General Microbiology Nickolas V. Kapp Ph.D

What is a Microbe Smaller than 0.1mm Includes bugs, things, germs, viruses, protozoan, bacteria, animalcules, small suckers

Nomenclature Carolus Linnaeus (1735) Genus species By custom once mentioned can be abbreviated with initial of genus followed by specific epithet. E. coli When two organisms share a common genus are related.

Why study Microbiology Microbes are related to all life. –In all environments –Many beneficial aspects –Related to life processes (food web, nutrient cycling) –Only a minority are pathogenic. –Most of our problems are caused by microbes

Microbes in research 10 trillion human cells 10x this number microbes Easy to grow Biochemistry is essentially the same Simple and easy to study

Diversity of Microbes Bacteria-single celled prokaryotes Protozoa-eukaryotic, single celled, colonial, many ways of nutrition Fungi- absorb nutrients, single celled filamentous Viruses-acellular entities Others- worms, insects

A timeline of Microbiology Fig 1.4 Some highlights –1665 Hooke –1673 van Leeuwenhoek’s microscopes –1735 Linnaeus Nomenclature –1798 Jenner vaccine –1857 Pasteur Fermentation –1876 Koch germ theory of disease

The Golden Age of Microbiology Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

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). Fermentation and Pasteurization

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. Fermentation and Pasteurization Figure 1.4

1835: Agostino Bassi showed a silkworm disease was caused by a fungus. 1865: Pasteur believed that another silkworm disease was caused by a protozoan. 1840s: Ignaz Semmelwise advocated hand washing to prevent transmission of puerperal fever from one OB patient to another. 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. 1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, used to prove that a specific microbe causes a specific disease. The Germ Theory of Disease

Treatment with chemicals is chemotherapy. 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. 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. 1930s: Sulfonamides were synthesized. The Birth of Modern Chemotherapy

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. The Birth of Modern Chemotherapy Similar to Figure 1.5

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. Proteomics is looking at the gene products Modern Developments in Microbiology

Principles of Microscopy Metric units (table 3.1) –Micrometer –Nanometer –angstrom

Compound light microscopy Basic parts –Eyepieces (ocular lens) –Base –Condenser –Iris diaphragm –Objective lens –Body tube –Mechanical stage –Adjustment knobs

Magnification Calculation: –Objective power x ocular power = total power Parafocial Paracentric Microscopic measurement –Micrometer? Why must we calibrate it?

Modern Developments in Microbiology Diagnostics Prevention Use as a tool Surveys and vigilance

What you should know? What are microbes? What types of microbes? Some history Highlights The Magic Bullet Microbes and human Welfare Microbes and Human Disease The CDC