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  1. Zulpa AK, Barathan M, Iyadorai T, Mariappan V, Vadivelu J, Teh CSJ, et al.
    World J Microbiol Biotechnol, 2023 Oct 06;39(12):333.
    PMID: 37801157 DOI: 10.1007/s11274-023-03767-1
    pks+ Escherichia coli (E. coli) triggers genomic instability in normal colon cells which leads to colorectal cancer (CRC) tumorigenesis. Previously, we reported a significant presentation of pks+ E. coli strains in CRC patients' biopsies as compared to healthy cohorts. In this work, using an in vitro infection model, we further explored the ability of these strains in modulating cell cycle arrest and activation of apoptotic mediators in both primary colon epithelial cells (PCE) and CRC cells (HCT-116). Sixteen strains, of which eight tumours and the matching non-malignant tissues, respectively, from eight pks+ E. coli CRC patients were subjected to BrDU staining and cell cycle analysis via flow cytometry, while a subset of these strains underwent analysis of apoptotic mediators including caspase proteins, cellular reactive oxygen species (cROS) and mitochondrial membrane potential (MMP) via spectrophotometry as well as proinflammatory cytokines via flow cytometry. Data revealed that all strains exerted S-phase cell cycle blockade in both cells and G2/M phase in PCE cells only. Moreover, more significant upregulation of Caspase 9, cROS, proinflammatory cytokines and prominent downregulation of MMP were detected in HCT-116 cells indicating the potential role of pks related bacterial toxin as anticancer agent as compared to PCE cells which undergo cellular senescence leading to cell death without apparent upregulation of apoptotic mediators. These findings suggest the existence of discrepancies underlying the mechanism of action of pks+ E. coli on both cancer and normal cell lines. This work propounds the rationale to further understand the mechanism underlying pks+ E. coli-mediated CRC tumorigenesis and cancer killing.
  2. Hasmukharay K, Ngoi ST, Saedon NI, Tan KM, Khor HM, Chin AV, et al.
    BMC Infect Dis, 2023 Apr 18;23(1):241.
    PMID: 37072768 DOI: 10.1186/s12879-023-08206-y
    BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a major concern in the global healthcare system. However, data from Asian regions dealing with the singularity of this infection in older persons is lacking. We aimed to identify the differences in the clinical characteristics and outcomes of MRSA bacteremia between adults aged 18-64 and ≥ 65 years.

    METHODS: A retrospective study cohort was conducted at the University Malaya Medical Centre (UMMC) on cases of MRSA bacteremia from 2012 to 2016. Patient demographic and clinical data were collected for risk factors analyses.

    RESULTS: New cases of MRSA bacteremia showed a trend of increase from 0.12 to 100 admissions in 2012 to 0.17 per 100 admissions in 2016 but a drop was observed in 2014 (0.07 per 100 admissions). Out of the 275 patients with MRSA bacteremia, 139 (50.5%) patients were aged ≥ 65 years old. Co-morbidities and severity at presentation were significantly higher among older adults, including diabetes mellitus (p = 0.035), hypertension (p = 0.001), and ischemic heart disease (p 

  3. Maniam L, Vellasamy KM, Ong TA, Teh CSJ, Jabar KA, Mariappan V, et al.
    PeerJ, 2023;11:e15305.
    PMID: 37361034 DOI: 10.7717/peerj.15305
    BACKGROUND: Uropathogenic Escherichia coli (UPEC) is the predominant agent causing various categories of complicated urinary tract infections (cUTI). Although existing data reveals that UPEC harboured numerous virulence determinants to aid its survival in the urinary tract, the reason behind the occurrence of differences in the clinical severity of uninary tract infections (UTI) demonstrated by the UPEC infection is poorly understood. Therefore, the present study aims to determine the distribution of virulence determinants and antimicrobial resistance among different phylogroups of UPEC isolated from various clinical categories of cUTI and asymptomatic bacteriuria (ASB) E. coli isolates. The study will also attempt a relational analysis of the genotypic characteristics of cUTI UPEC and ASB E. coli isolates.

    METHODS: A total of 141 UPEC isolates from cUTI and 160 ASB E. coli isolates were obtained from Universiti Malaya Medical Centre (UMMC). Phylogrouping and the occurrence of virulence genes were investigated using polymerase chain reaction (PCR). Antimicrobial susceptibility of the isolates to different classes of antibiotics was determined using the Kirby Bauer Disc Diffusion method.

    RESULTS: The cUTI isolates were distributed differentially among both Extraintestinal Pathogenic E. coli (ExPEC) and non-ExPEC phylogroups. Phylogroup B2 isolates were observed to possess the highest average aggregative virulence score (7.17), a probable representation of the capability to cause severe disease. Approximately 50% of the cUTI isolates tested in this study were multidrug resistant against common antibiotics used to treat UTI. Analysis of the occurrence of virulence genes among different cUTI categories demonstrated that UPEC isolates of pyelonephritis and urosepsis were highly virulent and had the highest average aggregative virulence scores of 7.80 and 6.89 respectively, compared to other clinical categories. Relational analysis of the occurrence of phylogroups and virulence determinants of UPEC and ASB E. coli isolates showed that 46.1% of UPEC and 34.3% of ASB E. coli from both categories were distributed in phylogroup B2 and had the highest average aggregative virulence score of 7.17 and 5.37, respectively. The data suggest that UPEC isolates which carry virulence genes from all four virulence genes groups studied (adhesions, iron uptake systems, toxins and capsule synthesis) and isolates from phylogroup B2 specifically could predispose to severe UTI involving the upper urinary tract. Therefore, specific analysis of the genotypic characteristics of UPEC could be further explored by incorporating the combination of virulence genes as a prognostic marker for predicting disease severity, in an attempt to propose a more evidence driven treatment decision-making for all UTI patients. This will go a long way in enhancing favourable therapeutic outcomes and reducing the antimicrobial resistance burden among UTI patients.

  4. Ng HK, Puah SM, Teh CSJ, Idris N, Chua KH
    PeerJ, 2023;11:e15304.
    PMID: 37214089 DOI: 10.7717/peerj.15304
    BACKGROUND: Acinetobacter baumannii was reported to have resistance towards carbapenems and the ability to form an air-liquid biofilm (pellicle) which contributes to their virulence. The GacSA two-component system has been previously shown to play a role in pellicle formation. Therefore, this study aims to detect the presence of gacA and gacS genes in carbapenem-resistant Acinetobacter baumannii (CRAB) isolates recovered from patients in intensive care units and to investigate their pellicle forming ability.

    METHODS: The gacS and gacA genes were screened in 96 clinical CRAB isolates using PCR assay. Pellicle formation assay was performed in Mueller Hinton medium and Luria Bertani medium using borosilicate glass tubes and polypropylene plastic tubes. The biomass of the pellicle was quantitated using the crystal violet staining assay. The selected isolates were further assessed for their motility using semi-solid agar and monitored in real-time using real-time cell analyser (RTCA).

    RESULTS: All 96 clinical CRAB isolates carried the gacS and gacA genes, however, only four isolates (AB21, AB34, AB69 and AB97) displayed the ability of pellicle-formation phenotypically. These four pellicle-forming isolates produced robust pellicles in Mueller Hinton medium with better performance in borosilicate glass tubes in which biomass with OD570 ranging from 1.984 ± 0.383 to 2.272 ± 0.376 was recorded. The decrease in cell index starting from 13 hours obtained from the impedance-based RTCA showed that pellicle-forming isolates had entered the growth stage of pellicle development.

    CONCLUSION: These four pellicle-forming clinical CRAB isolates could be potentially more virulent, therefore further investigation is warranted to provide insights into their pathogenic mechanisms.

  5. 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.

  6. 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.
  7. 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.

  8. Hor JW, Lim SY, Khor ES, Chong KK, Song SL, Ibrahim NM, et al.
    J Mov Disord, 2021 Dec 24.
    PMID: 34937162 DOI: 10.14802/jmd.21085
    Objective: Converging evidence suggests that intestinal inflammation is involved in the pathogenesis of neurodegenerative diseases. Previous studies on fecal calprotectin in Parkinson's disease (PD) were limited by small sample sizes, and literature regarding intestinal inflammation in multiple system atrophy (MSA) is very scarce. We investigated the levels of fecal calprotectin, a marker of intestinal inflammation, in PD and MSA.

    Methods: We recruited 169 subjects (71 PD, 38 MSA, and 60 age-similar nonneurological controls). Clinico-demographic data were collected. PD and MSA were subtyped and the severity assessed using the MDS-UPDRS and UMSARS, respectively. Fecal calprotectin and blood immune markers were analyzed.

    Results: Compared to controls (median: 35.7 [IQR: 114.2] μg/g), fecal calprotectin was significantly elevated in PD (median: 95.6 [IQR: 162.1] μg/g, p = 0.003) and even higher in MSA (median: 129.5 [IQR: 373.8] μg/g, p = 0.002). A significant interaction effect with age was observed; between-group differences were significant only in older subjects (i.e., ≥ 61 years) and became more apparent with increasing age. A total of 28.9% of MSA and 18.3% of PD patients had highly abnormal fecal calprotectin levels (≥ 250 μg/g); however, this difference was only significant for MSA compared to controls. Fecal calprotectin correlated moderately with selected blood immune markers in PD, but not with clinical features of PD or MSA.

    Conclusions: Elevated fecal calprotectin suggests a role for intestinal inflammation in PD and MSA. A more complete understanding of gut immune alterations could open up new avenues of research and treatment for these debilitating diseases.

  9. Ngoi ST, Muhamad AN, Teh CSJ, Chong CW, Abdul Jabar K, Chai LC, et al.
    Pathogens, 2021 Dec 09;10(12).
    PMID: 34959557 DOI: 10.3390/pathogens10121602
    The rise of antimicrobial resistance (AMR) among clinically important bacteria, including respiratory pathogens, is a growing concern for public health worldwide. Common causative bacteria for upper respiratory tract infections (URTIs) include Streptococcus pneumoniae and Haemophilus influenzae, and sometimes Staphylococcus aureus. We assessed the β-lactam resistant trends and mechanisms of 150 URTI strains isolated in a tertiary care hospital in Kuala Lumpur Malaysia. High rates of non-susceptibility to penicillin G (38%), amoxicillin-clavulanate (48%), imipenem (60%), and meropenem (56%) were observed in S. pneumoniae. Frequent mutations at STMK and SRNVP motifs in PBP1a (41%), SSNT motif in PBP2b (32%), and STMK and LKSG motifs in PBP2x (41%) were observed in S. pneumoniae. H. influenzae remained highly susceptible to most β-lactams, except for ampicillin. Approximately half of the ampicillin non-susceptible H. influenzae harboured PBP3 mutations (56%) and only blaTEM was detected in the ampicillin-resistant strains (47%). Methicillin-susceptible S. aureus (MSSA) strains were mostly resistant to penicillin G (92%), with at least two-fold higher median minimum inhibitory concentrations (MIC) for all penicillin antibiotics (except ticarcillin) compared to S. pneumoniae and H. influenzae. Almost all URTI strains (88-100%) were susceptible to cefcapene and flomoxef. Overall, β-lactam antibiotics except penicillins remained largely effective against URTI pathogens in this region.
  10. Chong KN, E HC, Zaki RA, Mohd SH, Majid HA, Ng AK, et al.
    Asia Pac J Clin Nutr, 2021 Dec;30(4):632-642.
    PMID: 34967192 DOI: 10.6133/apjcn.202112_30(4).0010
    BACKGROUND AND OBJECTIVES: Maternal diet during pregnancy may impact infant respiratory morbidity. The aim was to determine the association between antenatal maternal diet and respiratory morbidity of their infants during their first 6 months of life.

    METHODS AND STUDY DESIGN: This prospective cohort study included healthy motherinfant pairs. Maternal diet during the last trimester was determined with a validated food frequency questionnaire. Infant respiratory morbidity was solicited at 1, 3 and 6 months.

    RESULTS: Three hundred mother-baby pairs were recruited. Maternal consumption of milk and dairy products was associated with reduced respiratory symptoms at 1 month (aOR 0.29 [95% CI: 0.10, 0.86], p=0.03) and 3 months old (aOR 0.43 [95% CI: 0.20, 0.93], p=0.03), while intake of confectionery items was associated with increased unscheduled doctor visits at 3 months (aOR 2.01 [95% CI 1.33, 3.06], p=0.001) and increased nebuliser treatment at both 3 months (aOR 1.88 [95% CI 1.12, 3.17], p=0.02) and 6 months (aOR 1.64 [95% CI 1.05, 2.54], p=0.03). Finally, at 6 months, hypertensive disorders during pregnancy was associated with increased nebuliser treatment (aOR 17.3 [95% CI 1.50, 199], p=0.02) while exclusive breastfeeding was associated with reduced incidence of respiratory symptoms (OR 0.47 [95% CI 0.26, 0.83], p=0.01).

    CONCLUSIONS: Increased antenatal maternal consumption of milk and dairy products may reduce respiratory morbidity while increased consumption of confectionery items may increase respiratory morbidity in their infants during the first 6 months of life.

  11. Thong KL, Tham KBL, Ngoi ST, Tan SC, Yussof WNW, Hanapi RA, et al.
    Transbound Emerg Dis, 2021 Nov 01.
    PMID: 34724597 DOI: 10.1111/tbed.14368
    Vibrio cholerae O1 El Tor variants have been the major causative agents of cholera worldwide since their emergence in the 2000s. Cholera remains endemic in some regions in Malaysia. Therefore, we aimed to investigate the genetic characteristics of the V. cholerae O1 El Tor strains associated with outbreaks and sporadic cases to elucidate the molecular evolution among the strains circulating in this region. A total of 45 V. cholerae O1 El Tor strains isolated between 1991 and 2011 were examined. All strains were subjected to phenotypic characterization, and molecular characterization including detection of virulence genes and CTX prophage (CTXΦ) by Polymerase Chain Reaction (PCR), and genotyping by Pulsed-Field Gel Electrophoresis (PFGE). All strains were phenotypically confirmed as El Tor biotype and were mostly Ogawa serotype (96 %). Antimicrobial susceptibility testing showed that the outbreak strains isolated in 1991 (Sabah) and 2009 (Terengganu) were all multidrug-resistant while the sporadic strains were resistant to erythromycin and furazolidone only. All strains (n = 45) were resistant to erythromycin. The virulence genes ctxA, ctxB, ompW, rfb, rtxC, tcpA, tcpI, rstR, zot and hlyA were present in all strains. The outbreak strains isolated in 1991 harboured El Tor cholera toxin gene (ctxB3) while sporadic strains from 2004 to 2011 harboured classical ctxB1. Four distinctive CTXΦ arrays were identified among the El Tor variants, one of which co-occurred with El Tor strains during the 2009 outbreak in Terengganu. PFGE analysis revealed that a genetically diverse El Tor variants population persisted in Sabah. The co-existence of multiple El Tor variants together with the prototypic El Tor strains suggested a multiclonal emergence of V. cholerae O1 El Tor variants in this region. This article is protected by copyright. All rights reserved.
  12. 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.
  13. Niek WK, Teh CSJ, Idris N, Thong KL, Ngoi ST, Ponnampalavanar SSS
    Folia Microbiol (Praha), 2021 Oct;66(5):741-749.
    PMID: 34089493 DOI: 10.1007/s12223-021-00877-x
    Biofilm formation is an important physiological process in Staphylococcus aureus (S. aureus) that can cause infections in humans. In this study, the ability of 36 methicillin-resistant S. aureus (MRSA) clinical isolates to form biofilm was studied based on genotypic and phenotypic approaches. These isolates were genotyped based on the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and biofilm-associated genes (icaAD) via polymerase chain reactions. Phenotyping was performed based on the determination of the strength of biofilm formation of MRSA isolates in vitro. The most prevalent MSCRAMMs and biofilm-associated genes were clfA, eno, and icaD, followed by clfB. The fnbB (38.9%) and ebpS (11.1%) occurred less frequently among the MRSA isolates, while bbp and fnbA genes were absent from all isolates. The MRSA isolates were mostly moderate to strong biofilm formers, despite the heterogeneity of the MSCRAMM profiles. MRSA isolates from different infection sources (primary, catheter-related bloodstream, or secondary infections) were capable of forming strong biofilms. However, persistent bacteraemia was observed only in 19.4% of the MRSA-infected individuals. This study suggested that persistent MRSA bacteraemia in patients might not be associated with the biofilm-forming ability of the isolates.
  14. Nallappan D, Chua KH, Ong KC, Chong CW, Teh CSJ, Palanisamy UD, et al.
    Food Funct, 2021 Jul 05;12(13):5876-5891.
    PMID: 34019055 DOI: 10.1039/d1fo00539a
    Obesity is a driving factor in the onset of metabolic disorders. This study aims to investigate the effects of the myricetin derivative-rich fraction (MD) from Syzygium malaccense leaf extract on high-fat diet (HFD)-induced obesity and its associated complications and its influence on uncoupling protein-1 (UCP-1) and gut microbiota in C57BL/6J mice. Mice were randomly assigned into four groups (n = 6) and given a normal diet (ND) or high-fat diet (HFD) for 10 weeks to induce obesity. The HFD groups (continued with HFD) were administered 50 mg kg-1 MD (treatment), 50 mg kg-1 metformin (positive control) and normal saline (HFD and ND controls) daily for four weeks via oral gavage. The ten-week HFD-feeding resulted in hyperglycemia and elevated urinary oxidative indices. The subsequent MD administration caused significant weight reduction without appetite suppression and amelioration of insulin resistance, steatosis and dyslipidemia. Besides, MD significantly reduced lipid hydroperoxides and protein carbonyls in tissue homogenates and urine and elevated Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and reduced glutathione (GSH) and thus, alleviated oxidative stress. The weight reduction was correlated with downregulation of inflammatory markers and the increased UCP-1 level, suggesting weight loss plausibly through thermogenesis. The Akkermansia genus (reflects improved metabolic status) in the HFD50 group was more abundant than that in the HFD group while the non-enzymatic antioxidant markers were strongly associated with UCP-1. In conclusion, MD ameliorates obesity and its related complications possibly via the upregulation of UCP-1 and increased abundance of Akkermansia genus and is promising as a therapeutic agent in the treatment of obesity and its associated metabolic disorders.
  15. Mobasseri G, Thong KL, Teh CSJ
    Int Microbiol, 2021 May;24(2):243-250.
    PMID: 33469786 DOI: 10.1007/s10123-021-00161-5
    Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has been associated with a wide range of infections in humans and animals. The objective of this study was to determine the genomic characteristics of two multiple drug resistant, ESBLs-producing K. pneumoniae strains isolated from a swine in 2013 (KP2013Z28) and a hospitalized patient in 2014 (KP2014C46) in Malaysia. Genomic analyses of the two K. pneumoniae strains indicated the presence of various antimicrobial resistance genes associated with resistance to β-lactams, aminoglycosides, colistin, fluoroquinolones, phenicols, tetracycline, sulfonamides, and trimethoprim, corresponding to the antimicrobial susceptibility profiles of the strains. KP2013Z28 (ST25) and KP2014C46 (ST929) harbored 5 and 2 genomic plasmids, respectively. The phylogenomics of these two Malaysian K. pneumoniae, with other 19 strains around the world was determined based on SNPs analysis. Overall, the strains were resolved into five clusters that comprised of strains with different resistance determinants. This study provided a better understanding of the resistance mechanisms and phylogenetic relatedness of the Malaysian strains with 19 strains isolated worldwide. This study also highlighted the needs to monitor the usage of antibiotics in hospital settings, animal husbandry, and agricultural practices due to the increase of β-lactam, aminoglycosides, tetracycline, and colistin resistance among pathogenic bacteria for better infection control.
  16. Ngoi ST, Chong CW, Ponnampalavanar SSS, Tang SN, Idris N, Abdul Jabar K, et al.
    Antimicrob Resist Infect Control, 2021 04 23;10(1):70.
    PMID: 33892804 DOI: 10.1186/s13756-021-00936-5
    BACKGROUND: Knowledge on the epidemiology, genotypic and phenotypic features of antimicrobial-resistant (AMR) ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli) and their association with hospital-acquired infections (HAIs) are limited in Malaysia. Therefore, we evaluated the AMR features and resistance mechanisms of the ESKAPEE pathogens collected in a tertiary hospital located in the capital of Malaysia.

    METHODS: A total of 378 AMR-ESKAPEE strains were obtained based on convenience sampling over a nine-month study period (2019-2020). All strains were subjected to disk diffusion and broth microdilution assays to determine the antimicrobial susceptibility profiles. Polymerase chain reaction (PCR) and DNA sequence analyses were performed to determine the AMR genes profiles of the non-susceptible strains. Chi-square test and logistic regression analyses were used to correlate the AMR profiles and clinical data to determine the risk factors associated with HAIs.

    RESULTS: High rates of multidrug resistance (MDR) were observed in A. baumannii, K. pneumoniae, E. coli, and S. aureus (69-89%). All organisms except E. coli were frequently associated with HAIs (61-94%). Non-susceptibility to the last-resort drugs vancomycin (in Enterococcus spp. and S. aureus), carbapenems (in A. baumannii, P. aeruginosa, and Enterobacteriaceae), and colistin (in Enterobacteriaceae) were observed. Both A. baumannii and K. pneumoniae harbored a wide array of extended-spectrum β-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaOXA). Metallo-β-lactamase genes (blaVEB, blaVIM, blaNDM) were detected in carbapenem-resistant strains, at a higher frequency compared to other local reports. We detected two novel mutations in the quinolone-resistant determining region of the gyrA in fluoroquinolone-resistant E. coli (Leu-102-Ala; Gly-105-Val). Microbial resistance to ampicillin, methicillin, and cephalosporins was identified as important risk factors associated with HAIs in the hospital.

    CONCLUSION: Overall, our findings may provide valuable insight into the microbial resistance pattern and the risk factors of ESKAPEE-associated HAIs in a tertiary hospital located in central Peninsular Malaysia. The data obtained in this study may contribute to informing better hospital infection control in this region.

  17. Teh CSJ, Lau MY, Chong CW, Ngoi ST, Chua KH, Lee WS, et al.
    J Microbiol Methods, 2021 04;183:106184.
    PMID: 33662480 DOI: 10.1016/j.mimet.2021.106184
    Diseases caused by typhoidal and non-typhoidal Salmonella remain a considerable threat to both developed and developing countries. Based on the clinical symptoms and serological tests, it is sometimes difficult to differentiate the Salmonella enterica serovar Paratyphi A (S. enterica serovar Paratyphi A) from serovar Typhi (S. enterica serovar Typhi). In this study, we developed a quadruplex real-time polymerase chain reaction (PCR) assay with an internal amplification control (IAC), to simultaneously differentiate S. enterica serovar Paratyphi A from serovar Typhi and to detect other Salmonella serovars which cause salmonellosis in humans. This assay was evaluated on 155 salmonellae and non-salmonellae strains and demonstrated 100% specificity in species differentiation. Inclusion of an IAC did not affect the efficiency of the assay. Further evaluation using a blind test on spiked stool, blood and food specimens showed that the detection limit was at 103 -104 CFU/mL (or g) and a high PCR efficiency with different targets (R2 > 0.99), except for S. enterica serovar Paratyphi A in blood. This assay has been applied to clinical specimens to detect the causative agents of gastrointestinal infections and has successfully identified 6 salmonellosis patients from the 50 diarrhoea patients. The quadruplex real-time PCR developed in this study could enhance the detection and differentiation of salmonellae. This assay could be applied to stools, blood and food based on the notable performance in the simulation tests and field evaluation.
  18. Yap PC, Ayuhan N, Woon JJ, Teh CSJ, Lee VS, Azman AS, et al.
    Molecules, 2021 Mar 19;26(6).
    PMID: 33808805 DOI: 10.3390/molecules26061727
    A total of 20 of isolates of lactic acid bacteria (LAB) were selected and screened for antagonistic activity against clinical strains of 30 clinical isolates of extremely drug-resistant (XDR) Acinetobacter baumannii using the well diffusion assay method. Results showed that 50% of the highly LAB strains possessed inhibitory activity against (up to 66%) of the XDR A. baumannii strains tested. The supernatant of the twenty LAB strains was subjected to gas chromatography mass spectrometry (GCMS) revealed that the common compound found in the active isolates against XDR A. baumannii was 3-Isobutyl-2,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione, a known potential diketopiperazine group. The molecular docking study against potential antibacterial targets with selected ligands was performed to predict the binding mode of interactions, which is responsible for antibacterial activity. The docking analysis of the potent compounds supported the potential antibacterial activity exhibiting high inhibition constant and binding affinity in silico.
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