PMC5833197_01
CO2 plots (measured with reflectance photometry-BacT/ALERT 3D) of two of our patient's false-positive blood cultures compared to two true-positive blood cultures. The y-axis depicts reflectance units and the x-axis depicts time in days. The vertical line represents the time that the culture was flagged positive. Note the linear CO2 increase of our case's blood cultures. A lag phase, a log phase, and a stationary phase can be seen in both true-positive cultures. In the last example, however, the lag phase is longer and the log phase is shorter, mimicking a linear appearance.
CRIM2018-7090931.001.jpg
PMC5833197_01_CRIM2018-7090931.001.jpg
fig1
However, no microorganisms could be identified on microscopy and appropriate subcultures, and the CO2 plot of positive blood cultures was linear (in contrast to the exponential rise of CO2 in true-positive cultures) (Figure 1).