Sanderson K, Wescombe L, Kirov S M, Champion A, Reid D W
Respiratory Research Group, Menzies Research Institute, University of Tasmania, Hobart, Australia.
Eur Respir J. 2008 Aug;32(2):329-33. doi: 10.1183/09031936.00152407. Epub 2008 May 14.
The cystic fibrosis (CF) lung environment is poorly defined, but data suggest that bacteria may encounter reduced oxygen tensions and possibly an anaerobic environment. Pseudomonas aeruginosa produces the potent toxin cyanide under strictly microaerobic conditions. Evidence of bacterial cyanogenesis in the CF lung was investigated in the present study by measuring sputum cyanide concentrations. Sputum cyanide was measured in seven stable CF patients, as well as before and after intravenous antibiotic therapy during a hospital admission in a further eight patients experiencing acute exacerbations. All patients were chronically infected with P. aeruginosa. Comparative sputum data were obtained from nine CF patients with no documented P. aeruginosa infection and 10 healthy, nonsmoking normal controls. High levels of cyanide were detected in all the P. aeruginosa-infected stable CF patients (median (range) 0.56 (0.37-2.81) microg.mL(-1)), and in seven out of eight acute sputum samples (0.73 (0-1.43) microg.mL(-1)). In contrast, cyanide was not detectable in sputum from eight out of nine CF patients without P. aeruginosa infection or in any of the normal controls. Intravenous antibiotic treatment significantly reduced sputum cyanide levels (median 0.73 to median 0.0 microg.mL(-1)). The cyanide detected indicates that the cystic fibrosis lung provides a predominantly microaerobic environment for Pseudomonas aeruginosa. Cyanide is likely to be a potentially important virulence factor in Pseudomonas aeruginosa-infected cystic fibrosis patients.
囊性纤维化（CF）患者肺部的环境尚不明确，但数据表明细菌可能会遇到氧分压降低的情况，甚至可能处于厌氧环境。铜绿假单胞菌在严格的微需氧条件下会产生强效毒素氰化物。本研究通过测量痰液中的氰化物浓度，对CF患者肺部细菌产生氰化物的证据进行了调查。对7名病情稳定的CF患者的痰液氰化物进行了测量，另外8名急性加重期住院患者在静脉使用抗生素治疗前后也进行了测量。所有患者均长期感染铜绿假单胞菌。从9名无铜绿假单胞菌感染记录的CF患者和10名健康、不吸烟的正常对照者中获取了对比痰液数据。在所有感染铜绿假单胞菌且病情稳定的CF患者中均检测到高浓度的氰化物（中位数（范围）为0.56（0.37 - 2.81）μg·mL⁻¹），8份急性痰液样本中有7份（0.73（0 - 1.43）μg·mL⁻¹）。相比之下，9名无铜绿假单胞菌感染的CF患者中有8名的痰液以及所有正常对照者的痰液中均未检测到氰化物。静脉使用抗生素治疗显著降低了痰液中的氰化物水平（中位数从0.73降至中位数0.0μg·mL⁻¹）。检测到的氰化物表明，囊性纤维化患者的肺部为铜绿假单胞菌提供了主要的微需氧环境。氰化物可能是铜绿假单胞菌感染的囊性纤维化患者中一个潜在的重要毒力因子。
