Module 35Realize the burden of foodborne and waterborne infectious diseases:How many illnesses result from foodborne diseases48 millionUnderstand how the CDC can monitor foodborne diseases in the U.S. populationThe CDC can monitor foodborne disease in the U.S. population with FoodNet in 10 statesWhere do many bacterial foodborne pathogens originateMicroorganism that colonize or contaminate foodUnderstand the methods of food preservation:Describe the difference between perishable, and semiperishable, and nonperishable foods- Perishable- can provide environments that increase populations of natural or pathogens microbes during storage- Semiperishable- such as hard fruits and potatoes, can be stored for longer times- Nonperishable- have properties that prevent microbial growth, or no microbes to begin with. Usually dry with low water content or sterilized by heatBe able to briefly state how each food preservation method works-Refrigeration- low temperature = slow growth-Acidity- acidic ph less than 5 inhibits growth of most pathogens. add salt to food to pickle-Drying- reduce water content. NaCl of > 7.5% inhibits most bacteria but fungi and some gram + can grow-Chemical Preservatives - sodium benzoate, nitrate, nitrite, sorbic acid, propionate act as growth inhibitors and are GRAS by FDA-Radiation- radiation kills microbes, reduce viable numbers by 10-fold. wide variety of food, will reduce but may not eliminate microbes-Heat- pasteurization = short term heating to reduce microbes. canning = heating in a sealed container offer complete sterility is not achieved-Microbial Fermentation- Microorganisms fermentable sugar and produce end products that inhibit growth of pathogenKnow the difference between food infection and food poisoning:Be able to define food infection and food poisoning- Food infection- consume organism- Food poisoning- consume toxinDescribe the major type of enterotoxin produced by Staphylococcus and the symptoms it can cause- Major type of enterotoxin produced by Staphylococcus is aurous - Symptoms- nausea, vomiting, and diarrheaUnderstand the diseases caused by Salmonella:Know what a serotype is and how Salmonella serotypes are named- Salmonella serotypes- subspecies of salmonella enteric- Named- based on location where that serotype was first identified Be able to briefly describe why it takes so long to investigate food infection outbreaksIt could take 1-10 days after patients is sick to develop symptoms Know the significant facts about the Typhoid Mary case- Worked at a series of home as a cook in New York- Family members became ill after she began working in each home- Mary then moved to another home and infected family members there- Was forcefully quarantined twice, but continued to violate orders by working as a cook- Was quarantined for 23 years until her deathDemonstrate knowledge of three major bacterial food pathogens: Salmonella, E. coli, and Campylobacter:Know the two antigens used for serotyping E. coli- O antigen (LPS)- H antigen (flagella protein)What does the acronym STEC mean; what is the most common serotype of STEC- STEC- Shiga toxin- producing E. coli - Serotype- O157:H7 Describe Campylobacteriosis symptoms and what food the bacterium is commonly found in- Symptoms- Diarrhea, cramping, fever, and nausea- Found- in the intestinal tact of over 90% poultry and in unpasteurized milkUnderstand the molecular techniques (pulsed field electrophoresis, genome sequencing) are and how they distinguish different serotypes of bacterial species- Pulsed field electrophoresis- used for separation of large restriction enzyme fragments of genomic DNA from pathogens isolated from patients- Genome sequencing- two serotypes would be identical but there could be observed differences in the chromosome arrangement between the strains- How they can distinguish different serotypes of bacteria species is by separation of the DNA fragments of each chromosome would result in different patterns call DNA fingerprintsKnow the methods used for investigation of foodborne and waterborne outbreaks:Describe what a serotype isGroup of microorganisms they share a specific antigen determinedBe able to describe how restriction enzymes can be used to “serotype” bacterial pathogens- Salmonella Typhi –chromosome rearrangement- Separation of DNA fragments results in different patterns DNA fingerprintingKnow in a general way what pulsed field gel electrophoresis is and how it works-Used for separation of large restriction enzyme fragments of genomic DNA from pathogens of isolated from patients-Cut restriction enzyme with endonuclease, observe band pattern of DNA fingerprint, compared to pulse net databaseUnderstand why foodborne and waterborne outbreaks need to be investigated:Be able to describe the ultimate goal of investigating waterborne and foodborne outbreaksMatch the suspected source of a pathogen with specific illnesses in the communityExplain the limitations of 16S rRNA gene sequencing for these investigations.Many food bacterial pathogens would have identical sequencesUnderstand the differences between the FoodNet, PulseNet, and Genome Tracker program-FoodNet - ~15 survalience databased to watch for foodborne illnesses-PulseNet - DNA fingerprint database, pulse field electrophoresis patterns of pathogens-Genome Tracker - "whole genome sequencing" program. 13 labs that contribute to sequences of food outbreaksUnderstand the benefits and methods of processing municipal water:How are cholera and Legionnaire’s disease transmitted.- Cholera - fecal contaminated water- Legionnaires - Lives as part of a microbial biofilm community in water storage tanks, air conditioning systems, soil and aquatic habitatsKnow the important facts about the Legionella outbreak news story.12 people in Flint have died as a result of Legionnaire's
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