Erickson David L, Endersby Ryan, Kirkham Amanda, Stuber Kent, Vollman Dolina D, Rabin Harvey R, Mitchell Ian, Storey Douglas G
Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
Infect Immun. 2002 Apr;70(4):1783-90. doi: 10.1128/IAI.70.4.1783-1790.2002.
Individuals with cystic fibrosis (CF) are commonly colonized with Pseudomonas aeruginosa. The chronic infections caused by P. aeruginosa are punctuated by acute exacerbations of the lung disease, which lead to significant morbidity and mortality. As regulators of virulence determinants, P. aeruginosa quorum-sensing systems may be active in the chronic lung infections associated with CF. We have examined the levels of autoinducer molecules and transcript accumulation from the bacterial populations found in the lungs of patients with CF. We detected biologically active levels of N-(3-oxododecanoyl)-L-homoserine (3-oxo-C12-HSL) and N-butyryl-L-homoserine lactone (C4-HSL) in sputum from CF patients. Interestingly, it appears that C4-HSL is less frequently detected than 3-oxo-C12-HSL in the lungs of patients with CF. We also examined the transcription of the autoinducer synthase gene lasI and showed that it is frequently expressed in the lungs of patients with CF. We observed a significant correlation between the expression of lasI and four target genes of the Las quorum-sensing system. Taken together, our results indicate that quorum-sensing systems are active and may control virulence factor expression in the lungs of patients with CF.
患有囊性纤维化（CF）的个体通常会被铜绿假单胞菌定植。由铜绿假单胞菌引起的慢性感染会因肺部疾病的急性加重而间断发作，这会导致显著的发病率和死亡率。作为毒力决定因素的调节因子，铜绿假单胞菌群体感应系统可能在与CF相关的慢性肺部感染中发挥作用。我们已经检测了CF患者肺部细菌群体中自诱导分子的水平和转录积累情况。我们在CF患者的痰液中检测到了具有生物活性水平的N-（3-氧代十二烷酰基）-L-高丝氨酸（3-氧代-C12-HSL）和N-丁酰-L-高丝氨酸内酯（C4-HSL）。有趣的是，在CF患者的肺部，似乎C4-HSL的检测频率低于3-氧代-C12-HSL。我们还检测了自诱导合成酶基因lasI的转录情况，并表明它在CF患者的肺部经常表达。我们观察到lasI的表达与Las群体感应系统的四个靶基因之间存在显著相关性。综上所述，我们的结果表明群体感应系统是活跃的，并且可能控制CF患者肺部毒力因子的表达。
