Drilling Amanda, Morales Sandra, Jardeleza Camille, Vreugde Sarah, Speck Peter, Wormald Peter-John
Department of Surgery-Otolaryngology Head and Neck Surgery, The Queen Elizabeth Hospital, Woodville South, South Australia, Australia.
Am J Rhinol Allergy. 2014 Jan-Feb;28(1):3-11. doi: 10.2500/ajra.2014.28.4001.
Staphylococcus aureus is the most common organism in recalcitrant chronic rhinosinusitis (CRS) and is often resistant to traditional antibiotic therapy. Bacteriophages ("phages") are a potential candidate for a new, effective therapy. For phages to be useful in the setting of CRS, two minimum requirements must be presented: (1) phages must be effective against S. aureus biofilms and (2) phages must have a broad spectrum of activity. This study aimed to assess the in vitro activity of a phage cocktail (CockTail of Staphylococcus aureus specific bacteriophage [CT-SA]) against S. aureus biofilms and a broad panel of strains isolated from patients with CRS.
The study examined 66 clinical isolates (CIs) of S. aureus. All isolates were tested for the susceptibility to phage lysis by spotting CT-SA onto bacterial lawns. To measure its effect on S. aureus biofilms, a minimum biofilm eradication concentration assay was used, using five S. aureus isolates. Biofilms of these isolates were grown, treated with CT-SA for 48 hours, fluorescently stained, and viewed using confocal scanning laser microscopy.
CT-SA lysed 62 of 66 (94%) CIs of S. aureus. CT-SA treatment yielded significant reductions in biofilm mass for 4/5 CIs tested and for ATCC 25923. Challenge of S. aureus with a single phage resulted in the emergence of bacteriophage-insensitive mutants (BIM) with a frequency of 10(-7), and challenge with CT-SA completely prevented their development.
This study indicates that phage cocktail CT-SA can effectively eliminate S. aureus, in planktonic and biofilm forms, from the great majority of CIs from this hospital setting. In addition, its potential effect in preventing the emergence of BIMs was also established. Thus, CT-SA has the potential to treat S. aureus infection and biofilm in CRS patients.
金黄色葡萄球菌是顽固性慢性鼻-鼻窦炎（CRS）中最常见的病原体，且常常对传统抗生素治疗耐药。噬菌体是一种新型有效治疗方法的潜在候选者。要使噬菌体在CRS治疗中发挥作用，必须满足两个最低要求：（1）噬菌体必须对金黄色葡萄球菌生物膜有效；（2）噬菌体必须具有广泛的活性谱。本研究旨在评估一种噬菌体鸡尾酒（金黄色葡萄球菌特异性噬菌体鸡尾酒[CT-SA]）对金黄色葡萄球菌生物膜以及从CRS患者中分离出的多种菌株的体外活性。
本研究检测了66株金黄色葡萄球菌临床分离株（CIs）。通过将CT-SA点种在细菌菌苔上，检测所有分离株对噬菌体裂解的敏感性。为了测量其对金黄色葡萄球菌生物膜的影响，使用5株金黄色葡萄球菌分离株进行了最低生物膜清除浓度测定。使这些分离株形成生物膜，用CT-SA处理48小时，进行荧光染色，然后使用共聚焦扫描激光显微镜观察。
CT-SA裂解了66株金黄色葡萄球菌CIs中的62株（94%）。CT-SA处理使所检测的5株CIs以及ATCC 25923的生物膜量显著减少。用单一噬菌体攻击金黄色葡萄球菌会导致噬菌体不敏感突变体（BIM）以10^(-7)的频率出现，而用CT-SA攻击则完全阻止了它们的产生。
本研究表明，噬菌体鸡尾酒CT-SA能够有效地从该医院环境中的绝大多数CIs中清除浮游和生物膜形式的金黄色葡萄球菌。此外，还证实了其在预防BIMs出现方面的潜在作用。因此，CT-SA有潜力治疗CRS患者的金黄色葡萄球菌感染和生物膜。
