The U.S. Food and Drug Administration (FDA) has cleared for marketing a new rapid blood test for drug-resistant staph infections, say FDA officials.

Methicillin-resistant staphylococcus aureas, or MRSA, is a strain of bacteria that is resistant to all of the penicillin-based antibiotics typically used to treat the infection. MRSA can be much harder to treat than a traditional staph infection and can lead to fatal cases of blood poisoning and pneumonia.

MRSA is typically found in hospitals and nursing homes, and is most dangerous for the elderly and people with compromised immune systems. There have been minor outbreaks reported, however, among HIV-positive people who may have contracted MRSA in gyms, steam rooms and saunas. MRSA can also infect people with healthy immune systems.

A diagnosis of MRSA can be tricky, as the standard test for it can take up to two days to yield results. The new rapid test can be completed within two hours, which will allow physicians to more confidently and aggressively treat cases of MRSA when they are found.