he diluent used will depend on the tests to be performed. If enumeration tests only are
being performed on a swab Peptone Saline Diluent (PSD) can be used as the diluent. If
the swab will be subjected to detection of Salmonella species, in addition to enumeration
tests BPW can be used. Detection of pathogens other than Salmonella from swabs
requires the addition of selective enrichment media. Due to this only one pathogen can be
sought per swab. Cloths or other environmental samples for detection of a single pathogen
are prepared by adding 500mL of the appropriate enrichment medium. If a cloth or other
environmental sample is being investigated for more than one pathogen by enrichment or
if enumeration tests are being performed in addition to pathogen testing neutralising
diluent should be added, the sample homogenised and the resulting liquid aliquoted to
perform these tests. The resulting suspension can be mixed with the enrichment media for
the pathogens of interest. If this is performed a comment must be added to the report to
reflect that the entire sample was not tested (see section 9)