Why do we care?

Pathology

Hansen’s Disease

Bubonic Plague

PLAGUE CURES HOW THEY WORK WHAT THEY REALLY DID

Carry flowers or wear a strong perfume

The smells would help to ward away the

diseaseNothing

Coat the victims with mercury and place

them in oven.

Combination of mercury and heat

would kill disease. Mercury is poisonous and the oven caused serious burns.

Give a strong dose of laxatives

Disease is defecated out

Strong doses of laxatives can cause death from dehydration.

Pathology

Pathology

Tuberculosis

Escherichia coli

Pathology

Fermented Foods

Medical Research Medications Vaccines Restriction

enzymes

Environmental Issues Decomposition Ethanol Insecticides Nitrogen fixation

Genetic RecombinationTransformation

Bacterium absorbs DNA from environment

Plasmid with ampicillin resistance

Genetic Recombination Conjugation

Pilus extends between cellsCopy of a plasmid is donated

Plasmid with ampicillin resistance

Plasmid with ampicillin resistance

Genetic RecombinationTransduction

Virus carries host DNA to next host

Gene with ampicillin resistance

Gene with ampicillin resistance

Oxygen ToleranceObligate AnaerobesFacultative AnaerobesObligate Aerobes

Bacterial Size

Bacterial Morphology

Coccus

Bacillus

Spiral

Bacterial MorphologyCoccus

Diplococcus

Streptococcus

Staphylococcus

Outer Coverings Cell Membrane Wall (peptidoglycan)

Gram+

• Simple, thick wallGram-

• Thin wall• Outer membrane

CapsuleAdheres cell to food Disguises against host

immune system

Identification: Gram Staining

+ -

Crystal VioletIodine

EthanolSafranin

A B C

D

IH

GFE

EndosporesDNA, ribosomes, and some

cytoplasm encasedBacterial defense against

temperature, pH, chemicals, and aridity

When Bacteria AttackInvasion

Cells consume host tissuesStreptococcus mutans

•Cells live on surface of teeth•Exposure to sugar enables

production of…•Plaque•Acid

When Bacteria AttackExotoxins

Poisons released to weaken hostClostridium botulinumClostridium tetaniVibrio cholerae

When Bacteria Attack

EndotoxinsPoisons located in outer membraneEscherichia coli, Salmonella