Diagnosis of severe soft tissue infections
Indications for Testing
Special Instructions and Forms
1. Tissue Culture
1. Tissue Culture
Aliases (clinical indications)
Diabetic foot infection
Toxic Shock Syndrome
Tissue in sterile container
Specimen Minimum Volume
If tissue is detectable, it can be accepted for culture. Specimens too large to fit inside a sterile urine container are accepted, but reported with a warning comment if the specimen is received in a non-sterile container.
Warning comment: “Precious specimen received in a non-sterile container. Growth may represent environmental contamination.”
|Tissue in sterile container||Maximum 4 hours transportation||Maximum 2 days transportation||Indefinite transportation|
Reject Due To
|Necrotic Tissue||The medical microbiologist may choose to reject a necrotic specimen based on the expectation of heavy mixed bacterial growth, if this result would not be diagnostically helpful.|
|Repeat specimens||NO rejection of repeat specimens|
Identification and susceptibility of bacteria causing invasive infections of skin, muscle, bone, joint or other human tissues.
Invasive bacterial infections of tissues include necrotizing fasciitis, surgical wound infections, diabetic foot infections, osteomyelitis, endocarditis and septic arthritis. These infections require surgery for source control. During surgery, tissue is collected to allow identification and susceptibility testing of bacteria. This tissue is a precious specimen since it is collected surgically, and contains large numbers of bacteria which are protected during transportation by the tissue structure. Tissue specimens should be cultured for aerobes and anaerobes, and may require prolonged incubation including broth incubation. Generally speaking, growth of any bacteria will be considered pathogenic, however, if tissue is necrotic, growth may represent flora.
Tissue is applied to multiple selective and non-selective media and incubated aerobically and anaerobically, in order to optimize growth of all organisms present. All organisms detected will be identified with susceptibility, according to the microbiologist’s assessment.
- No growth
Identification and susceptibility provided according to cascade policy. Interpretive comments may be added.
Garcia, L. (Ed.). (2010). Clinical Microbiology Procedures Handbook, 3rd Edition. Washington, DC: ASM Press.
- Tissue is macerated if appropriate
- Tissue is applied to selective and non-selective media and broth
- Media are incubated aerobically and anaerobically at 35°C for 48 hours. Broth are incubated for seven days at 35°C.
- Bacterial growth is identified.