UPMC Eye Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
J Ocul Pharmacol Ther. 2010 Dec;26(6):557-62. doi: 10.1089/jop.2010.0097. Epub 2010 Oct 28.
The aim of this study was to analyze the effect of azithromycin (AZM) 1% ophthalmic solution in DuraSite® (AzaSite®) on biofilm formation by Staphylococcus aureus and coagulase-negative staphylococci in vitro.
Susceptible and resistant clinical strains (n = 8) of S. aureus and coagulase-negative staphylococci were challenged with serial dilutions of AzaSite® and its components: AZM, benzalkonium chloride (BAK), and the DuraSite drug delivery vehicle. After 20 h of incubation, bacterial growth was quantified using a spectrophotometer (A = 600 nm). Plates were stained with crystal violet and biofilm formation was quantified spectrophotometrically at A = 590 nm.
AzaSite® and AZM inhibited bacterial growth (P < 0.05) and biofilm formation (P < 0.05) in AZM-susceptible strains at all studied dilutions. AZM-resistant strains treated with AzaSite® exhibited a significant reduction in biofilm formation (P < 0.05) at subinhibitory concentrations (1.25%-5%). AZM had no effect on bacterial growth in resistant strains but conferred a small reduction in biofilm formation at concentrations from 1.25 to 10 mg/mL in most strains. DuraSite® inhibited biofilm formation at concentrations between 10% and 2.5% in all studied strains (P < 0.05), without affecting bacterial growth. BAK inhibited bacterial growth and biofilm formation in all strains between concentrations of 0.042 and 0.375 mg/mL (P < 0.05).
AzaSite®, AZM, or BAK prevented biofilm formation by inhibiting growth of AZM-susceptible strains. AzaSite®, AZM, and DuraSite® also reduced biofilm formation at subinhibitory concentrations for growth. Our data indicate that AZM has a moderate inhibitory effect on biofilm formation, whereas DuraSite® appears to play a greater role in the inhibition of staphylococcal biofilm formation by AzaSite®.
本研究旨在分析 1%阿奇霉素（AZM）眼用溶液（DuraSite®，AzaSite®）对金黄色葡萄球菌和凝固酶阴性葡萄球菌体外生物膜形成的影响。
采用 AzaSite®及其成分（AZM、苯扎氯铵（BAK）和 DuraSite 药物输送载体）对敏感和耐药临床分离株（金黄色葡萄球菌和凝固酶阴性葡萄球菌，n=8）进行连续稀释，孵育 20 小时后，使用分光光度计（A=600nm）定量细菌生长。结晶紫染色平板，A=590nm 处分光光度法定量生物膜形成。
在所有研究稀释度下，AzaSite®和 AZM 均抑制了敏感株的细菌生长（P<0.05）和生物膜形成（P<0.05）。用 AzaSite®处理的 AZM 耐药株在亚抑菌浓度（1.25%-5%）下表现出生物膜形成的显著减少（P<0.05）。AZM 对耐药株的细菌生长没有影响，但在大多数菌株中，浓度为 1.25 至 10mg/mL 时，生物膜形成减少。DuraSite®在所有研究菌株中均抑制生物膜形成，浓度为 10%至 2.5%（P<0.05），而不影响细菌生长。BAK 在 0.042 至 0.375mg/mL 浓度之间抑制所有菌株的细菌生长和生物膜形成（P<0.05）。
AzaSite®、AZM 或 BAK 通过抑制敏感株的生长来防止生物膜形成。AzaSite®、AZM 和 DuraSite® 还在亚抑菌浓度下减少生长时的生物膜形成。我们的数据表明，AZM 对生物膜形成具有中度抑制作用，而 DuraSite®似乎在抑制 AzaSite®引起的金黄色葡萄球菌生物膜形成方面发挥更大作用。
