Antibiotics

Categories of antibiotics Use of bacteriostatic vs bactericidal antibiotic Therapeutic index better for bacteriostatic antibiotic Resistance to bactericidal antibiotic Protein toxin mediates disease – use bacteriostatic protein synthesis inhibitor. Antibiotic susceptibility testing (in vitro) Minimum inhibitory concentration (MIC) Lowest concentration that results in inhibition of visible growth Minimum bactericidal concentration (MBC) Lowest concentration that kills 99.9% of the original inoculum. Combination therapy Prevent emergence of resistant strains Temporary treatment until diagnosis is made Antibiotic synergism Penicillins and aminoglycosides CAUTION: Antibiotic antagonism Penicillins and bacteriostatic antibiotics Antibiotics vs chemotherapeutic agents vs antimicrobials. Spectinomycin (bacteriostatic): Mode of action - Spectinomycin reversibly interferes with m-RNA interaction with the 30S ribosome. It is structurally similar to the aminoglycosides but does not cause misreading of mRNA. Spectrum of activity - Used in the treatment of penicillin-resistant Neisseria gonorrhoeae Resistance - Rare in Neisseria gonorrhoeae Continua »