Displaying publications 41 - 60 of 247 in total

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  1. Fulltext Enhanced Pharmaceutically Active Compounds Productivity from Streptomyces SUK 25: Optimization, Characterization, Mechanism and Techno-Economic Analysis
    Al-Shaibani MM, Radin Mohamed RMS, Zin NM, Al-Gheethi A, Al-Sahari M, El Enshasy HA
    Molecules, 2021 Apr 25;26(9).
    PMID: 33923072 DOI: 10.3390/molecules26092510
    The present research aimed to enhance the pharmaceutically active compounds' (PhACs') productivity from Streptomyces SUK 25 in submerged fermentation using response surface methodology (RSM) as a tool for optimization. Besides, the characteristics and mechanism of PhACs against methicillin-resistant Staphylococcus aureus were determined. Further, the techno-economic analysis of PhACs production was estimated. The independent factors include the following: incubation time, pH, temperature, shaker rotation speed, the concentration of glucose, mannitol, and asparagine, although the responses were the dry weight of crude extracts, minimum inhibitory concentration, and inhibition zone and were determined by RSM. The PhACs were characterized using GC-MS and FTIR, while the mechanism of action was determined using gene ontology extracted from DNA microarray data. The results revealed that the best operating parameters for the dry mass crude extracts production were 8.20 mg/L, the minimum inhibitory concentrations (MIC) value was 8.00 µg/mL, and an inhibition zone of 17.60 mm was determined after 12 days, pH 7, temperature 28 °C, shaker rotation speed 120 rpm, 1 g glucose /L, 3 g mannitol/L, and 0.5 g asparagine/L with R2 coefficient value of 0.70. The GC-MS and FTIR spectra confirmed the presence of 21 PhACs, and several functional groups were detected. The gene ontology revealed that 485 genes were upregulated and nine genes were downregulated. The specific and annual operation cost of the production of PhACs was U.S. Dollar (U.S.D) 48.61 per 100 mg compared to U.S.D 164.3/100 mg of the market price, indicating that it is economically cheaper than that at the market price.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/pathogenicity
  2. A simplified multiplex PCR assay for fast and easy discrimination of globally distributed staphylococcal cassette chromosome mec types in meticillin-resistant Staphylococcus aureus
    Ghaznavi-Rad E, Nor Shamsudin M, Sekawi Z, van Belkum A, Neela V
    J Med Microbiol, 2010 Oct;59(Pt 10):1135-1139.
    PMID: 20616192 DOI: 10.1099/jmm.0.021956-0
    A multiplex PCR assay was developed for the identification of major types and subtypes of staphylococcal cassette chromosome mec (SCCmec) in meticillin-resistant Staphylococcus aureus (MRSA) strains. The method uses a novel 9 valent multiplex PCR plus two primer pairs for S. aureus identification and detection of meticillin resistance. All 389 clinical MRSA isolates from Malaysia and 18 European isolates from the Harmony collection harbouring different SCCmec types that we tested were correctly characterized by our PCR assay. SCCmec type III and V were by far the most common types among both hospital- and community-acquired Malaysian MRSA isolates, with an apparent emergence of MRSA harbouring the IVh type.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification*; Methicillin-Resistant Staphylococcus aureus/genetics*
  3. Fulltext In Vitro Evaluations and In Vivo Toxicity and Efficacy Studies of MFM501 against MRSA
    Johari SA, Mohtar M, Syed Mohamad SA, Mohammat MF, Sahdan R, Mohamed A, et al.
    Biomed Res Int, 2017;2017:8032865.
    PMID: 28536702 DOI: 10.1155/2017/8032865
    Previously we have discovered a synthetically derived pyrrolidone alkaloid, MFM501, exhibiting good inhibitory activity against 53 MRSA and MSSA isolates with low cytotoxicity against three normal cell-lines with IC50 values at >625 µg/ml. Time-kill assay, scanning electron microscopy (SEM) analysis, in vivo oral acute toxicity test, and mice peritonitis model were carried out in this study. In the time-kill study, MFM501 showed a less than 3 log10 decrease in bacterial colony concentration value (CFU/ml) which represented a bacteriostatic action while displaying a time-dependent inhibitory mechanism. Following that, SEM analysis suggested that MFM501 may exert its inhibitory activity via cytoplasmic membrane disruption. Moreover, MFM501 showed no toxicity effect on treated mice at an estimated median acute lethal dose (LD50) value of more than 300 mg/kg and less than 2000 mg/kg. For the efficacy test, a mean effective dose (ED50) of 87.16 mg/kg was obtained via a single dose oral administration. Our data demonstrated that MFM501 has the potential to be developed further as a new, safe, and effective oral-delivered antibacterial agent against MRSA isolates.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/ultrastructure
  4. Profiling of gene expression in methicillin-resistant Staphylococcus aureus in response to cyclo-(L-Val-L-Pro) and chloramphenicol isolated from Streptomyces sp., SUK 25 reveals gene downregulation in multiple biological targets
    Zin NM, Al-Shaibani MM, Jalil J, Sukri A, Al-Maleki AR, Sidik NM
    Arch Microbiol, 2020 Oct;202(8):2083-2092.
    PMID: 32494868 DOI: 10.1007/s00203-020-01896-x
    Chloramphenicol (CAP) and cyclo-(L-Val-L-Pro) were previously isolated from Streptomyces sp., SUK 25 which exhibited a high potency against methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to profile gene expression of MRSA treated with CAP and cyclo-(L-Val-L-Pro) compounds using DNA microarray. Treatment of MRSA with CAP resulted in upregulation of genes involved in protein synthesis, suggesting the coping mechanism of MRSA due to the inhibition of protein synthesis effect from CAP. Most upregulated genes in cyclo-(L-Val-L-Pro) were putative genes with unknown functions. Interestingly, genes encoding ribosomal proteins, cell membrane synthesis, DNA metabolism, citric acid cycle and virulence were downregulated in MRSA treated with cyclo-(L-Val-L-Pro) compound, suggesting the efficacy of this compound in targeting multiple biological pathways. Contrary to CAP, with only a single target, cyclo-(L-Val-L-Pro) isolated from this study had multiple antimicrobial targets that can delay antibiotic resistance and hence is a potential antimicrobial agent of MRSA.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/genetics*
  5. Fulltext Prodigiosin inhibits bacterial growth and virulence factors as a potential physiological response to interspecies competition
    Yip CH, Mahalingam S, Wan KL, Nathan S
    PLoS One, 2021;16(6):e0253445.
    PMID: 34161391 DOI: 10.1371/journal.pone.0253445
    Prodigiosin, a red linear tripyrrole pigment, has long been recognised for its antimicrobial property. However, the physiological contribution of prodigiosin to the survival of its producing hosts still remains undefined. Hence, the aim of this study was to investigate the biological role of prodigiosin from Serratia marcescens, particularly in microbial competition through its antimicrobial activity, towards the growth and secreted virulence factors of four clinical pathogenic bacteria (methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa) as well as Staphylococcus aureus and Escherichia coli. Prodigiosin was first extracted from S. marcescens and its purity confirmed by absorption spectrum, high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). The extracted prodigiosin was antagonistic towards all the tested bacteria. A disc-diffusion assay showed that prodigiosin is more selective towards Gram-positive bacteria and inhibited the growth of MRSA, S. aureus and E. faecalis and Gram-negative E. coli. A minimum inhibitory concentration of 10 μg/μL of prodigiosin was required to inhibit the growth of S. aureus, E. coli and E. faecalis whereas > 10 μg/μL was required to inhibit MRSA growth. We further assessed the effect of prodigiosin towards bacterial virulence factors such as haemolysin and production of protease as well as on biofilm formation. Prodigiosin did not inhibit haemolysis activity of clinically associated bacteria but was able to reduce protease activity for MRSA, E. coli and E. faecalis as well as decrease E. faecalis, Salmonella Typhimurium and E. coli biofilm formation. Results of this study show that in addition to its role in inhibiting bacterial growth, prodigiosin also inhibits the bacterial virulence factor protease production and biofilm formation, two strategies employed by bacteria in response to microbial competition. As clinical pathogens were more resistant to prodigiosin, we propose that prodigiosin is physiologically important for S. marcescens to compete against other bacteria in its natural soil and surface water environments.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development
  6. Fulltext Anti-methicillin-resistance Staphylococcus aureus (MRSA) compounds from Bauhinia kockiana Korth. And their mechanism of antibacterial activity
    Chew YL, Mahadi AM, Wong KM, Goh JK
    BMC Complement Altern Med, 2018 Feb 20;18(1):70.
    PMID: 29463252 DOI: 10.1186/s12906-018-2137-5
    BACKGROUND: Bauhinia kockiana originates from Peninsular Malaysia and it is grown as a garden ornamental plant. Our previous study reported that this plant exhibited fairly strong antioxidant and antimicrobial activities. This paper focused on the assessment of the antibacterial activity of B. kockiana towards methicillin-resistance Staphylococcus aureus (MRSA), to purify and to identify the antibacterial compounds, and to determine the mechanism of antibacterial activity.

    METHODS: Antibacterial activity of B. kockiana flower was evaluated qualitatively and quantitatively using disc diffusion assay and microbroth dilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of extracts were examined. Phytochemical analysis was performed to determine the classes of phytochemicals in the extracts. Bioactivity guided isolation was employed to purify the antibacterial agents and identified via various spectroscopy methods. Scanning electron microscopy (SEM) technique was used to evaluate the antibacterial mechanism of extract and compounds isolated.

    RESULTS: B. kockiana flower was found to exhibit fairly strong antibacterial activity towards both strains of MRSA bacteria used, MIC varies from 62.5-250 μg/mL. Tannins and flavonoids have been detected in the phytochemical analysis. Gallic acid and its ester derivatives purified from ethyl acetate extract could inhibit MRSA at 250-500 μg/mL. SEM revealed that the cells have undergone plasmolysis upon treatment with the extract and compounds.

    CONCLUSION: Tannins and polyphenols are the antibacterial components towards MRSA in B. kockiana. Massive leakage of the cell content observed in treated cells showed that the phytochemicals have changed the properties of the cell membranes. Amphiphilic nature of the compounds exhibited the antibacterial activity towards MRSA via three stages: (1) cell membrane attachment; (2) cell membrane fluidity modification; and (3) cell membrane structure disruption.

    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/growth & development
  7. Fulltext Prevalence, trend and antimicrobial susceptibility of Methicillin Resistant Staphylococcus aureus in Nigeria: a systematic review
    Abubakar U, Sulaiman SAS
    J Infect Public Health, 2018;11(6):763-770.
    PMID: 29933910 DOI: 10.1016/j.jiph.2018.05.013
    BACKGROUND: Evidence to demonstrate the prevalence and trend of Methicillin Resistant Staphylococcus aureus (MRSA) infection in Nigeria is scarce. This review evaluates the prevalence, trend and antimicrobial susceptibility of clinical MRSA isolates reported in published studies.

    METHOD: Electronic search (PubMed, Scopus and Google scholar) was conducted using the following search terms: "MRSA OR Methicillin Resistant Staphylococcus aureus AND Nigeria." Reference list of selected studies was scanned to identify more studies. Studies published between 2007 and 2017 that tested at least 30 non-duplicate S. aureus isolates were selected. An independent reviewer extracted data from the studies using a standardized form.

    RESULTS: Twelve studies were included in this review. Overall, prevalence of MRSA infection increased from 18.3% (2009) to 42.3% (2013). The prevalence of MRSA infection was less than 50% in all the regions during the period under review. There was a decline in the prevalence of MRSA infection in the North-East (from 12.5% to 8.0%) between 2007 and 2012, and an increase in the South-West (from 20.2% to 47.4%) between 2006 and 2010. Wound, blood and urine specimens had the highest proportion of MRSA isolates. Non-susceptibility of MRSA strains to cotrimoxazole and tetracycline was greater than 85%.

    CONCLUSION: Prevalence of MRSA infection in Nigeria is rising, albeit regional variations. Non-susceptibility to commonly prescribed, orally available and inexpensive antibiotics was high. Antimicrobial resistance surveillance system, infection control, and antimicrobial stewardship interventions are recommended.

    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
  8. Fulltext Biophysical characterization of antibacterial compounds derived from pathogenic fungi Ganoderma boninense
    Abdullah S, Oh YS, Kwak MK, Chong K
    J Microbiol, 2021 Feb;59(2):164-174.
    PMID: 33355891 DOI: 10.1007/s12275-021-0551-8
    There have been relatively few studies which support a link between Ganoderma boninense, a phytopathogenic fungus that is particularly cytotoxic and pathogenic to plant tissues and roots, and antimicrobial compounds. We previously observed that liquid-liquid extraction (LLE) using chloroformmethanol-water at a ratio (1:1:1) was superior at detecting antibacterial activities and significant quantities of antibacterial compounds. Herein, we demonstrate that antibacterial secondary metabolites are produced from G. boninense mycelia. Antibacterial compounds were monitored in concurrent biochemical and biophysical experiments. The combined methods included high performance thin-layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. The antibacterial compounds derived from mycelia with chloroform-methanol extraction through LLE were isolated via a gradient solvent elution system using HPTLC. The antibacterial activity of the isolated compounds was observed to be the most potent against Staphylococcus aureus ATCC 25923 and multidrug-resistant S. aureus NCTC 11939. GC-MS, HPLC, and FTIR analysis confirmed two antibacterial compounds, which were identified as 4,4,14α-trimethylcholestane (m/z = 414.75; lanostane, C30H54) and ergosta-5,7,22-trien-3β-ol (m/z = 396.65; ergosterol, C28H44O). With the aid of spectroscopic evaluations, ganoboninketal (m/z = 498.66, C30H42O6), which belongs to the 3,4-seco-27-norlanostane triterpene family, was additionally characterized by 2D-NMR analysis. Despite the lack of antibacterial potential exhibited by lanostane; both ergosterol and ganoboninketal displayed significant antibacterial activities against bacterial pathogens. Results provide evidence for the existence of bioactive compounds in the mycelia of the relatively unexplored phytopathogenic G. boninense, together with a robust method for estimating the corresponding potent antibacterial secondary metabolites.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development
  9. Community-acquired methicillin-resistant Staphylococcus aureus in a Malaysian tertiary centre
    Rashid ZZ, Bahari N, Othman A, Jaafar R, Mohamed NA, Jabbari I, et al.
    Southeast Asian J Trop Med Public Health, 2013 Jan;44(1):104-8.
    PMID: 23682444
    Abstract. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a pathogen recognized to be distinct in both phenotype and genotype from hospital-acquired MRSA. We have identified CA-MRSA cases in Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia, including their antibiotic susceptibility patterns and genotypic characteristics. Cases were identified during January to December 2009 from routine clinical specimens, where culture and antibiotic susceptibility results yielded pauci-resistant MRSA isolates suspected as being CA-MRSA. The patients' clinical data were collected and their specimens were sent for molecular confirmation and analysis. Five cases of CA-MRSA were identified, which had a multi-sensitive pattern on antibiotic susceptibility tests and were resistant to only penicillin and oxacillin. All cases were skin and soft-tissue infections, including diabetic foot with gangrene, infected scalp hematoma, philtrum abscess in a healthcare worker, thrombophlebitis complicated with abscess and infected bedsore. All five cases were confirmed MRSA by detection of mecA. SCCmec typing (ccr and mec complex) revealed SCCmec type IV for all cases except the infected bedsore case. Panton-Valentine leukocidin gene was positive in all isolates. As clinical features among methicillin-sensitive Staphylococcus aureus, CA-MRSA and "nosocomial CA-MRSA" are indistinct, early recognition is necessary in order to initiate appropriate antibiotics and infection control measures. Continual surveillance of pauci-resistant MRSA and molecular analysis are necessary in order to identify emerging strains as well as their epidemiology and transmission, both in the community and in healthcare setting.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/growth & development*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
  10. Fulltext In vitro inhibitory and cytotoxic activity of MFM 501, a novel codonopsinine derivative, against Methicillin-Resistant Staphylococcus aureus clinical isolates
    Johari SA, Mohtar M, Mohammad SA, Sahdan R, Shaameri Z, Hamzah AS, et al.
    Biomed Res Int, 2015;2015:823829.
    PMID: 25710030 DOI: 10.1155/2015/823829
    28 new pyrrolidine types of compounds as analogues for natural polyhydroxy alkaloids of codonopsinine were evaluated for their anti-MRSA activity using MIC and MBC value determination assay against a panel of S. aureus isolates. One pyrrolidine compound, MFM 501, exhibited good inhibitory activity with MIC value of 15.6 to 31.3 μg/mL against 55 S. aureus isolates (43 MRSA and 12 MSSA isolates). The active compound also displayed MBC values between 250 and 500 μg/mL against 58 S. aureus isolates (45 MRSA and 13 MSSA isolates) implying that MFM 501 has a bacteriostatic rather than bactericidal effect against both MRSA and MSSA isolates. In addition, MFM 501 showed no apparent cytotoxicity activity towards three normal cell lines (WRL-68, Vero, and 3T3) with IC50 values of >625 µg/mL. Selectivity index (SI) of MFM 501 gave a value of >10 suggesting that MFM 501 is significant and suitable for further in vivo investigations. These results suggested that synthetically derived intermediate compounds based on natural products may play an important role in the discovery of new anti-infective agents against MRSA.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/cytology; Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/physiology*
  11. Fulltext Emergence of SCCmec type III with variable antimicrobial resistance profiles and spa types among methicillin-resistant Staphylococcus aureus isolated from healthcare- and community-acquired infections in the west of Iran
    Mohammadi S, Sekawi Z, Monjezi A, Maleki MH, Soroush S, Sadeghifard N, et al.
    Int J Infect Dis, 2014 Aug;25:152-8.
    PMID: 24909489 DOI: 10.1016/j.ijid.2014.02.018
    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of public health importance. The prevalence of MRSA and its antimicrobial resistance pattern, as well as SCCmec and spa types, remain unclear both in the community and in the hospitals of the western region of Iran.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification; Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/genetics*
  12. Fulltext Draft Genome Sequence of Methicillin-Resistant Staphylococcus aureus KT/Y21, a Sequence Type 772 (ST772) Strain Isolated from a Pediatric Blood Sample in Terengganu, Malaysia
    Suhaili Z, Lean SS, Yahya A, Mohd Desa MN, Ali AM, Yeo CC
    Genome Announc, 2014;2(2).
    PMID: 24723714 DOI: 10.1128/genomeA.00271-14
    Here, we report the draft genome sequence of a methicillin-resistant Staphylococcus aureus (MRSA) strain, KT/Y21, isolated from a blood sample of a pediatric patient. This strain belongs to sequence type 772 (ST772), harbors the staphylococcal cassette chromosome mec element (SCCmec) type V, and is positive for the Panton-Valentine leukocidin (PVL) pathogenic determinant.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
  13. Short communication: prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis
    Jamali H, Radmehr B, Ismail S
    J Dairy Sci, 2014;97(4):2226-30.
    PMID: 24534509 DOI: 10.3168/jds.2013-7509
    The aims of this study were to determine the prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis in Varamin, Tehran Province, Iran. All of the isolated Staph. aureus were identified by morphology and culture and confirmed using the API Staph identification system (bioMérieux, Marcy-l'Étoile, France). Antibiotic resistance genes were detected by PCR with oligonucleotide primers specific for each gene. Staphylococcus aureus was recovered from 43 of 207 (20.1%) bovine clinical milk samples. Using disk diffusion, methicillin-resistant Staph. aureus was detected in 5 of 43 (11.6%) samples. The pathogen showed high resistance against penicillin G (86%) and tetracycline (76.7%). The blaZ (penicillin) (86%), tetM (tetracycline), and ermC (erythromycin) genes (39.5% each) were the most prevalent antibiotic resistance genes. The findings of this study are useful for designing specific control programs for bovine clinical mastitis caused by Staph. aureus in this region of Iran.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/metabolism
  14. Quantitative PCR analysis of genes expressed during biofilm development of methicillin resistant Staphylococcus aureus (MRSA)
    Atshan SS, Shamsudin MN, Karunanidhi A, van Belkum A, Lung LT, Sekawi Z, et al.
    Infect Genet Evol, 2013 Aug;18:106-12.
    PMID: 23669446 DOI: 10.1016/j.meegid.2013.05.002
    Staphylococcus aureus biofilm associated infections remains a major clinical concern in patients with indwelling devices. Quantitative real-time PCR (qPCR) can be used to investigate the pathogenic role of such biofilms. We describe qPCRs for 12 adhesion and biofilm-related genes of four S. aureus isolates which were applied during in vitro biofilm development. An endogenous control (16S rRNA) was used for signal normalization. We compared the qPCR results with structural analysis using scanning electron microscopy (SEM). The SEM studies showed different cellular products surrounding the aggregated cells at different times of biofilm formation. Using qPCR, we found that expression levels of the gene encoding fibronectin binding protein A and B and clumping factor B (fnbA/B and clfB), which involves in primary adherence of S. aureus, were significantly increased at 24h and decreased slightly and variably at 48 h when all 4 isolates were considered. The elastin binding protein (ebps) RNA expression level was significantly enhanced more than 6-fold at 24 and 48 h compared to 12h. Similar results were obtained for the intercellular adhesion biofilm required genes type C (icaC). In addition, qPCR revealed a fluctuation in expression levels at different time points of biofilm growth of other genes, indicating that different parameter modes of growth processes are operating at different times.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/metabolism; Methicillin-Resistant Staphylococcus aureus/physiology*
  15. Fulltext Acute haematogenous community-acquired methicillin-resistant Staphylococcus aureus osteomyelitis in an adult: case report and review of literature
    Dhanoa A, Singh VA, Mansor A, Yusof MY, Lim KT, Thong KL
    BMC Infect Dis, 2012;12:270.
    PMID: 23098162 DOI: 10.1186/1471-2334-12-270
    Methicillin-resistant Staphylococcus aureus (MRSA) has of late emerged as a cause of community-acquired infections among immunocompetent adults without risk factors. Skin and soft tissue infections represent the majority of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clinical presentations, whilst invasive and life-threatening illness like necrotizing pneumonia, necrotizing fasciitis, pyomyositis, osteomyelitis and sepsis syndrome are less common. Although more widely described in the pediatric age group, the occurrence of CA-MRSA osteomyelitis in adults is an uncommonly reported entity.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  16. Comparative evaluation of five culture media with triplex PCR assay for detection of methicillin-resistant Staphylococcus aureus
    Al-Talib H, Yean CY, Al-khateeb A, Singh KK, Hasan H, Al-Jashamy K, et al.
    Curr Microbiol, 2010 Jul;61(1):1-6.
    PMID: 20033170 DOI: 10.1007/s00284-009-9567-8
    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) is responsible for nosocomial and community-acquired infections. Hence, rapid and accurate laboratory diagnosis of MRSA is a vital constituent of control measures. The present study evaluated five different methods for the identification of MRSA. A total of 207 S. aureus clinical isolates that consisted of 89 MRSA and 118 methicillin-susceptible S. aureus (MSSA) strains confirmed by PCR were tested. MRSA strains were evaluated by five different methods: chromogenic MRSA agar (CMRSA), oxacillin resistance screening agar base (ORSAB), mannitol salt oxacillin agar (MSO), mannitol salt cefoxitin agar with two different concentrations of cefoxitin [4 microg/ml (MSC-4) and 6 microg/ml (MSC-6)]. The results of the different methods were compared to mecA PCR as the gold standard. MSC-6 showed only six false-positive MRSA in comparison with PCR. The sensitivities and specificities of MSC-6, MSC-4, MSO-4, ORSAB, and CMRSA were as follows: 98.9/94.9%, 100/83.1%, 89.9/87.3%, 97.8/96.6%, and 95.5/94.9%, respectively. In comparison with PCR, it was found that both MSC-6 and ORSAB were relatively the least expensive screening tests ($0.70 and $1.00, respectively). In conclusion, all methods were comparable, but MSC-6 was the least expensive medium for MRSA screening.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  17. Fulltext Transcriptional profiles of the response of methicillin-resistant Staphylococcus aureus to pentacyclic triterpenoids
    Chung PY, Chung LY, Navaratnam P
    PLoS One, 2013;8(2):e56687.
    PMID: 23437212 DOI: 10.1371/journal.pone.0056687
    Staphylococcus aureus is an important human pathogen in both hospital and the community that has demonstrated resistance to all currently available antibiotics over the last two decades. Multidrug-resistant isolates of methicillin-resistant S. aureus (MRSA) exhibiting decreased susceptibilities to glycopeptides has also emerged, representing a crucial challenge for antimicrobial therapy and infection control. The availability of complete whole-genome nucleotide sequence data of various strains of S. aureus presents an opportunity to explore novel compounds and their targets to address the challenges presented by antimicrobial drug resistance in this organism. Study compounds α-amyrin [3β-hydroxy-urs-12-en-3-ol (AM)], betulinic acid [3β-hydroxy-20(29)-lupaene-28-oic acid (BA)] and betulinaldehyde [3β-hydroxy-20(29)-lupen-28-al (BE)] belong to pentacyclic triterpenoids and were reported to exhibit antimicrobial activities against bacteria and fungi, including S. aureus. The MIC values of these compounds against a reference strain of methicillin-resistant S. aureus (MRSA) (ATCC 43300) ranged from 64 µg/ml to 512 µg/ml. However, the response mechanisms of S. aureus to these compounds are still poorly understood. The transcription profile of reference strain of MRSA treated with sub-inhibitory concentrations of the three compounds was determined using Affymetrix GeneChips. The findings showed that these compounds regulate multiple desirable targets in cell division, two-component system, ABC transporters, fatty acid biosynthesis, peptidoglycan biosynthesis, aminoacyl-tRNA synthetase, ribosome and β-lactam resistance pathways which could be further explored in the development of therapeutic agents for the treatment of S. aureus infections.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/pathogenicity
  18. Fulltext Draft Genome Sequences of Four Nosocomial Methicillin-Resistant Staphylococcus aureus (MRSA) Strains (PPUKM-261-2009, PPUKM-332-2009, PPUKM-377-2009, and PPUKM-775-2009) Representative of Dominant MRSA Pulsotypes Circulating in a Malaysian University Teaching Hospital
    Neoh HM, Mohamed-Hussein ZA, Tan XE, B Raja Abd Rahman RM, Hussin S, Mohamad Zin N, et al.
    Genome Announc, 2013 Jan;1(1).
    PMID: 23405328 DOI: 10.1128/genomeA.00103-12
    Here, we report the draft genome sequences of four nosocomial methicillin-resistant Staphylococcus aureus strains (PPUKM-261-2009, PPUKM-332-2009, PPUKM-377-2009, and PPUKM-775-2009) isolated from a university teaching hospital in Malaysia. Three of the strains belong to sequence type 239 (ST239), which has been associated with sustained hospital epidemics worldwide.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
  19. Fulltext Inhibition of penicillin-binding protein 2a (PBP2a) in methicillin resistant Staphylococcus aureus (MRSA) by combination of ampicillin and a bioactive fraction from Duabanga grandiflora
    Santiago C, Pang EL, Lim KH, Loh HS, Ting KN
    BMC Complement Altern Med, 2015;15:178.
    PMID: 26060128 DOI: 10.1186/s12906-015-0699-z
    The inhibition of penicillin-binding protein 2a (PBP2a) is a promising solution in overcoming resistance of methicillin resistance Staphylococcus aureus (MRSA). A potential approach in achieving this is by combining natural product with currently available antibiotics to restore the activity as well as to amplify the therapeutic ability of the drugs. We studied inhibition effects of a bioactive fraction, F-10 (isolated from the leaves of Duabanga grandiflora) alone and in combination with a beta-lactam drug, ampicillin on MRSA growth and expression of PBP2a. Additionally, phytochemical analysis was conducted on F-10 to identify the classes of phytochemicals present.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/growth & development; Methicillin-Resistant Staphylococcus aureus/metabolism
  20. Fulltext Prevention of cell-surface attachment and reduction of penicillin-binding protein 2a (PBP2a) level in methicillin-resistant Staphylococcus aureus biofilms by Acalypha wilkesiana
    Santiago C, Lim KH, Loh HS, Ting KN
    BMC Complement Altern Med, 2015;15:79.
    PMID: 25880167 DOI: 10.1186/s12906-015-0615-6
    Formation of biofilm is known to enhance the virulence of methicillin-resistance Staphylococcus aureus (MRSA), which is associated with persistent infections in hospital settings. The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics. We have isolated 9EA-FC-B bioactive fraction from Acalypha wilkesiana Müll. Arg. that reverses ampicillin resistant in MRSA through inhibition of the antibiotic resistant protein, penicillin-binding protein 2a (PBP2a). In this study, we aimed to investigate the effects of 9EA-FC-B on MRSA biofilm forming capacity.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/metabolism; Methicillin-Resistant Staphylococcus aureus/pathogenicity
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