Microbiology sample advice

Bacteriology Sample Advice

Good sample preparation will avoid contamination, or change in the relative numbers of bacteria during sample transportation.

Please avoid ‘dry’ swabs as bacteria may dessicate and die. Use of Amies charcoal swabs is recommended for routine bacteriology.

Tissue biopsies for culture should be submitted with a small quantity of sterile lactated ringers solution (isotonic saline is too acidic) to prevent tissue dessication.

EDTA samples are not suitable for bacterial culture.

Nutrient type broth such as that in blood culture bottles should only be used when samples are collected from normally sterile sites (e.g. joints, blood, CSF etc).

Urine: please submit urine in a boric acid tube and always fill to the fill-line. Urine is normally sterile until it reaches the mid urethra. The distal urethra (and genital tract) contains resident bacteria.Voided and catheterised samples of urine may be contaminated by the resident bacteria. Cystocentesis samples of urine may be contaminated by resident bacteria from the skin. Please always indicate the method of collection to assist with interpretation of culture results.

Mycology Sample Advice

Please submit:

  • Dermatophytes: hair plucks
  • Fungal infection (e.g. Aspergillus): tissue biopsies (as per bacteriology above) / fluid in sterile container