"The use of biocides, also called antibacterials, has become increasingly popular for regular household use. While originally developed to control transmission of infectious disease agents among sick patients, these same products are increasingly incorporated into domestic household cleaners, healthcare products, clothes, and plastics," says Bonnie Marshall, one of the study researchers.
In contrast to alcohols, peroxides and bleach, which quickly dissipate from environmental surfaces, common antibacterial chemicals such as triclosan and quaternary ammonium compounds leave residues which can exert a more prolonged effect on the microbiology of the application site. Given that triclosan-resistant mutants of E. coli and Staphylococcus aureus have been isolated in the laboratory, concern has developed over the effect of home usage of residue-producing biocides on the microbiology of the home. Of particular interest is the possibility that prolonged application may promote higher levels of antibiotic resistance in the normal and/or disease-causing bacteria.
Marshall and her colleagues performed a "snapshot" survey of the aerobic bacteria from bathroom and kitchen surfaces of 38 households located in the greater Boston and Cincinnati areas. They evaluated the total numbers of gram-negative and gram-positive bacteria, including potential pathogens, as well as the frequency of bacterial resistance to six different antibiotics. There were large variations among identical sites in different homes, and significant numbers of bacteria could be recovered, even from sites
Contact: Jim Sliwa
American Society for Microbiology