What are microbes?

algae

bacteria

cyanobacteria

protozoa

mold

yeasthelminths

viruses

Taxonomy

http://www.linnean.org/html/history/linnaeus_biography.htm

http://www.nhm.ac.uk/library/linn/

Taxonomy

www.amazon.comwww.amazon.com

Five kingdom system

Plantae

Animalia

Fungi

Monera

Protista

Three Domain System

Animals

Plants

Marine group 1

EUKARYA EUBACTERIA

ARCHAEA

Fungi

Paramecium

Porphyra

Dictylostelium

Entamoeba

Naegleria

Euglena

Trypanosoma

Physarum

Encephalitozoan

ValrimorphaHexamita

Giardia

Trichomonas

ChromatiumRiftia

E. coli

Organisms visible to human eye

Chlorobium

Agrobacterium

ThermusThermomicrobium

AquifexThermotoga

Bacillus

Cytophaga

Epulopiscium

Synechococcus

Methanococcus

Methanobacterium

Methanopyros

Thermococcus

Haloferax

Methanospirillum

Methanosarcina

Sulfolobus

ThermoproteusThermofilum

pSL50

pSL4pSL22

pSL12

pJP27

pJP78

Black, J.G. (2002) Fig. 9.13

Taxonomical “ranks”

Human Being

Kingdom Animalia

Phylum Chordata

Class Mammalia

Order Primata

Family Homindae

Genus Homo

Species H. sapiens

after Alcamo Fig. 3.4

Bacterial nomenclature

• Genus + species

• e.g.:– Escherichia (genus) coli (species)– Bacillus subtilis– Enterococcus faecalis

OR, OR, underlineunderline if handwritten: if handwritten:

Enterococcus faecalisEnterococcus faecalis

• strains? (subspecies)strains? (subspecies)

Where do bacteria come from?

chroococcalean formchroococcalean form

PalaeolyngbyaPalaeolyngbya

www.ucmp.berkeley.edu/ bacteria/cyanofr.html

Where do bacteria live?

• EVERYWHERE! (almost)

• humans host 1014 bacterial cells in 1013 human cells!

• NOT found inside tissues (of organisms)

What do microbes do?

• Eat, grow, and divide!!

• How to accomplish?– modify metabolism– make toxins– structural

modifications

www.microbiologyonline.org.uk/ faq.html

Why do we care?

• Disease

• Agriculture

• Food and beverages

• Chemicals

• Basic research

• Biotechnology

How did microbiology become a science?

• Anthony van Leeuwenhoek (late 1600’s)

microscope

micrograph

Spontaneous generation controversy

www.darwin.museum.ru/site_bac/ etap/etap2_A.htm

Pasteur & Tyndall end

spontaneous generation controversy

Disease transmission?

www.ghosthunting.org.uk/ cemetary3.htm

miasmamiasma

Fracastoro

delp

iano

.com

/mill

enni

um/h

tml/

body

_fra

cast

oro.

htm

l

“seeds” of contagion

infection

symptoms courses

Semmelweis

www.personal.psu.edu/faculty/ j/e/jel5/micro/art.htm

John Snow

www.soi.city.ac.uk/ ~dk708/pg1_1.htm

Germ Theory of Disease

Joseph Lister

Lister

pw

1.n

etco

m.c

om

/~ag

uld

o/ a

gg

a/b

t/tx

t/b

t189

9.h

tm

www.umanitoba.ca/.../medicine/ history/lister/anessurg.html

Koch establishes causative link between B. anthracis & anthrax

www.robert-koch-stiftung.de/ ziele.html

Robert KochRobert Koch

http://www.vdem.state.va.us/prepare/terrorismtoolkit/anthraxoverview.htm

Suspected microbe must be present in EVERY case of the disease

Must isolate & grow pure culture of microbe

Diseased subjects Microbe not typically found in healthy subjects

Cultured microbe must cause disease when inoculated into a healthy, susceptible host

Same microbe must be isolated from diseased experimental host

Koch’s Postulates

Exceptions to Koch’s postulates

• Organism can’t be cultured– e.g. Mycobacterium leprae

• Combination of pathogens

• Ethical considerations

“Golden Age” of Microbiology: Late 1800s

DISEASEAnthraxGonorrheaTyphoid feverMalariaTuberculosisCholeraDiphtheriaTetanusDiarrheaPneumoniaMeningitisGas gangrene

CAUSATIVE AGENTBacillus anthracisNeisseria gonorrheaSalmonella typhiPlasmodium spp.Mycobacterium tuberculosisVibrio choleraCorynebacterium diphtheriaeClostridium tetaniEscherichia coliStreptococcus pneumoniaeNeisseria meningitidisClostridium perfringens

YEAR1867187918841880188218831883-841885-891885188618871892

What’s included in “microbiology”?

Basic research microbiology

MicrobiologyMicrobiology

Applied microbiology

BacteriologyPhycologyMycology

ProtozoologyParasitology

Virology

Microbial metabolismMicrobial geneticsMicrobial ecologyM

icro

bial

taxo

nom

y

ImmunologyEpidemiology

Etiology

In relation to diseaseBy processBy kind of organism

Aft

er B

lack

(2

002)

Mic

robi

olog

y: P

rinci

ples

& E

xplo

ratio

ns,

5th

Ed

. T

abl

e 1.

2

What’s included in “microbiology”?

Basic research Basic research microbiologymicrobiology

MicrobiologyMicrobiology

Applied microbiology

Infection controlChemotherapy

Environmental microbiology

Food/Beverage technologyPharmaceutical microbiologyGenetic engineering

IndustrialEnvironmentalDisease-related

Aft

er B

lack

(2

002)

Mic

robi

olog

y: P

rinci

ples

& E

xplo

ratio

ns,

5th

Ed

. T

abl

e 1.

2