Last Lectures: The Peanut Butter Contamination Crisis and Genetically Engineered Foods - P, Study notes of Food Microbiology

Download Last Lectures: The Peanut Butter Contamination Crisis and Genetically Engineered Foods - P and more Study notes Food Microbiology in PDF only on Docsity! 4/9/2009 1 Last Lectures The Peanut Learning Experience AND Genetically Engineered Foods The News Release -2006 The Facts Peanut Butter Processed May 6, 2006. Distribution began August First Cases of Salmonellosis August, 2006 January, 2007 Production Run “2111” Peter Pan and Great Value HOW DID THEY (CDC, FDA) KNOW THAT? …How did they figure it out? 4/9/2009 2 Aug 06- Jan 07 398 Reported Cases Salmonellosis – all Caused by Salmonella enterica Tennessee Why is this UNUSUAL: distribution of most salmanellosis cases (~40,000/year) are all sorts of S. enterica Serovars no pattern. This serovar is a rare one never before isolated with such frequency ! How do they know this? It caught attention because, this one is one of the rare Lactose positive Salmonella serogroups Remember how Salmonella is this differentiated from Escherichia ? AND Salmonella is traditionally associated with chicken, pork and in 1993 an outbreak from powdered milk, infant diet formulas! Salmonella Taxonomy Gram Negative rods, facultative, catalase pos, oxidase neg Closely related to Escherichia coli Serogroups: 1941 – 100 serogropus of S. enterica 1964 – 900 serogroups now > 2 400 serogroups - , . -based on H and O antigens. IMViC -+-+, Lactose neg, all H2S pos. Copy of an earlier slide: in SalmonellaE. coli is IMViC ++--, Lactose pos, H2S neg 4/9/2009 5 How did FDA, CDC find Association with Peanut Butter Questionnaires to Victims and their Families: What poultry, meat, milk products did you eat? Asked weeks and months after the episode. Investigation of these they got lots of Salmonella types but not S. Tennessee Had to go to a full food Questionnaire….the main thing in common besides drinking water, milk, etc…was PEANUT BUTTER of Specific Brands. Some families still had the original jars….these then were tested and were positive for S. Tennessee The Plant The Raw Product 4/9/2009 6 The Basic Peanut Butter Process Dry Nuts Shelled, Shake Free of Debris Roasted ~350 Fo 20-25 min while tumbling Ground to a Paste with added Peanut Oil and other flavors, salt, etc. M t lik l ft i l i di t b tt k tos e y a er commerc a gr n ng, peanu u er ep at warm temp to keep it fluid to fill jars. Small (10 lb/roast) Peanut Roaster. Back at the ConAgra ConAgra produces 55 brands nationwide, does millions of pounds of meat products, etc… Then in 2007: Feb 15: Food Recall all “21111” Feb 15: FDA closes the plant in Georgia for Inspection … How did S. Tennessee get into peanut butter? Feb 20: ConAgra says recall will cost $50-60 million This will have a marginal effect on their stock share price…could drop $0.06- $0.08/share The Unanswered Questions 1. Were the peanuts contaminated?….or was the roasting process faulty or contaminating the product. 2. Did contamination occur AFTER roasting? Contaminated ingredient? Contamination through the equipment? Contaminated jars? 3. What is the fate of S. Tennessee when it gets into Peanut butter? Can it grow? Does it just maintain itself? What titers of S. Tennessee in the peanut butter AND what is the ID50?? 4/9/2009 7 The Peanut Crisis in 2009 Genetic Engineering of Foods Summary of Genetic Engineering Techniques 4/9/2009 10 Using the Right Vectors pSE420 , Invitrogen Corp. A biotech company. Polylinker Site Phage M13 Vector for Cloning and Sequencing Polylinker in lacZ Gene 4/9/2009 11 Pro and Eu-karyotic Vector for E. coli and Yeast terminator and polyadenylator Cloning from Eukaryotic mRNA Finding a Gene from Protein Structure 4/9/2009 12 Getting Genes into Plants Agrobacterium is a Plant Pathogen Agrobacterium Ti plasmid Ti = tumor inducing Ae Leaf segments are transferred to agar dish. é ~—S" it € ga ZB3 Agar plate with growth hormones and kanamycin Plants are regenerated from leaf segments. ‘These kanamycin- resistant plants contain the foreign gene. 4/9/2009 Industrial gene transfer 15 4/9/2009 16 Soybeans treated with Glyphosphate1 1. “Round Up”, Monsanto Corp. Soybeans with Weeds Soybeans resistant to Glyphosate in a Field Treated with Glyphosate 4/9/2009 17 Tobacco Plants and Bt toxin Gene in Chloroplasts with Armyworm Larvae Bt = Bacillus thuringensis a. Normal plant b. Plant with Bt toxin gene in chloroplast Tomato Plant with Bacillus thuringensis toxin Vaccines in Plants