AUTHOR=Başaran Tunahan Irmak , Berber Didem , Gökalsın Barış , Tramice Annabella , Tommonaro Giuseppina , Abbamondi Gennaro Roberto , Erginer Hasköylü Merve , Toksoy Öner Ebru , Iodice Carmine , Sesal Nüzhet Cenk 

TITLE=Extremophilic Natrinema versiforme Against Pseudomonas aeruginosa Quorum Sensing and Biofilm

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00079

DOI=10.3389/fmicb.2020.00079

ISSN=1664-302X

ABSTRACT=<p><italic>Pseudomonas aeruginosa</italic> is an opportunistic pathogen that causes high morbidity and mortality rates due to its biofilm form. Biofilm formation is regulated via quorum sensing (QS) mechanism and provides up to 1000 times more resistance against conventional antibiotics. QS related genes are expressed according to bacterial population density via signal molecules. QS inhibitors (QSIs) from natural sources are widely studied evaluating various extracts from extreme environments. It is suggested that extremely halophilic Archaea may also produce QSI compounds. For this purpose, we tested QS inhibitory potentials of ethyl acetate extracts from cell free supernatants and cells of <italic>Natrinema versiforme</italic> against QS and biofilm formation of <italic>P. aeruginosa</italic>. To observe QS inhibition, all extracts were tested on <italic>P. aeruginosa lasB-gfp</italic>, <italic>rhlA-gfp</italic>, and <italic>pqsA-gfp</italic> biosensor strains and biofilm inhibition was studied using <italic>P. aeruginosa</italic> PAO1. According to our results, QS inhibition ratios of cell free supernatant extract (CFSE) were higher than cell extract (CE) on <italic>las</italic> system, whereas CE was more effective on <italic>rhl</italic> system. In addition, anti-biofilm effect of CFSE was higher than CE. Structural analysis revealed that the most abundant compound in the extracts was <italic>trans</italic> 4-(2-carboxy-vinyl) benzoic acid.</p>