Selections from Chapter 11, 19-21: Domains; Archaea and Bacteria

Question 1

Define: extremophile (most famous)

Answer 1

microbe that requires extreme conditions of temperature, pH, and/or salinity to survive

Question 2

Define: methanogen (most common)

Answer 2

methane generating
-obligate anaerobe
-converts CO2 or acids into methane

Question 3

Define: beta-lactamase

Answer 3

enzymes that destroy beta-lactam antibodies
in S. aureus

Question 4

Define: M protein

Answer 4

in membrane & prevents “tagging” by immune system &
attack by phagocytosis

Question 5

Define: buboes

Answer 5

swollen inflamed lymph nodes

Question 6

Define: type III secretion
system

Answer 6

Flagella like structure
pathogen can attack cells that are trying to phagocytosis it to destroy it or attack blood cells to lysis & release materials
-a virulence factor that enables enteric bacteria to insert chemicals directly into the cytosol of the eukaryotic cell

Question 7

Identify the common features of organisms in the Domain Archaea

o Describe the general characteristics of each Genus described (3)

Answer 7

Common features:
Cell type: prokaryotic
Cell walls: not peptidoglycan
Cell membranes: phospholipids
-may be branched fatty acids
-form monolayer
Unique rRNA
-discover by C. woese
DNA contains INTRONS used for coding
Most famous live in extreme environments (extremophiles)

Question 8

Identify the common features of organisms in the Domain Bacteria
o List the common features for each Phylum described (4)

Answer 8

Firmicutes (5 genus)
-LOW GC. Gram-positive, includes endospore-formers & bacteria important to health & industry

Actinobacteria (2 genus)
-high G+C, Gram-positive, many are pleomorphic, common in soil

Proteobacteria (4 classes, 1 has family)
-Greek god→ many shapes, Gram- negative (lipid A), 5 classes (alpha, beta, gamma, epsilon, & delta)

Spirochaetes (2 genus)
-Gram- negative, coiled morphology = spirochete, more via AXIAL FILAMENTS (internal endoflagella) to corkscrew through environment / burrow in tissue, many are normal oral flora

Question 9

ARCHAEA
Sulfolobus

Answer 9

ACIDOPHILE: optimum 2 pH
THERMOPHILE: optimum 70°
Found in sulfur rich hot springs (Yellowstone)
Uses SULFER for respiration instead of oxygen

Question 10

ARCHAEA
Halobacterium

Answer 10

HALOPHILE: grow in salty environment optimum 17-25% salt
Found in Great Salt Lake
BACTERIORHODOPSIN: purple pigment
-used to harvest sunlight (phototroph)

Question 11

ARCHAEA
Methanobacterium

Answer 11

METHANOGEN: convert CO2 or acids into methane
Largest group of archaea
Found in marshes, swamps, marine sediments, intestines of animals
Used in sewage treatment
BIOGAS: methane from digestion of sludge, organic wastes(cow manure or landfill waste) by Methanobacterium
-gas stove produce gas by archaea

Question 12

Staphylococcus aureus
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 12

FIRMICUTES (pathogen)
-cause human diseases (food poisoning)

-TOXIC SHOCK SYNDROME: fever, vomiting, rash, low BP, loss of sheets of skin/ fetal in 5% of cases due to low BP → shock (tampons super absorbing & not changing, transfer normal flora to tampon & when applied put into great environment to grow

KEY VIRULENCE FACTORS
-Enzymes: beta lactamase: enzymes that destroys beta lactam antibodies
-Toxins: turns on immune cells inappropriately which causes missive immune response that leads to symptoms (TOXIC SHOCK SYNDROME)

TREATMENT: treat symptoms; antibiotics MRSA-methicillin

Question 13

Streptococcus pyogenes
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 13

FIRMICUTES (pathogen)
-causes strep throat, scarlet/rheumatic fever, kidney disease

-RHEUMATIC FEVER: autoimmune complication of untreated pharyngitis (strep throat) common cause of ❤️valve damage in world more uncommon in developed world b/c access to antibiotics

KEY VIRULENCE FACTORS
-Antiphagocytic factors:
-capsule → prevents binding by phagocytosis
- M protein →in membrane & prevents “tagging” by immune system &
attack by phagocytosis

Question 14

Streptococcus mutans
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 14

FIRMICUTES (pathogen)
-present in mouth, found in pits & fissure of teeth, fermentative metabolism produce acid (sugars → acid)

DENTAL CARIES: erosion of tooth enamel, causes pain, difficulty eating, tooth loss, infection

VIRULENCE KEY FACTORS:
-produces a glycocalyx (dextran made from glucose) to attach to cells & produce a biofilm
- sucrose (table sugar) → glucose (dextran) + fructose (acid which erodes tooth enamel)

TREATMENT & PREVENTION
-remove all infected tooth & replace w/filling
PREVENTION: brushing w/fluoride & flossing to remove biofilm / change diet use xylitol instead of table sugar (sucrose) b/c S. mutans can’t use

Question 15

Lactobacillus
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 15

FIRMICUTES (normal flora)
-normal flora of digestive system & genital system
-produce bactercins H2O2 & lactic acid to kill of pathogenic bacteria
DIGESTIVE SYSTEM:
-may prevent biofilm formation on teeth
-used as probiotic for IBS & gastric ulcers

REPRODUCTIVE SYSTEM:
-production of lactic acid prevents growth of Candida albicans (fungus that causes yeast infections) & bacteria that cause bacterial vaginosis

OTHER: saurkraut, yogurt, cheese

Question 16

Clostridium difficile
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 16

FIRMICUTES (normal flora)
-rod-shaped, obligate anaerobe, normal flora of the gut/ transmitted by fecal-oral route

C. DIFF COLITIS
-common nosocomial infection caused by long-term antibiotic use ( other gut flora are killed off C difficile flourished
- watery diarrhea, cramping, fever
-severe cases: diarrhea 10-15X per day pt, dies from dehydration or perforation of colon which leads to sepsis

KEY VIRULENCE FACTORS:
-toxins: TcdA & TcdB toxins kill cells of the colon leading to areas of severe inflammation “pseudomembranes”

TREATMENT
-stop antibiotics (that kill normal flora)
-fluid & electrolyte replacement
-fecal transplant

Question 17

Mycobacterium
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 17

ACTINOBACTERIA (pathogen)
-not very virulent b/c slow growing
-transmission and/or disease rates are very low

KEY VIRULENCE FACTORS
- mycolic acid = waxy layer (can survive in dried droplets for 8 months)
-prevents digestion in phagosomes of phagocyte

TREATMENT: long term multiple antibiotics (means antibiotic exposure to all growing cells)

Question 18

Mycobacterium tuberculosis
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 18

ACTINOBACTERIA
-persistent cough w/blood and/or spit, pain in chests
-advanced disease fever, weakness can vary in multiple ORGANS INVOLVED carried by infected macrophages moving from tissue to tissue

1° tuberculosis
-tubercle gets walled off
signs & symptoms subside but change tubercle can rupture
-most people stay in 1° 85%

2° tuberculosis
-infected lungs & multiple organs

Question 19

Class Alphaproteobacteria
Rickettsia rickettsii
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 19

PROTEOBACTERIA (pathogen)
-capable of growing @ low nutrients
-includes nitrogen fixers, plant symbionts, pathogens

RICKETTSIA rICKETTSII
-extremely small, obligate intracellular parasites

ROCKY MOUTAIN SPOTTED FEVER
-transmitted by tick vector-infection damages capillaries →spotted rash, low BP, fever, chills, muscle pain, nausea, vomiting. 5% mortality w/ treatment

KEY VIRULENCE FACTORS
-Enzyme to destroy phagosome membrane (induce phagocytosis→ destroy membrane →released into cytoplasm →continue to grow cell

TREATMENT:
-remove tick vector & treat w/antibiotics (b4 infection grows too long)
-ealry treatment is key to prevent complications

Question 20

Class betaproteobacteria
Bordetella pertussis
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 20

PROTEOBACTERIA (pathogen)
-can use nutrients that come from anaerobic decomposition of organic matter(H2, ammonia, methane)
BORDETELLA pERTUSIS
-non motile, aerobic (lungs), coccobacillus

WHOOPING COUGH
-cold like symptoms that progress to persistent deep cough w/whoop sound
-40-50 coughing spells per day, vomiting, exhaustion, turning blue, broken ribs
-adults asymptomatic need to be vaccinate to protect children, half of infants must be hospitalized

KEY VIRULANCE FACTORS
-pertussis toxin is an adhesion (attach to tracheal cells)
-tracheal cytotoxin prevents cilia movement & kills ciliated cells in trachea

TREATMENT & PREVENTION
-Tetanus, Diphtheria, & pertussis vaccine prevents illness
-mostly treat the symptoms, immune system kills bacteria

Question 21

Class gammaproteobacteria
Family Entreobacteriaceae
Yersinia pestis

o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 21

PROTEOBACTERIA (pathogen)
-largest group of proteobacteria

FAMILY: ENTEROBACTERIACEA
-intestine dwellers, facultative anaerobes “enterics” include “coliforms”
GENUS: YERSINIA

VIRULENCE FACTORS in SOME ENTERICS
-capsules, fimbriae
-exotoxins → often cause diarrhea
-hemolysis & siderophores
-Type 3 secretion system

YERSINIA pESTIS
BUBONIC PLAGUE
-transmitted by fleas, rodent revisors
-high fever& buboes
-common in CA mountains & high desert especially after El Nino
-last human case 2015 Yosemite 2 campers

KEY VIRULENCE FACTORS
-uses t3ss to inject toxins into phagocytic cells- induces apoptosis=self destruct for cells

TREATMENT & PERVENTION
-easily treatable w/ antibiotics → early detection is key
-controlled of rodents & fleas = control of disease in population

Question 22

Class Episilonproteobacteria
Helicobacter pylori
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 22

PROTEOBACTERIA (pathogen)
-slender vibrios

HELICOBACTER pYLORI
-microaerophilic vibrio (7-10% O2)
-causes peptic ulcers & gastritis (long-term→ stomach cancer)

VIRULENCE FACTORS
-protein to inhibit acid damage to lacterium
Enzymes inhibit phagocytosis
-flagella to swim in mucus (flagella allows swim thru muscular layer, invade epithelial cells in the stomach lining where normal have thick muscular layer, allow bacteria to get deeper b/c acid

TREATMENT
-2 or 3 antibiotics in combination w/drugs to prevent acid production

Question 23

Borrella burgdorferi
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 23

SPIROCHAETES (pathogen)
-slow growing microaerophile

LYME’S DISEASE
-transmitted by IXODUS tick vector (deer tick)
-fever, headache, fatigue, bull’s eye rash, arthritis
-can cross placenta & cause stillbirth

COMPLICATION IN DIAGNOSIS
-not all pt. report same symptoms
-recent evidence repot more species involved

TREATMENT & PREVENTION
-Avoid ticks
-most pt. respond w/ antibiotics

Question 24

Trephoema pallidum
o For each individual described:
 List the taxonomic lineage

 Is it normal flora or a pathogen?
 Normal flora:
o List body location(s) normally found, describe how it
benefits human health

 Pathogens:
o describe the disease it causes, describe virulence factors,
describe treatment and prevention options

Answer 24

SPIROCHAETES (pathogen)
-cannot grow in the lab; maintain in the animals, cell culture

SYPHILLS
-STD can cross placenta (abortion or mental retardation)

DISEASE PROGRESSION
PRIMARY: chancre (rep, painless, hard, lesion) on genitals (lesion contains bacteria
SECONDARY: chancre disappears, sore throat, headache, mild fever, myalgia, rash
-latency-most people remain in this stage after 2 syphilis
TERITARY: dementia, blindness, paralysis, ❤️failure, gummas (large painful lesions)
-neurosyphilis: can occur @ any stage; meningitis; psychosis

TREATMENTS:
-penicillin @ all stages
-tertiary: difficult to treat severe symptoms/ result of hyperimmune wide-response/ some symptoms may be permanent
-used to cure syphilis w/mercury cause own neurological disfunction