Assessing the impact of handwashing soaps on the population dynamics of carbapenemase-producing and non-carbapenemase-producing Enterobacterales.

Carbapenemase-producing bacteria have persistent environmental reservoirs in handwashing sinks. This study assessed the impact of handwashing soaps on the population dynamics of carbapenemase-producing Enterobacterales (CPE) and non-CPE. A number of isolates were grown in minimal media with or without two hand soaps marketed for use in health care. Soap A led to increased growth of all isolates except for Escherichia coli. Soap B did not lead to increased growth. The main difference between the formulations was that Soap B contained DMDM hydantoin, a preservative agent and sensitizer. These results show that environmental persistence of CPE may be sustained by common handwashing practices with soap, but further research is required.