The recently published second USP-NF supplement also contained – for
many surprisingly – a new chapter for the microbiological quality
<1117> MICROBIOLOGICAL BEST LABORATROY PRACTICES
This chapter summarises all activities necessary to manage a
microbiological lab according to Good Laboratory Practices.
This GLP is different from the GLP addressing e.g. pre-clinical studies.
The new USP chapter addresses labs working under GMP conditions.
It specifically mentions that, due to the known variances of
microbiological results, fulfilling the requirements is extremely
In particular the chapter covers
- media preparation and quality control,
- maintenance of microbiological cultures,
- maintenance of lab equipment,
- lab layout and operations,
- training of personnel,
- maintenance of lab records as well as
- interpretation of assay results.
According to the authors, the reasons making an interpretation of
microbiological study results difficult are:
- Micro organisms are omnipresent in nature and typical impurities
from the environment; this is especially the case for micro organisms
being in contact with humans and occurring in many microbiological
- Lab personnel can cause the contamination during sample handling or
during conducting the test.
- Micro organism distribution in the sample and in the environment is
frequently not homogeneous.
- Microbiological tests often vary considerably. Minor variances from
the expected result can thus not be significant.
Discussions during audits and inspections especially with regard to the
last item are most likely well known to everybody involved in
microbiological quality control.
Altogether the chapter provides a good practice oriented overview over
working in microbiological labs according to GMP.
Dr Ulrich Herber
On behalf of the European Compliance Academy (ECA)