Biofilm formation by E. coli and S. aureus on cellphone cover: sensitivity to commercially available sanitizers

Presence of pathogens on the cellphones and their accessories poses a significant risk for public health. This study aimed to determine the biofilm-forming capability of S. aureus and E. coli on pieces made from a different commercially available cell phone and aadditionally to test the effectiveness of the most common commercially available sanitizers. Therefore, bacterial biofilm biomasses were quantitatively determined on cellphone covers using crystal violet assay in the presence and absence of common sanitizers. This study revealed that S. aureus and E. coli could form biofilms on the surfaces of all cellphones covers. Additionally, the sanitizers that contain sodium hypochlorite 5.25% and those composed of 38.9% ethanol and 0.05% dodecyl dimethyl ammonium chloride showed the highest log reduction in the number of viable cells after 5 minutes of exposure against biofilms formed by both E. coli and S. aureus compared to other tested sanitizers (chloroxylenol 4.8%, 2-propanol 64%, and ethanol 70%). Moreover, 4.8% chloroxylenol and 70% ethanol-based sanitizers showed log reductions significantly higher than 2-propanol-based ones. In conclusion, cellphone covers were shown to be suitable surfaces for microbial biofilm formation produced by S. aureus and E. coli. The antimicrobial activity of commercially available sanitizers against these bacterial biofilms was variable, with sodium hypochlorite and ethanol/dodecyl dimethyl ammonium chloride sanitizer being the most effective.