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November 1998


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Winfried RAPATZ <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Mail List <[log in to unmask]>
Wed, 25 Nov 1998 07:18:52 +0100
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Dear Fausto,
I would do the identification on the found colonies and not do a selective plating in the first run.
How do you identify pathogens under the microscope?
Kind regards
Winfried Rapatz
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>>> Fausto Silva <[log in to unmask]> 24 November 1998  14:06  >>>
Hi everyone

I'd like to ask all you experts on the above subject out there the following:

We have to update our validation procedure for various reasons:

1 - because we only used to do it once and the GMP guide wants it thrice in a
row for the initial validation followed by two re-qualifications per year (1

2 - Because we only used sterile broth and should be using freshly prepared
broth, and should have included the manufacturing step, which was previously not

Now, the dilemma comes with the environmental control, we did a comprehensive
surface bioload check with RODACs for bacteria and yeasts/moulds, as well as
swabs for all the same surfaces which where then plated on selective agars, MSA,
CET and MAC. This involves 17 surfaces , (that means all three air locks as well
as the supporting environment outside L.A.F and the area under L.A.F.) so to do
this 3 times for each run and repeat it thrice sounds a bit too much, could I
rather pick suspect colonies from the RODACs, do microscopy and if they look
like pathogens proceed with  identification? Or should I concentrate on the
critical area (under L.A.F.) ?

Besides this we do RODACs on the operators gowns, and a hand check for
pathogens, where I feel that for the hands I should be doing counts rather in
order to evaluate the bioload on the operators gloved hands, don't you agree,
here again suspect colonies could be picked up and identified further if

I'd appreciate any comments, as I am quite under pressure to re-do this
procedure but have to at the same time analyse daily work and time is of extreme
importance for after all this there isn't much of it left to re-think such an

Thanking you all in advance.

Fausto Silva

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