Food Safety and Quality Assurance: Foods of Animal Origin (Hubbert, Hagstad, Spangler, Hinton and Hughes)

Question 1

Can use electronic cell counters on goats milk?

Answer 1

no

Question 2

Milk screening test: Standard Plate Count

Answer 2

-quantitative and doesn’t differentiate between pathogens and nonpathogens

Question 3

What does Increased bacterial numbers after pasteurization indicate ?

Answer 3

the presence of thermophilic organisms

Question 4

Milk transport and storage-milk temperature requirements

Answer 4

Milk transport and storage-milk must not be >5° F warmer than at pickup when delivered to the plant.

Question 5

Poultry Production: Procedures

Answer 5

Procedures
• Shipping broilers-potential bruising and broken bones
• Slaughter
• Defeathering-mild scald and hard scald
• Processing-
o Heads of older hens and turkeys are left attached
o Heads of broilers are removed
o Legs are cut off (carcasses not washed after this point)
o Removal of giblets, removal of lungs, removal of ovaries/testis
o Chiller-rapid chilling
o Packing/grading
Processing produces are large amount of inedible material
• Disposal methods-burial, incineration, composting, rendering

Question 6

Irradiation in meat preservation

Answer 6

• Destroys foodborne pathogens found in meat
• May be effective even after a product is frozen and boxed
• Uses ionizing radiation from a radioactive isotope of cobalt or from devices that generate a stream of electrons or X-rays
• Also maintains the freshness of food by inhibiting the production of microbial enzymes that breakdown cellular integrity
• 4 treatments-
o Radappertiziation-destroys all organisms
o Radicidation-inactivates non-spore-forming pathogens
o Radurization-destroys spoilage organisms
o Disinfestation-destroys insects
• Is considered to be an “additive” to food
• Approved for use in pork, poultry, fruits, vegetables, spices and grains
• WHO and Codex support food irradiation

Question 7

Chemicals (curing agents) in meat preservation

Answer 7

• Pathogenic or spoilage microorganisms are destroyed because an unfavorable environment is created
• Water-largest single ingredient of any curing preparation
• Salt-bacteriostatic agent inhibiting microbial growth by increasing osmotic pressure
• Nitrate/nitrite salts
o Color fixative and preservative
o Often used concurrently
o Protect against C. botulinum
o Nitrates must be converted to nitrites to be effective
o Bacterial reduction of nitrate to nitrite is pH dependent (less at acidic pH)
o Toxic if ingested in high quantities (restricted use)
o Nitrosamines=carcinogenic
• Sugar-reduce the flavor that salts add to a product
• Phosphates
o Adjunct to curing agents to improve the water-holding capacity of the product
o Causes increase pH
o Can be toxic (restricted)
• Ascorbates
o Adjunct to curing agents
o Fix color of product and prevent fading
o Minimal bacteriostatic effect on spoilage and mold-producing microorganisms
• Acids
o Lactic and acetic acids
o Decrease of 1 pH unit increases the bacteriostasis 10 fold
• Gases
o CO2 –decrease growth of surface contaminants
o Ozone-bactericidal action on airborne microorganisms
 Disadvantages:
• Odor that may mask abnormal meat odors
• Hazardous to human health
• Accelerate development of fat rancidity
• Application of curing agents
o Dry or liquid form to the surface
o “Stitch-pumping”-injection into a major vessel

Question 8

Trichina control

Answer 8

• In US-meat inspection doesn’t include microscopic exam for trichinae in pork. Many pork products are processed as RTE (ready-to-eat)
• Cysts-killed at an internal temp of 137ºF or frozen to -40ºF

Question 9

Control of inedible and condemned meat and poultry products (Rendering)

Answer 9

Inedible-those not normally used for human food
Condemned-materials normally used but have been rejected
Rendering
• Separating fat from its connective tissue stroma
• Final treatment of inedible offal
• Low temp (120°F)-C. perfringens, Staph aureus and Salmonella survive
• High temp (239°F-270°F)-produce inedible fats and meals. Possible recontamination of the meal during further handling
• Dry rendering-generally used for condemned and inedible products destined for animal feed
• Wet rendering-remove liquid fat from edible meat
• Centrifuge-continual addition of meat to the system rather than batches. Bacterial contamination can be a serious problem.

Question 10

Control of inedible and condemned meat and poultry products (Edible Products and Environmental controls)

Answer 10

Edible Products
• Lard-pork-produced from the “killing” fats (removed during the sanitary dressing procedure) and “cutting” fats
• Rendered pork fat
• Tallow-beef or mutton fatty tissue
• Oleo-high grade tallow from beef or mutton
• Partially defatted tissue-lean, edible product from beef and pork fatty trimmings removed during boning
Environmental controls
• Prevent cross-contamination with edible products
• Separate and segregate equipment
Product controls-identify

Question 11

Milk Processing: Pasteurization

• purpose
• time/temp requirements

Answer 11

• Purpose:
o Destroy any pathogenic microorganisms in milk
o Enhance the shelf-life of milk and milk products
• Also inactivates enzymes in milk that cause deterioration (lipase) and rancidity
• Time/temp requirements
o 145°F/30 min (long-time holding)
o 161°F/15 sec (high temp-short time)
o 280°F/2 sec (ultra-pasteurized)
• C. jejuni and L. monocytogenes-occasionally from consumption of milk
o C jejuni-fragile
o L. monocytogenes-some strains are both thermoduric and psychrotrophic. Some microorganisms can repair and restore even under refrigeration

Question 12

Milk Processing: Pasteurization

-Equipment

Answer 12

Equipment
• Clarifier-centrifugal device to remove any solid foreign material. Can also be used to separate cream and skimmed fractions
• HTST unit-pasteurizer
• Homogenizer
o Milk is pumped through a small orifice under high pressure
o Temp must be sufficient to inactivate lipase
• UHT-138°F/2 sec

Question 13

Milk Processing: Pasteurization:

- Evaluating effectiveness

Answer 13

Evaluating effectiveness
• Salt conductivity test
• Phosphatase inactivation curve
• Mesophile test- UK
• Coliform test-presence of coliforms results from contamination from a source after pasteurization.
Milk products-those that have a higher fat content than milk and/or contain added sweeteners have to be heated to 150°F for 30 min or 166°F for 15sec. Increase in temp needed because the product is more viscous.
• Cheese-soft cheeses made from raw milk can be a source of Brucella or Salmonella, because the pH is not low enough to kill pathogens.
o 4 organisms-Salmonella, Listeria, enteropathogenic E. coli, Staph aureus
 From contaminated equipment or personnel
 All can be eliminated by pasteurization 148°F for 16 sec
o 2 points of production
 Holding the milk in vat pasteurizers at a temp insufficient for pasteurization but adequate for microbial growth
 Heating the curd at normal body temp
• Nonfat dried milk-any enterotoxin present before the milk is dried will maintain its toxicity even though the microorganisms are killed.
• Ice cream-foodborne illness if raw or inadequately pasteurized ingredients are used.

Question 14

Egg Processing

Answer 14

Washed at 90°F with alkaline detergent
Egg products more likely to have microbial contamination than shell eggs
Minimize contamination during egg-breaking
• Only edible quality eggs should be used
• Eggs candled to remove undesirables
• Eggs should be spray washed and sanitized before breaking
• Separate washing and breaking rooms to decrease contamination via aerosols
• A separate draw off room with positive-pressure air flow
Internal contamination of eggs by Salmonellae from the environment
Egg Inspection Act (1970)-all whole eggs for use in egg products must be pasteurized at 140°F for 3 ½ min
Higher temps required for separated yolks and for products having added salt or sugar (usually an HTST unit)

Question 15

Aquatic Animal Processing: quality determined by and goals of processing

Answer 15

Quality determined by:
• Quality of the environment they came from prior to harvest
• Standards of sanitation during harvest, handling, storage, processing
Goals of processing:
• Decrease temp of fish
• Keep level of microbial contamination to a minimum

Question 16

Aquatic Animal Processing: Steps in processing:

Answer 16

Steps in processing:
• Bleeding-must be done soon
• Gutting-removes the digestive enzymes and bacteria that initiate spoilage in freshly caught fish. May also be helpful to prevent the migration of parasites (anisakid nematodes) from the gut into the flesh of the fish.
• Washing-clean, cold water to decrease surface slime and spoiling bacteria. Is usually done whether the fish have been bled and gutted or not
• Icing-temp control is the most important element in the preservation and processing of fish. (Holding temp 32-39°F). Used crushed ice or refrigerated seawater
• Storage-shallow trays or boxes

Question 17

Aquatic Animal Processing: Crustacean and Mollusk:

Answer 17

Crustacean and Mollusk:
• Crustaceans are extremely prone to post-mortem deterioration. Lobsters, crabs and crayfish are iced and shipped alive.
• Exoskeleton-increase amount of handling and cleaning and increases opportunity for contamination
• Mollusks-
o iced and shipped directly
o Consumption-increased risk as a large amount are consumed raw

Question 18

Deterioration of food

Microorganisms:

Answer 18

•	3 Groups
1.	Psychrotrophic
o	Do well at refrigerator temps
o	Spoilage bacteria (Altermonas putrefaciens)
2.	Mesophilic
o	Intermediate temp range
o	Most of the pathogens
o	Staph aureus (68-113°F)
3.  Thermophilic
o	High temps
o	Spoilage bacteria (Lactobacillus thermophilus)
•	Psychrophiles-psychrotrophes capable of replication at extremely low temps (32-45°F)
•	Thermoduric-“endure” high temps

Question 19

L. monocytogenes and Yersinia enterocolitica found in milk post-pasteurization

Answer 19

• L. monocytogenes and Yersinia enterocolitica are psychrotrophic
o L. monocytogenes-multiplies slowly at 34°F
o Y. enterocolitica-can survive -3°F for 30 days in milk

Both microorganisms are destroyed by pasteurization but have created problems in milk and milk products indicating post-pasteurization contamination followed by replication during refrigeration

Question 20

Deterioration of meat:

- Factors

Answer 20

Deterioration of meat:
• Meat quality: the physical or chemical properties that relate to its processing and palatability characteristics.
• 5 Factors
1. Water-holding capacity-natural moisture content of muscle is 68-78%. Excessive moisture lost in processing or through improper cooking will result in a less tender product that is perceived to be poorer quality.
2. Color-influences the consumer’s perception of the quality more than actual palatability.
3. Texture
4. Tenderness-collagen of connective tissue and contractile apparatus of myofibrillar proteins.
5. Marbling-intramuscular fat

Question 21

Deterioration of meat:

• Causes of meat deterioration

Answer 21

• Causes of meat deterioration
1. Microbial changes-
o Usually occurs as a product is handled in the plant
o Growth of contaminating microorganisms depends on environmental conditions as well as the inherent characteristics of meat itself
o 7 different microbial changes:
 acid production
 gas production-risk of serious intoxication
 slime formation-mass accumulation of microbes on the meat surface (Lactobacilli, Micrococci and yeasts)
 mold growth-vacuum packaging is helpful
 greening-bacterial greening from surface contamination after processing. H2O2 causes greening
 green rings-associated with heavy population of bacteria before cooking and processing
 green cores-increase processing temp to 155°F to prevent
2. Enzymatic changes-
o Proteinases-most commonly exogenous origin (papain, bromelin and ficin)
o Lipases-oxidative rancidity. Free fatty acids butyric acid/rancidity
3. Oxidative changes-
o Fat is especially susceptible
o Prevention-
• antioxidants of inert gases can be added
• storing the product away from heat and out of light
• wrapping to prevent exposure to air

Question 22

Deterioration of Milk

Answer 22

Deterioration of Milk
• Contamination of raw milk-spoilage organisms (especially psychrotrophic) are the main cause of high bacterial counts in raw milk
o Equipment-usual source of spoilage organisms
o Mastitis-composition of milk is altered
o Hygiene
o Storage temp (< 40°F)
• Bacteria in pasteurized dairy products-4 sources
1. Raw milk
2. Plant personnel
3. Processing equipment
4. Environment of the plant
• Thermoduric microorganisms present in raw milk can survive pasteurization if plentiful and clumped
• Personnel-usually responsible for most contamination present in finished dairy products
• Control-systematic sampling at each critical control point
• Rancidity-caused by the enzymatic hydrolysis of milk lipids to free fatty acids
1. Endogenous enzymes-present in normal milk (lipoprotein lipase)
2. Microbial enzymes-produced by psychrotrophic bacteria (pseudomonads). Very heat stable and can retain some activity after HTST and UHT treatment.
• Causes of rancidity-
1. Induced lipolysis-milk lipase system is activated by physical or chemical means.
o May be caused by faulty milking equipment (disrupts fat globule membrane)
o Also when fresh milk is subjected to a specific sequence of temp changes: cooling, warming, cooling
2. Spontaneous lipolysis-associated with milk from cows in late lactation or with a poor level of nutrition (decrease protein fat globules less stable)
3. Microbial lipolysis-hydrolytic rancidity may result from mastitis or from contamination during processing
o Increased rancidity with increased SCC
o Post-pasteurization contamination is a common cause of lipolysis in milk
4. Acid degree value-measure of rancidity
o Normal milk 0.4
o Slightly rancid 1.2
o Rancid 1.5

Question 23

Deterioration of Eggs

Answer 23

Deterioration of Eggs
• Egg quality-mostly determined by the length of time and other conditions of storage since the egg was laid
• Albumen-as the egg ages, the thick albumen deteriorates progressively
o Haugh unit-quality of an egg’s albumen
• Yolk-less firm with time. Flash-candling-to monitor egg quality.
• Spoilage-main cause is microbial decomposition of the egg
o Pseudomonas, Proteus, Alcaligenes
o Protection of the egg:
 Shell and shell membrane
 Albumen-inhibitors to bacterial growth (lysozyme)
• Salmonella Enteritidis (1990)-recontamination of rendered feed was the primary source of infection for laying hens which transmitted the microorganism vertically into eggs.
o Control: inedible eggs destined for animal feed must be denatured to prevent human consumption and then pasteurized to prevent spread.
o Flocks linked to human outbreaks should be tested (+ birds sent to slaughter and eggs to a breaker)
o Proper washing destroys all S. Enteritidis on the exterior shell. Heat treatment at 130°F for 15 min can also protect shell further

Question 24

Deterioration of Shellfish

Answer 24

• Time/temp dependent
• 3 types:
1. Autolytic spoilage-begins immediately after death of fish, rapid, caused by enzymes in the gut and muscles
2. Bacterial spoilage-bacteria from the gills (surface slime) and intestinal tract, most of the undesirable changes are the result of bacterial growth
 Contamination with microorganisms such as Salmonellae and Staph is generally the result of unsanitary conditions during handling and processing
 Vibrio spp and C. botulinum (E) can be present in unpolluted surface waters
 Foodborne illness caused by marine pathogens is usually associated with consumption of raw shellfish or uncooked, smoked, fermented or salted fishery products.
 Scombroid toxicity-also in a few nonscombroid fish (mahimahi, sardines, etc) from bacterial decarboxylation of histadine.
 Shellfish contain greater amounts of free amino acids than fin fish. This facilitates bacterial growth and spoilage. Pseudomonas, Proteus, Clostridium, Aerobacter, Escherichia, Strep, Lactobacilli and yeasts
3. Rancidity-result of oxidation of the oils present in the tissues. Icing, freezing, salt curing will retard the spoilage to some degree.

Question 25

Foodborne disease outbreak (def):

Answer 25

an incident in which 1) 2 or more persons experience a similar illness after ingestion of a common food and 2) epidemiological analysis implicates the food as the source of illness. A few exceptions (ie 1 case of botulism or chemical poisoning constitutes and outbreak).

Question 26

Outbreaks of known cause are those for which lab evidence is obtained and specified criteria are met. Outbreaks of unknown etiology are subdivided into 4 subgroups by incubation period of illness:

Answer 26

• <1hr-probable chemical poisoning
• 1-7 hr-probable Staphylococcus food poisoning
• 8-14 hr-probable C. perfringens poisoning
• 14 hr-other infectious or toxic agent

Question 27

Infectious vs. Intoxication

Answer 27

• Intoxications-involve pathogenic changes in the host caused by the ingestion of preformed toxins
• Infections-result from replication of the microorganism in the host after ingestion

Question 28

Bacteria associated with foodborne intoxication

Answer 28

• The preformed toxin may remain in the food if resistant to inactivation
• Staphylococcal toxin
o Source/incubation period-coagulase+ Staph aureus phage types I and III
 Enterotoxins: A, B, C1, C2, C3, D, E (A and D being more often involved because they can be produced over a wider range of growth conditions)
 Source-resp tract and skin from food handlers
 Incubation: 1-6 hours
o Associated foods:
 Meat
 Cheese/dairy
 Fish/shellfish
 Salads
 Pastries with cream filling
 Salt-preserved foods
o Prevention
 Sanitation to prevent contamination by food handlers
 Storing food < 40°F to inhibit growth, > 170°F for 20 min to destroy the microorganism or 250°F for 60 min to destroy the toxin
• Botulinum
o Types: serotypes A,B, E, F (F-canning meat)
o Source-ubiquitous saprophyte in soil, isolated from GI tract and contaminated wounds
o Incubation period- 2 hours to 8 days (1-2 day average)
o Neurotoxin-interface with the synthesis and/or release of acetylcholine at nerve endings
o Associated foods: foods canned at home (not fruits canned in sugar syrup) and seafood.
o Control-killing the vegetative organisms by cooking is NOT sufficient
 250°F for 20 min destroys spores
 176°F for 5 min destroys the toxin
o Botulism in babies (infant botulism)-toxin is produced in vivo in the infant gut rather than being ingested preformed in food. Usually 1-6 mo of age. Honey is a high risk factor!

Question 29

Bacteria associated with foodborne infection

Answer 29

• C. perfringens (A, C, D)-anaerobe, spores may survive cooking, slow cooling allows multiplication
o Associated foods-meat/poultry, gravy, soups and stews
o Incubation period-2-22 hours
o Type A (sometimes D)-gastroenteritis
o Type C-necrotic enteritis-high case fatality rate
o Transmission
 Ubiquitous organism
 Common inhabitant of gut of humans and animals
 Institutions or commercial food operations where many people handle food and where large quantities are prepared
o Control-spores destroyed at 212°F for 30 min, will multiply at pH 5 and up
• Salmonellae- >2,000 serovars
o S. Typhimurium-a nonhost-adapted serovar and is associated most commonly with animal and human salmonellosis
o Disease-many infections are subclinical
 Incubation <72 hours. Persons who consume more of the vehicle have shorter incubation periods are affected more severely
o Source
 Foods-poultry, meats, gravy, eggs, fish, milk
 Nonhuman reservoirs are a source of nonhost-adapted salmonellae for human foodborne disease
 Can persist in dairy herds for years.
o Control
1. Breaking the cycle
 Control rendering so that animal feeds containing animal by-products are free of viable salmonellae
 Shortening the interval between the time an animal leaves the farm and slaughter (decrease environmental buildup)
 Using proper cooking temps
 Pasteurization
2. Public education
3. Contamination prevention
o Typhoid and paratyphoid
 Nonzoonotic foodborne disease (S. Typhi and S. Paratyphi A, B, C)
 Typhoid-incubation 2-3 weeks
o Healthy carriers possible who shed intermittently
o Diarrhea not a helpful sign; constipation more frequent
o May see rose spots on torso
 Paratyphoid-incubation 1-2 days
o Clinical onset is abrupt-rose spots may be seen
o Human carriers are problems
o Cattle-S. paratyphi B shed in feces and milk
• Campylobacter jejuni
o Gram (-), microaerophilic, thermophilic organism, grows best at 109.4°F
o Can’t replicate < 86°F
o Can survive refrigeration and freezing
o Disease-
 Incubation 2-10 days (3-5 day avg)
 Disease usually last 3 days but illness may reoccur for periods of up to 2 weeks.
o Reservoir
 Ubiquitous in foods of animal origin
 Contamination rates of raw poultry may reach 90%
o Transmission
 Poultry is the predominant source but also traced to raw meat and milk
 Is sensitive to drying
 Immature companion animals also a source
o Control
 Pasteurization, proper treatment of drinking water
 Proper cooking is the only practical control measure. Microwaving may not be effective to remove contamination
• Enterococcus faecalis
o ß-hemolytic, Lancefield group D
o Inhabits GI tract of humans and animals
o Fecal contaminated water or unsanitary food handling
o Common in milk and milk products
o Strict sanitation is the only practical means of control
• Hemolytic Streptococci
o Interspecies spread is most common with Lancefield groups A (S. pyogenes), B (S. agalactia), D (S. bovis)
o Often spread by aerosol
o Incubation < 12 hours to 3 days
o Spread through mastitic milk (strep throat) and can lead to glomerulonephritis or rheumatic fever
• Bacillus cereus
o Aerobic, spore-forming saprophyte gram (+) rod
o Poor sanitation or improper handling
o Toxins
 Hydrolyze starch (enterotoxin) similar to C. perfringens
 Inability to hydrolyze starch (emetic toxin) similar to Staph aureus intoxication
o Incubation 1-5 hours
o Rice, pasta, cooked meat, milk, ice cream, cream sauces
• Shigella spp
o Results from unsanitary practices
o Problem in daycares due to fecal-oral transmission
o 1-3 day incubation period
• Brucella spp
o Incubation period 3-21 days (but signs may not occur for several months)
o B. melitensis causes most severe illness (B. suis more severe than B. abortus)
o Ingestion of raw milk, occupational disease, undercooked pork/sausage
o Killed by pasteurization
o Soft cheeses from raw milk are a hazard in areas where the disease if prevalent (can survive for 6 mo)
o Eradication of brucellosis in domestic animals is essential as it eliminates occupational exposure
• Mycobacterium spp
o M. tuberculosis-human reservoir
o M. bovis- bovine reservoir
o M. africanum-wild primates and humans in Africa
o M. avium-swine, poultry, humans
 Infection from the environment
o Disease
 4-12 weeks before observable lesions or a tuberculin rxn
 Inhalation (pulmonary)
 Ingestion (extrapulmonary)
 Cattle to people transmission is mainly by inhalation; therefore, pulmonary disease predominates in both
o Control-pasteurization of milk and eradication of infection are the primary means of eliminating human exposure
• Francisella tularensis-tularemia
o May be contracted by oral, resp and cutaneous routes (tick bite/arthropod)
o Type A more virulent (rabbits)
o Type B less virulent (aquatic species, ie muskrats)
o Incubation 1-10 days (3-5 avg)
o Typhoid form-ingestiongastroenteritis and bronchopneumonia
o Strict hygienic habits when handling small game
o 135°F for 10 minutes prevents foodborne transmission
• Vibrio cholerae
o 0:1 serogroup consistently produces cholera toxin
o Disease
 Few hours-5 days (2-3 day avg)
 The only foodborne disease required by international health regulations to be reported to WHO
o Source
 Contamination of foods (vegetables, fish and pork)
 Associated with “night soil” (sewage) used for fertilizer on vegetable crops and also sewage contamination of drinking water
 May be found in water of coastal estuariesshellfish from these areas are significant sources of infection
• Vibrio parahaemolyticus
o Obligate halophile (NaCl for growth)
o Incubation period 4hr-14 days (avg 12-14 hr)
o Source-raw or improperly cooked and/or improperly handled seafood (normal flora of shellfish)
o Control-proper handling and storage (organism is sensitive to refrigeration, freezing and heat)
• Vibrio vulnificus
o Halophilic, most virulent
o May produce wound infections among healthy persons handling raw shellfish
o Septicemia in immunocompromised people
• Vibrio alginolyticus
o Considered a fish spoilage microorganism
o Associated with wound infections
• Aeromonas hydrophila
o In a variety of environments
o Can grow and produce toxin at refrigeration temps
• Yersinia enterocolitica
o Asymptomatic infections are not uncommon
o 0:3 and 0:8 serotypes associated with human illness
o Ingestion of raw/undercooked pork (chitterlings)
o Can grow at refrigeration temps
o Incubation period 1-several days
• Listeria monocytogenes
o Disease
 Human disease-meningitis, septicemia, abortion
 Immunocompromised at high risk from foodborne exposure, case fatality rate >25%
 Neonatal illness
 More than half of all uterine infections result in early onset neonatal illness with the remainder resulting in fetal death
o Source
 Nonspore-forming motile, gram (+) bacillus
 Has been isolated from most food of animal origin
 1/2a, 1/2 b and 4b-high proportion of human infections
o Epidemiology
 Incubation 1 day- 2 mo (few days to 3 weeks)
 Soft cheeses and ready-to-eat deli foods
o Control
 Can survive for long periods in refrigerated food (and multiply)
 Avoid undercooking (>155°F)
 Adequate pasteurization and prevent post-pasteurization contamination
• E. coli
o 4 types of pathogenesis
 Enteropathogenic (EPEC)-adheres to intestinal epithelium and may produce cytotoxins
 Enteroinvasive (EIEC)-invades intestinal epithelium and produces Shiga-like toxins
 Enterotoxigenic (ETEC)-produces heat-labile and heat-stable enterotoxins and specific adhesion fimbria
 Enterohemorrhagic (EHEC)-produces Shiga-like toxin (verotoxin) aka “STEC”
o Serologic typing based on somatic (O), capsular (K), flagellar (H) and fimbrial (F) antigens
o Diseases
 Incubation 1/2 to 5 days (12-72 hr avg)
 EIEC-fever, dysentery
 ETEC-dehydration, shock
 EHEC-incubation 4-8 days. Hemolytic uremic syndrome, hemorrhagic colitis or thrombocytopenic purpura
o Source
 Person to person contact or ingestion of food contaminated by infected persons
 Only EHEC affecting humans that also has a reservoir in animals (note-book was done in 1996-not a true statement now)
o Control
 Sanitary food handling practices
 Pasteurization because E. coli 0157:H7 from healthy cows is possible