A failure in the sterilization process at a Birmingham pharmacy appears to have caused the infection that sickened 19 people in Alabama hospitals, nine of whom died, the state health department said. Investigators found exact matches of the bacteria on a water faucet, a container and a device used to mix intravenous nutritious supplements at Meds IV, State Health Officer Don Williamson said. But there are still questions about how the contamination occurred. The Alabama Department of Public Health and the federal Centers for Disease Control and Prevention have been investigating the outbreak of Serratia marcescens in five hospitals around Birmingham and one in Prattville. It is linked to bags of TPN, total parenteral nutrition -- a supplement given intravenously to patients too sick to eat -- mixed by Meds IV and sent to those hospitals in January, February and March. Williamson said that samples of the bacteria were taken from Meds IV's compounding room, grown out and run through a genetic fingerprinting process.