PA0305 attenuates the virulence factors production of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a human opportunistic pathogen. It is known that many \nvirulent factors production of the bacteria were modulated by acyl-homoserine lactones as \nsignal. molecules of quorum sensing system. Since acyl-homoserine lactone may also act directly \nas virulence factors in mammalian hosts, degradation of acyl-homoserine lactone may be \ninteresting not only to stop the quorum sensing system, but also to reduce directly the \nvirulence effects. Previous study proved that P.aeruginosa PA0305 protein is an acylase. It degraded the acyl-homoserine lactone from middle to long acyl-side chain of acyl-homoserine lactone. including N-3-oxo-dodecanoyl-homoserine lactone. one of the P.aeruginosa signal \nmolecules. The aim of this study is to investigate the quenching effect of pa0305 to the quorum \nsensing system of P.aeruginosa. \nThe over-expression of pa0.305 gene reduced the accumulation of 3-oxo-C12-HSL signal \nmolecule although the accumulation of the other one. N-butanoyl-homoserine lactone, was \nnot changed. In addition. the elastolytic activity were reduced in P. aeruginosa wild type and \ncomplemented strains however the pyocyanin production was decreased during the logarithmic phase, not changed after reached the stationary phase. This study showed that the \nimplementation of pa0.305 attenuated the production of some P.aeruginosa virulence factors \nwhich were quorum sensing-dependent genes.