Bacteria and Disease
• A pathogen is a disease-causing agent.
• Bacteria can damage the tissues of the affected organism directly or release toxins that harm the body.
Antibiotics
•Compounds that block the growth and reproduction of bacteria.
•Examples: penicillin & tetracycline
Tooth decay
Lyme disease
Tetanus
Tuberculosis
Salmonella food poisoning
Pneumonia
Cholera
Streptococcus mutans
Borrelia burgdorferi
Clostridium tetani
Mycobacterium tuberculosis
Salmonella enteritidis
Streptococcus pneumoniae
Vibrio cholerae
Regular dental hygiene
Protection from tick bites
Current tetanus vaccination
Vaccination
Proper food-handling practices
Maintaining good health
Clean water supplies
Disease Pathogen Prevention
Common Diseases Caused by Bacteria
Controlling Bacteria
•Sterilization – destroys bacteria by subjecting them either to great heat or chemical action.
• Disinfectants are chemical solutions that kill bacteria.
Controlling Bacteria
• Food is refrigerated because bacteria grow slower at low temperatures.
• Food can be sterilized by cooking at high temperatures.
Helpful Bacteria:
Nitrogen fixation
(Nitrogen Cycle)
convert nitrogen gas into nitrates in
the soil used by plants
Helpful Bacteria
Saprobes: break down dead organic matter
(decomposers)
Food flavorings: produced by fermentation
vinegar, yogurt, cheese, sour cream, pickles, sauerkraut
Antibiotic production:some bacteria produce antibiotics that will kill other forms of bacteriaBioremediation – help clean-up oil spillsWorks in Landfills to break down wastes (including some hazardous wastes)Waste- water treatment plants
Helpful Bacteria
• Provide Vitamin K (E coli)- clots blood & keeps bones strong
• Keep invading bacteria, viruses, & yeast in check.
• Make Lactase-enzyme needed to break down dairy products
Bacteria Reproduction•Binary fission – asexual
reproduction. The prokaryote replicates DNA and divides in half. (Mitosis)
•Conjugation – sexual reproduction. A hollow bridge forms between two cells and genes move from one cell to another. (Increases diversity.)