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

MARIANA LEGIZAMÓN; CLAUDIA PRIETO; LAURA BELTINA LEON; CECILIA BEATRIZ FÍGOLI; PABLO MARTINA; MARISA BETIOL; FERNANDO RENTERÍA; OSVALDO YANTORNO; ALEJANDRA BOSCH

Sevilla

Conferencia; 40th European Cystic Fibrosis Conference; 2017

European Cystic Fibrosis Society

Quorum sensing signals expressed by Burkholderia contaminans clinical isolates recovered from cystic fibrosis patients.Objectivs: All Burkholderia cepacia complex (Bcc) species investigated so far employ quorum-sensing (QS) systems that rely on N-acyl-homoserine lactone (AHL) signal molecules to express certain phenotypic traits in a population density-dependent manner and are thought to play important roles in lifestyle changes. It has been reported that Bcc members are able to synthesize C4-HSL to C10-HSL molecules (AHL). The aim of the present work is to get insights into the QS signals expressed by B. contaminans clinical isolates, and analyze the distribution of the expression of the QS signals among isolates recovered from CF patients suffering chronic infectionsMethods: A total of 84 B. contaminans clinical isolates recovered from sputum cultures from cystic fibrosis patients attended at 3 CF treatment CF centers in Argentina during a 10-year period was analyzed. The QS signals expression was investigated using biosensors strains, Chromobacterium violaceum CV026 and VIR07, where the violacein pigment acted as indicators of the induction of these biosensing strains by the action of AHLs. We also used Fourier transform infrared (FT-IR) spectroscopy and HPLC MS/MS-MRM to chemically identify the type of AHL molecule synthesized.Results: The combined use of these technologies allowed us to identify, for the first time, the presence of N-octanoylhomoserine lactone (C8-HSL) as the main AHL expressed by B. contaminans isolates, followed by C10-HSL. In addition, we found that this signals were present mainly in the first isolates recovered along the chronic infections. Conclusion: Our results revealed evidences of the expression of mainly C8-HSL molecules in B. contaminans isolates recovered from sputum samples of cystic fibrosis patients, and a phenotypic adaptation that could contribute to the regulation of virulence along chronic lung infections.