Microbiology Course Overview

### Course Overview

Focus: Basic principles of microbiology.
Topics: Microbial cell structure and function, diversity, metabolism, control, and importance in human activities.
Prerequisites: BIOL1020: Diversity of Life I (BIOL1051: Biodiversity I) and BIOC1015: Introduction to Biochemistry (or BIOC1351: Introductory Biochemistry).

### Textbook

### Course Outline

### Assessments

In-Course Tests: 2
Final Exam: 1
Practical Assessments: Lab reports, skills, calculations, quizzes, lab test.

### Lecture Objectives

Microbiology Definition: The study of microscopic organisms.
Microscopy: Magnification is required to visualize microorganisms.
Microorganisms: Exist as single cells or clusters of cells (excluding viruses, which are acellular).
History: Covers spontaneous generation, the germ theory, and key figures like van Leeuwenhoek, Pasteur, and Koch.

### Microorganisms

Major Groups: Bacteria, viruses, fungi (molds), protozoa, helminths, algae.
Bacterial Cell Types: Various morphologies (shapes) and structures.
Bacterial Cell Wall: Protects bacteria and gives them shape.
Virus Types: Diverse morphologies and mechanisms of infection.
Fungal Types: Includes yeasts and molds.
Comparison of Sizes: Microorganism sizes range from nanometers to millimeters.

### History

Prominent Discoveries: Microscopy, disproval of spontaneous generation, development of medical microbiology, microbiological techniques.

### Antonie Van Leeuwenhoek (1632-1723)

Contribution: Dutch amateur microscope builder who observed and described "wee animacules" (microorganisms).
Microscopes: Built simple microscopes of his own design.
Royal Society of London: Published his observations in 1684.
Drawings: Published drawings of bacteria in 1684.

Definition: The theory that life arises from non-living matter.
Historical Examples: Aristotle believed dust created fleas, maggots arose from rotting meat, and bread or wheat produced mice.
Experiments: Francesco Redi (1626-1697) performed experiments to challenge spontaneous generation.

### Disproval of Spontaneous Generation

Louis Pasteur: French chemist who disproved spontaneous generation.
Experiment: Swan-necked flasks experiment demonstrated that microorganisms in the air were the source of putrefaction.
Conclusion: "Life only comes from previously existing life."

### Louis Pasteur (1822-1895)

Accomplishments: Developed the Pasteur flask, Pasteur pipette, and pasteurization.
Vaccines: Contributed to early vaccine development.
Disease Control: Developed cures for rabies, anthrax, chicken cholera, and silkworm diseases.

### Robert Koch (1843-1910)

Contribution: Developed experimental method used to determine whether a specific microorganism causes a disease.
Antrax: Proved Bacillus anthracis caused anthrax.
Tuberculosis: Awarded the 1905 Nobel Prize for his work on tuberculosis.
Koch’s Postulates: Established criteria to identify the specific cause of an infectious disease.

### Limitations to Koch’s Postulates

Normal Flora: Some microorganisms are part of normal flora but can cause disease under certain conditions.
Opportunistic Pathogens: Microorganisms that cause disease in individuals with compromised immune systems.
Subclinical Infection: Some individuals may carry a pathogen without showing symptoms.
Challenges: Not all pathogenic microorganisms can be grown in pure culture, and suitable animal models may not be available.
Ethical Concerns: Some experiments involving humans or animals are not ethically feasible.

### Ferdinand Cohn (1828-1898)

Contribution: German botanist known for his studies of bacteria, algae, and fungi.
Founder of Bacteriology: Considered one of the founders of bacteriology.
Bacterial Classification: Classified bacteria into four groups based on shape.
Endospores: Showed that Bacillus bacteria can form endospores under stressful conditions.

### Martinus Beijerinck (1851-1931)

Contribution: Dutch microbiologist recognized for his work in virology and environmental microbiology.
Soil and Water Bacteria: Studied bacteria in soil and water, including nitrogen-fixing bacteria (Azotobacter).
Tobacco Mosaic Virus: Investigated tobacco mosaic virus and determined it was caused by a virus.
Enrichment Culture: Developed the principles of enrichment culture.

Early Work: Pioneering discoveries in microbiology led to understanding the role of microorganisms in infectious diseases.
Modern Techniques: Scientific advancements in microbiology paved the way for modern practices and medical microbiology.