ANTIMICROBIALS 2 Flashcards
how many deaths attributed to antibiotic resistance now and the predictions by 2050
what is antibiotic resistance
what are the origins of antibiotic resistance
what are the two types of antibiotic resistance and some examples
how does antibiotic resistance spread within a bacterial population?
naturally competent=can naturally pick up extracellular DNA and bring it into their genome
what are some mechanisms of antibiotic resistance
remember the ones that are circled
resistance due to low permeability
bacteria can change the size of the pores to increase impermeability
intrinsic resistance: baseline level of resistance shared across every member of that particular species (because membranes are species specific)
antibiotic resistance due to drug efflux
the pumps come in a variety of different flavors
bacteria increase the expression of these pumps to get resistance (some bacteria can also acquire the gene)
antibiotic resistance due to target mutation or modification
quinolones: class of antibiotic that target topoisomerase (disrupt DNA replication)
its target is gyrB
through one single nucleotide mutation in the binding pocket of gyrB, there is resistance
quinolone cannot bind there anymore
antibiotic resistance due to drug modification or degradation
some bacteria have beta lactamase encoded in their genome (such as pseudomonas)
bacteria also have different flavors of beta lactamases, but now there are some that can cleave any lactam ring
now we are trying to make beta lactamase inhibitors (combination medications)
antibiotic resistance due to aminoglycoside modification
what are super bugs
carbapenem is the last resort, so if you are resistant to it youre cooked
how does human behaviour promote antibiotic resistance
human travel also affects it, we spread our drug resistant bacteria around the world
how do we find new antibiotics
no new drugs were approved between 2003 and 2011
no new classes approved in more than 20 years
no new targets found
