Antiseptics/Disinfectants Flashcards
What’s the difference between antiseptics and disinfectants
Antiseptics applied to skin, disinfectants applied to surfaces
MOA of glutaraldehyde
Cross links proteins in cell wall/outer membrane and elsewhere in cell
MOA of Quaternary Amines
generalized membrane damage involving phospholipid bilayers of inner/cytoplasmic membrane
MOA of chlorhexidine
low concentrations affect membrane integrity, high concentrations cause congealing of cytoplasm
-Widely used in hospitals and homes bc efficacy on skin and low irritability
MOA of Halogens
oxidation of thiol groups to disulfides, sulfoxides or disulfoxides
MOA of Peroxygens
hydrogen peroxide: activity due to formation of free hydroxyl radicals (•HO), which oxidizes thiol groups in enzymes and proteins
peracetic acid: disruption of thiol groups in proteins
Chlorhexidine effect on bacterial spores
Prevents development of spores/inhibits spore outgrowth
Chlorhexidine effect on mycobacteria
Mycobacteriostatic but not mycobacteriocidal (MOA unknown)
Chlorhexidine effect on nonsporulating bacteria
Membrane-active agent, causes protoplast and spheroplast lysis, high conc. causes precipitation of proteins and nucleic acids
Chlorhexidine effect on yeasts
membrane-active agent, causing protoplast lysis and intracellular leakage, high concentrations cause intracellular coagulation
Chlorhexidine effect on viruses
low activity against many viruses; lipid enveloped viruses more sensitive than nonenveloped; effect possibly on viral envelope (e.g., lipid moieties)
Chlorhexidine effect on protozoa
has activity against trophozoites, less toward cysts
What 3 infectious agents are most resistant to antiseptics/disinfectants
Prions most resistant
Coccida (cryptosporidium)
Spores (Bacillus, C. difficile)
How do biofilms contribute to antibiotic resistance?
- Limited penetration of Abx
- Abx neutralization through enzymes
