Mechanisms of Antibiotic Resistance Flashcards
How does natural resistance occur?
Target is not present (eg no cell wall), target not accessible, developmental structure/state (persistor cells and biofilms more resistant), and metabolism
What are biofilms?
Communities of micro-organisms in a 3D structure with interfaces - resistant to antimicrobial agents and host defences
What is a persistor cell?
Tolerant, metabolically inert subpopulation of cells - enriched in biofilms
What are the 3 types of horizontal gene transfer?
Transformation (natural competence), transduction (bacteriophage) and conjugation (sex pili)
Cross resistance vs multiple resistance
Cross - single mechanisms related to antibiotics
Multiple - multiple mechanisms unrelated to antibiotics
What are the mechanisms of antimicrobial drug resistance?
Altered permeability (influx and efflux) and inactivation (beta-lactamase - ESBL, and chloramphenicol acetyl transferase)
What do beta-lactamases do?
Break open the beta-lactam ring