PROGRAM
“Efficacy of Hot Water Surface Pasteurization vs. Chlorine and Experimental Sanitizing Wash Treatments for Reducing Populations of Salmonella Poona on Inoculated Whole Cantaloupe Melons”
Numerous outbreaks of salmonellosis by Salmonella Poona have been associated with the consumption of cantaloupes. Commercial washing processes for cantaloupes are limited in their ability to inactivate and/or remove this human pathogen. The objective of this study was to compare the efficacy of hot water surface pasteurization at 76°C for 3 min to that of various chlorine and experimental sanitizer solutions for the inactivation of Salmonella on inoculated cantaloupe surfaces. Whole cantaloupes, surface inoculated with S. Poona RM 2350 to a final cell concentration of 5-6 log CFU/cm2 were stored at 4°C or room temperature (RT = 19±1°C) for up to 48 h prior to processing. Washing treatments with tap water at 76°C for 3 min at 24 and 48 h post inoculation resulted in excess of 5 and 3 log CFU/cm2 reductions in S. Poona, and yeast and mold populations, respectively. All washing treatments with aqueous sanitizers at RT for 20 min treatments resulted in less than 2 log reductions in S. Poona, and yeast and mold populations. These results demonstrate the utility of hot water for the inactivation of Salmonella on cantaloupes and provide a framework to producers of fresh-cut melon for the potential use of hot water as an intervention treatment for enhancing the microbiological safety and extending the shelf life of this commodity. Storage of untreated inoculated cantaloupes at RT for up to 48 h post inoculation caused a significant (p<0.05) increase in S. Poona as compared to storage at 4°C. This indicated that cantaloupes should be refrigerated as soon as possible following harvesting to suppress the growth of any possible contaminant on the rind. These findings will assist food industry and regulatory agencies in establishing processing guidelines to guard against pathogens, thereby decreasing the incidence of food poisoning outbreaks.
Dr. Annous is currently with the USDA – Eastern Regional Research Center – Food Safety Intervention Technologies Research Unit. He received his Ph.D. in Food Science from the University of Illinois; an M.S. in Food Science, a diploma in Agricultural Engineering, and a B.S. in Biological Chemistry, all from the American University of Beirut in Lebanon. His research has been focused on microbial food safety for the past 13 years: 1.) Physiology of biofilm formation by human pathogens on fresh produce and its role in resistance to sanitation treatments; 2.) Potential sources of fresh produce contamination with human pathogen—farm to table; 3.) Development of intervention technologies, thermal and non-thermal, for effective decontamination of fresh produce; and 4.) Development and validation of Biosafety Level Two pilot plant facility for processing fresh produce.
“Four Decades of NMR Research at Merck: A Retrospective”
The pharmaceutical industry is an ideal area for NMR research since the spectroscopist is exposed to a broad diversity of challenges. This seminar will draw upon the experience obtained in dealing with problems that have a direct bearing on drug development.
Examples of NMR contributions in the core areas of natural products, metabolites and microbiological fermentation products will be presented. The NMR role in the synthetic efforts leading to the vaccine Pedivax® will be described. Purity issues become increasingly important with very small samples and steps taken to maximize the success rate for samples in the 1-10 microgram range will be discussed. Human interest issues crop up from time to time and those considered of particular interest are included. The pharmaceutical industry is not immune to criminal activities and several cases in which NMR played a key role will be presented. A personal research project, still under development, which provides information on the local electronic environment of protons will be described. The utility of the technique, which exploits chemical shift differences between benzene and a relatively inert control solvent (e.g., CDC13) will be illustrated. Finally, although NMR frequently allows the spectroscopist to take very strong stands on structural issues, misjudgments are possible and a striking example serves as a lesson to all of us.
Dr. Arison obtained his undergraduate training at the University of Michigan and received his Ph.D. degree in organic chemistry from the Polytechnic University of New York in 1967. Aside from a one-year stint on the Manhattan Project, his entire career was spent at Merck where he was involved in NMR research for well over three decades. In addition to the general application of NMR to structure determination, considerable experience was obtained in dealing with problems having a direct bearing on drug development. These include identification of metabolites, microbiological fermentation products, biotransformations, natural products and peptides (including conformation). Analytical procedures were developed for dealing with special problems, e.g., analysis of samples in the very low microgram range, extending purity analysis by NMR to better than 1%. NMR is eminently suitable for detective work and was applied successfully in forensic problems. He has approximately 200 publications and close to 50 patents. He retired from Merck in January, 2004.
“Integrated Omics in Systems Biology: The New Frontier for Environmental Biotechnology”
Integration of the latest omics techniques for discovery science in environmental biotechnology with field studies and applications in bioremediation.
Dr. Hazen received his B. S. and M. S. degrees in Interdepartmental Biology from Michigan State University. His Ph.D., from Wake Forest University, is in Microbial Ecology. He is currently the Head of the Ecology Department and the Center for Environmental Biotechnology at E. O. Lawrence Berkeley National Laboratory. Dr. Hazen is an adjunct professor in engineering, biology and microbiology at 8 universities around the country. He is a fellow of the American Academy of Microbiology and has authored more than 179 scientific publications, not including more than 500 abstracts and chapters in several books. He has received more than $70 million in competitive research funding on more than 55 different projects from NIH, NSF, EPA, DOE, DOD, SERDP, WRRI, Sea Grant, and several private granting entities. He has 14 patents on 5 bioremediation processes that are being used in 40 states and several countries; these technologies have been licensed to more than 30 companies. His area of specialty is environmental microbiology, especially as it relates to bioremediation, subsurface microbiology, and aquatic ecology. One of his main research areas has been the microbial ecology of environmental stress.