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.)