Antibiotic Resistance Flashcards
4 mechanisms by which bacteria resist drugs
drug inactivating enzymes
alteration of antibiotic’s target
decreased antibiotic uptake
increased antibiotic elimination
examples of drug inactivating enzymes
beta lactamase
penicillinase
chloramphenicol acetyltransferase (CAT)
example of altering drug’s target
inhibition of protein synthesis can be prevented by altering structure of ribosome — moving binding site for antibiotic to a non-functional part of the ribosome
explain decreased antibiotic uptake
Proteins on surface of cell change, no longer allow antibiotic entry
drug can’t reach target
how is a porin involved in resistance?
a protein on the surface of a bacterium; can change so drug is no longer allowed inside
explain increased antibiotic elimination
cell pumps antibiotic out as soon as it enters
what is the function of efflux pumps?
increased Ab elimination - pump it out as soon as it enters bacterium
2 methods by which bacteria acquire resistance
spontaneous mutation (vertical gene transfer)
conjugation (horizontal GT)
what are r-plasmids?
plasmids containing multiple resistance genes that are transferred from cell to cell during conjugation
give examples of bacteria families/species that have resistance (6)
Family Enterobacteriacea
- Enterococcus sp.*
- Staphylococcus aureus*
- Streptococcus pneumoniae*
- Mycobacterium tuberculosis*
- Clostridioides difficile*
2 causes of prevalence of resistance
misuse of antibiotics
overuse of antibiotics
2 examples of Ab overuse
doctor prescribes them to a patient who does not have a bacterial infection
they are fed to livestock
how does stopping an Ab prescription contribute to resistance?
if drug is stopped prematurely, highly resistanct bacteria live after less resistant cells die
selects for resistant cells
cells spread to others, or cause a more resistant infection in original patient
may need a different antibiotic to clear resistant infection
what are superbugs?
what is the more scientific term for them?
Strains of bacteria, viruses, parasites, fungi, etc that are resistant to most medications commonly used to eliminate them
“multi-resistant bacteria”
what are 5 examples of resistant bacteria “superbugs”?
Carbapenum-resistant Enterobacteriaceae (CRE)
Multidrug-resistant Acinetobacter
Drug-resistant Neisseria gonorrhoeae
Methicillin-resistant Staphylococcus aureus (MRSA)
Clostrioides difficile
