Investigation of Bacterial Contamination of Liquid Soaps Used in Public Restroom

Abstract

Handwashing with soap is an important practice to reduce the transmission of potentially pathogenic microorganisms, but liquid soaps with refillable dispensers are prone to extrinsic bacterial con-tamination. This study investigated the bacterial contamination of liquid soaps in 58 public restrooms in six buildings. The bacteria were identified by a biochemical test and MALDI-TOF mass spectro-photometry. The antimicrobial susceptibility was determined using the Vitek II system. Of the 58 restrooms examined, 27(46.55%) were using a refill dispenser, of which 25(92.59%) were contaminated with bacteria. The bacteria recovered from the soaps ranged from 1.6x103 to 2.7×105 CFU/mL. Serratia liquefaciens (12), Achromobacter xylosoxidans (9), S. marcescens (4), Staphy-lococcus pastueri(1), and Achromobacter spanius(1) were isolated. Except for one A. xylosoxidans, bacteria of the same species isolated in the same building showed a unique resistance pattern. In conclusion, handwashing with contaminated soap may play a role in the transmission of bacteria in public health settings. Therefore, it is necessary to limit the use of refillable liquid soaps in the restrooms of hospitals used by patients with reduced immunity.

Keywords

• bacterial contamination
• handwashing
• liquid soaps
• public restroom
• refillable dispenser