Current Microbiology

, Volume 66, Issue 4, pp 418–420 | Cite as

The Presence of Quorum-Sensing Genes in Pseudomonas isolates Infecting Cystic Fibrosis and Non-cystic Fibrosis Patients

  • Leandro Reus Rodrigues Perez
  • Alice Beatriz Mombach Pinheiro Machado
  • Afonso Luís Barth


Ninety-one Pseudomonas aeruginosa isolates recovered from cystic fibrosis and non-cystic fibrosis patients were evaluated regarding the ability to form biofilm and acyl-homoserine lactones production and for the presence of five quorum-sensing (QS) regulatory genes (lasI, lasR, rhlI, rhlR, and vfr). Most isolates (90.1 %) presented all five QS genes. Five isolates shown to be lasI/lasR-deficient were not able to produce biofilm in vitro. Moreover, one isolate harboring all five QS genes was also not able to form a biofilm. The function of rhlR gene may be compensated by the las QS system. However, in our study, all isolates which were deficient for the rhlR gene were also deficient for the lasI/lasR system. This may point to some hierarchy in QS regulation which may pose a potential for controlling biofilm infections due to P. aeruginosa.


Cystic Fibrosis Burkholderia Pseudomallei Cystic Fibrosis Isolate lasR Gene Average Optic Density 
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We are grateful to the staff of molecular biology at Hospital de Clínicas de Porto Alegre (HCPA) and Ana Lúcia Souza Antunes for technical support with the PCR procedure and phenotypic tests.


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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Leandro Reus Rodrigues Perez
    • 1
  • Alice Beatriz Mombach Pinheiro Machado
    • 2
  • Afonso Luís Barth
    • 1
    • 2
  1. 1.Ciências Farmacêuticas, Faculdade de FarmáciaUniversidade Federal do Rio Grande do Sul (UFRGS)Porto AlegreBrazil
  2. 2.Unidade de Microbiologia e Biologia MolecularHospital de Clínicas de Porto AlegrePorto AlegreBrazil

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