Week 5 - Principles of Antimicrobial Therapy

Question 1

What is a primary pathogen

Answer 1

Cause infection in a host despite immune status

Question 2

What is a opportunistic pathogen

Answer 2

causing infection in a host where there immune status is impacted

Question 3

Infectivity

Answer 3

Ability for a pathogen to establish in a host

Question 4

Virulence

Answer 4

how harmful the pathogen is once established

Question 5

Incubation period

Answer 5

the period between the pathogen invading and the host showing clinical symptoms

Question 6

Period of infectivity

Answer 6

Period the host is infectious to others

Question 7

Local vs systemic infection

Answer 7

local infection involves the skin or a single organ

systemic infection involves the entire body

Question 8

Signs of a local infection

Answer 8

redness
swelling
heat
oedema
loss of function

Question 9

Signs of a systemic infection

Answer 9

unwell
fever, malaise
vomiting
diahorrea
shortness of breath
abdominal cramps
rash

Question 10

Erythrocyte Sedimentation Rate (ESR)

Answer 10

Increases in presence of infection
compare to:
Males 1-15mm/hr
females 1-20mm/hr

can increase with pregnancy, anemia, old age –> ESR should be intereptreded in regards to the factors

Question 11

C-reactive protein (CRP)

Answer 11

increases in response to tissue and organ infection

measure to monitor treatment of infection with antibiotics

Rises and falls quickly in response to antibiotics - if not falling quickly = antibiotics not working?

Question 12

Difference between gram positive and gram negative

Answer 12

gram positive = easier to treat with antibiotics as there is only one cell wall

gram negative = harder to treat with antibiotics as there is 2 cell walls

Question 13

How to do a wound culture method

Answer 13

1. take a swab from the wound/area of infection
2. culture of 24-48 hours
3. determine organism

Question 14

What is AMT

Answer 14

any antibiotic that targets a microbe

Question 15

Principles of AMT

Answer 15

• accurate diagnosis
• only when needed
• broad to narrow spectrum
• for shortest duration possible

Question 16

Goals of AMT

Answer 16

to inhibit or suppress growth of invading pathogen so the normal hosts mechanisms can cure the patient

Question 17

Classification of the antimicrobial drug

Answer 17

Bactericidal - inhibits the growth of the pathogen

bacteria-static - supresesses the growth of the pathogen

Question 18

Directed therapy vs empirical therapy

Answer 18

Directed therapy = directing the antibiotic at the organism

empirical therapy - is stating with broad spectrum then doing a culture then going to directed therapy

Question 19

Targets for antimicrobials

Answer 19

1. Cell wall synthesis
2. disruption of membrane permeability
3. protein synthesis inhibitors
4. essential metabolite synthesis inhibitors

Question 20

Concentration dependent characteristics vs time dependent characteristics

Answer 20

Concentration - effect of increasing concentration = depends on concentration administrated rather than time in contact.
Higher the peak blood level = better

Time - requires time to produce therapeutic effect

Question 20

Antimicrobial resistance

Answer 20

general way antibiotic when administriated:
susceptible: pathogen inhibits growth of pathogen at concentration that is below toxic for humans

resistance: when the concentration is above the toxic level for humans

Question 20

Superinfection

Answer 20

gut flora is disrupted by antibiotics which results in secondary infection
- canda or staph

Question 20

Prophylactic vs empirical vs direct use of antibiotics

Answer 20

prophylactic = preventing an infection where there is a clinical risk of infection

Empirical = targeting an already established infection (broad spectrum)

Direct = targeting a direct organism identified by a culture (narrow spectrum)

Question 21

Types of resistances

Answer 21

Innate: the organisms DNA causes the resistance to the antibiotic

acquired: the organisms DNA changes or is altered = resistance to antibiotic