Quorum sensing signals expressed by Burkholderia contaminans clinical isolates recovered from cystic fibrosis patients

M. LEGUIZAMÓN; C. PRIETO; P. MARTINA; A. BOSCH

Sevilla

Congreso; 40th European Cystic Fibrosis Conference; 2017

European Cystic Fibrosis Society

Aim: All cBc species investigated sofar employ quorum-sensing (QS) systems that rely on N-acyl-homoserinelactone (AHL) signal molecules to express certain phenotypic traits in apopulation density-dependent manner and is thought to play important roles inlifestyle changes. It has been reported that cBc members are able to synthesizeC4-HSL to C10-HSL molecules. However, according to our knowledge, nothing hasbeen reported in this regard for clinical isolates of B. contaminans. The aim of the present work is to get insights intothe QS signals expressed by B. contaminans clinical isolates, and comparatively analyze the expression of theQS signals among isolates recovered from long-term infections in CF patientssuffering chronic infections.Methods: A total of 65 B. contaminans isolates recoveredfrom serial sputum cultures from 13 chronically infected patients attended at 3CF treatment centers in Argentina during a 10-year period (2004-2013) wasanalyzed. The QS signals expression were investigated using biosensors strains,Fourier transform infrared (FT-IR) spectroscopy and HPLC MS/MS.Results: The combined use of these technologies allowed us to identify thepresence of one acyl homoserine lactone (AHL), namely N-octanoylhomoserinelactone (C8-HSL) which was the main QS signals found for B. contaminans and in addition smaller amounts of C10-HSL couldbe detected. The comparative study performed resulted in a lower proportion oforganisms that produce these signals in the isolates recovered from chronicinfections than the isolates from transients infectionsConclusion: Our results reveal evidence of synthesis andexpression of AHL-QS molecules in Bcontaminans under the conditions tested, and phenotypic adaptation of B. contaminans isolates during chroniclung infections that could contribute to increase the capacity of thesebacteria to survive and persist in their host