The U.S. Food and Drug Administration has approved a blood culture test that can determine if Staphylococcus aureus bacteria infections are methicillin resistant (MRSA) or methicillin susceptible (MSSA).

The KeyPath MRSA/MSSA Blood Culture Test can distinguish between the diseases within approximately five hours after any bacterial growth is first detected in a sample, the FDA said. The distinction between MSSA and MRSA is important: Some MSSA infections can be treated using certain antibiotics, whereas MRSA infections are resistant to most antibiotics.