Effect of andrographolide on QS regulating virulence factors production in Pseudomonas aeruginosa / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of andrographolide on virulence factors production in Pseudomonas aeruginosa.</p><p><b>METHOD</b>Growth rate, pyocyanin, proteolytic activity and elastase activity were measured with or without the presence of andrographolide. The effect of andrographolide on pyocyanin production, proteolytic activity and elastase activity in PAO-JP2 was investigated simultaneously.</p><p><b>RESULT</b>The andrographolide did not affect the growth of PAO1 in planktonic culture. The production of pyocyanin, proteolytic activity and elastase activity were significanthy suppressed in P. aeruginosa cultures grown in the presence of andrographolide. However, these effects were not observed in PAO-JP2.</p><p><b>CONCLUSION</b>The inhibiting effect of andrographolide on virulence factors production in P. aeruginosa may play a role in its anti-infection activity.</p>

Effect of andrographolide on the mRNA expression of MexAB-OprM efflux pump of Pseudomonas aeruginosa PAOI strain / 中华传染病杂志

Objective To develop a real-time polymerase chain reaction(PCR)system to determine transcriptional level of MexAB-OprM multidrug efflux pump gene and to investigate the impact of androgra- pholide on MexAB-OprM gene transcription in Pseudomonas aeruginosa.Methods The fragments of mexB gene of mexAB-oprM operon and 30S rRNA gene rpsL were amplified and cloned into two plas- mids respectively.These plasmids were used as external standards for real-time PCR.Real-time PCR was applied to measure the mRNA transcripition of mexB and rpsL gene in Pseudomonas aeruginosa growing in medium with different concentrations of andrographolide.Results The plasmids for standard curve were constructed successfully.The relative mexB mRNA expressions in 50,100,150 and 200?g/mL andrographolide were 0.04?0.03,0.06?0.07,0.09?0.03 and 0.04?0.03 respectively, which were significantly lower than that in the control(0.24?0.04,P0.05).Conclusion Andrographolide can reduce the transcriptional level of MexAB-OprM,which may he one mechanism for its anti-infection effect.