Viability Assay for Monitoring Decontamination of Pathogenic Bacteria

The objective of the Phase I program was to develop a rapid, automated means of monitoring the efficacies of decontaminants on bacterial pathogens using fluorescent probes. During Phase I, Luna developed several fluorescence-based viability assaysexploiting the metabolism of the tester strains E. coli, S. aureus, and B. globigii. Acid-production and general reduction and oxidative metabolism were used with selected fluorescent probes to monitor the efficacy of decontaminants such as alcohols,quats, H2O2, and hypochlorite on bacteria and bacterial spores. The assays were simple, rapid and the fluorescence responses of decontaminant-treated organisms correlated directly with plate count enumerations. Their use in determining general bacterialloads (CFU/ml) was also demonstrated. During Phase II, Luna proposes to include representative tester strains for V. cholera and Y. pestis and expand the assay formats to include specific fluorogenic substrates and a wider variety of decontaminants. Theassays will be refined for use with bacterial spores and optimized long-term storage conditions. In addition, during Phase II, the assays will be adapted for automated high-throughput formats and their potential use as field tests for monitoringdecontamination and viable bacterial loads will be examined. The broader applications of affinity fluorosomes include monitoring weapons and other surfaces for residual pathogens after decontamination. These assays also have potential applications in thepharmaceutical industry as a rapid means of antimicrobial susceptibility testing and in the environmental fields whereby monitoring of non-treated or treated water sources for bacterial loads or soluble hazardous compounds is desired.