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Volume 37, Number 1, February 2004

Effects of PNPG on cell growth cycle, motility machinery and quorum sensing in Serratia marcescens


Jun-Rong Wei, Yu-Tze Horng, Hsin-Chih Lai, Kwen-Tay Luh, Shen-Wu Ho
School and Graduate Institute of Medical Technology, College of Medicine, National Taiwan University, Taipei; and Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan, ROC

Received: January 20, 2003    Revised: February 24, 2003    Accepted: May 9, 2003   

 

Corresponding author:

Dr. Hsin-Chih Lai, School and Graduate Institute of Medical Technology, College of Medicine, National Taiwan University, Taipei, Taiwan 100, ROC. E-mail: hclai@ha.mc.ntu.edu.tw This e-mail address is being protected from spam bots, you need JavaScript enabled to view it



 

Methods:

p-Nitrophenylglycerol (PNPG) effectively inhibits swarming of the enterobacterium Proteus mirabilis. The underlying mechanism of inhibition is unclear. We have now found that both PNPG also inhibits motility and swarming in another enterobacterium, Serratia marcescens. While the peak promoter activities of the flagellar master operon (flhDCSm), the flagellin structural gene (hagSm) and the nuclease gene (nucASm) in S. marcescens increased with increasing PNPG concentration, the expression of these genes was delayed in accordance with the reduced growth rate. As the quorum-sensing system is involved in the regulation of swarming in S. marcescens, we also examined the effect of PNPG on the production of quorum-sensing signal molecules and found that their expression was delayed with a reduced level. PNPG, therefore, had a pleiotropic effect on all aspects of S. marcescens physiology relating to swarming. The underlying molecular mechanism remains to be elucidated.

 



 

Key words:

Bacterial genes, bacterial proteins, gene expression regulation, movement, Serratia marcescens



 



 

J Microbiol Immunol Infect 2004;37:1-7.