Characterization of lasR-deficient clinical isolates of Pseudomonas aeruginosa

作者：Yao Wang, Leiqiong Gao, Xiancai Rao, Jing Wang, Hua Yu, Junru Jiang, Wei Zhou, Jin Wang, Yonghong Xiao, Mengwen Li, Yan Zhang, Kebin Zhang, Li Shen, Ziyu Hua · 发表于：Scientific Reports · 年份：2018 · DOI：10.1038/s41598-018-30813-y · 被引用次数：66 · 研究领域：Bacterial biofilms and quorum sensing、Antibiotic Resistance in Bacteria、Vibrio bacteria research studies

Pseudomonas aeruginosa is a prevalent opportunistic pathogen that causes fatal infections in immunocompromised individuals. Quorum sensing (QS) is a cell-to-cell communication process that controls virulence gene expression and biofilm formation in P. aeruginosa. Here, the QS systems and the relevant virulence traits in clinical P. aeruginosa isolates were characterized. Eleven out of the ninety-four P. aeruginosa isolates exhibited a biofilm-deficient phenotype. Two biofilm-deficient isolates, one from blood and the one from pleural effusion, appeared to carry a same mutation in lasR. These two isolates differed in the ability to produce QS-regulated virulence factors, but contained the same functionally deficient LasR with the truncated C-terminal domains and belonged to the same multilocus sequence type (ST227). Chromosomal lasR complementation in these lasR mutants verified that lasR inactivation was the sole cause of las deficiency. LasR was not absolutely required for rhl signal in these lasR mutants, suggesting the presence of lasR-independent QS systems. We provided evidence that the virulence gene expression are not regulated in the same manner in these isolates. These results support the hypothesis that conventional QS hierarchy can be smashed by naturally occurring lasR mutation in clinical P. aeruginosa isolates and that complex QS hierarchy may play a role in maintaining infection of this opportunistic pathogen.