Microarray Bactericidal Testing of Natural Products Against Yersinia intermedia and Bacillus anthracis

Abstract : To address the Defense Department's need for safe, effective protection against biological warfare agents (BWA's), natural products with a historical record of bactericidal efficacy such as bacteriocins, biosurfactants, lytic enzymes and essential oils or their active components were tested against non-pathogenic Bacillus anthracis and the plague pathogen surrogate Yersinia intermedia. Unlike the traditional well diffusion or spot lawn tests, the microplate/microarray test method used in these studies greatly simplified screening and interpretations of dose-response testing of the natural compounds as it relates to decontamination applications. Growth of treated cultures was measured turbidometrically with a microplate reader. Dose-response plots were made from the resulting turbidometric data to assess bactericidal efficacy of the test compounds. Several natural compounds were found effective against Yersinia and B. anthracis cells and spores using this method. These results show the promise of natural compounds in the development of environmentally responsible BWA decontamination preparations.