title: Autoinducer-2 regulates Pseudomonas aeruginosa PAO1 biofilm formation and virulence production in a dose-dependent manner.
abstract: BACKGROUND
  Pseudomonas aeruginosa is an opportunistic pathogen that is the leading cause of iatrogenic infections in critically ill patients, especially those undergoing mechanical ventilation. In this study, we investigated the effects of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation of P. aeruginosa PAO1.
  
  
  RESULTS
  The addition of 0.1 nM, 1 nM, and 10 nM exogenous AI-2 to P. aeruginosa PAO1 increased biofilm formation, bacterial viability, and the production of virulence factors. However, compared to the 10 nM AI-2 group, higher concentrations of AI-2 (100 nM and 1 μM) reduced biofilm formation, bacterial viability, and the production of virulence factors. Consistent with the changes in morphology, gene expression analysis revealed that AI-2 up-regulated the expression of quorum sensing-associated genes and genes encoding virulence factors at lower concentrations and down-regulated these genes at higher concentrations.
  
  
  CONCLUSIONS
  Our study demonstrated that exogenous AI-2 acted in a dose-dependent manner to regulate P. aeruginosa biofilm formation and virulence factors secretion via modulating the expression of quorum sensing-associated genes and may be targeted to treat P. aeruginosa biofilm infections.
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China. 413745308@qq.com.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. 413745308@qq.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. 413745308@qq.com.
authors.forename: Hongdong
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Pharmacy, Chongqing Red Cross Hospital, Chongqing, China. 434437163@qq.com.
authors.forename: Xingyuan
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China. 937461502@qq.com.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. 937461502@qq.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. 937461502@qq.com.
authors.forename: Zhengli
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China. 15123231768@qq.com.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. 15123231768@qq.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. 15123231768@qq.com.
authors.forename: Yakun
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. 274756349@qq.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. 274756349@qq.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ai
authors.affiliation: Department of Paediatrics, Children's Hospital of Fudan University, Shanghai, China. doy1122@126.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China. yujialin468@163.com.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. yujialin468@163.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. yujialin468@163.com.
authors.forename: Jialin
authors.initials: J
authors.lastname: Yu
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D007783:Lactones / Q000378:metabolism*; D050296:Microbial Viability / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D053038:Quorum Sensing; D015398:Signal Transduction; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D007783:Lactones; C091088:N-octanoylhomoserine lactone; D037521:Virulence Factors; D006714:Homoserine