Staphylococcus aureus Screening at the University of Iowa Hospitals and Clinics

Effective at 3 PM, Wednesday, April 25, 2012, Staphylococcus aureus (SA) nares screening will be performed with the new Cepheid Xpert SA Nasal Complete PCR assay.  The main difference between this assay and the previously used Cepheid MRSA assay is that the Nasal Complete assay can also identify the presence of Methicillin Susceptible SA (MSSA) in addition to Methicillin Resistant SA (MRSA).  The presence of either MRSA or MSSA will be reported.  However, it must be noted that the presence of MSSA does NOT require the patient to be in Contact Isolation.

Sample acquisition, transport and turn-around time will be the same as previous.  This assay is only validated for nasal screening.  SA testing on nasal swabs will now be done exclusively by PCR and culture for this sample type will no longer be available.   However, S. aureus detection for all other sample types will continue to be done by culture. 

There are three possible results that will be reported from the Nasal Complete PCR assay. These possible results are listed individually below:

1.  MRSA PCR Negative; S. aureus PCR Negative.  This result would indicate the absence of any SA.

2.  MRSA PCR Positive; S. aureus PCR Positive.  This result is consistent with the presence of MRSA.

3.  MRSA PCR Negative; S. aureus PCR Positive.  This result is consistent with the presence of MSSA.

If you have any questions, please consult the Lab Services Handbook ( or contact Stacey Klutts, M.D., Ph.D., Medical Director of the Clinical Microbiology Laboratory, at 356-2990; Pager 1966