Preparation of stock solutions of macrolide and ketolide compounds for antimicrobial susceptibility tests.
Stock solutions of telithromycin, ABT-773, azithromycin, clarithromycin, erythromycin, roxithromycin and dirithromycin were each prepared with eight different combinations of solvents and diluents. Broth microdilution trays were then prepared and frozen at -60 degrees C. Standard quality control strains were evaluated periodically during a 12-week storage time. There were no significant changes in MICs with different solvents and diluents. It was concluded that the easiest approach was to dissolve each compound in water with a small volume (< 2.5 microL/mL) of glacial acetic acid added in a dropwise fashion, followed by further dilutions in deionised water.
Barry
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The Clinical Microbiology Institute, 9725 SW Commerce Circle, Suite A-1, Wilsonville, OR 97070, USA. cmi@hevanet.com
Bryskier
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A
Traczewski
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M
Brown
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S
D019342:Acetic Acid; D006193:Haemophilus influenzae / Q000187:drug effects*; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D012996:Solutions; D012997:Solvents; D013211:Staphylococcus aureus / Q000187:drug effects*; D013296:Streptococcus pneumoniae / Q000187:drug effects*; D014867:Water
D018942:Macrolides; D012996:Solutions; D012997:Solvents; D014867:Water; D019342:Acetic Acid