Nose (anterior nares)

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.

Setup

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

Followup Examine the BA and MRSA plates after 24 and 48 hours incubation. Identify S. aureus.

Examine VCN at 24, 48 and 72 hours and identify N. meningitidis

Reporting

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.