Matthew or Dawnita Nilles wrote:
>> In article <kwarner-2501971023530001 at cha-nc9-34.ix.netcom.com>,
>kwarner at unccvm.uncc.edu (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
