Microbio Exam II: total set

How are bacterial cultures preserved

1. deep freezing (-50 - -95)
2. lyphophilization (freeze drying into powder form)

What is the order of classification

domain, phylum, class, order, family, genus, species

Four main phyla of bacteria

1. proteobacteria
2. actinobacteria
3. firmicutes
4. bacteroidetes

Phylum proteobacteria

all share a common cell envelope that stains gram negative, very diverse metabolism

Five classes of proteobacteria

1. alphaproteobacteria
2. betaproteobacteria
3. gammaproteobacteria
4. deltaproteobacteria
5. epsilonproteobacteria

alphaproteobacteria

obligate or facultative intracellular bacteria, oligotrophs

oligotroph

capable of growing at very low levels of nutrients

Examples of alphaproteobacteria

rickettsia, nitrogen fixing bacteria (nitrosomonas, nitrobacter), rhizobium (legumes), agrobacterium tumifaciens (crown gall)

Rickettsia species

gram negative, highly pleomorphic, obligate intracellular

Rickettsia rickettsii

causes Rocky Mountain spotted fever, transmitted by ticks

betaproteobacteria

can survive in a wide range of environments, wide range of metabolic strategies

betaproteobacteria example

Neisseria

Neisseria

gram -, diplococci, require moisture + C02, fastidious (require chocolate agar)

Neisseria gonnorrhoeae

causes gonorrhea

Neisseria meningitides

causes bacterial meningitis

gammaproteobacteria

largest subgroup of proteobacteria

gammaproteobacteria examples

pseudomonas, legionella, the enterobacteriaceae

pseudomonas

gram -, baciilus, aerobic, highly motile, grows in soils, infects surgical wounds, forms biofilms in lungs of CF patients, antibiotic resistant

Legionella pneumophila

intracellular pathogen causing pneumonia, grows in warm water systems (AC, humidifier), grows inside ameba and human macrophages

How is legionella transmitted

inhalation of aerosolized ameba with legionella growing inside

enterobacteriaceae

inhabit intestinal tract, ferment carbs, facultative anaerobes

enterobacteriaceae examples

salmonella, escherichia

salmonella enterica subtypes (2)

1. salmonella enterica typhimurium; causes typhoid fever
2. salmonella enterica serovors: causes food born illnesses

Escherichia coli

indicator of fecal contamination, causes food born illness and UTIs

Shigella

gammaproteobacteria, shigatoxin causes bacillary dysentery

Klebsiella pneumoniae

gammaproteobacteria, causes pneumonia

serratia

gammaproteobacteria, makes red pigment, causes nosocomial infections like UTIs from catheters

Yersinia pestis

gammaproteobacteria, causes plague

erwinia

gammaproteobacteria, plant pathogens that secrete pectinases to hydrolyze pectin

deltaproteobacteria

mostly sulfate and sulfur reducing bacteria

deltaproteobacteria examples

bdellovibrio, dsulfovibrio, myxobacterium

Bdellovibrio

gram -, comma shaped rod, obligate aerobe, motile, infects other bacteria

desulfovibrio

gram -, comma shaped rod, reduce sulfur, produce H2S, used for removal of toxic and radioactive waste

myxobacterium

gram negative, swarms, move by gliding, used to study signaling

epsilonbacteria

slender gram negative rods that are helical or curved

Two important examples of epsilonbacteria

campylobacter and helicobacter

campylobacter jejuni

gram -, spiral shaped rod, microaerophilic, infects chickens, causes severe enteritis in humans

helicobacter pylori

gram -, spiral-shaped rod, microaerophilic, damages the lining of the stomach causing chronic gastritis, ulcers, and stomach cancer

Four classes of gram - non-proteobacteria

1. chlamydia
2. spirochetes
3. CFB group
4. planctomycetes

1. Chlamydias

lack cell wall, obligate parasites or pathogens

chlamydia trachomatis

causes pelvic inflammatory disease and blindness

Life cycle of chlamydia

1. elementary body attaches to host and is taken in by endocytosis
2. elementary body forms reticulate body which replicates
3. reticulate bodies form more elementary bodies
4. cell lyses which releases elementary bodies to infect other cells

elementary body

small dense resistant cell in chlamydia lifecycle that allows for infectious transmission

reticulate body

large vegetative cell in chlamydia lifecycle that is noninfectious

chlamydia psittaci

causes respiratory psittacosis in birds and humans

chlamydia pneumoniae

causes mild pneumonia

Spirochaetes

spiral shaped, have endoflagella in periplasm

Spirochaete examples

treponema, borrelia

treponema pallidum

causes syphilis

borrelia burgdorferi

causes lyme disease

borrelia recurrens

causes louse born relapsing fever

What does the CFB group stand for

cytophaga, fusobacterium, and bacteroidetes

cytophaga

motile aquatic bacteria that glide, degrade cellulose and chitin in soil

fusobacteria

anaerobic, cause dental abcesses in the mouth

Bacteroidetes

inhabitants of the human colon, gram - bacillus, obligate anaerobes, ferment indigestible sugars

Proteus

gammaproteobacteria, swarming motility, colonies form concentric rings, UTIs, kidney stones

bacteroides thetaiotaomicron

specializes in degradation of complex polysaccharides in the large intestine

planctomycetes

gram -, budding bacteria, have organelles that resemble eukaryotes

Planctomycetes example

gemmata obscuriglobus: has membrane around DNA resembling eukaryotic nucleus

Domain Bacteria; Gram Positive:

1. Low GC (firmicutes)
2. High GC (actinobacteria)

Firmicutes (low GC) two divisions

1. endospore forming bacteria
2. non-endospore forming lactic acid bacteria

1. Firmicutes: endospore forming bacteria

clostridium and bacillus

bacillus thuringiensis

insecticide, insects that feed on crystal get intestinal blockage

bacillus anthracis

anthrax

bacillus cereus

food poisoning , causes white strings in starchy food

clostridium

obligate anaerobes, produce endospores that give cells club shape, soil and aquatic sediments

clostridium tetani

causes tetanus, spastic paralysis

clostridium botulinum

causes botulism, blocks Ach leading to flaccid paralysis

clostridium perfringens

causes gas gangrene, necrosis of tissues

clostridium difficile

causes severe colitis and antibiotic diarrhea

Firmicutes (G+, low GC): non-spore formers

lactic acid bacteria, listeria species, gram + cocci

lactic acid bacteria

firmicutes, lactococcus and lactobacillus are found in the vagina and oral cavity

Listeria species

intracellular pathogens, firmicutes, affect GI tract and nervous system

congenital listeria monocytogenes

results in premature delivery, miscarriage, and stillbirth

Firmicutes: Gram positive cocci

enterococcus, streptococcus, staphylococcus

streptococcus

cocci in chains, aerotolerant, fermentative

Two groups of streptococci

1. pyogenes (strep throat)
2. viridans (dental caries)

grouped based on cell surface glycoproteins

streptococcus pyogenes

causes strep throat, beta hemolysis

streptococcus agalactiae

causes neonatal sepsis and meningitis, beta hemolysis

streptococcus pneumoniaea

causes pnemoni, alpha hemolysis

streptococcus mutans

causes dental caries, alpha hemolysis

enterococcus

genus of fecale origin, causes nosocomial infections

enterococcus faecalis and enterococcus faecium

infect surgical wounds and urinary tract

VRE

vancomycin resistant enterococcus

staphylococcus

grape-like clusters of cocci, facultative anaerobe, tolerate drying and high salt

staphylococcus aureus

causes wound infections, antibiotic resistant, produces enterotoxin

MRSA

methicillin resistant staphylococcus aureus, causes skin scaled syndrome

mycoplasmas

bacteria lack a cell wall, pleomorphic, smallest self replicating organisms, fried egg appearance

mycoplasma pneumonieae

causes mild pneumonia

Two divisions of Actinobacteria (G+, high GC)

1. actinomycetes (form filaments)
2. non-filament forming

Actinomycetes

form mycelia with branching filaments, play an important role in soil ecology

actinomyces israelii

anaerobe, causes endocarditis

Most important genus in actinomycetes

streptomyces - streptomyces coelicolor produces many antibiotics

Frankia genus

actinobacteria, nitrogen fixing in alder trees

nocardia genus

actinobacteria, form fragmenting filaments, acid fast

nocardia asteroides

causes pulmonary infections

Actinobacteria: non-filamentous

acid fast, cell walls contain mycolic acid, dont form mycelia

Gardnerella vaginalis

gram variable, pleomorphic, causes bacteria vaginosis

corynebacterium diptheriae

have metachromatic granules, causes diptheria

diptheria

membrane of bacteria in the throat blocks air from reaching the lungs, prevented by DTAP vaccine