MicrobiologyB.E Pruitt & Jane J. Stein

AN INTRODUCTIONEIGHTH EDITION

TORTORA • FUNKE • CASE

Chapter 11, part CThe Prokaryotes:

Domains Bacteria and Archaea

The (delta) Proteobacteria

Delta Proteobacteria include the genera Myxococcus and Bdellovibrio which prey on other bacteria and Desulfovibrio which are dissimilatory sulfur reducers.

• Bdellovibrio. Prey on other bacteria

• Desulfovibrionales. Use S instead of O2 as final electron acceptor, form H2S

• Myxococcales. Gliding. Cells aggregate to form myxospores

The (delta) Proteobacteria

The (delta) Proteobacteria

Figure 11.10a

The (delta) Proteobacteria

Figure 11.1b

The (epsilon) Proteobacteria

Epsilon-proteobacteria include the genera Campylobacter and Helicobacter which are human pathogens

• Campylobacter• One polar flagellum• Gastroenteritis

The (epsilon) Proteobacteria

Figure 11.1a

• Helicobacter• Multiple flagella • Peptic ulcers• Stomach cancer

The (epsilon) Proteobacteria

Figure 11.1b

The Nonproteobacteria Gram (-)

Other groups that don’t fit anywhere

Sulfur bacteria

• Oxygenic photosynthesis• Gliding motility• Fix nitrogen

Cyanobacteria

Cyanobacteria

Figure 11.12a-c

• Anoxygenic photosynthesis• Purple and green sulfur bacteria

• Chlorobi maybe proteobacteria• Other anoxygenic are non-sulfur purple and

green• Use organic compounds

Anoxygenic Photosynthetic Bacteria

2H2O + CO2

light(CH2O) + H2O + O2

2H2S + CO2

light(CH2O) + H2O + 2S0

• Obligate intracellular parasites

• Gram(-)

• C. trachomatis• Trachoma• STD, urethritis

• C. pneumoniae• C. psittaci

• Causes psittacosis• Parrots? Wild birds

Assorted other phyla of bacteria -Chlamydiae

In Bergey's Manual, Volume 5

Figure 11.22a

In Bergey's Manual, Volume 5

Figure 11.22b

• Borrelia• Leptospira• Treponema

Spirochaetes

Figure 11.23

Leptosporsis

MODE OF TRANSMISSION: Contact of the skin or mucous membranes with contaminated water, soil or vegetation; direct contact with urine or tissues of infected animals; occasionally through ingestion of contaminated food or by inhalation of droplet aerosols of contaminated fluids

INCUBATION PERIOD: Usually 10 days with a range of 4-19 daysCOMMUNICABILITY: Direct transmission from person to person is rare;

leptospires may be excreted in urine for usually 1 month but has been observed as long as 11 months after the acute

DISSEMINATION RESERVOIR: Farm and pet animals, including cattle, dogs, horses and swine; rats and other rodents act as the normal carrier host; wild animals, including deer, squirrels, foxes, skunks and even reptiles and amphibians may be infected; in Europe, field mice, voles, Shrews and hedgehogs are common reservoirs; in carrier animals, an asymptomatic infection occurs

ZOONOSIS: Yes - direct and indirect contact with urine, abortion products, and materials contaminated with urine from infected animals

• Anaerobic• Bacteroides. In mouth and large intestine

• Bacteroides are gram-negative, nonsporeforming, anaerobic, and rod-shaped bacteria

• Bacteroides are one of the most numerous of the intestinal bugs and we get to see a great many everyday as about 30 % of what comes out of the intestine is bacteria! 1 billion per gram of feces

• Veillonella - hydrogen sulfide producer in mouth• Veillonella are Gram-negative cocci that are the anaerobic counterpart of

Neisseria. These non-motile diplococci are part of the normal flora of the mouth. The reason this organism is important is not due to its pathogenicity. Instead, we include Veillonella because it can be and is often mistaken for the more serious gonococcal infection. The most common species isolated from humans is V. parvula. Veillonella species are negative for almost every biochemical test with the exception of an occasional strain being positive for catalase.

Bacteroidetes

• Fusobacterium• Found in mouth• Strict anaerobe• May be involved in

dental diseases• Could spread• Lemierre

Syndrome• Rare

dissemination of Fusobacterium

Fusobacteria

Figure 11.24