Chapter 1 Outline:

Introduction and History of Microbiology

Define:Microbiology

– the study of little life formsMicrobe, microorganism, agent

-- microbe = microorganisms and nonliving agents

-- microorganism = small organism-- agent – nonliving entity studied in

microbiologyGerm, pathogen

-- disease-causing microbe

List several ways in which microbes affect us: Photosynthesis Nitrogen fixing Break down wastes/organic matter Part of normal flora on/in our bodies Used to produce food: yogurt, bread,

wine, etc. Make vaccines, insulin, enzymes Bioremediation: cleaning up pollution,

ex. Oil spills Pathogens

Photosynthetic cyanobacteria

Nitrogen fixingN2 amino acids (used to build proteins)

Break down wastes/organic matter

Normal flora (microbiota)

Foods produced by microbes

Making products Example:

+

E. coli

Bacterial chromosome

Human insulin gene

Human insulin

Human insulin gene inserted into chromosome

Bioremediation

Alaska-in-pictures.comhttp://www.alaska-in-pictures.com/bioremediation-project-3253-

pictures.htm

Naming and classifying microbesNaming

OrganismsScientific names2 partsgenus + specific epithet = species

nameunderlined or in italicsgenus capitalized; specific epithet

notNon-living (like viruses and prions)

Usually named for disease, condition

ClassifyingOrganisms3 Domains:Eubacteria (true bacteria, includes pathogens)Archaea (archaebacteria, live in extreme env.)Eukarya (plants, animals, fungi, protistans)Prokaryotes vs. eukaryotesNon-living (viruses)Based on characteristics, such as DNA vs. RNA

Virus classification Type of nucleic acid Ds (double-stranded) or ss (single-stranded) Enveloped vs. non-enveloped Shape

Types of microbes studied in microbiology:1. bacteria:

prokaryoticunicellularpeptidoglycan cell walldivide by binary fission

Figure 1.1a

2. viruses: acellularnucleic acid + protein coat (capsid)parasitic in host cells

3. fungi: eukaryoticsecrete digestive enzymes and absorb nutrientsmolds, yeasts, etc.

Figure 1.1b

4. protists (sometimes called protozoans): eukaryoticunicellularclassified by means of movement, ex. Amoeba

Figure 1.1d

Giardia movie clip 1_13_giardia.mov.zip

5. helminths: multicellular worms – usually diagnosed by

microscopy ex. Tapeworms, pinworms

6. prions: infectious proteinsnewly discovered

Ex. Mad Cow disease, Creutzfeldt-Jakob disease, scrapie, kuru

Normal protein and prion

7. the immune system:body’s response to pathogenaction of pathogenhumoral vs. cellular immunity(antibodies) (T cells—virally infected cells,

cancer) 

Figure 1.1e

Antibodies attaching to bacterium

T cells

Branches of microbiology: Bacteriology Virology Mycology Parasitology Molecular biology Immunology

History of microbiologyAncient times

Production/preservation of foodsEmbalming

1600s to 1800Robert Hooke and his “cells” of corkAntony van Leeuwenhoek sees first living

“animalcules”Francesco Redi and his jars of meat (starts to

disprove spontaneous generation)Edward Jenner and the first vaccine (against

smallpox)

Figure 1.2 - Overview

courtesy of CDC/ Jean RoyPublic Health Image Library

History of microbiology1800s

Louis Pasteur disproves spontaneous generation with swan neck flasksHis other work:Fermentation processes caused by microbesWine industry and pasteurization (control of microbes)Silkworm disease caused by protozoanRabies vaccine and Joseph MeisterIsolation of viruses by filtration through porcelain

Figure 1.3 - Overview

Courtesy of CDC/ Dr. William A. ClarkPublic Health Image Library

Bacillus anthracis

A case of cutaneous anthrax

Courtesy of CDCPublic Health Image Library

History of microbiologyThe Germ Theory

Robert Koch (“coke”) and Bacillus anthracisdiseases had been associated with bad/immoral behavior, punishment from God, evil spells, swamp vapors, etc. … not microbes…until Koch

 Koch’s Postulates:1. Disease and microbe must always be present together in host.2. Isolate microbe in pure culture.3. Infect new, healthy host with microbe from pure culture and produce disease again.4. Reisolate microbe from 2nd host in pure culture.(Development of agar and establishment of pure cultures were crucial to Koch’s Postulates.)

Robert Koch1843-1910

History of microbiology

Joseph Lister: surgeon who first sterilized surgical instruments and wounds

Ignaz Semmelweis: hand hygiene prevents childbed fever

Hand Hygiene: Not a New Concept

Maternal Mortality due to Postpartum Infection General Hospital, Vienna, Austria, 1841-1850

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MDs Midwives

Semmelweis’ Hand Hygiene Intervention

~ Hand antisepsis reduces the frequency of patient infections ~

Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999.

History of microbiology1900s:

Paul Ehrlich and salvarsan: first chemical treatment for disease (syphilis)Sulfa drugsAlexander Fleming and penicillin1940s and WWII – mass production of penicillin1950s – Age of Antibiotics begins1953 – structure of DNA1970s – restriction enzymes (molecular “scissors”) discovered1980s – PCR = polymerase chain reaction; copying DNA1997 – prions2000 – the Human Genome Project2001 – 9/11/2001 and bioterrorism2003 – new disease called SARS; first case of the “bird”flu2005 – growing awareness of the avian flu; world governments mobilize/prepare2009 – H1N1 influenza (swine flu)

Alexander Fleming

Figure 1.5

Kary B. MullisThe Nobel Prize in Chemistry 1993

the polymerase chain reaction (PCR) method

Dr Bruce Ivins, a a biodefense researcher at Fort Detrick. Photograph: Frederick News Post/AP

“Detrick anthrax scientist commits suicide as FBI closes in”August 01, 2008

The End