Koch and his Postulates - 1. the microorganism must be present in every case of the disease but
absent in healthy individuals
2. the suspected organism must be isolated and grown in a pure culture
3. the same disease must result when the isolated microorganism is inoculated into a healthy host
4. the same microorganism must be isolated again from the diseased host
Developments due to Koch's Postulates - 1. Agar (Fanny Hess)
2. Petri Dish (Richard Petri)
3. Nutrient broth and nutrient agar
4. Method for isolated microorganisms
5. Aseptic techniques
Agostini Bassi (1773-1856) - - showed that a disease of silkworms was caused by a fungus
Alexander Fleming - 1928
1. discovered the first antibiotic
-observed that Penicillin fungus made an antibiotic, penicillin, that killed S. aureus
Antony van Leeuwenhoek - 1632-1723
,First person to observe and describe microorganisms accurately with microscope that could magnify 50-
300 times
Called microbes --> animalcules
-had giardiasis at the time
Atomic Force Microscope - 1. sharp probe moves over surface of specimen at constant distance
2. used to study surfaces that do not conduct electricity well.
Bacillus anthracis
-Gram +/Gram - ?
-Spore Forming?
-Motile?
-Pathogenic?
-Morphology?
-Clinical Signs
-Sensitive to?
-Lifestyle - -Gram +
-forms endospores
-non-motile
-cutaneous --> most common /inhalation --> most deadly
-large rods/single short chain
-Ferdinand Cohn 1872
-edema factor/lethal/protective antigen
-Penicillin
-Mesophile, faculative anaerobe
Binomial Nomenclature - Carolus Linnaeus (1750)
, genus is always capitalized, the species is lowercase
can abbreviate after first use
Classification Schemes
Two Groups
Five Kingdoms
Three Domain System - Two Groups - Aristotle
= Plantae + Animalia
Five Kingdoms
Monera, Protista, Plantae, Animalia, Fungi
Three Domain System
- Carl Woese
- Bacteria, Archaea, Eukarya
Clostridium difficile
-Gram +/Gram - ?
-Spore Forming?
-Motile?
-Pathogenic?
-Morphology?
-Clinical Signs
-Sensitive to?
-Lifestyle - Gram +
-spore forming
-motile