Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Microbiology and Immunology, Kaohsiung Medical University, Kaohsiung, Taiwan.
J Microbiol Immunol Infect. 2017 Feb;50(1):46-54. doi: 10.1016/j.jmii.2014.12.007. Epub 2015 Jan 10.
BACKGROUND/OBJECTIVES: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized as a leading pathogen and has been shown to be genetically different from the health care-associated MRSA (HA-MRSA). Photodynamic therapy (PDT) is considered a potential alternative method for the treatment of resistant bacterial infections, but the effect of PDT on CA-MRSA is unknown. The purpose of this study was to compare the bactericidal effects of toluidine blue O (TBO) on CA-MRSA and HA-MRSA and investigate the photodynamic inactivation effects of TBO (TBO-PDI) against bacterial virulence factors.
TBO-PDI effects were determined by measuring the survival fractions for four strains and bactericidal activities for 26 CA-MRSA isolates and 26 HA-MRSA isolates. The influences of TBO-PDI on DNA fragmentation and the activities of protease, lipase, staphylococcal α-hemolysin, and enterotoxin were studied.
TBO-PDI has effective bactericidal activity against both CA- and HA-MRSA. However, the bactericidal activity of TBO-PDI was significantly higher against HA-MRSA than CA-MRSA isolates. In addition, TBO-PDI treatment using a sublethal TBO concentration led to reduced production of several virulence factors, including protease, lipase, staphylococcal α-hemolysin, and enterotoxin.
Although TBO-PDI is slightly less effective against CA-MRSA than HA-MRSA isolates, TBO-PDI could reduce the production of virulence factors at a sublethal TBO concentration, which would be beneficial for treating CA-MRSA infections.
背景/目的：社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）被认为是一种主要病原体，其与医院获得性耐甲氧西林金黄色葡萄球菌（HA-MRSA）在遗传上有所不同。光动力疗法（PDT）被认为是治疗耐药细菌感染的一种潜在替代方法，但 PDT 对 CA-MRSA 的效果尚不清楚。本研究旨在比较甲苯胺蓝 O（TBO）对 CA-MRSA 和 HA-MRSA 的杀菌效果，并研究 TBO 的光动力灭活作用（TBO-PDI）对细菌毒力因子的影响。
通过测量四种菌株的存活分数和 26 株 CA-MRSA 分离株和 26 株 HA-MRSA 分离株的杀菌活性来确定 TBO-PDI 的效果。研究了 TBO-PDI 对 DNA 片段化和蛋白酶、脂肪酶、葡萄球菌α-溶血素和肠毒素活性的影响。
TBO-PDI 对 CA-和 HA-MRSA 均具有有效的杀菌活性。然而，TBO-PDI 对 HA-MRSA 的杀菌活性明显高于 CA-MRSA 分离株。此外，使用亚致死 TBO 浓度的 TBO-PDI 处理导致几种毒力因子（包括蛋白酶、脂肪酶、葡萄球菌α-溶血素和肠毒素）的产生减少。
尽管 TBO-PDI 对 CA-MRSA 的效果略低于 HA-MRSA 分离株，但 TBO-PDI 可在亚致死 TBO 浓度下降低毒力因子的产生，这将有利于治疗 CA-MRSA 感染。
