Evaluation of newly developed oxygen meters with multi-channels and disposable oxygen electrode sensors for antimicrobial susceptibility testing.
The objective of this study was to investigate the applicability of new oxygen meters with multi-channels and disposable oxygen electrode sensors (DOX-96) on the antimicrobial susceptibility testing of clinical bacterial isolates. The oxygen amount in the wells of 96-well plates was converted into current through electrodes. Bacterial inoculation decreased the oxygen amount in the wells because viable bacteria consume the oxygen. On the other hand, a failure of bacteria to consume oxygen was observed in the presence of potent antimicrobial agents, representing a serious arrest of bacterial metabolism usually leading to stasis or death. Based on these results, the minimum inhibitory concentration was determined by DOX-96 (MICdox). The MICdox showed good agreement with MIC measured by the standard broth microdilution method (98.2%). DOX-96 was also useful for turbid samples such as Mueller-Hinton broth containing 0.1% lipid emulsion. The MICdox in turbid samples showed good agreement with those in clear samples (100.0%). These results indicate that the newly developed DOX-96 is very useful in antimicrobial susceptibility testing even in turbid clinical samples such as colloidal products and turbid biological components.
Kitahara
Takashi
T
Department of Hospital Pharmacy, Nagasaki University School of Medicine. kitappy@net2.nagasaki-u.ac.jp
Koyama
Nao
N
Matsuda
Junichi
J
Hirakata
Yoichi
Y
Kamihira
Shimeru
S
Kohno
Shigeru
S
Nakashima
Mikiro
M
Sasaki
Hitoshi
H
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D004566:Electrodes; D007201:Indicator Dilution Techniques; D008826:Microbial Sensitivity Tests / Q000295:instrumentation*; D009391:Nephelometry and Turbidimetry; D010100:Oxygen / Q000032:analysis*; D010101:Oxygen Consumption
D000900:Anti-Bacterial Agents; D010100:Oxygen