The role of the temperature-regulated acyltransferase (PA3242) on growth, antibiotic resistance and virulence in Pseudomonas aeruginosa

摘要

Pseudomonas aeruginosa (PAO1) is an important opportunistic pathogen that thrives in various environments. It is known that the structural variations of the lipopolysaccharide (LPS), including lipid A moiety play an important role in encountering environmental changes. Genes PA3242 and PA0011 have recently been reported to be responsible for secondary-acylation of lipid A in P. aeruginosa. In this study, we confirmed that the PA3242-dependant secondary acylation affects the growth, antibiotic resistance and virulence of PAO1 and functions as a more predominant acyltransferase than PA0011. PA3242 mutant showed inhibited growth at 37 degrees C and inviability at 28 degrees C in rich medium LB. The inactivation of PA3242 leads to more sensitivity to a wide range of antibiotics than PAO1(Delta PA0011). Moreover, the virulence of PAO1(Delta PA3242) was attenuated more significantly than that of PAO1 and PAO1(Delta PA0011). The outer membrane integrity and stability of PAO1(Delta PA3242) were seriously compromised. Furthermore, PAO1(Delta PA3242) lost most of pilus and exhibited severely damaged cell envelope, which is probably responsible for the deficiency of swimming, swarming and twitching. These results partially explained the decreased antibiotic resistance and attenuated virulence of PAO1(Delta PA3242) compared to PAO1(Delta PA0011) and PAO1. Our study demonstrated that PA3242-dependent secondary acylation of lipid A plays a predominant role in growth, antibiotic resistance and virulence of PAO1 than PA0011. (C) 2016 Published by Elsevier Ltd.