Antibiotics Flashcards
what is Antibiotics
any compound (natural or synthetic) that inhibits the growth of, or actively kills micro-organisms
what are the principles of Antimicrobial Therapy
Identification of pathogen
–>acid fast stain
Susceptibility testing and resistance
–>put antibodies in bacteria cultures and see which one is the best at eliminating the bacteria
what are the types of antibiotics
- beta-lactasms
- Macrolides
- Quinolones
- Aminoglycosides
- Tetracyclines
- Sulfonamides
- Glycopeptides
What are 2 types of antibiotics action
bacteriocidal: kill bacteria
Bacteriostatic:
inhibit growth of susceptible bacteria, lead to bacteria death
What are the Four common mechanisms of action of antibiotics
- Interference with cell wall synthesis
- Interference with protein synthesis
- Interference with DNA replication
- Acting as a metabolite to disrupt critical metabolic reactions inside the bacterial cell
characteristic of Beta-Lactam Antibiotics
- Broad & most commonly used class of antibiotics
- has a B-lactam ring as the primary structure
- bactericidal
- Chemical manipulation of the side chain led to new agents with advanced spectrum of antimicrobial activity
what are some beta-Lactam Antibiotics
- Penicillins
- Cephalosporins
- macrolides
- tetracyclines
- Carbapenems
- ->merepenem
- ->doripenem
- Monobactams
- ->Aztreonam
What is the Mechanism of Action of penicillins
- Penicillins enter the bacteria via the cell wall
- Inside the cell they bind to penicillin-binding protein
- Once bound, normal cell wall synthesis is disrupted
- Result: bacteria cells die from cell lysis
*Penicillins do not kill other cells in the body
What is the indication of Penicillins:?
*narrow spectrum
Prevention and treatment of infections caused by Gram-positive bacteria
What is narrow-spectrum antibiotic
effective against only a specific group of bacteria.
What is narrow-spectrum antibiotic
effective against only a specific group of bacteria.
Examples of pencillins
amoxicillin
ampicillin
cloxicillin
methicillin
how does Antibiotic Resistance work in bacteria
- bacteria secrete beta lactamase
- which therefore breaks down the B-lactam ring inactivating the antibiotic
What is Staphylococcus aureus
a MRSA because it has beta lactmase
features of Cephalosporins
- Structurally related to penicillin
- bactericidal via inhibiting cell wall synthesis
What is the relationship between generation of Cephalosporins and its effectiveness?
increase in generation , less effectie against gram +ve