RESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) is a multi-drug resistant pathogenic bacteria, which has seriously threatened human health for a long time. Discovery of novel anti-MRSA lead compounds with high efficiency and low toxicity represents an important research focus in the realm of antibiotic studies. Owing to their structural diversity and complexity, natural products have exhibited unique advantages and great potential in the development of anti-MRSA new drugs. This review summarizes the studies of anti-MRSA natural products and their relevant medicinal chemistry reported since 2010.
RESUMEN
Marine endophytic bacteria are a valuable source of novel antibacterial in combating pathogenic isolates of methicillin-resistant Staphylococcus aureus (MRSA), a global nosocomial problem today. The aim of this study was to assess in vitro anti-MRSA activity of extracts from bacteria endophyte of marine sponge Haliclona fascigera collected from Setan Island, South Coast of West Sumatra, Indonesia. Anti-MRSA activity test carried out by the agar diffusion method using paper disk. The endophytic bacteria from sponge were isolated using dilution method and pour plate method on NA media. From the sponge were obtained 26 isolates of bacterial endophytic then propagated in NB media. The liquid media was then extracted using ethyl acetate solvent. Antimicrobial activity test carried out by the agar diffusion method using paper disk. The antibacterial activity assay was conducted with the extract concentrations of 5 %. Chloramphenicol was used as a positive control agent. The zone of inhibition was measured and expressed in millimeters. There were 12 isolates of the bacteria that considered active to MRSA. Mean of inhibition zones ranged from 11.1±0.17 to 15.17±0.76. Characterization and identification of endophytic bacteria were conducted to several bioactive bacteria. The identification method was performed using Gram staining and biochemical test.
RESUMEN
Aim: Phyllanthus columnaris Müll.Arg. was found to possess anti-methicillin resistant Staphylococcus aureus (antiMRSA) activities. This study aimed at isolating, identifying and evaluating the active compounds from the stem bark of Phyllanthus columnaris Müll.Arg. against MRSA. Methodology and results: Stem bark extracts (methanol, acetone and aqueous) of Phyllanthus columnaris were subjected to anti-MRSA screening by disc diffusion method. MIC and MBC tests were carried out to compare the lowest concentration to inhibit and kill the sixteen MRSA tested among the three extracts. TLC bioautography were performed to detect the bioactive compounds. Isolation of the two active compounds was performed by means of preparative TLC. Morphological and ultra-structure alterations of the MRSA treated with bioactive compounds after 24 h were revealed by scanning and transmission electron microscopy. Both methanol and acetone extracts exhibited good anti-MRSA activity with the lowest minimum inhibitory concentration (MIC) value for both extracts were 0.78 mg/mL and the lowest minimum bactericidal concentration (MBC) were 1.56 mg/mL. Bioassay-guided chromatography by bioautography revealed two active anti-MRSA compounds from both tannin-free methanol and acetone extracts and characterized as stigmasterol and lupeol by nuclear magnetic resonance (NMR) spectral data. Scanning and transmission electron microscopy of MRSA treated with stigmasterol and lupeol showed cell wall disruption, release of cytoplasmic compounds and decreased in cellular volume. Conclusion, significance and impact of study: Results obtained herein, may suggest that the stem bark of Phyllanthus columnaris possess anti-MRSA and the two of the active compounds isolated were stigmasterol and lupeol. Their anti-MRSA effects up to the morphological and ultra-structure studies were not reported earlier