Activity of Hospital Disinfectants against Vegetative Cells and Spores of Clostridioides difficile Embedded in Biofilms.

spores can survive in the environment in either mono- or mixed-species biofilms. However, no previous studies have investigated chemical disinfection of spores embedded in biofilms. Thus, the purpose of this study was to assess the effectiveness of hospital disinfectants against spores embedded within biofilms. Five unique strains embedded in three different biofilm types grown for 72 or 120 h were exposed to seven different hospital disinfectants. abundance [as log(number of CFU/milliliter)] was calculated after manufacturer-determined contact times along with biofilm biomass and microscopy. The primary analysis compared differences between vegetative cell and spore counts as well as amounts of biomass after exposure to disinfectants. vegetative cells and spores were recovered from biofilms regardless of the type of biofilm growth or biofilm growth time. No disinfectant was able to completely eliminate from the biofilms. Overall, Clorox, -phthalaldehyde (OPA), and Virex were most effective at killing spores regardless of biofilm age, ribotype, or wash conditions (whether biofilms are washed or unwashed) ( = 0.001, each). Clorox and OPA were also effective at killing total vegetative cell growth ( = 0.001, each), but Virex was found to be ineffective against vegetative cell growth in biofilms ( = 0.77). Clorox and Virex were most effective in reducing biomass, followed by Nixall, OPA, and Vital Oxide. No disinfectant was able to completely eliminate embedded within biofilms although differences among disinfectants were noted. Future research will be required to determine methods to eradicate this persister reservoir.