rise to the emergence of new STs was observed, suggesting that host and environmental factors play a crucial role in the evolutionary changes of B. pseudomallei.
  5. Fulltext Relapse of chronic melioidosis in a paediatric cystic fibrosis patient: first case report from Malaysia
    Mariappan V, Thavagnanam S, Vellasamy KM, Teh CJS, Atiya N, Ponnampalavanar S, et al.
    BMC Infect Dis, 2018 Sep 05;18(1):455.
    PMID: 30185168 DOI: 10.1186/s12879-018-3371-7
    BACKGROUND: Burkholderia pseudomallei is the causative agent of melioidosis, which is a potentially life threatening disease endemic in Southeast Asian countries. In Malaysia, cystic fibrosis (CF) is an uncommon condition. The association between CF and B.pseudomallei infections has been reported previously. However, this is the first case report of a pediatric melioidosis relapse and co-infection with other Gram-negative bacteria in Malaysia.

    CASE PRESENTATION: A 14-year-old Chinese Malaysian boy presented with a history of recurrent pneumonia, poor growth and steatorrhoea since childhood, and was diagnosed with CF. B. pseudomallei was cultured from his sputum during three different admissions between 2013 and 2016. However, the patient succumbed to end stage of respiratory failure in 2017 despite antibiotics treatment against B.pseudomallei. The isolates were compared using multilocus-sequence typing and repetitive-element polymerase chain reaction (PCR), and confirmed that two of the isolates were of same sequence type, which may indicate relapse.

    CONCLUSIONS: CF patients should be aware of melioidosis in endemic regions, as it is an emerging infectious disease, especially when persistent or recurrent respiratory symptoms and signs of infection occur. The high prevalence rates of melioidosis in Malaysia warrants better management options to improve quality of life, and life expectancy in patients with CF. Travel activities to endemic regions should also be given more consideration, as this would be crucial to identify and initiate appropriate empiric treatment.

  6. Fulltext Molecular Characterization of Carbapenem Resistant Klebsiella pneumoniae in Malaysia Hospital
    Lau MY, Teng FE, Chua KH, Ponnampalavanar S, Chong CW, Abdul Jabar K, et al.
    Pathogens, 2021 Mar 02;10(3).
    PMID: 33801250 DOI: 10.3390/pathogens10030279
    The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) is a great concern, as carbapenems are the last-line therapy for multidrug-resistant Gram-negative bacteria infections. This study aims to report the epidemiology of CRKP in a teaching hospital in Malaysia based on the molecular genotypic and clinical characteristics of the isolates. Sixty-three CRKP strains were isolated from a tertiary teaching hospital from January 2016 until August 2017. Carbapenemase genes were detected in 55 isolates, with blaOXA-48 (63.5%) as the predominant carbapenemase gene, followed by blaNDM (36.5%). At least one porin loss was detected in nine isolates. Overall, 63 isolates were divided into 30 clusters at similarity of 80% with PFGE analysis. Statistical analysis showed that in-hospital mortality was significantly associated with the usage of central venous catheter, infection or colonization by CRKP, particularly NDM-producers. In comparison, survival analysis using Cox proportional hazards regression identified a higher hazard ratio for patients with a stoma and patients treated with imipenem but a lower hazard ratio for patients with NDM-producing CRKP. OXA-48 carbapenemase gene was the predominant carbapenemase gene in this study. As CRKP infection could lead to a high rate of in-hospital mortality, early detection of the isolates was important to reduce their dissemination.
  7. First detection of Klebsiella quasipneumoniae producing OXA-181 carbapenemase in Malaysia
    Lau MY, Ponnampalavanar S, Lee WS, Jabar KA, Chua KH, Idris N, et al.
    J Infect Chemother, 2020 Oct;26(10):1058-1061.
    PMID: 32546330 DOI: 10.1016/j.jiac.2020.05.009
    The emergence of carbapenemase-producing Enterobacteriaceae has become a major global concern. OXA-48-like carbapenemase gene and its variants have been increasingly reported worldwide. This study reported the first OXA-181-producing Klebsiella quasipneumoniae isolate in Malaysia. This bacterium was isolated from blood specimen of a three-year-old boy with Alagille syndrome who had liver biopsy on October 2016. He had undergone liver transplant in India ten months previously. The genotypic and phenotypic characteristics of the strain were elucidated in this study. To our best knowledge, this is the first report of OXA-181-producing K. quasipneumoniae in Malaysia.
  8. Fulltext Elucidating the survival and response of carbapenem resistant Klebsiella pneumoniae after exposure to imipenem at sub-lethal concentrations
    Low YM, Chong CW, Yap IKS, Chai LC, Clarke SC, Ponnampalavanar S, et al.
    Pathog Glob Health, 2018 10;112(7):378-386.
    PMID: 30380366 DOI: 10.1080/20477724.2018.1538281
    The increasing prevalence of antibiotic resistant pathogens poses a serious threat to global health. However, less emphasis has been placed to co-relate the gene expression and metabolism of antibiotic resistant pathogens. This study aims to elucidate gene expression and variations in metabolism of multidrug resistant Klebsiella pneumoniae after exposure to antibiotics. Phenotypic responses of three genotypically distinct carbapenem resistant Klebsiella pneumoniae (CRKP) strains untreated and treated with sub-lethal concentrations of imipenem were investigated via phenotype microarrays (PM). The gene expression and metabolism of the strain harboring blaNDM-1 before and after exposure to sub-lethal concentration of imipenem were further investigated by RNA-sequencing (RNA-Seq) and 1H NMR spectroscopy respectively. Most genes related to cell division, central carbon metabolism and nucleotide metabolism were downregulated after imipenem treatment. Similarly, 1H NMR spectra obtained from treated CRKP showed decrease in levels of bacterial end products (acetate, pyruvate, succinate, formate) and metabolites involved in nucleotide metabolism (uracil, xanthine, hypoxanthine) but elevated levels of glycerophosphocholine. The presence of anserine was also observed for the treated CRKP while FAPγ-adenine and methyladenine were only present in untreated bacterial cells. As a conclusion, the studied CRKP strain exhibited decrease in central carbon metabolism, cell division and nucleotide metabolism after exposure to sub-lethal concentrations of imipenem. The understanding of the complex biological system of this multidrug resistant bacterium may help in the development of novel strategies and potential targets for the management of the infections.
  9. Fulltext Characterisation of Non-Carbapenemase-Producing Carbapenem-Resistant Klebsiella pneumoniae Based on Their Clinical and Molecular Profile in Malaysia
    Lee YQ, Sri La Sri Ponnampalavanar S, Chong CW, Karunakaran R, Vellasamy KM, Abdul Jabar K, et al.
    Antibiotics (Basel), 2022 Nov 21;11(11).
    PMID: 36421313 DOI: 10.3390/antibiotics11111670
    Non-carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae (NC-CRKP) confers carbapenem resistance through a combination of chromosomal mutations and acquired non-carbapenemase resistance mechanisms. In this study, we aimed to evaluate the clinical and molecular profiles of NC-CRKP isolated from patients in a tertiary teaching hospital in Malaysia from January 2013 to October 2019. During the study period, 54 NC-CRKP-infected/colonised patients' isolates were obtained. Clinical parameters were assessed in 52 patients. The all-cause in-hospital mortality rate among NC-CRKP patients was 46.2% (24/52). Twenty-three (44.2%) patients were infected, while others were colonised. Based on the Charlson Comorbidity Index (CCI) score, 92.3% (48/52) of the infected/colonised patients had a score of ≥ 1. Resistance genes found among the 54 NC-CRKP isolates were blaTEM, blaSHV, blaCTX-M, blaOXA, and blaDHA. Porin loss was detected in 25/54 (46.3%) strains. None of the isolated strains conferred carbapenem resistance through the efflux pumps system. In conclusion, only 25/54 (46.3%) NC-CRKP conferred carbapenem resistance through a combination of porin loss and the acquisition of non-carbapenemase resistance mechanisms. The carbapenem resistance mechanisms for the remaining strains (53.7%) should be further investigated as rapid identification and distinction of the NC-CRKP mechanisms enable optimal treatment and infection control efforts.
  10. The Detection of Hypermucoviscous Carbapenem-Resistant Klebsiella pneumoniae from a Tertiary Teaching Hospital in Malaysia and Assessment of Hypermucoviscous as Marker of Hypervirulence
    Kong ZX, Karunakaran R, Abdul Jabar K, Ponnampalavanar S, Chong CW, Teh CSJ
    Microb Drug Resist, 2021 Oct;27(10):1319-1327.
    PMID: 33877888 DOI: 10.1089/mdr.2020.0096
    Background: Hypermucoviscous carbapenem-resistant Klebsiella pneumoniae (hmCRKp) is emerging globally and approaching the worst-case scenario in health care system. Aims: The main objective in this study was to determine the hypermucoviscous characteristics among the carbapenem-resistant K. pneumoniae (CRKp) isolated from a teaching hospital in Malaysia. The association of hypermucoviscous phenotype with the virulence traits and clinical presentations were also investigated. Methods: A retrospective study was conducted in University Malaya Medical Centre (UMMC). The presence of hypermucoviscous K. pneumoniae was identified among a collection of CRKp clinical isolates (first isolate per patient) from 2014 to 2015 using string test. Correlation between clinical and microbial characteristics of the hmCRKp was investigated. Results: A total of nine (7.5%) hmCRKp were detected among 120 CRKp isolates. Majority of the isolates were hospital acquired or health care-associated infections. None of the patients had typical pyogenic liver abscess. All of the hmCRKp isolates harbored carbapenemase genes and were multidrug resistant. K1/K serotype, peg-344, allS, and magA were not identified among hmCRKp isolates, whereas aerobactin siderophore receptor gene (iutA), iroB, rmpA, and rmpA2 were detected. Only three hmCRKp isolates were resistant to serum bactericidal. Conclusions: All the isolates presented inconclusive evidence for the interpretation of hypervirulence. Therefore, more study should be performed in the future to have a better understanding of the virulence mechanisms in correlation with the clinical and microbial determinants.
  11. Fulltext A retrospective study on molecular epidemiology trends of carbapenem resistant Enterobacteriaceae in a teaching hospital in Malaysia
    Kong ZX, N Karunakaran R, Abdul Jabar K, Ponnampalavanar S, Chong CW, Teh CSJ
    PeerJ, 2022;10:e12830.
    PMID: 35223201 DOI: 10.7717/peerj.12830
    BACKGROUND: Carbapenem resistant Enterobacteriaceae (CRE) has rapidly disseminated worldwide and has become a global threat to the healthcare system due to its resistance towards "last line" antibiotics. This study aimed to investigate the prevalence of CRE and the resistance mechanism as well as the risk factors associated with in-hospital mortality.

    METHODS: A total of 168 CRE strains isolated from a tertiary teaching hospital from 2014-2015 were included in this study. The presence of carbapenemase genes and minimum inhibitory concentration of imipenem, meropenem and colistin were investigated. All carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) strains were characterised by PFGE. The risk factors of patients infected by CRE associated with in-hospital mortality were determined statistically.

    RESULTS: The predominant CRE species isolated was K. pneumoniae. The carbapenemases detected were blaOXA-48, blaOXA-232, blaVIM and blaNDM of which blaOXA-48 was the predominant carbapenemase detected among 168 CRE strains. A total of 40 CRE strains harboured two different carbapenemase genes. A total of seven clusters and 48 pulsotypes were identified among 140 CRKp strains. A predominant pulsotype responsible for the transmission from 2014 to 2015 was identified. Univariate statistical analysis identified that the period between CRE isolation and start of appropriate therapy of more than 3 days was statistically associated with in-hospital mortality.

  12. Fulltext A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia
    Yap PSX, Chong CW, Ponnampalavanar S, Ramli R, Harun A, Tengku Jamaluddin TZM, et al.
    PeerJ, 2023;11:e16393.
    PMID: 38047021 DOI: 10.7717/peerj.16393
    BACKGROUND: The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance.

    METHODS: Therefore, an inventory surveillance of the ESBL-Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated.

    RESULTS: A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The blaCTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring blaCTX-M-1 only, 27 isolates (21.3%) co-harbouring blaCTX-M-1 and blaTEM, and ten isolates (7.9%) co-harbouring blaCTX-M-1, blaTEM and blaSHV. A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes.

  13. Fulltext Molecular evidence of Burkholderia pseudomallei genotypes based on geographical distribution
    Zulkefli NJ, Mariappan V, Vellasamy KM, Chong CW, Thong KL, Ponnampalavanar S, et al.
    PeerJ, 2016;4:e1802.
    PMID: 26998408 DOI: 10.7717/peerj.1802
    Background. Central intermediary metabolism (CIM) in bacteria is defined as a set of metabolic biochemical reactions within a cell, which is essential for the cell to survive in response to environmental perturbations. The genes associated with CIM are commonly found in both pathogenic and non-pathogenic strains. As these genes are involved in vital metabolic processes of bacteria, we explored the efficiency of the genes in genotypic characterization of Burkholderia pseudomallei isolates, compared with the established pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) schemes. Methods. Nine previously sequenced B. pseudomallei isolates from Malaysia were characterized by PFGE, MLST and CIM genes. The isolates were later compared to the other 39 B. pseudomallei strains, retrieved from GenBank using both MLST and sequence analysis of CIM genes. UniFrac and hierachical clustering analyses were performed using the results generated by both MLST and sequence analysis of CIM genes. Results. Genetic relatedness of nine Malaysian B. pseudomallei isolates and the other 39 strains was investigated. The nine Malaysian isolates were subtyped into six PFGE profiles, four MLST profiles and five sequence types based on CIM genes alignment. All methods demonstrated the clonality of OB and CB as well as CMS and THE. However, PFGE showed less than 70% similarity between a pair of morphology variants, OS and OB. In contrast, OS was identical to the soil isolate, MARAN. To have a better understanding of the genetic diversity of B. pseudomallei worldwide, we further aligned the sequences of genes used in MLST and genes associated with CIM for the nine Malaysian isolates and 39 B. pseudomallei strains from NCBI database. Overall, based on the CIM genes, the strains were subtyped into 33 profiles where majority of the strains from Asian countries were clustered together. On the other hand, MLST resolved the isolates into 31 profiles which formed three clusters. Hierarchical clustering using UniFrac distance suggested that the isolates from Australia were genetically distinct from the Asian isolates. Nevertheless, statistical significant differences were detected between isolates from Malaysia, Thailand and Australia. Discussion. Overall, PFGE showed higher discriminative power in clustering the nine Malaysian B. pseudomallei isolates and indicated its suitability for localized epidemiological study. Compared to MLST, CIM genes showed higher resolution in distinguishing those non-related strains and better clustering of strains from different geographical regions. A closer genetic relatedness of Malaysian isolates with all Asian strains in comparison to Australian strains was observed. This finding was supported by UniFrac analysis which resulted in geographical segregation between Australia and the Asian countries.
  14. Spotted Fever Group Rickettsioses and Murine Typhus in a Malaysian Teaching Hospital
    Kho KL, Koh FX, Singh HK, Zan HA, Kukreja A, Ponnampalavanar S, et al.
    Am J Trop Med Hyg, 2016 10 05;95(4):765-768.
    PMID: 27402519
    Limited information is available on the etiological agents of rickettsioses in southeast Asia. Herein, we report the molecular investigation of rickettsioses in four patients attending a teaching hospital in Malaysia. DNA of Rickettsia sp. RF2125, Rickettsia typhi, and a rickettsia closely related to Rickettsia raoultii was detected in the blood samples of the patients. Spotted fever group rickettsioses and murine typhus should be considered in the diagnosis of patients with nonspecific febrile illness in this region.
  15. Fulltext Candida species and oral mycobiota of patients clinically diagnosed with oral thrush
    Karajacob AS, Azizan NB, Al-Maleki ARM, Goh JPE, Loke MF, Khor HM, et al.
    PLoS One, 2023;18(4):e0284043.
    PMID: 37068057 DOI: 10.1371/journal.pone.0284043
    Overgrowth of Candida yeasts in the oral cavity may result in the development of oral thrush in immunocompromised individuals. This study analyzed the diversity and richness of the oral mycobiota of patients clinically diagnosed with oral thrush (OT), follow-up of oral thrush patients after antifungal therapy (AT), and healthy controls (HC). Oral rinse and oral swab samples were collected from 38 OT patients, 21 AT patients, and 41 healthy individuals (HC). Pellet from the oral rinse and oral swab were used for the isolation of oral Candida yeasts on Brilliance Candida Agar followed by molecular speciation. ITS1 amplicon sequencing using Illumina MiSeq was performed on DNA extracted from the oral rinse pellet of 16 OT, 7 AT, and 7 HC oral rinse samples. Trimmed sequence data were taxonomically grouped and analyzed using the CLC Microbial Genomics Module workflow. Candida yeasts were isolated at significantly higher rates from oral rinse and swab samples of OT (68.4%, p < 0.001) and AT (61.9%, p = 0.012) patients, as compared to HC (26.8%). Predominance of Candida albicans specifically, was noted in OT (60.5%, p < 0.001) and AT (42.9%, p = 0.006) vs. HC (9.8%), while non-albicans Candida species was dominant in HC. Analysis of oral mycobiota from OT patients showed the presence of 8 phyla, 222 genera, and 309 fungal species. Low alpha diversity (Shannon index, p = 0.006; Chao-1 biased corrected index, p = 0.01), varied beta diversity (Bray-Curtis, p = 0.01986; Jaccard, p = 0.02766; Weighted UniFrac, p = 0.00528), and increased relative abundance of C. albicans (p = 3.18E-02) was significantly associated with the oral mycobiota of OT vs. HC. This study supported that C. albicans is the main etiological agent in oral thrush and highlights the association of fungal biodiversity with the pathophysiology of oral thrush.
  16. Fulltext Comparison of two nested PCR methods for the detection of human malaria
    Anthony C, Mahmud R, Lau YL, Syedomar SF, Sri La Sri Ponnampalavanar S
    Trop Biomed, 2013 Sep;30(3):459-66.
    PMID: 24189676 MyJurnal
    Battling malaria will be a persistent struggle without the proper means to diagnose the parasitic infection. However, the inherent limitations of microscopy, the conventional method of diagnosing malaria, affect the accuracy of diagnosis. The present study aimed to compare the accuracy of two different set of primers targeting the small subunit ribosomal RNA (ssRNA) and the dihydrofolate reductase-thymidylate synthase linker region (dhfr-ts) in detecting species specific malaria infections by nested PCR. The sensitivity and specificity of nested PCR assay using the two primers were calculated with reference to microscopy as the 'gold standard'. The results show that 18S rRNA primers had 91.9% sensitivity and 100% specificity in detecting human Plasmodium species as opposed to dhfr-ts primers which had 51.4% sensitivity and 100% specificity. The higher sensitivity of 18S rRNA primers suggests that it may be a better diagnostic tool for detecting human malaria.
  17. Methicillin-resistant Staphylococcus aureus bacteraemia, 2003-2015: Comparative evaluation of changing trends in molecular epidemiology and clinical outcomes of infections
    Niek WK, Teh CSJ, Idris N, Sit PS, Lee YQ, Thong KL, et al.
    Infect Genet Evol, 2020 11;85:104567.
    PMID: 32980576 DOI: 10.1016/j.meegid.2020.104567
    Methicillin-resistant Staphylococcus aureus (MRSA) is a prominent pathogen causing invasive infections such as bacteraemia. The continued excessive use of antibiotics to treat MRSA infections has resulted in the evolution of antimicrobial resistant of S. aureus. This study aims to perform a comparative evaluation of changing trends in molecular epidemiology of MRSA and clinical characteristics of patients. This study shows that ST22-MRSA-IV has gradually replaced ST239-MRSA-III as the predominant MRSA clone in the tertiary teaching hospital studied. Independent predictors of mortality among patients included devices in situ at the time of infection, pre-exposure to macrolides, catheter-related bloodstream infection and mono-microbial infection. Hence, our study affirmed community-associated MRSA, which was previously identified from individuals without any exposure to healthcare settings, has now emerged in healthcare settings, causing healthcare-associated MRSA infections.
  18. Concurrent loss of co-stimulatory molecules and functional cytokine secretion attributes leads to proliferative senescence of CD8(+) T cells in HIV/TB co-infection
    Saeidi A, Chong YK, Yong YK, Tan HY, Barathan M, Rajarajeswaran J, et al.
    Cell Immunol, 2015 Sep;297(1):19-32.
    PMID: 26071876 DOI: 10.1016/j.cellimm.2015.05.005
    The role of T-cell immunosenescence and functional CD8(+) T-cell responses in HIV/TB co-infection is unclear. We examined and correlated surrogate markers of HIV disease progression with immune activation, immunosenescence and differentiation using T-cell pools of HIV/TB co-infected, HIV-infected and healthy controls. Our investigations showed increased plasma viremia and reduced CD4/CD8 T-cell ratio in HIV/TB co-infected subjects relative to HIV-infected, and also a closer association with changes in the expression of CD38, a cyclic ADP ribose hydrolase and CD57, which were consistently expressed on late-senescent CD8(+) T cells. Up-regulation of CD57 and CD38 were directly proportional to lack of co-stimulatory markers on CD8(+) T cells, besides diminished expression of CD127 (IL-7Rα) on CD57(+)CD4(+) T cells. Notably, intracellular IFN-γ, perforin and granzyme B levels in HIV-specific CD8(+) T cells of HIV/TB co-infected subjects were diminished. Intracellular CD57 levels in HIV gag p24-specific CD8(+) T cells were significantly increased in HIV/TB co-infection. We suggest that HIV-TB co-infection contributes to senescence associated with chronic immune activation, which could be due to functional insufficiency of CD8(+) T cells.
  19. Fulltext Attrition of TCR Vα7.2+ CD161++ MAIT cells in HIV-tuberculosis co-infection is associated with elevated levels of PD-1 expression
    Saeidi A, Tien Tien VL, Al-Batran R, Al-Darraji HA, Tan HY, Yong YK, et al.
    PLoS One, 2015;10(4):e0124659.
    PMID: 25894562 DOI: 10.1371/journal.pone.0124659
    Mucosal-associated invariant T (MAIT) cells are evolutionarily conserved antimicrobial MR1-restricted CD8(+) T cells co-expressing the semi-invariant TCR Vα7.2, and are numerous in the blood and mucosal tissues of humans. MAIT cells appear to undergo exhaustion in chronic viral infections. However, their role in human immunodeficiency virus type 1 (HIV-1) mono-infection and HIV/tuberculosis (TB) co-infection have seldom been elaborately investigated. We conducted a cross-sectional study to investigate the frequencies and phenotypes of CD161(++)CD8(+) T cells among anti-retroviral therapy (ART)/anti-TB therapy (ATT) treatment-naïve HIV/TB co-infected, ART/TB treated HIV/TB co-infected, ART naïve HIV-infected, ART-treated HIV-infected patients, and HIV negative healthy controls (HCs) by flow cytometry. Our data revealed that the frequency of MAIT cells was severely depleted in HIV mono- and HIV/TB co-infections. Further, PD-1 expression on MAIT cells was significantly increased in HIV mono- and HIV-TB co-infected patients. The frequency of MAIT cells did not show any significant increase despite the initiation of ART and/or ATT. Majority of the MAIT cells in HCs showed a significant increase in CCR6 expression as compared to HIV/TB co-infections. No marked difference was seen with expressions of chemokine co-receptor CCR5 and CD103 among the study groups. Decrease of CCR6 expression appears to explain why HIV-infected patients display weakened mucosal immune responses.
  20. Fulltext Susceptible and protective HLA class 1 alleles against dengue fever and dengue hemorrhagic fever patients in a Malaysian population
    Appanna R, Ponnampalavanar S, Lum Chai See L, Sekaran SD
    PLoS One, 2010;5(9).
    PMID: 20927388 DOI: 10.1371/journal.pone.0013029
    The human leukocyte antigen alleles have been implicated as probable genetic markers in predicting the susceptibility and/or protection to severe manifestations of dengue virus (DENV) infection. In this present study, we aimed to investigate for the first time, the genotype variants of HLA Class 1(-A and -B) of DENV infected patients against healthy individuals in Malaysia.
Related Terms
    Try searching for something
Filters
Contact Us

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

External Links