Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea.
Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea.
J Hosp Infect. 2020 Oct;106(2):295-302. doi: 10.1016/j.jhin.2020.07.010. Epub 2020 Jul 15.
The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study.
To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates.
MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet.
Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin).
Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.
抗菌药物亚抑菌浓度（sub-MICs）对金黄色葡萄球菌生物膜形成能力的影响需要进一步研究。
研究氯己定和莫匹罗星的亚 MICs 对临床耐甲氧西林金黄色葡萄球菌（MRSA）分离株生物膜形成的影响。
从一家三级医院血流感染患者中收集 MRSA 分离株。通过结晶紫染色测量生物膜质量来评估氯己定和莫匹罗星亚 MICs 对生物膜形成的基础水平和诱导作用。
在测试的 112 株 MRSA 分离株中，63 株（56.3%）和 44 株（39.3%）分别属于序列型（ST）5 和 ST72 谱系，这是韩国主要的医疗保健和社区相关克隆。与 ST72 分离株相比，ST5 分离株更有可能具有氯己定 MIC≥4（73.0%比 29.5%）、对莫匹罗星耐药（23.8%比 0%）、agr 功能障碍（73.0%比 9.1%）和 qacA/B 基因（58.7%比 2.3%）。与 ST72 分离株相比，ST5 分离株的生物膜形成能力基础水平经常更强（77.3%比 12.7%）。氯己定和莫匹罗星的亚 MICs 分别促进了所有分离株中 56.3%和 53.6%的生物膜形成。在 ST5 分离株中，生物膜诱导更为普遍（氯己定 85.7%，莫匹罗星 69.8%），而在 ST72 分离株中则不太普遍（氯己定 15.9%，莫匹罗星 27.3%）。
氯己定和莫匹罗星的亚 MICs 促进了一半的临床 MRSA 分离株的生物膜形成。我们的结果表明，暴露于氯己定后，ST5MRSA 生物膜可以与其他一些细菌毒力因子一起被诱导，这可能使该克隆在医疗保健环境中具有生存优势。
