Molecular Labeling and Cell Detection of Food Pathogens on Food Processing Surfaces for ISS and Planetary Outpost

Food processing surfaces were cleaned and treated with low-levels of Listeria and Salmonella for surface swabbing. Swabs were placed in the appropriate enrichment broth for 6-18 hours. Immunomagnetic separation of the bacteria from the media was followed with Syto 62 fluorescent tagging and RBD2100 enumeration. Capture efficiencies for each organism were typically >80% and RBD2100 and standard plate counts correlations were >0.9 (R²). In a second method bacteria were centrifuged from the media, fixed, and hybridized with Cy-5 labeled rRNA specific probes. RBD analysis showed the presence of pathogen specific populations from the contaminated surface swabs.