Week 10 Antibiotics, Antifungals, Antiretrovirals Flashcards
An infection involves the invasion and ………..?
Multiplication of pathogenic micro-organisms in body tissues causing disease by local cellular injury, secretion of a toxin or by antigen-antibody reaction in the host. Primarily classified as a local or systemic infection
Colonisation is the localised presence of?
Micro-organisms in body tissues or organs; these micro-organisms can be pathogenic or part of normal flora
Bacteraemia is the?
Presence of viable bacteria in the circulatory system
Septicaemia refers to?
A systemic infection caused by micro-organism multiplication in the circulation.
The treatment of an infectious disease depends on the?
Micro-organism responsible, and different groups of anti microbial drugs used to treat different microorganisms
Antibiotics are natural?
Substances derived from certain organisms (bacteria, fungi and other) that can suppress growth of or destroy microorganisms
The goal of antimicrobial therapy is to?
To destroy or suppress the growth of infectious micro-organisms so that normal host defences can control the infection
The success of antimicrobial therapy depends on?
i) achieving a sufficient concentration of the drug at the site of infection
ii) the bacterial load
iii) the phase of the bacterial growth
iv) the minimum inhibitory concentration of the antimicrobial therapy
v) pharmokinetics
Bacteriostatic agents inhibit?
Bacterial growth, allowing the host natural defence mechanisms time to remove the pathogen
Bactericidal agents cause?
Bacteria cell death by lysis of the bacteria wall and eradicating the infection, which is important where host defences are impaired
Bactericidal agents cause?
Bacteria cell death by lysis of the bacteria wall and eradicating the infection, which is important where host defences are impaired
Antimicrobial agents exert bacteriostatic or bactericidal effects in one of four ways that include?
i) inhibiting cell wall synthesis
ii) disrupting or altering membrane permeability
iii) inhibiting protein synthesis
iv) inhibiting synthesis of essential metabolites
Intrinsic resistance refers to the?
Organisms innate chromosomal (genetic) make-up that predictably specifies the resistance
Acquired resistance occurs in an organism as a result of?
An organism changing or mutation in its genetic make-up or because of acquisition of new genetic information or DNA, particularly a resistance or mechanism that the organism did not previously have.
Resistance can occur in one of several ways including?
i) the antimicrobial is unable to reach the target site of its action; pseudomonas
ii) the microorganism produces an enzyme that modifies or destroys the structure of the drug rendering it inactive
iii) the target site of the drug is altered therefore drug can no longer bind to the target
iv) drug can be pumped out by an efflux pump, can be found in both gram positive and gram negative bacteria; an example tetracycline resistant staphylococcus aureus
v) bypass pathways may develop that compensate for the loss of function due to the antimicrobial drug
Strategies to combat antimicrobial drug resistance includes?
Proper and judicious use of antimicrobial drugs
Limiting use use of drugs, unless advised by a specialist
Selective control/ restriction and removal of antimicrobial agents or classes
Use of antimicrobials in rotation or cyclic patterns
Use of combinations of antimicrobials to prevent resistance
Improved knowledge base of the relationship between the pharmacokinetics of the drug and its anti-infective ability to prevent selection pressure
Infection that occurs during antimicrobial therapy?
Is a superinfection, an infection that occurs during antimicrobial therapy delivered for therapeutic or prophylactic reasons
Inhibition of bacterial growth?
Bacteriostatic
