title: Revision of standards for adjusting the cation content of Mueller-Hinton broth for testing susceptibility of Pseudomonas aeruginosa to aminoglycosides.
abstract: A multilaboratory study was undertaken to reassess the amount of calcium and magnesium that should be added to Mueller-Hinton broth when testing Pseudomonas aeruginosa against amikacin, gentamicin, isepamicin, netilmicin, and tobramycin. To achieve parity with agar dilution tests, cation-adjusted broth should contain 20 to 25 mg of calcium and 10 to 12.5 mg of magnesium per liter rather than the 50- and 25-mg/liter supplements recommended previously. For quality control of tests with contemporary media, MIC control limits should be adjusted by lowering the current MIC limits by at least 1 doubling-dilution interval.
authors.affiliation: Clinical Microbiology Institute, Tualatin, Oregon 97062.
authors.forename: A L
authors.initials: AL
authors.lastname: Barry
authors.forename: L B
authors.initials: LB
authors.lastname: Reller
authors.forename: G H
authors.initials: GH
authors.lastname: Miller
authors.forename: J A
authors.initials: JA
authors.lastname: Washington
authors.forename: F D
authors.initials: FD
authors.lastname: Schoenknect
authors.forename: L R
authors.initials: LR
authors.lastname: Peterson
authors.forename: R S
authors.initials: RS
authors.lastname: Hare
authors.forename: C
authors.initials: C
authors.lastname: Knapp
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002412:Cations; D003470:Culture Media / Q000592:standards*; D006801:Humans; D008274:Magnesium; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D002412:Cations; D003470:Culture Media; D008274:Magnesium