Biocides

Abstract

The use of chemical biocides in medical, industrial and domestic environments is a first line defense in the prevention and control of microbial growth. Although biocide treatments eliminate most surface contamination, some microorganisms may survive and give rise to substantial problems, and numerous reports have highlighted the survival of microorganisms after cleaning and disinfection in different environments. Microorganisms may have intrinsic resistance to biocides which is commonly associated with cellular impermeability. However, the continuous exposure to biocides may increase microbial resistance by cellular mutations or acquisition genetic elements. The increasing use of biocides is also a concern related to their putative environmental toxicity. Therefore, new biocidal solutions are needed to combat effectively the evolution of microbes developing resistance while having a low or no environmental toxicity impact. Phytochemicals are an attractive source of eco-friendly, relatively inexpensive and widely available new broad-spectrum antimicrobials with low levels of cutaneous cytotoxicity and environmental toxicity. This article will highlight the cleaning and disinfection processes in microbial growth control as well as the properties of biocides commonly used, the processes involved in their antimicrobial action, the factors influencing their efficacy, and the mechanisms of cellular and biofilm resistance. In addition, it will cover the main classes of phytochemicals with antimicrobial properties and their mode of action.