"But before he replaced the 'bone flap'—the section of skull that is removed to allow access to the brain—he soaked it for an hour in a solution teeming with Enterobacter aerogenes, a common fecal bacterium."

"Then he reattached it to Egan’s skull, using tiny metal plates and screws. Muizelaar hoped that inside Egan’s brain an infection was brewing.... The surgeons had no data to suggest what might constitute a therapeutic dose of Enterobacter, or a safe delivery method. The procedure was heretical in principle: deliberately exposing a patient to bacteria in the operating room violated a basic tenet of modern surgery.... For four weeks, Egan lay in intensive care, most of the time in a coma. Then, on the afternoon of November 10th, Muizelaar learned that a scan of Egan’s brain had failed to pick up the distinctive signature of glioblastoma. The pattern on the scan suggested that the tumor had been replaced by an abscess—an infection—precisely as the surgeons had intended...."

From "Bacteria on the Brain/A brilliant surgeon offered an untested treatment to dying patients. Was it innovation or overreach?"