Biocides are commonly used in cleaning hospitals and home environments, sterilizing medical equipment and decontaminating skin before surgery. At the correct strength, biocides kill bacteria and other microbes. But if lower levels are used, the bacteria can survive and become resistant to treatment.
Researchers exposed S. aureus taken from the blood of patients to low concentrations of several biocides. Exposure to low concentrations of a variety of biocides resulted in the appearance of resistant mutants.