Week 5 - Principles of Antimicrobial Therapy Flashcards
What is a primary pathogen
Cause infection in a host despite immune status
What is a opportunistic pathogen
causing infection in a host where there immune status is impacted
Infectivity
Ability for a pathogen to establish in a host
Virulence
how harmful the pathogen is once established
Incubation period
the period between the pathogen invading and the host showing clinical symptoms
Period of infectivity
Period the host is infectious to others
Local vs systemic infection
local infection involves the skin or a single organ
systemic infection involves the entire body
Signs of a local infection
redness
swelling
heat
oedema
loss of function
Signs of a systemic infection
unwell
fever, malaise
vomiting
diahorrea
shortness of breath
abdominal cramps
rash
Erythrocyte Sedimentation Rate (ESR)
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
C-reactive protein (CRP)
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?
Difference between gram positive and gram negative
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
How to do a wound culture method
- take a swab from the wound/area of infection
- culture of 24-48 hours
- determine organism
What is AMT
any antibiotic that targets a microbe
Principles of AMT
- accurate diagnosis
- only when needed
- broad to narrow spectrum
- for shortest duration possible
Goals of AMT
to inhibit or suppress growth of invading pathogen so the normal hosts mechanisms can cure the patient
Classification of the antimicrobial drug
Bactericidal - inhibits the growth of the pathogen
bacteria-static - supresesses the growth of the pathogen
Directed therapy vs empirical therapy
Directed therapy = directing the antibiotic at the organism
empirical therapy - is stating with broad spectrum then doing a culture then going to directed therapy
Targets for antimicrobials
- Cell wall synthesis
- disruption of membrane permeability
- protein synthesis inhibitors
- essential metabolite synthesis inhibitors
Concentration dependent characteristics vs time dependent characteristics
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
Antimicrobial resistance
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
Superinfection
gut flora is disrupted by antibiotics which results in secondary infection
- canda or staph
Prophylactic vs empirical vs direct use of antibiotics
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)
Types of resistances
Innate: the organisms DNA causes the resistance to the antibiotic
acquired: the organisms DNA changes or is altered = resistance to antibiotic
