Chap. 1- Humans and the Microbial World

the study of microorganims

major groups of microorganisms (3)

• prokaryotic: bacteria (and archaea)

• eukaryote: algae, fungi, protozoa

• acellular microbes: viruses

Robert Hooke (1665)

• used crude (simple) microscope to view individual cells

• beginning of cell theory: all living organisms are composed of cells

Antonie van Leeuwenhoek (1673)

• amateur lens grinder

• built microscopes that could view living microorganisms- called them ‘animalcules’ 

Spontaneous Generation

belief that some forms of life can arise from non-living matter

Biogenesis

living matter arises from pre-existing living matter

Louis Pasteur (1861)

• used swan neck flasks to disprove the theory of spontaneous generation 

• developed the principle of aseptic technique

aseptic technique

• showed that microscope yeast (fungi) convert sugar to alcohol using process called fermentation

  • in the absence of oxygen- anaerobic

• souring then occurs when bacteria turn the alcohol into vinega

Joseph Lister (1860’s)

• used phenol to clean surgical instruments and treat surgical wounds

• reduced incidence of surgical wound infections-led to development of disinfectants and antiseptics

Robert Koch (1876)

• investigated the cause of anthrax

• isolated bacteria from the blood of infected cows

  • particular bacterium was present in all cases of the disease

Edward Jenner (1798)

• developed vaccine for smallpox

• observed: people who were preciously sick with mild disease cowpox, did not get sick with smallpox

• He purposefully inoculated young boy with cowpox

  • boy became mildly ill

  • recovered and became immune to smallpox

Louis Pasteur (1880)

• bacterium that caused fowl cholera lost its ability to cause disease when grown in the lab for long period of time

  • still able to induce immunity to fowl cholera when injected into healthy birds

Paul Ehrlich (1980)

• noticed certain dyes stained bacteria differently than they stained animal cells

• proposed: chemical might be found that would harm disease causing microbes w/o harming the host

  • selective toxicity

• eventually discovered salvarsan

  • beginning of chemotherapy (the use of drugs to treat disease)

selective toxicity

• ability to target sites that are relative specific to the microorganism responsible for infection

• sometimes these sites are unique to microorganism or simply more essential to survival to the microorganism than to the host

salvarsan

an arsenic derivative that could be used to treat syphilis

Alexander Fleming (1928)

• noticed mold inhibited bacterial growth on contaminated plates

  • produced a natural compound called penicillin

penicillin

• the first antibiotic

• an antimicrobial chemical produced naturally by bacteria or fungi

naming system for microorganisms

• whole name is italics or underlined

• general name

  • capitalized

• specific name

  • lower case

pasteurization

solution was to heat beer or wine after fermentation- which would kill + prevent spoilage

vaccination

purposeful exposure to a killed or weakened microbe in order to induce an immune response