What is a bactericidal?
Antimicrobial that kills bacteria.
What is a bacteriostatic?
Antimicrobial that inhibits growth of bacteria.
What is a sensitive organism?
Inhibited or killed by antimicrobial available at site of infection.
What is a resistant organism?
Not inhibited or killed by antimicrobial available at the site of infection.
What does MIC stand for?
Minimal Inhibitory Concentration
What is MIC?
Minimum concentration of antimicrobial needed to inhibit visible growth.
What does MBC stand for?
Minimal bactericidal concentration.
What is MBC?
Minimum concentration of antimicrobial needed to kill a given organism.
What are the 3 routes of administration?
Topical
Systemic
Parenteral
How are topical routes administered?
Applied to a surface
How are systemic routes administered?
Taken internally, either orally or parenterally.
How are parenteral routes administered?
Either intravenously or intramuscularly.
What will inhibit cell wall synthesis?
Penicillin
Why are humans not affected by antibiotics that inhibit cell wall synthesis?
They don’t have a cell wall.
What can glycopeptides do to gram negative organisms?
Nothing
How are glycopeptides given?
Parenterly
What type of bacteria do aminoglycosides affect?
Serious gram-negative infections.
What reaction do aminoglycosides inhibit?
Protein synthesis
What are a useful alternative to penicillins in treatment of gram-positive infections?
Macrolides
What are staph. aureus, strep pyogenes and strep pneumoniae highly resistant to?
Tetracyclines
How can oxazolidinones be given?
Orally
What does daptomycin, cyclic lipopeptide, work actively against?
Gram positive (MRSA in particular).
How do antibiotics inhibit nucleic acid synthesis?
Interrupting the supply of precursors.
What is trimethoprim commonly used for?
UTIs
How are fluoroquinolones taken?
Orally and parenterally
How do fluoroquinolones attack DNA?
Directly
What type of bacteria do fluoroquinolones work against?
Gram negative
What type of bacteria is ciprofloxacin effective against?
Gram negative
Who can’t get ciprofloxacin?
Children
In some cases all strains can be naturally resistant to antibiotics. True or false?
True
What is strep always resistant to?
Vancomycin
What is required to test sensitivity?
Laboratory sensitivity testing.
What is a spontaneous mutation?
Change in structure of function which no longer allows antibiotic to act.
What is spread of resistance?
Gene for resistance spread from organism to organism or species to species. Can be carried on plasmids or transposons.
What does widespread use of antibiotics cause?
Selective advantage
What are beta-lactamases?
Bacterial enzymes which cleave the beta-lactam ring of the antibiotic and render it inactive.
What hospital strains produce beta-lactamase?
Staph aureus
What type of bacteria are beta-lactamase common in?
Gram-negative
What are the two ways to combat beta-lactamase?
Introduce a second component to protect the antibiotic from enzyme degradation.
Modify antibiotic side chain to produce new antibiotic resistance.
What produces extended spectrum beta-lactamase?
Gram negative organisms.
What are some gram negative organisms becoming resistant to?
Carbapenems
How do microorganisms develop resistance to beta-lactams?
Changing their structure of their penicillin binding proteins.
What is the biggest case of PBP changing?
MRSA
What does MRSA produce?
Beta-lactamase
What is MRSA resistant to?
Penicillins
What type of bacteria have become resistant to vancomycin?
Enterococci
What happens in vancomycin resistant enterococci?
Peptidoglycan precursor which is normally bound to has an altered structure.
What type of bacteria is rarely vancomycin resistant?
Gram positive