Penicillins Flashcards
What year and by who were penicillins discovered
1928, Alexander Flemming
What are 4 ways abx resistance is mediated(caused)?
1.Production and excretion of an enzyme that hydrolyzes the antimicrobial
2.Genetic alteration of the microbial site where antimicrobial binds
3.Alteration in cellular membrane proteins that prevent antimicrobials from penetrating into microbial cells
4.Transmembrane efflux pumps that transport antimicrobials from interior to exterior of the microbial cells
What is VRE and when did it emerge
vancomycin-resistant enterococci - emerged in 1980
What is CRE and when did it emerge
carbapenem-resistant enterobacterales - emerged in 2000s
Leading Risk Factors for having a drug-resistant pathogen:
Recent use of antimicrobials
Multiple medical comorbidities
Recent hospitalization or other skilled healthcare contact
Antibiotic Stewardship Strategies
Treatment for specific infectious disease
Formulary restrictions
Dose optimization
Prospective audits
Continuing education for prescribers
Define Antimicrobial:
The entire arsenal of drugs that have the activity to inhibit or kill microbes.
Define Antibiotic or Antibacterial
Specifically refers to antimicrobials that target bacteria
Define Bactericidal
Refers to 99.9% eradication of a bacterial colony in vitro in 24 hrs by an antimicrobial.
-No clinical utility in the designation. Not to be used for clinical decision-making.
Define Bacteriostatic:
Refers to an abx that kills bacteria but the result is less than 99.9% eradication in a 24hr period.
-No clinical utility in the designation. Not to be used for clinical decision-making.
What are Beta Lactams and what are they most effective at treating
Super class of abx and contains the most abx’s of any class. Most effective against rapidly replicating organisms.
What are the 4 major groups of abx within beta-lactams
Penicillins
Cephalosporins
Carbapenems
Monobactams
What is the active part of the beta-lactam abx
a 4-member ring known as the beta-lactam ring
What is the MOA of all beta-lactam abxs
B-lactams inhibit the biosynthesis of the bacterial cell wall by binding to bacterial enzymes, specifically the peptidoglycan structure, and leading to cell lysis.
What are three bacterial enzymes that help create cell wall/peptidoglycan synthesis
Transpeptidase
Carboxypeptidase
Endopeptidase
What is peptidoglycan?
a rigid envelope surrounding the cytoplasmic membrane of most bacterial species
What is minimum inhibitory concentration (MIC)?
the lowest concentration of an antimicrobial agent that will inhibit the visible growth of a microorganism after overnight incubation.
What are the 4 penicillin subclasses?
- Natural penicillins
- Aminopenicillins
- Antistaphylococcal penicillins
- Antipseudomonal or Extended-Spectrum penicillins
What are the four natural penicillins and how are they administered
Penicillin V - administered PO
Procaine penicillin - administered IM
Benzathine penicillin - administered IM
Penicillin G - administered IV
Penicillin G is reliable for treating which bacteria
reliable for treating Listeria monocytogenes