© 2001 by Jones and Bartlett Publishers

Early human interactions with microbes

Early Plagues

What did people THINK was causing disease?

The Miasma Theory

• People thought disease was spread by “miasmas”, or “bad quality of air”

Girolamo Fracastoro - 1546

• Named the disease syphilis in a poem

• Proposed disease could be transmitted by minute particles in three ways:

• Air

• Fomites (inanimate objects)

• Direct contact

1300s, 1600s Waves of Bubonic Plague

Brueghel's 1562 work "The Triumph of Death."

Pieter the Elder Brueghel/The Bridgeman Art Library/Getty Images

1666 The Bubonic Plague

• In the village Eyam, 259 out of 350 died from the plague• 1/3 of the population of London died in one wave of the plague• The origin of a familiar nursery rhyme: “Ring around the rosie”

Ring a ring of rosies

A pocket full of posies

Achoo! Achoo!

We all fall down.

Referred to the rose shaped splotches

A futile attempt to ward off “evil spirits”

Indicated the fits of sneezing

Death.

Village of Eyam

Village of Eyam

The Riley Graves

List of Plague victims 1665-1666

A. The Beginnings of Microbiology

1665 Robert Hooke

• Published Micrographie, a collection of observations of microbes

• described early microscopes

• included drawings of microscopic living things

• coined the term “cells”

1674 Anton van Leeuwenhoek

• Made microscopes that could magnify objects over 200 times

• Viewed protozoans, fungi, algae and bacteria

• Called them “animalcules”

B. The Transition Period

1600’s Spontaneous Generation

• The belief that rats, maggots, toads, and other living things “arose” out of lifeless objects

• For example: maggots were spontaneously generated from rotten meat

1670’s Francisco Redi - disputed spontaneous generation

Other important discoveries:

• 1798 Edward Jenner - Discovered vaccine for smallpox

• Mid 1800’s Semmelweis - Proved that handwashing in chlorine water stopped the spread of blood poisoning from corpses to maternity patients by doctors

• Snow – Proved that chlorination of water stopped cholera outbreaks

Map of London showing Cholera

outbreaks

C. The Golden Age of Microbiology

1857-Early 1900’s

Louis Pasteur - France

• Proved yeast had a role in wine fermentation

• Suggested microorganisms could be the cause of disease

• Pasteurization - heating to kill bacteria• Disproved spontaneous generation by

using a swan-necked flask• Created vaccines for anthrax and rabies

Robert Koch - Germany

• Isolated the anthrax bacterium• Transmitted them to healthy mice and

induced the disease• This led to Koch’s Postulates• Discovered pure culture techniques on solid

media (Agar)• Agar – a seaweed derived powder used to

solidify jams and jellies• Fanny Hesse – introduced agar into the lab

1909 – Paul Ehrlich develops a drug to cure syphillis

• Used chemicals to kill bacteria (Chemotherapy)

• The arsenic compound was named Salvarsan

• Known as a “Magic Bullet” to cure syphillis

1928- Alexander FlemingDiscovers Penicillin

• Mold grew in his Petri dish of bacteria

• A “zone of inhibition” surrounded the mold

• The mold extract was called penicillin