BIOL 222 Lecture Notes - Lecture 9: Lysogenic Cycle, Bacteriophage, Antitoxin
Document Summary
Biol 222 lecture 9 antibiotic resistance. Bacterial biofilm life cycle: attachment of bacterial cells to a surface, formation of micro-colonies (early maturation, formation of mature biofilms, detachment and dispersion of cells or clumps. Examples of biofilms: dental plaque consists of biofilms containing hundreds of bacterial species, biofilms can also form on agricultural products and cause outbreaks. Toxin-antitoxin (ta) systems consist of two linked genes in an operon; the antitoxin binds to and inhibits the toxin. Resistant cells grow in the presence of the antibiotic, whereas persister cells do not grow and go dormant. Resistance arises by mutation that: prevent drug uptake into cell, increase efflux pumps. Efflux pumps push drugs out of the cell: destroy or alter the target of the drug, acquire enzymes that degrade the antibiotic. These mutations can come about via transformation and conjugation. Phage therapy using bacteriophage to treat bacterial infection: advantages . Specific for a single bacterial species and will not disrupt the micro-biome.
