Defining the Vulnerable Period for Re-Establishment of Clostridium difficile Colonization after Treatment of C. difficile Infection with Oral Vancomycin or Metronidazole (original) (raw)
Figure 2
Concentrations of vancomycin and metronidazole in stool during and after Clostridium difficile infection (CDI) treatment.
The concentration of vancomycin was measured using an AxSym II fluorescence polarization immunoassay that was modified for stool samples by including an extraction of the sample in dilute ammonia to prevent nonspecific binding of vancomycin to protein in the stool. The limit of detection of the assay was 2 µg of vancomycin per ml. The concentration of metronidazole in stool was measured using a bioassay with Clostridium perfringens as the indicator organism. Samples from patients receiving concurrent systemic antibiotics for indications other than CDI were excluded.