Antibiotic Resistance Flashcards
What is a biofilm?
A collection give of one or more types of microorganism
What are organisms in biofilms resistant to?
Antimicrobial agents and host defences
What is a persister cell?
Dormant variants of regular cells that are enriched in biofilms
Are persister cells tolerant or resistant?
Tolerant
What is the rate of growth in persister cells?
Very slow
What is resistance?
When a drug is no longer active against an entire population of cells
What kind of advantage does resistance provide?
Selective
What are the two types of resistance?
Cross
Multiple
What is cross resistance?
A single mechanism that occurs with closely related antibiotics
What is multiple resistance?
Multiple mechanisms that occurs with unrelated antibiotics
What are four antimicrobial drug resistance mechanisms?
Altered permeability
Inactivation
Altered target site
Replacement of a sensitive pathway
What are the two types of altered permeability?
Altered influx
Active efflux
When influx is altered, what is reduced?
OmpF (quinolones)
In active efflux, what is active?
An energy dependent pump
What are inactivated in an antimicrobial drug resistance mechanism?
Beta-lactamase
Chloramphenicol acetyl transferase
What are the two types of beta-lactamases?
Penicillinase
Cephalosporinase
What do penicillinase and cephalosporinase include?
Clavulanic acid sensitive and insensitive
What is penicillinase resistant to?
Early penicillins such as amoxicillin
Is penicillinase largely gram positive or negative?
Positive
What is Extended Spectrum beta-lactamase (ESBL) resistant to?
All penicillins
third generation cephalosporins and monobactams?
What are three types of beta-lactamases?
Penicillinase
Extended spectrum beta-lactamses
Carabpenemase
What is carbapenemase (CPE) based in?
Serine
Metalloenzyme
What is carbapenemase resistant to?
All penicillins
All cephalosporins
Casrbapenems
