Quat Sanitizer - a Review of Efficacy

 A review article, Quaternary Ammonium Biocides: Efficacy in Application, published in Applied and Environmental Microbiology, looks at the use of quat, or quaternary ammonium, sanitizers and the fact that some organisms may be more tolerant than others.  It states that this is a tolerance issue, not a resistance issue.  So while the use of quat sanitizers are important, more information is needed in field application to understand real efficacy and survival.

 Applied and Environmental Microbiology
http://aem.asm.org/content/81/2/464.abstract?etoc
Quaternary Ammonium Biocides: Efficacy in Application

Charles P. Gerba
Department of Soil, Water, and Environmental Science, University of Arizona, Tucson, Arizona, USA

ABSTRACT

Quaternary ammonium compounds (QACs) are among the most commonly used disinfectants. There has been concern that their widespread use will lead to the development of resistant organisms, and it has been suggested that limits should be place on their use. While increases in tolerance to QACs have been observed, there is no clear evidence to support the development of resistance to QACs. Since efflux pumps are believe to account for at least some of the increased tolerance found in bacteria, there has been concern that this will enhance the resistance of bacteria to certain antibiotics. QACs are membrane-active agents interacting with the cytoplasmic membrane of bacteria and lipids of viruses. The wide variety of chemical structures possible has seen an evolution in their effectiveness and expansion of applications over the last century, including non-lipid-containing viruses (i.e., noroviruses). Selection of formulations and methods of application have been shown to affect the efficacy of QACs. While numerous laboratory studies on the efficacy of QACs are available, relatively few studies have been conducted to assess their efficacy in practice. Better standardized tests for assessing and defining the differences between increases in tolerance versus resistance are needed. The ecological dynamics of microbial communities where QACs are a main line of defense against exposure to pathogens need to be better understood in terms of sublethal doses and antibiotic resistance.