class #5- antibiotics and resistance Flashcards
what is an antibiotic
a compound known to exhibit growth-inhibiting properties, they are chemical and biological compounds
what is antibiotic resistance
The ability of an organism to grow and/or exist in the presence of antibiotics (bacteria change over time and no longer respond to meds)
what are some reasons for the rise of antimicrobial resistance
-over-prescription
-don’t take enough antibiotics
-antibiotics in food supply
-no new antibiotics
why have there been no new drugs within the past 50 years
drug development cannot keep up with new infections and antibiotic resistance
how do bacteria become genetically resistant to antibiotics?
-spread of resistance genes through genetic transfer events (conjugation, transformation, mutation)
what are some global threats discussed in this lecture
-MRSA (Methicillin resistant Staphylococcus aureus)
-VRE (Vancomycin Resistant Enterococci)
-Multidrug and extremenly resistant M. tuberculosis (XDR)
what does MRA stand for
multidrug-resistant
what does XDR stand for
extensively drug resistant
what is MRSA
Methicillin resistant Staphylococcus aureus- bacteria responsisble for difficult-to-treat infections in humans
what is VRE
Vancomycin Resistant Enterococci - responsible for hard to clear infections, can lead to complications and death
what are multidrug and extremely resistant M. tuberculosis strains
a pressing issue in developing countries, the latent/dormant phase results in carrier state. also a co-infection with HIV
what do antibiotics secrete
synthesize and secrete molecules that inhibit growth of other bacteria
what makes relevant and appropriate target for inhibition
bacterial features that are unique - protein translation, cell wall, outer membrane, DNA replication
what are the classes of antibacterial compounds
-methicillins
-protein synthesis inhibitors
-DNA/RNA inhibiting/altering
what is a beta-lactam antibiotic
modified antibiotics, they block cell wall biosynthesis by inhibiting the transpeptide linkage to peptidoglycan & results in weakened cell wall … easier for immune system to kill bacteria
what do bacteria fight back with
b-lactamases
what are b-lactamases
enzymes that are secreted by bacteria to cleave the b-lactam ring compounds
what did chemists respond to b-lactamases with
clavulanic acid
what is clavulanic acid
A b-lactamase inhibitor compound that is added to antibiotics
what are resistance mechanisms that bacteria use
dont let drug in, pump the drug out, inactive drug (b-lactamases chop up b-lactams), or mutate the target
what are biofilms
extracellular goo that protects bacteria from antibiotics
what are biofilms made up of
polysaccharides, protein, lipids, DNA, or a mix
what is a biofilm capsule
a slimy hydrophobic sticky covering to cells
what is an efflux pump
an active transporter in cells that moves out unwanted material
