Use of yogurt bacteria as a model surrogate to compare household cleaning solutions

With the growing number of pathogens that are responsible for human disease, there is an urgent need to compare the relative efficacy of various household cleaning chemicals. These chemicals play an important role in preventing the spread of disease in the home setting, but there is no uniform way of comparing these cleaning products. In addition, there is no readily available guidance for the consumer while purchasing household cleaning products in terms of their efficacy in destroying bacteria. This research addresses this need by studying the inactivation of yogurt bacteria in the presence of a variety of cleaning products. We found that several of the cleaning products (Citrus II Hospital Germicidal Deodorizing Cleaner, Lysol All-Purpose Cleaner, and Earth Essentials Multipurpose Cleaner) were very effective at rapidly destroying bacteria. On the other hand, several other cleaning products including soap and alcohol-based hand sanitizer were only partially efficacious. Water as a control and one other cleaner were not at all effective at destroying bacteria. We compared the efficacy of cleaning products on bacteria isolated from common public surfaces and found good correlation with the results from the yogurt model. The effective concentration of isopropyl alcohol in hand sanitizer was studied using this model system. The results support our hypothesis that yogurt bacteria are a safe and readily available model system that can be used to rank the relative efficacy of several commonly used household cleaning products, as well as potentially for other studies on bacterial inactivation.