1. Introduction to Bacteriology

2. What are some examples of microbes?
Chapter 1 The Microbial World and You
What is Microbiology?
Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye.
What are some examples of microbes?
Bacteria, fungi, protozoa, algae, viruses are examples!
Some are pathogenic
“Germ” refers to a rapidly growing cell.

3. Decompose organic waste
Chapter 1 The Microbial World and You
What is Microbiology?
Microbes:
Decompose organic waste
Are producers in the ecosystem by photosynthesis
Produce industrial chemicals such as ethyl alcohol and acetone
Produce fermented foods such as vinegar, cheese, and bread

4. Chapter 1 The Microbial World and You
What is Microbiology?

5. Knowledge of Microbes allows humans to Prevent food spoilage
Chapter 1 The Microbial World and You
What is Microbiology?
Knowledge of Microbes allows humans to
Prevent food spoilage
Prevent disease occurrence
Led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories.

6. Ancestors of bacteria were the first life on Earth.
Chapter 1 The Microbial World and You
History of Microbiology
Ancestors of bacteria were the first life on Earth.

7. The first microbes were observed in 1673.
Chapter 1 The Microbial World and You
History of Microbiology
The first microbes were observed in 1673.
In 1665, Robert Hooke (Englishman) reported that living things were composed of little boxes or cells.

8. Chapter 1 The Microbial World and You
History of Microbiology
, Antoni van Leeuwenhoek (Dutch) described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.

9. Many believed spontaneous generation:
Chapter 1 The Microbial World and You
History of Microbiology
Many believed spontaneous generation:
life can arise from non-living matter
In 1668, the Italian physician Francesco Redi performed an experiment to disprove spontaneous generation.
Can you think of an experiment that could disprove spontaneous generation?

10. Redi filled six jars with decaying meat. Conditions Results
Chapter 1 The Microbial World and You
History of Microbiology
Redi filled six jars with decaying meat.
Conditions
Results
3 jars covered with fine net
No maggots
3 open jars
Maggots appeared
From where did the maggots come?
What was the purpose of the sealed jars?
Spontaneous generation or biogenesis?

11. So now there are two hypotheses:
Chapter 1 The Microbial World and You
History of Microbiology
So now there are two hypotheses:
The hypothesis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a “vital force’ Forms life.
The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.

12. Nutrient broth placed in flask, heated, not sealed Microbial growth
Chapter 1 The Microbial World and You
History of Microbiology
1861: Louis Pasteur demonstrated that microorganisms are present in the air.
Conditions
Results
Nutrient broth placed in flask, heated, not sealed
Microbial growth
Nutrient broth placed in flask, heated, then sealed
No microbial growth
Spontaneous generation or biogenesis?

13. Chapter 1 The Microbial World and You
History of Microbiology
Next experiment, Pasteur’s S-shaped flask kept microbes out but let air in. These experiments form the basis of aseptic technique

14. The Golden Age of Microbiology 1857-1914
Chapter 1 The Microbial World and You
History of Microbiology
The Golden Age of Microbiology
Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

15. Pasteur showed that microbes are responsible for fermentation.
Chapter 1 The Microbial World and You
History of Microbiology
Pasteur showed that microbes are responsible for fermentation.
Fermentation is the conversation of sugar to alcohol to make beer and wine.
Microbial growth is also responsible for spoilage of food.
Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid).

16. Chapter 1 The Microbial World and You
History of Microbiology
Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time is called pasteurization.

17. The Germ Theory of Disease
Chapter 1 The Microbial World and You
History of Microbiology
The Germ Theory of Disease
1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteur’s work showing microbes are in the air, can spoil food, and cause animal diseases.

18. Chapter 1 The Microbial World and You
History of Microbiology
Koch's Postulates are used to prove the cause of an infectious disease.

19. Chapter 1 The Microbial World and You
History of Microbiology
Koch's Postulates are a sequence of experimental steps to relate a specific microbe to a specific disease.

20. Chemotherapy – treatment with chemicals
Chapter 1 The Microbial World and You
History of Microbiology
Chemotherapy – treatment with chemicals
Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics.
Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes.
Quinine from tree bark was long used to treat malaria.

21. Chemotherapy – treatment with chemicals
Chapter 1 The Microbial World and You
History of Microbiology
Chemotherapy – treatment with chemicals
1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis.
1930s: Sulfonamides were synthesized.

22. 1928: Alexander Fleming discovered the first antibiotic.
Chapter 1 The Microbial World and You
History of Microbiology
1928: Alexander Fleming discovered the first antibiotic.
He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus.
1940s: Penicillin was tested clinically and mass produced.

23. Bacteriology is the study of bacteria. Mycology is the study of fungi.
Chapter 1 The Microbial World and You
Modern Developments
Bacteriology is the study of bacteria.
Mycology is the study of fungi.
Parasitology is the study of protozoa and parasitic worms.
Recent advances in genomics, the study of an organism’s genes, have provided new tools for classifying microorganisms.

24. The science of classifying organisms
Chapter 1 The Microbial World and You
Classification of Microbes
Taxonomy
The science of classifying organisms
Provides universal names for organisms
Provides a reference for identifying organisms

25. Systematics or phylogeny
Chapter 1 The Microbial World and You
Classification of Microbes
Taxonomy
Systematics or phylogeny
The study of the evolutionary history of organisms
All Species Inventory ( )
To identify all species of life on Earth

26. Dumb Kings Play Chess On Funny Green Squares Taxonomic Hierarchy
Chapter 1 The Microbial World and You
Classification of Microbes
Taxonomic Hierarchy
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Dumb
Kings
Play
Chess On
Funny
Green
Squares

27. Taxonomic Hierarchy Domain
Chapter 1 The Microbial World and You
Classification of Microbes
Taxonomic Hierarchy
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Binomal Nomenclature uses the Genus and Species name to identify each creature.

28. There is a specific way to write each name.
Chapter 1 The Microbial World and You
Classification of Microbes
Taxonomic Hierarchy
Each name is Latinized
There is a specific way to write each name.
Homo sapiens
The first word is capitalized
Name is in italics
Homo sapiens
H. sapiens

29. Chapter 1 The Microbial World and You

30. Chapter 1 The Microbial World and You

31. Chapter 1 The Microbial World and You

32. Bacteria (or Eubacteria)
Chapter 1 The Microbial World and You
Bacteria (or Eubacteria)
Most abundant on earth
They are nitrogen fixers and recycle carbon
No membrane bound organelles

33. Archaea Methanogens Halophiles Hyperthermophiles
Chapter 1 The Microbial World and You
Archaea
Methanogens
Halophiles
Hyperthermophiles

34. Classification of Microbes
Chapter 1 The Microbial World and You
Classification of Microbes

35. This term has been replaced by microbiota.
Chapter 1 The Microbial World and You
Microbes and Human Disease
Bacteria were once classified as plants which gave rise to use of the term flora for microbes.
This term has been replaced by microbiota.
Microbes normally present in and on the human body are called normal microbiota.

36. Normal microbiota prevent growth of pathogens.
Chapter 1 The Microbial World and You
Microbes and Human Disease
Normal microbiota prevent growth of pathogens.
Normal microbiota produce growth factors such as folic acid and vitamin K.
Resistance is the ability of the body to ward off disease.
Resistance factors include skin, stomach acid, and antimicrobial chemicals.

37. When a pathogen overcomes the host’s resistance, disease results.
Chapter 1 The Microbial World and You
Microbes and Human Disease
When a pathogen overcomes the host’s resistance, disease results.
Emerging Infectious Diseases (EID): New diseases and diseases increasing in incidence

38. species –a collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly
strain or variety – a culture derived from a single parent that differs in structure or metabolism from other cultures of that species (biovars, morphovars)
type – a subspecies that can show differences in antigenic makeup (serotype or serovar), susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype).