Nasal swabs are not useful for determining bacteriologic pathogens of respiratory tract disease. They can be useful for identifying carriers of Staphylococcus aureus or, occasionally, Neisseria meningitidis. Specimens without any clinical history are processed to identify S. aureus only.
Direct Examination
Not indicated.
Culture
Media Incubation If nothing specifically requested, set up only:
| Media | Incubation |
| Blood Agar (BA) | CO2, 35°C x 48 hours |
If MRSA requested, set up only:
| MRSA select (MRSA) | O2, 35°C x 24 hours |
If Neisseria meningitidis requested add:
| Vancomycin-Colistin-Nystatin Agar (VCN) | CO2, 35°C x 72 hours |
Examine VCN at 24, 48 and 72 hours and identify N. meningitidis
Negative report
“No Staphylococcus aureus isolated” “No MRSA isolated” “No Neisseria meningitidis isolated” if appropriate.
Positive report
“Staphylococcus aureus” with sensitivity to oxacillin (OX) only. NP other antibiotics. “Methicillin Resistant Staphylococcus aureus” with appropriate susceptibilities (release all).
Neisseria meningitidis isolated.