Microbiology UTA 2460 Chapter 4

Prokaryotes

Bacteria and Archaea

ubiquitous

present, appearing, or found everywhere

Places prokaryotes are found:

hot springs, ice caps, deep ocean, skin and mucosal surfaces

TRUE OR FALSE: Prokaryotes are adaptable and resilient

TRUE

-they have the ability to switch metabolic or respiration methods

list 3 things prokaryotes provide for our habitats

-stability of ecosystems

-carbon/nitrogen fixation

-environmental cleanup

Some prokaryotes are bad for us, these cause:

-human pathogens

-climate change

symbiotic relationship

The relationship between two species that live in close association with each other

Mutualism

organism A: benefitted

organism B: benefitted

Amensalism

organism A: harmed

organism B: unaffected

Commensalism

organism A: benefitted

organism B: unaffected

Neutralism

organism A: unaffected

organism B: unaffected

Parasitism

organism A: benefitted

organism B: harmed

examples of symbiotic environments

-spores in soil

-skin cells as food source

-antimicrobial defense on skin

-gut nutrient metabolism

polymicrobial

prokaryotes that live in communities

cooperative communities result in

biofilm formation

competing communities result in

scarce resources

microbiome

prokaryotic + eukaryotic microbes

-resident

-transient

Standard for bacterial taxonomy

Bergey's Manual of Systematic Bacteriology

TRUE OR FALSE: Prokaryotes sexually reproduce

FALSE

Bacteria taxonomy is classified by:

staining (mostly)

Gram Negative Phyla

-proteobacteria

-spirochete

-CFB group

-planctomycetes

-phototrophic bacteria

Gram Positive Phyla

-actinobacteria

-firmicutes

Atypical Phyla (neither)

-tenericutes

Proteobacteria (-)

Class: Alphaproteobacteria

-oligotrophs (live in low nutrient environments)

-obligate intracellular (need host for metabolic activity)

-Chlamydia & Rickettsia

Chlamydia spp.

causative agents for lymphogranuloma venereum (STD)

Rickettsia spp.

causative agents for Rocky mountain spotted fever & typhus fevers

Proteobacteria (-)

Class: Betaproteobacteria

-Eutrophs (require many nutrients)

-survive in places like intestines

-Bordetella & Neisseria

Bordetella spp.

-causative agents whooping cough (pertussis) & kennel cough

-Produces toxins to paralyze lung cilia

Neisseria gonorrhea

causative agent for gonorrhea STD

Neisseria meningitides

causative agent for bacterial meningitis

Proteobacteria (-)

Class: gammaproteobacteria

-most diverse

-Pseudomonas, Pasteurella, Haemophilus, Vibrio, Legionella, Enterobacter family

Pseudomonas aeruginosa

common infection of wounds, urinary tract, & respiratory tract

Pasteurella haemolytica

causative agent for severe pneumonia in animals

Haemophilus influenza

causative agent for upper & lower respiratory infections (does not cause influenza)

Vibrio spp.

-commonly found in alkaline environments such as ocean ports & lagoons

-gastrointestinal disease, cellulitis, blood-borne infections

Vibrio cholera

causative agent of cholera and common to water contamination

Legionella pneumophila

causative agent for Legionnaire's disease and common to water contamination

Enterobacter family

includes E. coli, & Salmonella spp.

E. coli

-most mutualistic

-some produce Shiga toxin

Salmonella

can have multiple serotypes, many that cause salmonellosis

Coliforms

"E. coli - like" microbes that ferment lactose completely

Noncoliforms

cannot ferment lactose

Proteobacteria (-)

Class: deltaproteobacteria

-relatively small class

-includes sulfate reducing bacteria

-Parasitic Bdellovibrio spp. -Soil dwelling Myxobacteria "slime bacteria"

Desulfovibrio orale

-periodontal disease

Proteobacteria (-)

Class: epsilonproteobacteria

-smallest class

-microaerophilic

-Campylobacter & Helicobacter

Campylobacter spp

common to food poisoning

Helicobacter spp.

commonly beneficial but can cause ulcers and stomach cancer in susceptible people

Spirochetes (-)

-extremly thin

-hard to stain/culture

-axial filament similar to flagella

Treponema pallidum

causative agent for syphilis

Borrelia burgdorferi

Lyme disease

CFB group (-)

-Cytophaga

-Fusobacterium

-Bacteroides

Cytophaga spp.

gliding system for motility (mechanisms mostly unknown)

Fusobacteria spp.

inhabit mouth and can cause various oral diseases

Bacteroides spp.

- 30% of gut microbiome

- lower levels correlated with obesity

Planctomycetes (-)

-aquatic environments

-reproduce via budding (not binary fission)

-sessile & swarmer cells

sessile cells

immobile with holdfast appendage

swarmer cells

motile, unable to reproduce

Phototrophic bacteria

-group based on function, not taxonomy

-utilize sunlight for main energy source

-photosynthsize

-contains proteo & non proteobacteria

-purple & green bacteria due to "bacteriochlorophylls" & cyanobacteria

oxygenic

produces O2

anoxygenic

does not produce O2

Cyanobacteria

-oxygenic

-highly adaptable and diverse

-chlorophyll

-uses as biosorbents and human nutrition

Microsystis spp.

toxic algal blooms

anoxygenic photosynthesizers

1. purple sulfur bacteria

(oxidize hydrogen sulfide to elemental sulfur & sulfuric acid)

2. purple non sulfur bacteria

(use only hydrogen)

3. green sulfur bacteria

(oxidize sulfide)

4. green non sulfure bacteria

(oxidize non-sulfide substrates)

Gram (+) bacteria

-stain purple

-grouping by guanine and cytosine content

-Phylum Actinobacteria (high G+C content, >50%)

-Phylum Firmicutes (low G+C content <50%)

Actinobacteria (+)

-extremely diverse

-thin, filamentous to caccobacilli shape

-important to soil

-diff. peptidoglycans in cell wall

-Mycobacterium, Corynebacterium, Bifidobacterium, Gardnerella

Mycobacterium spp.

-Acid fast (+) due to mycolic acid in cell wall

-causative agent for tuberculosis & leprosy

Corynebacterium spp.

-Diaminopimelic acids in cell wall

-Most are non-pathogenic

- C. diphtheria is causative agent for diphtheria

Bifidobacterium spp.

-Filamentous & anaerobic

-Frequently used as probiotic

Gardnerella vaginalis

-Only one species

-Gram variable: inconsistent stain results

-Causative agent for bacterial vaginosis

Firmicutes (+)

-Low G+C content

-No other common characteristic

-Clostridium,Streptococcus, Lactobacillus,Enterococcus

(order: Lactobacillales) Bacillus,Staphylococcus (class: Bacilli)

Order Lactobacillales

contains bacilli & cocci

Genus Clostridium

-mostly obligate anaerobes

-Endospore producers

-Soil dwelling

-Common food contaminant

C. perfringens

agent for food poisoning and gangrene

C. tetani

producer of neurotoxin and agent for tetanus

C. botulinum

producer of botulinum neurotoxin

C. difficile

hospital infection, causes severe colitis

Genus Streptococcus

S. pyogenes- β-hemolytic cocci associated with pus production (pyogenic), strep throat

S. pneumoniae- causes pneumonia, respiratory infections, and a wide range of other diseases

Genus Lactobacillus

-Facultative anaerobes

-non-spore formers

-significant component of gut microbiome

-starter cultures for yogurt, cheese, sauerkraut, etc

Genus Enterococcus

-Diplicocci arrangement

-Anaerobic respiration

-Commensal gut microbe

-Common UTI pathogen

(E. faecium)

Genus Bacillus

-bacillus shaped aerobes or facultative anaerobes

-Endospore producers

-Important to industrial microbiology

B. anthracis

causative agent for anthrax

B. cereus

common food poisoning agent

B. thuringiensis

producer of insecticide compounds

Genus Staphylococcus

-cocci shaped facultative anaerobes

-Halophilic

-Nonmotile

S. aureus

common agent of skin infections; some can produce enterotoxins for food poisoningSome are very antibiotic resistant (MRSA & VRSA)

S. epidermidis

common flora on skin; can cause infection to open wounds

Atypical bacteria

Tenericutes

Genus Mycoplasma

-no cell wall/do not retain crystal violet

-pleomorphic

-Extremely small

-Cell wall antibiotics do not work

-Only classified by genome

M. pneumoniae

agent for walking pneumonia

Deeply branching bacteria

-Genera and species that are most common to the last universal common ancestor (LUCA)

-Provide clues to structure and function of ancient forms of life (LUCAs)

Aquificae

-gram (-)

-hyperthermophiles living in hot springs and oven vents

Thermotogae

-gram (-)

-hyperthermophilic anaerobes

-sheath-like outer membrane

Deinococci

-gram (+)

-polyextremophile (heat, vacuum, acidity tolerant)

Archaea

distinguished by:

-Membranes with branched isoprene chains & ether linkages to phosphate head

-Walls of surface layer proteins(some pseudopeptidoglycan)

-Genomes are much larger -Capable of methanogenesis

-Usually not in human microbiota

-Not directly associated with infectious diseases

Archaea membranes

branched isoprene chains & ether linkages to phosphate head

Domain: Archaea

Phylum: Crenarchaeota

-All aquatic microbes

-many extremophiles

Sulfolobus spp.

thermophiles & acidophiles; facultative anaerobic; used in biotech for production of affitins

Thermoproteus spp.

-strict anaerobic thermophiles

-arguably deepest branching Archaea

Domain: Archaea

Phylum: Euryarchaeota

mostly methanogens & anaerobes

Methanogens

-group of archaebacteria that produce methane as a by product of their metabolism

-Methanobacteria, Methanococci, Methanomicrobia