Modification of phospholipid composition in Pseudomonas by contact with tetradecyltrimethylammonium

BOERIS, P.S.; NIEVAS, F.; LUCCHESI, G.I.

Rosario, Santa Fe

Congreso; Reunión Anual. Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2006

Quaternary ammonium compounds (QAC) are cationic biocides included in antiseptic solutions. Some strains of Pseudomonas are resistant to QAC but little is known about of basis of this tolerance. The aim of this work was to know if the response to tetradecyltrimethylammonium (TDTMA), a QAC, involves changes in the phospholipid (PL) composition in species of the Pseudomonas genus. P. putida A ATCC 12633, P. putida KT2440 y P. aeruginosa PAO1, were exposed to 50 mg l-1 TDTMA for 15 min and PL composition was analyzed. In presence and absence of TDTMA, the PL pattern was qualitatively the same but the amount of each individual PL, measured by Pi concentration or 32Pi changed. Respect to control values, all strains showed an increase in phosphatidic acid (PA) (140%). Accompanying this change, phosphatidylglycerol increased 100% and cardiolipin decreased 60%. P. putida A ATCC 12633 was cultivated in a media containing gradually increasing TDTMA concentrations. Following the last culture grown in the presence of TDTMA (280 mg l-1) successive subcultures without TDTMA were made. In TDTMA-adapted bacteria the most significant change was a 380% increase in PA. This change was reverted after two subcultures without biocide. These results suggest that PL are involved in cellular responses to QAC, utilizing PA principally to neutralize the high positive charge density given for the TDTMA moiety.