Peng Xudong, Ekanayaka Sandamali A, McClellan Sharon A, Barrett Ronald P, Vistisen Kerry, Hazlett Linda D
Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 540 E. Canfield Avenue, Detroit, MI 48201, USA.
Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao 266071, China.
Pathogens. 2017 Oct 24;6(4):52. doi: 10.3390/pathogens6040052.
We selectively characterized three isolates from keratitis patients and how glycyrrhizin (GLY) affected them. Type III toxins were determined using polymerase chain reaction (PCR). Minimum Inhibitory Concentration (MIC) of GLY and assays for its effects on: time kill, bacterial permeability, and biofilm/adhesion were done. In vivo, C57BL/6 (B6) mice were treated topically with GLY after G81007 infection. Clinical score, photography with a slit lamp and RT-PCR were used to assess treatment effects. Isolates expressed and , but not . MIC for all isolates was 40 mg/mL GLY and bacteriostatic effects were seen for G81007 after treatment using time kill assays. From viability testing, GLY treatment significantly increased the number of permeabilized bacteria (live/dead assay). Isolates 070490 and G81007 formed more biofilms compared with R59733 and PAO1 (control). GLY-treated bacteria had diminished biofilm compared with controls for all isolates. GLY reduced adherence of the G81007 isolate to cultured cells and affected specific biofilm associated systems tested by reverse transcription PCR (RT-PCR). In vivo, after G81007 infection, GLY treatment reduced clinical score and messenger RNA (mRNA) expression of IL-1β, TNF-α, CXCL2 and HMGB1. This study provides evidence that GLY is bacteriostatic for G81007. It also affects biofilm production, adherence to cultured cells, and an improved keratitis outcome.
我们从角膜炎患者中选择性地鉴定了三株分离菌，并研究了甘草酸（GLY）对它们的影响。使用聚合酶链反应（PCR）测定III型毒素。测定了GLY的最低抑菌浓度（MIC）及其对时间杀菌、细菌通透性和生物膜/黏附的影响。在体内，G81007感染后，对C57BL/6（B6）小鼠进行GLY局部治疗。通过临床评分、裂隙灯摄影和逆转录聚合酶链反应（RT-PCR）评估治疗效果。分离菌表达了 和 ，但未表达 。所有分离菌对GLY的MIC为40mg/mL，在使用时间杀菌试验处理后，G81007呈现抑菌作用。通过活力测试，GLY处理显著增加了通透化细菌的数量（活菌/死菌试验）。与R59733和PAO1（对照）相比，分离菌070490和G81007形成了更多的生物膜。与对照相比，GLY处理的所有分离菌生物膜均减少。GLY降低了G81007分离菌对培养细胞的黏附，并影响了通过逆转录PCR（RT-PCR）检测的特定生物膜相关系统。在体内，G81007感染后，GLY治疗降低了临床评分以及白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、CXC趋化因子配体2（CXCL2）和高迁移率族蛋白B1（HMGB1）的信使核糖核酸（mRNA）表达。本研究提供了证据表明GLY对G81007具有抑菌作用。它还影响生物膜的产生、对培养细胞的黏附，并改善角膜炎的转归。
