@article{hegde_leon-velarde_stam_jaykus_odumeru_2007, title={Evaluation of BBL CHROMagar Listeria agar for the isolation and identification of Listeria monocytogenes from food and environmental samples}, volume={68}, ISSN={["1872-8359"]}, DOI={10.1016/j.mimet.2006.06.011}, abstractNote={The performance of BBL CHROMagar Listeria chromogenic agar for the detection of Listeria monocytogenes was evaluated for its ability to isolate and identify L. monocytogenes from food and environmental samples. The medium was compared to non-chromogenic selective agars commonly used for Listeria isolation: Oxford, Modified Oxford, and PALCAM. BBL CHROMagar Listeria had a sensitivity of 99% and 100% for the detection of L. monocytogenes from 200 natural and artificially inoculated food samples, respectively, with a colony confirmation rate of 100%. The sensitivity of non-chromogenic selective media for the detection of L. monocytogenes from these same samples was 97–99% with colony confirmation rates of 65–67.5%. From 93 environmental samples, BBL CHROMagar Listeria agar results correlated 100% with a Listeria spp. visual immunoassay (TECRA) performed on these same samples and the USDA–FSIS standard culture method for the isolation of L. monocytogenes. From environmental samples, the L. monocytogenes confirmation rate was 100% for BBL CHROMagar Listeria as compared to 50% for conventional agars tested. On BBL CHROMagar Listeria, L. monocytogenes forms a translucent white precipitation zone (halo) surrounding blue-pigmented colonies of 2–3 mm in diameter, with an entire border. BBL CHROMagar Listeria offers a high degree of specificity for the confirmation of suspect L. monocytogenes colonies, whereas non-chromogenic selective agars evaluated were not differential for L. monocytogenes from other Listeria species.}, number={1}, journal={JOURNAL OF MICROBIOLOGICAL METHODS}, author={Hegde, Veena and Leon-Velarde, Carlos G. and Stam, Christina M. and Jaykus, Lee-Ann and Odumeru, Joseph A.}, year={2007}, month={Jan}, pages={82–87} }
 @article{brinley_stam_truong_coronel_kumar_simunovic_sandeep_cartwright_swartzel_jaykus_et al._2007, title={Feasibility of utilizing bioindicators for testing microbial inactivation in sweetpotato purees processed with a continuous-flow microwave system}, volume={72}, ISSN={["0022-1147"]}, DOI={10.1111/j.1750-3841.2007.00371.x}, abstractNote={ABSTRACT:  Continuous‐flow microwave heating has potential in aseptic processing of various food products, including purees from sweetpotatoes and other vegetables. Establishing the feasibility of a new processing technology for achieving commercial sterility requires evaluating microbial inactivation. This study aimed to assess the feasibility of using commercially available plastic pouches of bioindicators containing spores of Geobacillius stearothermophilus ATCC 7953 and Bacillus subtilis ATCC 35021 for evaluating the degree of microbial inactivation achieved in vegetable purees processed in a continuous‐flow microwave heating unit. Sweetpotato puree seeded with the bioindicators was subjected to 3 levels of processing based on the fastest particles: undertarget process (F0 approximately 0.65), target process (F0 approximately 2.8), and overtarget process (F0 approximately 10.10). After initial experiments, we found it was necessary to engineer a setup with 2 removable tubes connected to the continuous‐flow microwave system to facilitate the injection of indicators into the unit without interrupting the puree flow. Using this approach, 60% of the indicators injected into the system could be recovered postprocess. Spore survival after processing, as evaluated by use of growth indicator dyes and standard plating methods, verified inactivation of the spores in sweetpotato puree. The log reduction results for B. subtilis were equivalent to the predesigned degrees of sterilization (F0). This study presents the first report suggesting that bioindicators such as the flexible, food‐grade plastic pouches can be used for microbial validation of commercial sterilization in aseptic processing of foods using a continuous‐flow microwave system.}, number={5}, journal={JOURNAL OF FOOD SCIENCE}, author={Brinley, T. A. and Stam, C. N. and Truong, V. D. and Coronel, P. and Kumar, P. and Simunovic, J. and Sandeep, K. P. and Cartwright, G. D. and Swartzel, K. R. and Jaykus, L. A. and et al.}, year={2007}, pages={E235–E242} }
 @article{eifert_curtis_bazaco_meinersmann_berrang_kernodle_stam_jaykus_kathariou_2005, title={Molecular characterization of Listeria monocytogenes of the serotype 4b complex (4b, 4d, 4e) from two turkey processing plants}, volume={2}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2005.2.192}, abstractNote={Most foodborne outbreaks of listeriosis have been found to involve a small number of closely related strains of Listeria monocytogenes serotype 4b. The ecology of these organisms and their reservoirs in nature or in the processing plant environment, however, remain poorly understood. Surveys of environmental samples from two turkey processing plants in the United States indicated presence of L. monocytogenes of the serotype 4b complex (serotype 4b and the closely related serotypes 4d and 4e). In addition, environmental and raw product samples from one plant repeatedly yielded isolates with genetic markers typical of two major serotype 4b epidemic clonal groups, ECI and ECII. The pulsed field gel electrophoresis (PFGE) profiles of these isolates, however, were clearly distinct from those of confirmed epidemic-associated strains. Furthermore, we observed minor but consistent differences in PFGE profiles of isolates that harbored ECI- or ECII-specific genetic markers, and that were obtained at different sampling times from the same plant. The findings suggest processing plant persistence (or repeated introductions) and genomic diversification of L. monocytogenes serotype 4b isolates that harbor ECI- or ECII-specific genetic markers. Such diversification would need to be taken into consideration in further efforts to elucidate the evolution and epidemiology of these organisms.}, number={3}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Eifert, J. D. and Curtis, P. A. and Bazaco, M. C. and Meinersmann, R. J. and Berrang, M. E. and Kernodle, S. and Stam, C. and Jaykus, L. -A. and Kathariou, S.}, year={2005}, pages={192–200} }