Abstract

Pseudomonas aeruginosa biofilms contribute heavily to chronic lung infection in cystic fibrosis patients, leading to morbidity and mortality. Nitric oxide (NO) has been shown to disperse P. aeruginosa biofilms in vitro, ex vivo and in clinical trials as a promising anti-biofilm agent. Traditional NO donors such as sodium nitroprusside (SNP) have been extensively employed in different studies. However, the dosage of SNP in different studies was not consistent, ranging from 500 nM to 500 μM. SNP is light sensitive and produces cyanide, which may lead to data misinterpretation and inaccurate predictions of dispersal responses in clinical settings. New NO donors and NO delivery methods have therefore been explored. Here we assessed 7 NO donors using P. aeruginosa PAO1 and determined that SNP and Spermine NONOate (S150) successfully reduced > 60% biomass within 24 and 2 h, respectively. While neither dosage posed toxicity towards bacterial cells, chemiluminescence assays showed that SNP only released NO upon light exposure in M9 media and S150 delivered much higher performance spontaneously. S150 was then tested on 13 different cystic fibrosis P. aeruginosa (CF-PA) isolates; most CF-PA biofilms were significantly dispersed by 250 μM S150. Our work therefore discovered a commercially available NO donor S150, which disperses CF-PA biofilms efficiently within a short period of time and without releasing cyanide, as an alternative of SNP in clinical trials in the future.

Key points

• S150 performs the best in dispersing P. aeruginosa biofilms among 7 NO donors.

• SNP only releases NO in the presence of light, while S150 releases NO spontaneously.

• S150 successfully disperses biofilms formed by P. aeruginosa cystic fibrosis clinical isolates.

中文翻译：

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一氧化氮供体的优化，用于研究铜绿假单胞菌临床分离物中的生物膜扩散反应。

摘要

铜绿假单胞菌生物膜在囊性纤维化患者的慢性肺部感染中起重要作用，导致发病率和死亡率。一氧化氮（NO）已被证明可以在体外，离体和临床试验中分散铜绿假单胞菌生物膜，这是一种很有前途的抗生物膜剂。传统的NO供体如硝普钠（SNP）已广泛用于不同的研究中。但是，不同研究中SNP的剂量不一致，范围从500 nM到500μM。SNP对光敏感并产生氰化物，这可能导致数据误解和临床环境中对弥散反应的预测不准确。因此，已经探索了新的NO供体和NO递送方法。在这里，我们评估了使用铜绿假单胞菌的7个NO供体PAO1并确定SNP和NO精胺（S150）分别在24小时和2小时内成功减少了> 60％的生物量。虽然这两种剂量都不会对细菌细胞产生毒性，但化学发光分析表明，SNP仅在M9培养基中曝光后才释放NO，而S150自发地表现出更高的性能。然后在13种不同的铜绿假单胞菌（CF-PA）分离株上测试了S150 ；大多数CF-PA生物膜被250μMS150显着分散。因此，我们的工作发现了市场上可买到的NO供体S150，它可以在短时间内有效分散CF-PA生物膜而不会释放氰化物，作为将来在临床试验中替代SNP的方法。

关键点

• S150在7个NO供体中分散铜绿假单胞菌生物膜的性能最佳。

• SNP仅在光照下释放NO，而S150自发释放NO。

• S150成功地分散了由铜绿假单胞菌囊性纤维化临床分离株形成的生物膜。