Guess what I found today, creamy white colonies on the surface of VRBGA.
The count was very high and the little devils had managed to grow up the
edge of the
plate and onto the surface.
They looked Klebs like and with all the growth there was alkaline reversion.
--
David Lawton
"Tim Marsh" <tpm at zoom.co.uk> wrote in message
news:8cnvpo$501$1 at quince.news.easynet.net...
> Dear All,
>> A colleague has been carrying out tests for Enterobacteriaceae using VRB-G
> (Violet Red Bile agar with Glucose, produced by Oxoid) agar. The test is
> carried out as a pour plate using VRB-G, which is also overlaid with
VRB-G.
>> Approx. 60 of the plates have grown creamy white colonies on the surface
of
> the overlay (not in the original test sample layer). I thought this might
> have been environmental contamination, but all control plates used show no
> growth.
>> The limited microscopy so far performed indicates that they are bacterial:
> small rods (slightly longer than Listeria sp.) and are also motile.
>> Can anyone enlighten me? Can you suggest what they might be or what the
> next stage of diagnosis might be?
>> Thank you for any help!
>> Tim
>> ( Please reply to tmarsh at wrl.co.uk )
>>
