Lecture 7

Question 1

Bacteria

Answer 1

• lack defined nucleus and membrane bound organelles
• H pylori, Legionella pneumophila, S aureus

Question 2

Motility

Answer 2

• flagella: move through environment
• pili: adhere to surfaces

Question 3

Capsule

Answer 3

protective layer of polysaccharides
- encapsulated streptococcus pneumoniae are more virulent and more fatal

Question 4

Gram positive

Answer 4

thick layer of peptidoglycan in cell walls
- purple

Question 5

Gram negative

Answer 5

outer membrane of lipopolysaccharides (LPS)
- pink
- LPS can be an endotoxin

Question 6

16s

Answer 6

primary classification technique for bacteria
- speciate bacteria that you can’t grow in culture

Question 7

Shapes

Answer 7

• cocci: round
• bacillus: rod
• spirilla: spiral

Question 8

bacterial growth

Answer 8

• nutrient availability, temperature, pH, oxygen levels

Question 9

Endospores

Answer 9

• highly resistant structures
• clostridium tetani, bacillus anthracis
• survival mechanism

Question 10

Virulence factors

Answer 10

• toxins, adhesins, capsules, enzymes
• plasmids often encode virulence genes

Question 11

• enterotoxigenic e.coli (ETEC)

Answer 11

• enterotoxigenic e.coli (ETEC) possess plasmid encoded enterotoxins

Question 12

Binary fission

Answer 12

• asexual reproduction
• e. coli can divide every 20 mins

Question 13

Horizontal gene transfer

Answer 13

• exchange of genetic material
• spread plasmids

Question 14

Bacteriophages

Answer 14

• viruses that infect bacteria
• antibiotic alternative

Question 15

infection

Answer 15

• bacterial virulence and host predisposition (immune deficiencies, anatomical defects)
• some diseases caused by toxins (botulism, s aureus)

Question 16

infection mechanisms

Answer 16

• pyogenic infection (inflammation, pus)
• granulomatous (granulomas)
• intoxication
• immunologic mediation (post infectious disease)
• neoplasia (cancer)

Question 17

common gram positive

Answer 17

s aureus, streptococcus pneumoniae, c botulinum

Question 18

common gram negative

Answer 18

e coli, pseudomonas aeruginosa, neisseria gonorrhoeae

Question 19

common mycobacteria

Answer 19

m tuberculosis, m leprae

Question 20

common spirochetes

Answer 20

• treponema, borrelia, leptospira
• syphilis, borrelia burgdorferi

Question 21

mycoplasma

Answer 21

• smallest free living organisms
• lack a cell wall
• penicillins and cephalosporins dont work (cell wall)
• chlamydia

Question 22

mycoplasma pneumoniae

Answer 22

• atypical pneumonia
• responsible for outbreaks in families, military bases, students
• PCR as diagnostic

Question 23

Chlamydia

Answer 23

• most common STI
• causse ocular infection - trachoma
• infants develop conjunctivitis or pneumonia
• PCR as diagnostic

Question 24

Capsular polysaccharide vaccines

Answer 24

prevent cause of pneumonia
- s pneumoniae, h influenzae, n meningitidis, s typhi

Question 25

toxoid vaccines

Answer 25

purify and inactivate toxin -> expose to make antibody - diptheria, tetanus

Question 26

purified protein vaccines

Answer 26

- purified protein antigen based vaccine - significant side effects - anthrax

Question 27

Live vaccines

Answer 27

- uses attenuated strain - TB, salmonella typhi in endemic areas

Question 28

Killed vaccines

Answer 28

- older, bad side effects - cholera, plague, Q fever in high risk situations

Question 29

Antitoxins

Answer 29

- neutralizing unbound toxins - tetanus, botulism, diptheria

Question 30

global burden

Answer 30

- bacteria second leading cause of death globally - s aureus, e coli, s pneumoniae, k pneumoniae, p aeruginosa - lower respiratory and bloodstream infections

Question 31

adults over 15

Answer 31

staph aureus

Question 32

children under 5

Answer 32

s pneumoniae

Question 33

antibiotic stewardship

Answer 33

use by one person impacts effectiveness for everyone