FDA Clears First Test to Quickly Diagnose and Distinguish MRSA and MSSA

On Friday, May 6, the FDA announced that it cleared the first test for Staphylococcus aureus (S.aureus) infections that is able to quickly identify whether the bacteria are methicillin resistant (MRSA) or methicillin susceptible (MSSA). The KeyPath MRSA/MSSA Blood Culture Test determines whether bacteria growing in a patient’s positive blood culture sample are MRSA or MSSA within about 5 hours after any bacterial growth is first detected in the sample. Aside from blood culture equipment, the test does not require any specific instruments to get results, which makes it useful in any laboratory. “Clearing this test gives health care professionals a test that can confirm S.aureus and then identify whether the bacteria is MRSA or MSSA,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics Device Evaluation and Safety in the FDA’s Center for Devices and Radiological Health. “This not only saves time in diagnosing potentially life-threatening infections but also allows health care professionals to optimize treatment and start appropriate contact precautions to prevent the spread of the organism.” According to the FDA, the clearance was based on a clinical study of 1,116 blood samples evaluated at four major U.S. hospital centers. Within the organisms determined to be S.aureus, the MRSA determination was 98.9% accurate (178/180) and the MSSA determination was 99.4% accurate (153/154). The KeyPath MRSA/MSSA Blood Culture Test is manufactured by MicroPhage Inc. of Longmont, Colo.