Stimulation of bacterial growth by heat-stable, norepinephrine-induced autoinducers

FEMS Microbiol Lett. 1999 Mar 1;172(1):53-60. doi: 10.1111/j.1574-6968.1999.tb13449.x.


The ability of norepinephrine to increase the growth of Escherichia coli in a serum-based medium has previously been shown to be due to the production of an autoinducer of growth during early log phase. Seventeen Gram-negative and 6 Gram-positive clinical isolates were examined for a similar ability to respond to norepinephrine, and to synthesise autoinducer. The majority of Gram-negative strains both produced and responded to heat-stable norepinephrine-induced autoinducers of growth. Most of these autoinducers showed a high degree of cross-species activity, suggesting the existence of a novel family of Gram-negative bacterial signalling molecules. In contrast, although a number of Gram-positive strains were able to respond to norepinephrine, the majority failed to produce autoinducers in the presence of norepinephrine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Culture Media, Conditioned
  • Gram-Negative Bacteria / drug effects*
  • Gram-Negative Bacteria / growth & development*
  • Gram-Negative Bacterial Infections / microbiology
  • Gram-Positive Bacteria / drug effects*
  • Gram-Positive Bacteria / growth & development*
  • Gram-Positive Bacterial Infections / microbiology
  • Humans
  • Norepinephrine / pharmacology*


  • Culture Media, Conditioned
  • Norepinephrine