Santiago Carolina, Lim Kuan-Hon, Loh Hwei-San, Ting Kang Nee
Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, Semenyih, Selangor 43500, Malaysia.
Molecules. 2015 Mar 10;20(3):4473-82. doi: 10.3390/molecules20034473.
Formation of biofilms is a major factor for nosocomial infections associated with methicillin-resistance Staphylococcus aureus (MRSA). This study was carried out to determine the ability of a fraction, F-10, derived from the plant Duabanga grandiflora to inhibit MRSA biofilm formation. Inhibition of biofilm production and microtiter attachment assays were employed to study the anti-biofilm activity of F-10, while latex agglutination test was performed to study the influence of F-10 on penicillin-binding protein 2a (PBP2a) level in MRSA biofilm. PBP2a is a protein that confers resistance to beta-lactam antibiotics. The results showed that, F-10 at minimum inhibitory concentration (MIC, 0.75 mg/mL) inhibited biofilm production by 66.10%; inhibited cell-surface attachment by more than 95%; and a reduced PBP2a level in the MRSA biofilm was observed. Although ampicilin was more effective in inhibiting biofilm production (MIC of 0.05 mg/mL, 84.49%) compared to F-10, the antibiotic was less effective in preventing cell-surface attachment. A higher level of PBP2a was detected in ampicillin-treated MRSA showing the development of further resistance in these colonies. This study has shown that F-10 possesses anti-biofilm activity, which can be attributed to its ability to reduce cell-surface attachment and attenuate the level of PBP2a that we postulated to play a crucial role in mediating biofilm formation.
生物膜的形成是耐甲氧西林金黄色葡萄球菌（MRSA）引起医院感染的主要因素。本研究旨在确定从大花八宝树植物中提取的F-10组分抑制MRSA生物膜形成的能力。采用生物膜产生抑制试验和微量滴定板黏附试验研究F-10的抗生物膜活性，同时进行乳胶凝集试验研究F-10对MRSA生物膜中青霉素结合蛋白2a（PBP2a）水平的影响。PBP2a是一种赋予对β-内酰胺类抗生素耐药性的蛋白质。结果表明，F-10在最低抑菌浓度（MIC，0.75mg/mL）时可抑制66.10%的生物膜产生；抑制细胞表面黏附超过95%；并且观察到MRSA生物膜中PBP2a水平降低。尽管氨苄西林在抑制生物膜产生方面（MIC为0.05mg/mL，84.49%）比F-10更有效，但该抗生素在防止细胞表面黏附方面效果较差。在氨苄西林处理的MRSA中检测到更高水平的PBP2a，表明这些菌落产生了进一步的耐药性。本研究表明，F-10具有抗生物膜活性，这可归因于其降低细胞表面黏附以及降低PBP2a水平的能力，我们推测PBP2a在介导生物膜形成中起关键作用。
