Micb 202: Bacterial Disease V - Therapy And Prevention

Front 1

What is the diff between antiseptic / disinfectant?

Back 1

antiseptic = body
disinfectant = inanimate objects

Front 2

Define MIC

Back 2

minimum inhibitory conc.
= min. conc of bacteriostatic antibiotics required to stop growth

Front 3

Can bacteria grow in presence of bactericidals when conc falls below MIC?

Back 3

no

Front 4

Can bacteria grow in presence of bacteriostatics when conc falls below MIC?

Back 4

yes

Front 5

What common featre do the beta-lactams have?

Back 5

the 4-membered beta-lactam ring

Front 6

Which bacteria usually more sensitive to antibiotics? Gram-(+) or (-)?

Back 6

Gram-(+)

Front 7

What are the optimal attributes of a chemotherapeutic agent?

Back 7

solubility
low MIC
broad spectrum
low freq of resistance
low rate of breakdown
low toxicity
non-allergenic

Front 8

How do beta-lactams inhibit growth?

Back 8

interfere with cell-wall synthesis during PDG synthesis

Front 9

What do polymyxins do?

Back 9

destabilize cell wall

Front 10

What do erythromycin, tetracyclines, and oxazolidinones do? Are they bacteriocidal or static?

Back 10

bind to ribosome and inhibit function. Bacteriostatic.

Front 11

What does nalidic acid, and ciprofloxacin do?

Back 11

intereferes with DNA gyrase activity (involved in unwinding during chromosome replication)

Front 12

What drugs interefere with protein synthesis via ribosome binding?

Back 12

erythromycin, tetracyclines, oxazolidinones

Front 13

What drugs interfere with DNA grase activity?

Back 13

nalidic acid, and ciprofloxacin

Front 14

What does rifampin do?

Back 14

interferes with DNA-directed RNA polymerase activity, inhibits transcription

Front 15

What do sulfonamides and trimethoprim do?

Back 15

interfere with folic acid metabolism

Front 16

Define antibiotic resistance

Back 16

acquired ability to resist effects of antibiotic, to which it is normally resistant

Front 17

Define efflux

Back 17

active transport to pump out unwanted substances

Front 18

Why are mycoplasmas (causative agent of pneumonia) resistant to penicillin?

Back 18

lack PDG

Front 19

Why are antibiotic-producing organisms a worry?

Back 19

they often have resistance genes as well, which can be passed on via horizontal xfer to other organisms

Front 20

What are the four types of horizontal gene transfer?

Back 20

conjugation
transduction
transformation
transposition

Front 21

Define transduction

Back 21

the transfer of DNA (viral or bacterial) from one cell to another via bacteriophage

Front 22

Define transformation

Back 22

the genetic alteration of a cell resulting from the introduction of foreign DNA

Front 23

Define conjugation

Back 23

transmission of DNA without fusion of gametes

Front 24

Define transposition

Back 24

a mutation in which a chromosomal segment is transferred to a new position on the same or another chromosome

Front 25

Mutation and selection is ___ gene transfer

Back 25

vertical

Front 26

What are the main contributors to the antibiotic resistance problem?

Back 26

agriculture industry (use 50% of antibiotics produced, 90% of which are growth-promoting agents)

over-prescription (20%/80%)

failure to complete prescription cycle

availability in developing countries of antibiotics without prescription

Front 27

What are four superbugs prevalent today?

Back 27

MRSA: methicillin-resistant Staphylococcus aureus
VRE: vancomycin-resistant Enterococcus
imipenem resistant Pseudomonas aeruginosa
penicillin resistant Streptococcus pneumoniae

Front 28

Define cocci

Back 28

microorganisms that are spherical

Front 29

What is the most common multi-drug resistant bacteria in hospitals?

Back 29

MRSA

Front 30

What is vancomycin? What does it do?

Back 30

a glycoprotein that interferes with synthesis of bacterial cell wall

Front 31

What is the cost of treating TB? Antibiotic resistant TB?

Back 31

$1200 vs $400,000

Front 32

Describe Linezolid

Back 32

an oxazolidinone
inhibits initiation of prot synthesis
bacteriostatic
limited spectrum
used for infections of blood, lungs, skin

Front 33

Describe Daptomycin

Back 33

a cyclic lipopeptide
causes depolarization of cell membrane potential
used for skin infections

Front 34

What are the four materials used in vaccines?

Back 34

killed bacteria
avirulent mutants of bacteria
components of bacteria
toxoids (detoxified toxins)

Front 35

Define active immunization

Back 35

injecting human with vaccine to induce antibody or cellular immune response

Front 36

Define passive immunization

Back 36

injecting pre-formed antibodies

Front 37

Give an example of passive immunization treatment

Back 37

hyperimmune gamma globulin used for botulism toxin

Front 38

Do vaccines lower the case fatility rate?

Back 38

no

Front 39

Do vaccines lower the mortality rate? The incidence rate?

Back 39

yes, yes

Front 40

M. tuberculosis is often an infection of the ___

Back 40

lungs

Front 41

M. tuberculosis survives and replicates in ___ after inducing an inflammatory reaction in lungs and being engulfed by phagocytic cells

Back 41

macrophages

Front 42

Does M. tuberculosis induce cell-mediated immunity? Is it effective?

Back 42

yes, not completely

Front 43

How is M. tuberculosis similar to HIV?

Back 43

They both tend to lie dormant than suddenly spring into action for poorly understood reasons

Front 44

M. tuberculosis is responsible for __% of all deaths in developing countries

Back 44

5%

Front 45

M. tuberculosis kills ___ people worldwide every year

Back 45

3 million

Front 46

More than ___ people are infected in the US with M. tuberculosis

Back 46

30,000

Front 47

M. tuberculosis is especially prevalent in ___

Back 47

poor people and AIDS patients in large american cities (ie New York)

Front 48

Describe the antibiotic treatment for M. tuberculosis

Back 48

therapy for 9-12 months with multiple antibiotics

Front 49

Describe the vaccine for M. tuberculosis

Back 49

live strain of Mycobacterium bovis, resulting in cell-mediated immune response