Gram Negative Bacteria (Chapter 4, Exam 2)

four classes of gram negative nonproteobacteria

Chlamydia

spirochetes

CFB group

Planctomycetes

CFB

Cytophaga, Fusobacterium, and Bacteroides

Phylum Chlamydiae

intracellular pathogens

chlamydias

chlamydias

absent or diminished cell walls but are not mycoplasmas

obligate parasites or pathogens

C. trachomatis

Life cycle of Chlamydiae

1. elementary body attaches to host cell (condensed DNA)

2. elementary body taken up by endocytosis (in cytoplasm)

3. elementary body differentiates into reticulate body (becomes uncondensed and thread like)

4. reticulate body replicates and persists in cell for long periods

5. Reticulate bodies develop into elementary bodies

6. Cell lyses,, releases elementary bodies and finds another hosts

elementary body cells

small, dense

cell resistant to drying and means of dispersal similar to endospores

specialized for infectious transmission

reticulate body

vegetative form divides by binary fission inside cytoplasm

noninfectious

multiples to form large transmission inoculum

eventually converts to elementary bodies, which are released when host cell disintegrates

Chlamydia trachomatis

-pelvic inflammatory disease

inflamed uterus, Fallopian tube, ovary

-causes blindness in humans and sexually transmitted disease

Chlamydophila psittaci

Causes respiratory Psittacosis in birds and humans

zoonosis

Chlamydophila pneumoniae

Causes mild pneumonia, bronchitis, and sinusitis

prevalent in college students

Phylum Spirochaetes

have outer membrane

identified by endoflagella in periplasm surrounded by outer sheath

dark field microscopy

include human pathogens in genus Treponema

-treoponema pallidum

genus Borreila

-B. burgdoreferi

-B. recurrens

Treponema pallidum

cause of syphillus

B. burgdorferi

Lyme disease

B. Recurrens

causes louse-borne relapsing fever from lice and ticks

Cytophaga

motile, aquatic bacteria that glide

-secrete slimy substance to slide in soil and find nutrients

-degade cellulose and chtiin in soil

Fusobacteria

Anaerobic

Are found in the mouth; cause dental abscesses

phylum bacteriodetes

obligate anaerobes

help digest plant and animal material

major inhabitants of human colon

gram negative bacillus, ferment indigestible sugar derivatives, break down toxins

Bacterioides thetaiotaomicron

usually mutualistic, although some species are opportunistic pathogens

opportunistic pathogens

normal microbiota that cause disease under certain circumstances

Bacteroides thetaiotaomicron

found in lumen of large intestine

specializes in degradation of complex polysaccharides, which gives us vitamins from plants we eat

photrophic bacteria

use sunlight as energy

contains non-proteobacteria and proteobacteria

oxygenic and anoxygenic photosynthesis

classified into sulfur and non sulfur bacteria

oxygenic photosynthesis

cyanobacteria, as well as eukaryotic plants and algae, produce oxygen from water as the carry out photosynthesis

2H2O+ CO2----light--> (CH2O) + H20 + O2

anoxygenic photosynthesis

photosynthesis in which O2 is not produced

use hydrogen sulfide as final electron acceptor

2H2S+ CO2---light--> (CH2O) + H20 + 2S0

purple sulfur bacteria and green sulfur bacteria use reduced sulfur compounds, such as hydrogen sulfide, instead of water and produce granules of sulfur (S0) rather than oxygen

Cyanobacteria

oxygenic phototrophs

blue/green

ex: Microcystis aeruginosa

Chlorobi

anoxygenic photosynthesis, green sulfur bacteria

sulfur deposited outside cell

ex: chlorobium

Chloroflexi

anoxygenic photosynthesis, green non-sulfur

ex: chloroflexus

Alphaproteobacteria (proteobacteria)

purple, non sulfur bacteria

anoxygenic

ex: Rhodospirillum

Betaproteobacteria (proteobacteria)

purple, non sulfur bacteria

anoxygenic

ex: Rhodocyclus

gammaproteobacteria (proteobacteria)

purple sulfur bacteria

anoxygenic

sulfur produced inside cell

Green sulfur bacteria

phylum Chlorobi

Green nonsulfur bacteria

phylum Chloroflexi

Purple sulfur/nonsulfur photosynthetic bacteria

proteobacteria

Phylum Cyanobacteria

produce oxygen

oxygenic photoautotrophs

many fix nitrogen and carbon dioxide

specialized cells called heterocysts

problem: blooms

critical role in change of planets anoxic atmosphere-how we have oxygen rich environment today

heterocysts

a specialized cell that engages in nitrogen fixation in some filamentous cyanobacteria

Blooms

- algae that grow into populations that grow out of control in masses

produce toxins that when ingested, can damage liver

Prochlorococcus

unicellular, nonfilamentous cyanobacterium

worlds most abundant photosynthetic organism

filamentous cyanobacterium

show heterocysts

nitrogen fixing activity is located

makes filaments fixing nitrogen

Purple sulfur bacteria

due to carotenoid pigemtns

presence of bacterial chlorophyll helps pigments capture light energy and transfer electrons to bacteriochlorophyll

Planctomycetes

gram negative, budding bacteria

DNA analysis places them among bacteria, but cell walls resemble archaea

organelle resembled eukaryotic nuclues

Gemmata obscuriglobus

Gemmata obscuriglobus

a bacterium that has its DNA inside a double membrane

resembles eukaryotic nuclues

Gammaproteobactiera

Enterobacteriaceae

called enterics

ferment carbs

facultative anaerobes, motile, commensals, and pathogens

Salmonella and Escherichia

enterics

inhibits intestinal tract

commensal

describes an organism that lives symbiotically with a host; this host neither benefits nor suffers from the association

normal flora

Salmonella

common form of foodborne illness

S. enterica, S. Bungori

S. enterica

food borne illness

in intestines of animals, can be transmitted to animals to humans

undercooked meat and raw eggs

S. typhi

typhoid fever

from water and feces

due to bad sanitation practices

transmitted person to person

Escherichia coli

indicator of fecal contamination

some strains cause food borne illness and urinary tract infections

Salmonella bungori

in cold blooded animals (lizards)

not a problem for humans

Shigella

bacillary dysentery

related to e.coli

produces shigella toxin

causes diarahhea

Klebsiella

K. pneumoniae--> causes pneumonia

in soil, nitrogen fixing

serratia

Produces red pigment

Common cause of nosocomial infections

found on catheters in UTI

Proteus

swarming motility

colonies form concentric rings

edges have lots of flagella and motile

center loses flagella and is less motile

converts Urea to ammonia, thus increasing pH and causing kidney stones

Yersinia

Y. pestis--> causes plague

transmitted via fleas

Erwinia

plant pathogens

secrete enzymes, pectinases, which hydrolyzes pectin

5 Major Phyla of Archaea

Crenarchaeota, Euryarchaeota, Korarchaeota, Nanoarchaeota, and Thaumarchaeota

none associated with infectious diseases

Archaea

cell wall: pseudopeptiglycan

rods, coccus, unusual morphology

-no direct human pathogens, but influence environment to cause disease and harm human health

Crenarchaeota

aquatic organisms

most abundant microorganisms in the oceans

Sulfolobus, Themoproteus

Sulfolobus

aerobic and anaerobic

thermophiles, 70-80C

acidophiles pH of 2-3.24

oxidizes sulfur and stores sulfuric acid in its granules

used in biotechnology for the production of thermostable and acid-resistant proteins

Thermoproteus

strictly anaerobic organisms, 85C

reduce sulfur or molecular hydrogen and use carbon dioxide or carbon monoxide as a source of carbon

deepest-branching genus of Archaea

living example of some of our planets earliest forms of life

Euryarchaeota

methane-producing archaea

can survive extremophiles or mesophiles

class: Halobacteria

methane producing archaea

methanogens

reduce carbon dioxide in the presence of hydrogen, producing methane

apart of normal microbiota

-in intestines, oral cavities, vagina

Halobacteria

require high salt concentration of sodium chloride in aquatic environment

perform photosynthesis using the protein bacteriorhodopsin

Microbial diversity

PCR indicates 10,000 bacteria per gram of soil

Two main types of microbiota

Permanent and transient (temporary)

Symbiotic relationships

Mutualism, amensalism, commensalism, neutralism, parasitism

Mutualism

Both populations benefit

Amensalism

Pop A harmed, pop B unaffected

Commensalism

Pop A benefitted, Pop B unaffected

Locations: skin, oral cavity, upper resp tract, intestines, urogenital tract

Neutralism

Both populations unaffected

Parasitism

Pop A benefitted, pop B harmed

Vaginal birth

Lactobacillus and bacteroides are prevalent

Changes in microbiota over time

Before puberty- pH neutral, staph

Menopause- diversity equal to before puberty, more prone to infections

Cesarean birth

Microbiome resembles human skin

Staphylococcus aureus