rogersj at nmripo.nmri.nnmc.navy.mil
Tue Mar 10 15:14:43 EST 1998
Fred & Rachel Brusseau <rbruss at ix.netcom.com> wrote in article
<35014CFB.7ECE70A3 at ix.netcom.com>...
> Basic Micro questions:
> Does anyone know where I can find a picture of a coliform growing on
> MacConkey? (preferably on the net, but books are OK).
A good lab manual should have the color pictures you are looking for.
Check a number of them in your library.
> Can anyone confirm that Mannitol will turn yellow with pathogenic
> staphylococcus, but stay orange with EVERYTHING else?
Anything that ferments the mannitol and can grow in the high salt
concentration will turn MSA yellow. I second the use of a catalase test
along with maybe a serum coagulation test. Again, always run controls.
> Is it true that ONLY beta hemolytic strep and pathogenic staphylococcus
> will form a clear ring on blood.
Not true. There are hemolytic Bacillus sp. out there too. B cereus can be
found the soil and in cows with mastidis, which may not be a concern
depending on your source of milk.
More information about the Microbio