Antimicrobials Flashcards
Paper discs impregnated with fixed concentrations of antibiotics are placed on agar surface and incubated
Disc diffusion: Kirby bauer technique
In Tube Dilution Method:serially diluted antibiotic solutions are mixed with standard inoculum of test organism
How is the MIC (minimal inhibitory concentration) determined?
The lowest concentration that inhibits the growth of the organism
How is the MBC (minimum bactericidal concentraion) determined
It is a conntinuation of the test tube dilution method, and is determined by inoculating the tubes that had no growth….the lowest concentration that when inoculated on agar still has no growth is the MBC
How is the serum bactericidal concentration (SBC) determined in Serum Assay
Serial dilutions of patients sera with antibiotic is made, the lowest sera concentration of antibiotic able to prevent bacterial growth is the SBC
NB?? less than 4dilutions is inadequate antibiotic conc.
List one antipseudomonal penicillin
Piperacillin
What is the brand name for Piperacillin+Tazobactam
Zosyn
List 4 antibiotic groups that have the cell wall as the target of action
penicillin
cephalosporin
carbapenems
glycopeptides
Which group of antibiotics targets the cell membrane
Polymixin B (last resort antibiotic becaue of its toxic effects, used with multidrug resistant organisms)
Which class of antibiotic affects protein synthesis?
Tetracyclines, aminoglycosides and macrolides
Which class of antibiotics affects nucleic acid synthesis
ciprofloxacin (DNA)
rifampicin (RNA)
Which class of antibiotic is an anttimetabolite ?
Cotrimoxazole
What should be used to treat penicillin resistant staph ?
cloxacillin/oxacillin- penicillinase resistant antibiotics
what antibiotic is used to treat ESBLs (extended spectrum betalactamase bacteria) ESBL E coli eg.
Carbapenem: Meropenem, Ertapenem, Imipenem
Group strep A is universally susceptible to which antibiotics ?
Penicillin
Amoxicillin
Augmentin
rocephin
ceftriaxone (3rd gen ceph)
