This will help to prevent organisms from dying due to enzyme action, change of pH, or lack of essential nutrients. Example. Amies transport medium widely used and effective in ensuring the survival of pathogens like the more delicate organisms such as Neisseria gonorrhoeae.
Cary - Blair medium in used as transport medium for faeces that may contain Salmonella, shigella, campylobacter or vibro species.
Example of Preservatives include boric acid added to urine and cetylpyridinium- chloride sodium chloride (CPC-Nacl) added to sputum for the isolation of M.tuberculosis.
Transport of microbiological specimens collected in a hospital
Specimen should reach to the laboratory as soon as possible or a suitable preservative or transport medium must be used.
Refrigeration at 4-10 0c can help to preserve cells and reduce the multiplication of commensals in unpreserved specimens.
However, specimens for isolation of Haemophilus, S. pneumoniae or Neisseria species, must never be refrigerated because cold kills these pathogens.
If specimen are to be mailed, the regulations regarding the sending of “pathological specimens” through the post should be obtained from the post office and followed exactly. When dispatching microbilogical speciemens: