Ch9 Antimicrobial Chemotheraphy

Agent kills or inhibits pathogen while not damaging host cells and tissue

Ratio of toxic dose to therapeutic dose

Antibiotic or anti microbial agent whose structure is slightly modified ( chem groups altered)

Range of bac a compound is effective against

Lowest any that will prevent growth

Effective against small range of pathogens

Effective against a wide range of pathogens

Filter paper disks w/ antibiotic placed over bacterial lawn. Clear area around = effective compound

Strip with gradient of antibiotic []. Shows MIC at the bottom of tear shaped zone

Antimicrobial drug that inhibits folic acid synthesis by competing with PABA. Effective against bacteria and some protozoa

antibiotics that interfere with cell wall synthesis. Cidal

Targeting tranglycossylase (can’t attach Nag & Nam) and transpeptidase ( no cross link)

Enzyme lactamase targets beta lactation ring

Drug of last resort for MRSA. Binds d Alanyl-d Alanyl site to prevent transpeptidase from forming cross link

Antibiotics that interfere with protein synthesis

Interfere with protein synthesis. Block/ distort A site so tRNA can’t bind Static

Have four quinolone ring that bind DNA gyrase prevent its function, interferes with DNA synthesis (no rep). Cidal

Interfere with folic acid synthesis by taking place of PABA blocking first step of folic acid synthesis

Also block folic acid synthesis but at a later step

Use of two drugs at once that allows lower doses of each to be used, block two steps of metabolic pathway.

Antiviral med. similar in structure to Guanosine, acts as chain terminator when it binds due to losing part of sugar ring