1. Antimicrobial Susceptibility Test and Assay Hoza, A.S BLS 206

9. Table 1: Basic sets of drugs for routine susceptibility tests (http :// w3 . whosea . org / ) Set 1 Set 2 Staphylococcus Benzyl penicillin Oxacillin Erythromycin Tetracycline Chloramphenicol Gentamicin Amikacin Co-trimoxazole Clindamycin Intestinal Ampicillin Chloramphenicol Co-trimoxazole Nalidixic acid Tetracycline Norfloxacin Enterobacteriaceae Urinary Sulfonamide Trimethoprim Co-trimoxazole Ampicillin Nitrofurantoin Nalidixic acid Tetracycline Norfloxacin Chloramphenicol Gentamicin Blood and tissues Ampicillin Chloramphenicol Cotrimoxazole Tetracycline Gentamicin Cefuroxime Ceftriaxone Ciprofloxacin Piperacillin Amikacin Pseudomonas aeruginosa Piperacillin Gentamicin Tobramycin Amikacin

14. Broth Dilution Method Day 1 Add 1 ml of test bacteria ( 1*10 6 CFU/ml ) to tubes containing 1 ml broth and concentration of antibiotic (mg/l) Controls: C1 = No antibiotic, check viability on agar plates immediately C2 = No test bacteria Bacterial conc.= 5*10 5 CFU/ml Incubate 35 o C, over night 128 64 32 16 8 4 2 C1 C2 64 32 16 8 4 2 1 C1 C2

15. Broth Dilution Method 0.01 ml (spread plate), Incubate 35 o C, o/n Day 2 Record visual turbidity Subculture non-turbid tubes to agar plates (use 0.01 ml standard loop) MIC = 16 mg/ml Day 3 Determine CFU on plates: At 16 mg/ = 700 CFU/ml > 0.1% of 5*10 5 CFU/ml MBC = 32 mg/ml 64 32 16 8 4 2 1 C1 C2 64 32 16

23. Disc Diffusion Method

25. Disc Diffusion Method

29. Come on, come on, it’s either one or the other.