Vol.53 No.2 February 2005
Antimicrobial susceptibility testing by chemiluminescence ATP assay
1)Department of Internal Medicine and 2)Division of Infection Control
Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo, Japan
Abstract
Antimicrobial susceptibility testing by chemiluminescence ATP assay is a new method for determining of minimum inhibitory concentrations (MICs) by the broth microdilution method. In this method bacterial ATP is measured by the luciferin-luciferase reaction. We tested 30 Staphylococcus aureus strains consisting of 15 methicillin-sensitive S. aureus (MSSA) strains, and 15 methicillin-resistant S. aureus (MRSA) strains for susceptibility to 12 antimicrobial agents and 15 Pseudomonas aeruginosa strains for susceptibility to 7 antimicrobial agents and compared the results to those obtained by the standard broth microdilution method. chemilumine-scence ATP assays were performed after incubating inoculated microdilution trays for 6 hr at 35°C.
In the result of the testing for MSSA, the rate of agreement between the results of the tests for ampicillin was only 60.0%. In addition to the result, the rate of agreement for ofloxacin was only 20.0%. The rates of agreement for MICs by the chemiluminescence ATP assay and standard broth microdilution method for MSSA was high for all antimicrobial agents except ampicillin and ofloxacin. The rate of agreement for MICs by the same two methods for MRSA was also high. On the other hand, the rate of agreement for MICs by the two methods for P. aeruginosa was low. The MIC determination method by the chemiluminescence ATP assay was more rapidly than the standard broth microdilution method. The chemiluminescence ATP assay may be the most sensitive testing when we choose the combination a sort of bacteria and antimicrobial agent.
Key word
chemiluminescent assay, ATP, Antibacterial activity
Received
December 13, 2004
Accepted
January 21, 2005
Jpn. J. Chemother. 53 (2): 128-133, 2005
