Over 3 5 billion years of microbes only

Over 3. 5 billion years of “microbes”; only 400 years of Microbiology!

What were some early fundamental discoveries? • First Microscopes {Jannsen (1590), Hooke (1665), and van Leeuwenhoek (1676)} • Debunking Spontaneous Generation {Redi (1668), Needham (1748), Spallanzani (1767), Pasteur (1861)} • Linking Microbes to Human Disease {Rhazes (900), Semmelweis (1847), Snow (1854), Lister (1867), Koch (1876)} • Discovering Immunity {Jenner (1798), Pasteur (1881, 1885), Metchnikoff (1884), and von Behring (1890)} • Agricultural and Environmental Microbiology {Bassi (1835), Berkeley (1845), Beijerinck (1889), and Winogradsky (1887)}

First Microscopes Zacharias Jannsen (1595), Robert Hooke (1665): first “cells” from cork; Micrographia, 1665

First Microscopes Antonie van Leeuwenhoek (1676): excellent simple microscopes; discovered and observed microbes, called them “animalcules”.

Debunking Spontaneous Generation Vitalism: life is independent of physical laws; there exists a special “life force”; different life forms can arise from dead life; organic matter will spontaneously generate new life; abiogenesis. Mechanism: life is part of the physical world; formation of new organic matter only requires proper physical, chemical and biological conditions; living organisms are required to form new organisms of the same type; “life begets life”. covered gauze open Fancesco Redi (1668): first scientific experiment to disprove abiogenesis.

Debunking Spontaneous Generation Does abiogenesis still apply to microbes? John Needham (1748): hot soup experiments always grew microbes; interpreted as strong support for spontaneous generation; actually sloppy technique. Lazzaro Spallanzani (1767): lengthy boiled broth experiments; microbes are in the air and broth; others claimed boiling altered a “vital force”. Louis Pasteur (1861): settled the issue; left flasks open to air, but flasks were “swan-necked” so microbes could not settle into the broth.

Linking Microbes to Human Disease Early Epidemiology (epidemiology = study of factors determining and influencing the frequency and distribution of disease, injury and other health related events. ) • Before Biological Inquiry: evil spirits, punishment for sins, miasma • Abu-Bakr Muhammed al-Razi (Rhazes) (900): Arabic doctor; tested relationship between urban location and rate of meat spoilage. • Giralmo Fracostoro (1546): “contagion is an invisible infectious organism that passes from one thing to another”; contact, fomites, and air cause spread. • Ignaz Semmelweis (1847): examine the cause of high incidence of puerperal sepsis (maternal fever after childbirth), blood poisoning; dirty doctors. • John Snow (1854): traced the pattern in cholera epidemic in London to the municipal water supply; imported country-side water lowered incidence.

The “Diseased” Wine of France Louis Pasteur (1857): Asked why wine soured & to cure the industry. Discovered yeast and fermentation; first evidence of microbial metabolism. Discovered acetogenic bacteria form vinegar from wine – souring. Is this like a disease? Napoleon III: Had to keep the sailors happy, but it kept going sour (vinegar).

“Germ Theory of Disease” Koch (1876 - 1910): He and his students discovered causative agents of numerous infectious diseases of humans. Success attributed to meticulous experimental design (Koch’s Postulates) and development of pure culture technology within his lab group. Franny E. Hesse proposed use of agar.

Koch’s Postulates: 1) Observe diseased mice. 2) Isolate microbe in pure culture. 3) Infect healthy mice to yield same disease (anthrax) 4) Isolate same microbe as before. (Modified version: see Box 1. 2)

Discovering Immunity (Immunology = Branch of biology that studies the humeral and cellular immune responses. ) • Edward Jenner (1798): cowpox as smallpox vaccine (Latin vacca = cow) • Louis Pasteur (1881, 1885): cholera, anthrax and rabies vaccines • Elie Metchnikoff (1884): phagocytosis • Emil von Behring (1890): diptheria and tetanus antitoxins produced.

Agricultural and Environmental Microbiology • Agostino Bassi (1835): silk worm fungal disease • M. J. Berkeley (1845): potato blight fungus • Martinus Beijerinck (1889, 1899): root nodules; tobacco mosaic virus (first virus). • Sergei Winogradsky (1887): N & S cycles

Find some of your own favorite 20 th century microbiologists! Dr. Rita Colwell. • Ecology of pathogens in marine environments • Director of the U. Maryland, Centre for Marine Biotechnology, • President of the American Society for Microbiology • President of the American Society for the Advancement of Science.