Staphylococcus aureus lysis

GS microHero at
Mon Jan 27 01:37:38 EST 1997

Matthew or Dawnita Nilles wrote:
> In article <kwarner-2501971023530001 at>,
> kwarner at (Keith Warner) wrote:
> > Here is the problem.  I am working with several isogenic strains of S.
> > aureus.  One of the strains will often lose turbidity after 3 to 4 hours
> > growth in broth and eventually become completely clear.  This clearing
> > occurs only after inoculation of fresh broth with an overnight broth
> > culture--never happens in broth when inoculating from a plate. Addition of
> > the lysate to spread plates of S. aureus, E. coli, and B. subtilis produce
> > 'plaques'. Filtration of the lysate with a 0.45 micron pore filter
> > eliminates plaque formation.  What's the story?
> Sounds like you found bacteriophage (viruses of bacteria) I don't know why
> you see plaques on E. coli and B. subtilis, phage are usually very host
> specific.
> Does anyone know if it could be Bdellovibrio (parasitic bacteria).
> Matt Nilles
> Dept. of Microbiol. and Immunol.
> Univ. of Kentucky

Doesn't sound like phage - 0.45 micron filter wouldn't take it out - at 
least not on mechanical filtration. Bdellovibrio - where would it come 
from? If it's in the staph strain you might expect it to wipe out the 
plate cultures too.

Graham Shepherd

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