Bacterial Classification-

A.Need for a classification system

B. Practicality versus Taxonomy

• Why is it important to be able to identify bacteria?

• What problems might you face in trying to identify bacteria?

• What strategies might you use to identify bacteria?

3

Medically Important Bacteria

Bacterial Taxonomy-

• Inherent Challenges

• 5 kingdoms versus 3 Domains

Fig. 1.14

Universal phylogenetic tree

6

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Coprinus

(mushroom

)

Zea (corn)

Achlya

Costaria

Porphyra

Para

mec

ium

Babesi

aD

icty

ost

eliu

mEnta

moeb

a

Eug

lena

Trypanosom

aPhysaru

m

Ence

phalito

zoon

Vainm

orpha

Trichomonas

Giardia

Cryptomonas

Homo

Eukarya

Naeg

leri

a

Methanotherm

us

Methanopyrus

Therm

ofilu

mTherm

oproteus

PyrodictiumSulfolobus

Methanospirillum

HaloferaxArchaeoglobus

Thermoplasm

a

Met

han

ococ

cusT

herm

oco

ccus

Mar

ine

low

tem

p

Meth

anob

acte

rium

Archaea

Gp. 3 low temp

Gp. 2 low temp

Gp. 1 low temp

Marine Gp. 1 low temp

pJP

27

pJP 78

pSL 22pSL 12

pS

L 50

Mito

chond

rion

Flavobacte

rium

Flex

ibac

ter

Plan

ctom

yces

Arg

obac

teri

um

Esch

erich

ia

Desu

lfovib

rio

Synechococcus

Gloeobacter

Chlamydia

ChlorobiumLeptonemaClostridiumBacillusHeliobacterium

Arthobacter

Chloroflexus

Thermus

Thermotoga

pOPS19

Chlo

ropla

st

Bacteria

pOPS66

Aquifex

EM17

Root

Rhod

ocy

clus

The History and Evolution of Bergey’s Manual 1. Bergey’s Manual of Determinative Bacteriology (1923-1994)

•9 Editions (1 volume each )-These are mainly phenetic

2. Bergey’s Manual of Systematic Bacteriology:

•1s t edition (4volumes);1984-1989; Mix Phylogenetic/Phenetic-5 Kingdoms 

• 2nd Edition (5 volumes) (2001-2012);Phylogenetic-3 Domains

 

Bergey’s Manual of Determinative Bacteriology

•First edition-1923 (one volume)

•Seventh edition-1957 (one volume)

•8th edition-1975 (one volume)

•9th edition-1994 (one volume)

Bergey’s Manual of Systematic Bacteriology-

•First edition -Published in 4 volumes:

•Volume 1 (1984) -Gram-negative Bacteria of general, medical, or industrial importance

•Volume 2 (1986) -Gram-positive Bacteria other than Actinomycetes

•Volume 3 (1989) -Archaeobacteria, Cyanobacteria, and remaining Gram-negative Bacteria

•Volume 4 (1989) -Actinomycetes

 

Bergey’s Manual of Systematic Bacteriology

•Second Edition-published in 5 volumes:

•Vol 1-(2001) The Archaea and the deeply branching and phototrophic Bacteria

•Vol 2-(2005)-The Proteobacteria

•Vol 3-(2009)- The Firmicutes

•Vol 4-(2011)- The Bacteroidetes, Spirochaetes, Tenericutes (Mollicutes), Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes

•Vol 5-(2012)- The Actinobacteria

Bergey’s Overview Volume 1-Domain Archae

14

15

Archaea: The Other Prokaryotes• Constitute third Domain Archaea• More closely related to Eukarya than to Bacteria• Contain unique genetic sequences in their rRNA• Have unique membrane lipids and cell walls

Extreme halophiles

Hot springs, home of thermophiles

Bergey’s Overview Volume 1 Domain Bacteria

18

Cyanobacteria (blue-green algae)

19

– Gram-negative cell walls– Extensive thylakoids with photosynthetic

chlorophyll pigments and gas inclusions

10 m

Stromatolite

Thylakoid membranes

(a)

20 microns

(d)

(c)(b)

(a2) (a3)

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Green Sulfur Bacteria

20

• Photosynthetic

• Contain photosynthetic pigment bacteriochlorophyll

• Do not give off oxygen as a product of photosynthesis

Bergey’s Overview Volume 2

21

Plague bacteria

bubos

24

• Obligate intracellular parasites– Rickettsias

• Very tiny, gram-negative bacteria

• Most are pathogens• Obligate intracellular

pathogens • Cannot survive or multiply

outside of a host cell• Rickettsia rickettisii –

Rocky Mountain spotted fever

Vacuole

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Nucleus

Rickettsial cells

Baca and Paretsky, Microbiological Reviews, 47(20);133, fig. 16, June 1983 © ASM

Volume 2-Domain Bacteria-Rickettsia

Rickettsia life cycle

Bergey’s Overview Volume 3

26

Clostridial myonecrosis (gas gangrene)

500 nm

Pleomorphic Mycoplasms

Genus Bacillus

Genus Staphylococcus

Staph infections

Strep throat

Strep infection complications

Necrotizing fasciatus

Bergey’s Overview Volume 4

35

Tuberculosis

TB test

leprosy

leprosy

Bergey’s Overview Volume 5

40

Fig. 21.23.a

Chalymidial eye infection

Syphilis bacterium

Syphilis shankars

Secondary syphilis

Tertiary syphilis

Taxonomy-What do I need to know for the Exam?

1. Bergeys Systematic Ed 1-Name of 4 Divisions in Kingdom Monera (and criterion for those Divisions)

2. Bergeys Systematic 2nd Ed.

A. Names of the 5 volumes and Domains included.

B. Number of phyla and classes in each of the volumes

C. For representative organisms discussed: name of the organism.Volume, Phylum and class/genus (if

applicable)