Molecular Laboratory Tests for the Diagnosis of Respiratory Tract Infection Due to Staphylococcus aureus

When Staphylococcus aureus is the cause of ventilator-associated pneumonia or a bacterial infection following influenza, the infections are devastating if not treated promptly. Disease due to methicillin-resistant S. aureus (MRSA) continues to be of concern throughout most of the United States. Currently, the U.S. Food and Drug Administration (FDA) has cleared polymerase chain reaction tests for detection of MRSA in nasal swab specimens; however, there are no FDA-cleared tests for identifying S. aureus in purulent respiratory secretions. The real-time polymerase chain reaction tests for S. aureus (primarily MRSA) in nares provide results in <2 h and have sensitivities ranging from 95% to 100%, with specificities of 96%-99%; these results are comparable to that of standard cultures, which can take up to 3-4 days for final results. The FDA is encouraged to work closely with industry providers to expedite the evaluation and clearance process for molecular diagnostic devices detecting S. aureus (including MRSA) in the diagnosis of respiratory tract infection.