Today’s plan

Diseases of the Respiratory and digestive systems  
 
 

Respiratory Diseases

•    Upper Respiratory
–Ear, nose, and throat
•
•    Lower Respiratory
–Voice box, trachea, lungs
–
•

Pharyngitis- “Sore throat”

•Inflammation of mucous membrane
•Only 5-10% are strep
•Most are viral
•Rhinovirus and adenovirus which cause the common cold
 

Common Cold

•Rhinovirus cause 50%
•Build immunity over time but so many varieties a vaccine is difficult
•Up to 70% of the population will carry these adenovirus and rhinovirus and be asymptomatic Endemic disease = always in the population
•Having antibodies to a virus does not mean immunity to the disease

 

Epidemiology

2. Significant or Interesting Human Diseases
A. Skin
B. Nervous system
C. Cardiovascular and lymphatic system
D. Digestive system
Food Poisoning
Clostridium botulinum
Staphylococcus aureus (again!)
Salmonellosis
Dysentery
E. coli O157:H7
Control of food poisoning
3 STD’s
 
Fig 25.1
Digestive System
•Stomach and small intestine low microbial diversity due to low pH
•Mouth and large intestine have huge amounts of bacteria
•Bacteria comprise up to 40% of fecal mass!
•100 billion bacteria per gram
 

Foodborne Illness Facts

 

Terms

•

 

Infection

•Multiplication of pathogens
•Incubation time to cause sickness
•Fever
•Intoxication-
•Toxins produced before ingestion
•Rapid onset of illness
•No fever
 

Common causes of food poisoning

Control: Proper canning methods must be used for preserving low-acid foods. Pressure processing is necessary to obtain the temperatures required to destroy the Clostridium botulinum spore. The toxin can be destroyed by boiling for 10 minutes at sea level (add 1 minute for every 1,000 feet above sea level). When the bacteria grows, it can produce a gas which causes canned items to bulge. Never taste food from leaking, bulging, or damaged cans; from cracked jars or with loose or bulging lids; from containers that spurt liquid when opened; or any canned food that has an abnormal odor or appearance. Discard any suspected canned foods by placing the container in a heavy garbage bag marked "POISON" and place the bag in a trash container that is not accessible to people, children or animals. Clean all surfaces that leaky containers may have contaminated with a chlorine/water solution (one tablespoon chlorine per gallon of warm water). Discard any sponges or cloths used for cleanup.
 
Botox injections
 

Common causes of food poisoning (toxins)

Clostridium botulinum
Bacillus cereus

Staphylococcus aureus

Clostridium perfringens
 

Staphylococcus aureus

Heat and salt tolerant
High tolerance to osmotic pressure
Resistant to drying and radiation
On skin, nasal passages, and cuts
Produces toxins that damage tissues, hemolysins
Heat stable toxin will survive 30 minutes of boiling
 

Figure 25.6

 

Bacteria that infect GI (annually)

Pathogen Cases Deaths
Listeria 1,500 250 - 500
 
 
Vibrio 10,000 50 - 100
 
 
E. coli O157:H7 725,000 100 - 200
Shigella
 
 
Salmonella 2 million 500 - 2,000
 
 
Campylobacter 4 million 200 - 1,000
 

 

Shigella
Bacillary dysentery (diarrhea with blood and mucus)
Shiga toxin released in large intestine destroying tissue
Diarrhea is the body’s defense mechanism
E. coli O157:H7 has a shigalike toxin acquired through transduction.
Very unlikely to happen, but when it does …
 
Salmonella enteritidis
Salmonella Sources
•Store foods properly
•
•Eggs are pasteurized/dairy products
Salmonella on chicken meat
Fear the sprout! Alfalfa sprouts

 

Protozoans and viruses
Industry Advances (radiation, improved monitoring and diagnostic tests)
At home (knowledge and antibacterial products)