Why Antibiotics Fail: UCSB biologists correct a flaw in the way bacterial susceptibility to these drugs is tested
When a patient is prescribed the wrong antibiotic to treat a bacterial infection, it’s not necessarily the physician who is at fault. The current antibiotic assay — standardized in 1961 by the World Health Organization and used worldwide — is potentially flawed. So says MCDB professor Michael Mahan, whose lab has developed a new antimicrobial susceptibility test that could transform the way antibiotics are developed, tested and prescribed. The standard test specifies how well drugs kill bacteria on petri plates containing Mueller-Hinton Broth, a nutrient-rich laboratory medium that fails to reproduce most aspects of a natural infection. Now, Mahan and colleagues have used a mouse model to demonstrate that a variety of antibiotics work differently against various pathogens when inside the mammalian body. Their findings appear in the journal EBioMedicine.