Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu, India.
J Appl Microbiol. 2018 Jul;125(1):56-71. doi: 10.1111/jam.13741. Epub 2018 Apr 23.
This study aimed to evaluate the antibiofilm potential of phytol and cefotaxime combinations (PCCs) against Acinetobacter baumannii and to elucidate the molecular mechanism of their antibiofilm potential through the transcriptomic approach.
Phytol and cefotaxime combination(s) (PCC(s) [160 μg ml + 8 μg ml for microbial type culture collection (MTCC) strain and 160 μg ml + 0.5 μg ml for clinical isolate] effectively inhibited the A. baumannii biofilm formation. Additionally, light, confocal laser scanning and scanning electron microscopic analyses validated the antibiofilm potential of PCCs. Furthermore, PCCs treated A. baumannii cells showed a decreased level of hydrophobicity index compared to their respective controls. Fourier-transform infrared (FT-IR) spectra of exopolysaccharide matrix extracted from PCCs-treated A. baumannii cells showed a visible decrease in absorbance of polysaccharides, nucleic acids and protein regions compared to the spectra of untreated controls. In the blood sensitivity assay, the PCCs-treated A. baumannii plates showed reduced a number of bacterial colonies compared to their control plates. Reduced level of catalase production was also observed in the PCCs treatment compared to their controls. Transcriptomic analysis revealed the downregulation of bfmR, bap, csuA/B, ompA, pgaA, pgaC and katE biofilm virulence genes in both the A. baumannii strains on treatment with PCCs.
The obtained results of this study indicate that PCCs have potent antibiofilm activity and downregulate the biofilm-related virulence genes expression in A. baumannii.
To the best of our knowledge, this is the pioneering study, which shows the antibiofilm effect of PCCs against A. baumannii along with their molecular mechanism. The antibiofilm effect of PCCs could be a successful strategy for eradicating infections related to A. baumannii biofilms in nosocomial settings.
本研究旨在评估叶绿醇和头孢噻肟组合（PCC）对鲍曼不动杆菌的抗生物膜潜力，并通过转录组学方法阐明其抗生物膜潜力的分子机制。
叶绿醇和头孢噻肟组合（PCC）（160μg/ml+8μg/ml 用于微生物类型培养物收集（MTCC）菌株，160μg/ml+0.5μg/ml 用于临床分离株）有效抑制了鲍曼不动杆菌生物膜的形成。此外，荧光、共聚焦激光扫描和扫描电子显微镜分析验证了 PCC 的抗生物膜潜力。此外，PCC 处理的鲍曼不动杆菌细胞的疏水性指数与各自的对照相比降低。与未经处理的对照相比，从 PCC 处理的鲍曼不动杆菌细胞中提取的胞外多糖基质的傅里叶变换红外（FT-IR）光谱显示多糖、核酸和蛋白质区域的吸光度明显降低。在血液敏感性测定中，与对照平板相比，PCC 处理的鲍曼不动杆菌平板上的细菌菌落数量减少。与对照相比，PCC 处理也观察到过氧化氢酶产量降低。转录组分析显示，在两种鲍曼不动杆菌菌株中，PCC 处理后 bfmR、bap、csuA/B、ompA、pgaA、pgaC 和 katE 生物膜毒力基因的表达下调。
本研究的结果表明，PCC 具有很强的抗生物膜活性，并下调鲍曼不动杆菌生物膜相关毒力基因的表达。
据我们所知，这是一项开创性的研究，它显示了 PCC 对鲍曼不动杆菌的抗生物膜作用及其分子机制。PCC 的抗生物膜作用可能是在医院环境中根除与鲍曼不动杆菌生物膜相关感染的成功策略。
