RAPID ATP METHOD FOR THE SCREENING AND IDENTIFICATION OF BACTERIA IN FOOD AND WATER SAMPLES

Abstract

Previously, measurement of microbial Adenosine Triphosphate (ATP) has been applied to enumerating bacterial populations in water, wastewater, marine environments, urine, milk, and various foods, just to name a few. However, two universal diculties were encountered in the application of this method: (1) Interference by non-microbial sources of ATP, and (2) Chemicals or metals in the sample. These two factors led to the limitation of sensitivity as well as false positives and negatives. Recent advances in instrumentation, reagents, and the inclusion of membrane ltration methods have resolved many of these problems. Studies performed in various countries including the US, Canada, and Poland have shown the rapid 5 min ATP test to have a correlation of from 85%{95% to the standard 48 h APC. The sample volume can also be increased by use of a unique cell concentrator, allowing for detection of as few as 200 cfu/ml. Additionally, by varying the size of the ltration membrane the system has been shown to separate and quantify the amount of yeast and bacteria in beverage or other samples within 5 min. This technology may also be utilized for the specic identication of select organisms by use of select lysing reagents (Listeria spp.) in lieu of a total extracting reagent, as well as specic antibody coated beads or chemiluminescence. The specic assays can be accomplished withing 20 min with a sensitivity of less than 10 3 cfu/ml.