Ch. 9 - Inhibiting Growth of Pathogens in Vivo Using Antimicrobial Agents Flashcards
Chemotherapy
The use of any chemicals (drug) to treat any disease/condition
Antimicrobial agents
The use of any chemical (drug) to treat an infectious disease either by inhibiting or killing the pathogen
Antibiotics
Substance produced by a microorganism that kills or inhibits the growth of other microorganisms
Semisynthetic antibiotic
Antibiotics chemically modified to kill a wider variety of pathogens or reduce side effects
Alexander Fleming
Discovered penicillin
-noticed that the farther away the bacteria were from the mould (which was creating penicillin), the better they grew
Staphylococcus aureus
Gram ( + )
Found in our microbiota, often found in our nose
=> staph infections
MRSA is most common
MRSA
Resistant to beta-lactams antibiotics.
- methicillin, oxacillin, penicillin, and amoxicillin.
Most MRSA infections are skin infections that often appear as a bump, a boil, or area that is red, tender and swollen, and is sometimes confused with a spider bite.
Bactericidal drugs
Agents that kill microbes
Bacteriostatic drugs
Agents that inhibit/slow the growth of microbes, but never actually kills it
How do antimicrobial agents work? (5)
- Inhibition of cell wall synthesis (Bactericidal)
- Damage to cell membrane (Bactericidal)
- Inhibition of nucleic acid synthesis (Bactericidal)
- Inhibition of protein synthesis (Bactericidal or Bacteriostatic)
- Inhibition of enzyme activity (Bacteriostatic)
Sulfonamide drugs
Competitive inhibitors, Bacteriostatic
Inhibit production of follic acid in bacteria that need p-aminobenzoic (PABA) to synthesis it
Without follic acid, bacteria cant produce certain essential proteins, so they die
Penicillin
Bactericidal,
Acts on mostly gram ( + )
Interferes with the synthesis and cross linking of peptidoglycan
Inhibits cell wall synthesis => destroy bacteria
narrow spectrum antibiotic
Use when we know specifically if we have gram ( - ) or ( + ) bacteria
ex: colistin
Broad spectrum antibiotics
Use when we arent sure if the bacteria is gram pos or neg
ex: ampicillin
Multi drug therapy
2+ drugs used simultaneously
ex: Tx tuberculosis