Data Sheet 1_Silver-coated silicone stents as an approach to prevent bacterial colonization of central airways after tracheobronchial stenting.pdf

RationaleTracheobronchial stents are used to treat central airway obstruction but frequently develop bacterial colonization that can lead to infection.
ObjectivesTo identify the microorganisms responsible for stent colonization and to evaluate the in vitro ability of silver-coated silicone to reduce their growth.
MethodsBacterial identification and quantification were performed on bronchial washings obtained prospectively from 30 patients before and at the first follow-up after stent placement. Bacterial viability on silver-coated silicone was determined for six clinical isolates and two collection-type strains by confocal microscopy and counts of bacterial colony-forming units.
Measurement and main resultsThe most frequently recovered pathogens were Pseudomonas aeruginosa (30%) and Staphylococcus aureus (23%). An increase in bacterial load of colonizing pathogens was observed at the first follow-up after stenting, with long-term persistence of the same bacterial genotype within those patients. Three P. aeruginosa and three S. aureus clinical isolates were selected to evaluate the effect of silver on bacterial colonization. Silver-coated silicone exhibited high bactericidal activity against all isolates tested, with bacterial death ranging from 88 to 96% for P. aeruginosa and from 77 to 88% for S. aureus.
ConclusionSilver-coated silicone significantly reduced the viability of the most common pathogens that colonized tracheobronchial stents and may represent a promising option for preventing stent-related infections.

研究背景：气管支气管支架（tracheobronchial stents）可用于治疗中心气道阻塞，但常发生细菌定植，进而引发感染。
研究目的：明确导致支架定植的微生物种类，并评估涂银硅酮（silver-coated silicone）体外抑制其生长的能力。
研究方法：前瞻性收集30例患者置入支架前及首次随访时的支气管灌洗液（bronchial washings），进行细菌鉴定与定量检测。针对6株临床分离菌株与2株标准菌株，采用共聚焦显微镜（confocal microscopy）与菌落形成单位（colony-forming units, CFU）计数法，测定涂银硅酮对细菌活力的影响。
测量指标与主要研究结果：最常分离获得的病原菌为铜绿假单胞菌（Pseudomonas aeruginosa，占比30%）与金黄色葡萄球菌（Staphylococcus aureus，占比23%）。支架置入后首次随访时，可观察到定植病原菌的载量升高，且该类患者体内同一细菌基因型持续存在。选取3株铜绿假单胞菌与3株金黄色葡萄球菌临床分离株，评估银制剂对细菌定植的作用效果。涂银硅酮对所有受试分离株均表现出显著杀菌活性，铜绿假单胞菌的细菌死亡率介于88%~96%，金黄色葡萄球菌则介于77%~88%。
研究结论：涂银硅酮可显著降低气管支气管支架最常见定植病原菌的活力，有望成为预防支架相关感染的极具前景的方案。