Honors Microbiology

Chapter 1 – Scope of Microbiology I. Why Study Microbiology? – Microbes have a major impact on human health, environment, and help maintain the balance of nature.

– Microbes play an important role in many of our foods and medicines

– The study of microbes provides insight into life processes in all life forms

Microbe Types Prokaryotes – 2 Domains/Superkingdoms Bacteria – Some pathogens – Science of Bacteriology Archaea – Environmental extremophiles – Novel biochemistry

Eukaryotic Microbes Algae (Protozoa/Plants) – Photosynthetic – Aquatic – Science of Phycology Fungi (Kingdom) – Decomposers – Single or multicellular – Science of Mycology

Viruses (Acellular) Simple structure – Capsid – Nucleic acid Obligate intracellular growth Science of Virology Smaller relatives – Viroids – Prions

Eukaryotic Parasites Protozoa (Kingdom) – Single celled – May be pathogenic – Science of Protozoology Helminths (Worms) – Microscopic life stages – Diagnosed microscopically – Sccience of Parasitology Arthropods – Cause/transmit disease

– Microbes are easily studied because: Have relatively simple structures Can be grown in large numbers Can reproduce quickly

II. Scope of Microbiology The microbes – include the bacteria, algae, fungi, viruses and protozoa Other organisms studied – helminths (worms) and arthropods Microbiologists study a variety of areas: – Particular organisms – Processes or functions – Health-related – applications

Anthrax Bacteria

Algae

Athlete’s foot fungus

Giardia lambia (protozoa)

Guinea worm infestation

Arthropods as disease vectors

III. Historical Roots Mosaic laws found in the Bible involve basic sanitation practices that are still used today in preventive medicine.

Greeks: – Set forth ethical standards for the practice of medicine

Hippocrates associated symptoms with illnesses and realized that disease could be transmitted via clothing and other objects

Hippocrates

Thucydides observed that people who survived plague would not get the disease again (immunology)

Thucydides

Romans: – Varro proposed that tiny animals entered the body and caused disease.

Lucretius cited “seeds” of disease in his written works

Lucretius

Jews practiced ancient laws of sanitation and alternative types of medical treatments which helped them survive the Bubonic Plague.

Development of the microscope: – Anton van Leeuwenhoek – first to make and use lenses to observe living microorganisms – Electron microscopes – developed in the 1930’s and 1940’s

Anton van Leeuwenhoek

First microscope

Robert Hooke – first to build a compound microscope, and coined the term “cell”

Robert Hooke

Hooke’s microscope

Electron microscopes – developed in the 1930’s and 1940’s

Electron Microscope

IV. Important scientists and their contributions to Microbiology Louis Pasteur: – Helped disprove the idea of spontaneous generation – Developed the technique of pasteurization – Associated specific organisms with particular diseases – Contributed to the development of vaccines

Louis Pasteur

Robert Koch: – Identified the bacterium that causes anthrax, and the bacterium that causes tuberculosis – Developed techniques for studying cells in vitro – Formulated a set of postulates to help establish the Germ Theory of Disease – Conducted research on cholera, typhoid fever, and sleeping sickness

Robert Koch

Ignaz Semmelweis – worked to reduce childbed fever by establishing more sanitary practices in patient examinations Joseph Lister – ‘father of antiseptic surgery’, developed aseptic techniques, formulated carbolic acid (phenol)

Ignaz Semmelweis

Joseph Lister

Edward Jenner – developed the vaccine for smallpox Elie Metchnikoff – discovered that certain cells in the body (“phagocytes”) could ingest microbes

Edward Jenner

Martinus Beijerinck – first to characterize viruses Wendell Stanley – isolated RNA viruses Hershey and Chase – isolated DNA viruses

Elie Metchnikoff

Paul Ehrlich – suggested that chemicals might selectively kill invading microbes; considered the “father of chemotherapy” Alexander Fleming – discovered penicillin Gerhard Domagk – developed sulfa drugs

Paul Ehrlich

Alexander Fleming

Gerhard Domagk

Walter Reed – discovered the cause of yellow fever Selman Waksman – developed streptomycin and other antibiotics

Walter Reed

Selman Waksman