Antimicrobial treatment

• Antibacterial- substance produced by a living organism (naturally produced) that inhibits the growth of bacteria
• Antifungal
• Antiviral
• Antiparasites : anti-helminthics , antiprotists

• Action of the drug and chemical structures
• Cell wall- inhibits cell wall synthesis (penicillin)
• DNA- how DNA is replicated (rifamycin)
• Protein syntheis- how proteins are made (tetracycline)
• RNA- how RNA is made or wroked on
• Metabolic distruption- interrupt normal metabolic processes (sulfanilamid)
• Membrane function- (polymeric)

• Selective toxicity- toxic to bacteria and not to us
• Bacteriostatic- how they affect the bacterial cell- once you take the drug/ environment away, the bacteria will start replicating again
• Bacteriocidal- how they affect the bacterial cell- don’t have to apply it for a very long time
• Therapeutic index- a number that informs us how good/ effective a drug is, effects the minimum toxic dose to the patient /(over) the minimum effective dose to kill the microbe
• Half-life- eliminatablity- drug sticks around in the body long enough to be effective but not to stick around forever, must be able to eliminate eventually
• Drug interactions- administer a drug to fight infection, is it going to be effective where we want it to be

• Narrow-spectrum- describes the target of the drug- effective against a limited number of organisms, in virtue of their genitic makeup/ cell wall type/ some characteristic
• Broad-spectrum- describes the target of the drug- effective against a wide range of organisms

• Famalies of drugs that have been altered to change the compotition
• makes the drug more effective or turns it into a broad spectrum
• They interfere with the peptidoglycan cross links
• ex- Penicillins and Cephalosporins
• Cephalosporins- 1st generation- only gram +, 2nd generation- gram + and gram -, 3rd generation- pseudomonades and some gram - (shifted spectrum but did not grow it)
• Penicillin G- effective against gram + cells, can't get into Gram - cells, not resistant to stomach acid, needs to be injected
• Penicillin V- acid resistant
• Ampicillin broad spectrum and acid resistant
• Methicillin- penicillinase resistant- doesn’t react with the beta lactam ring

Broad spectrum drugs that interfere with ribosome function by sitting in the ribosome during translation

• inteferes with folic acid production
• bacteria cells make their own folic acid which is PABA
• sulfa drugs interfere with this becasue it looks like PABA
• Ex- sulfanilamide

• interfere with DNA (gryase inhibitors)
• gyrase- super coling of DNA
• Without gyrase, the circular DNA will burst when trying to open it to replicate
• Ex- Ciprofloxacin

• Antifungals- Amphotericin B- interferes with cell membrane of fungal cells
• Antivirals- Acyclovir- interfere with viral nucleic acid function, used for herpes, Amantadine- blocking adherence of the virus to the target cell, used for influenza, Protease inhibitors- used for HIV, breaks the viral polypeptide
• Antiparasitics- Chloroquine- reduces severity of outbreaks

• Acquisition of R plasmids- done by conjugation, transformation and transduction
• Mutation of drug target- Ribosome changes, RNA polymerase changes, Multi drug pumps

• Improper use of antimicrobials- Using antibiotics when you shouldn’t
• Overuse of antimicrobials- Using to much of antibiotics
• Not taking all of the given medication

• Proper drug choice- infectious agent isn't responding to antibiotic, change antibiotic
• Proper dose- maintaining the dose in the body
• Proper drug therapy- completion of treatment
• Using prescribed drugs- not sharing drugs
• Expiration dates- less effective dose after expiration date

• Caused by improper use (overuse) of drugs
• Development of drug resistant organisms that may develop into diseases
• Loss of competition (of normal microbiota in the body)
• Ex- Candida albicans- Fungal member of normal microbiota. Long term treatment for something with antibiotics will wipe out bacterial microbiota causing a fungal infection