C. difficile growth, toxin characterization, and ribotyping

These experiments provide data on presence of toxigenic C. difficile including presence of the genes encoding toxins A, B, and the binary toxin. 

Ribotyping (RT) is considered a moderately discriminatory typing method which includes identification of the recent epidemic RT 027 strains and emerging strains such as the RT 078 and 106.  Our library is matched to the European library allowing for worldwide comparison of strains.

C. difficile susceptibility testing

C. difficile minimum inhibitory concentratio (MIC) susceptibility testing is performed by broth microdilution. MIC determinations are generally done for antibiotics used to treat C. difficile (metronidazole, vancomycin, and fidaxomicin) or antibiotics that may be causative for CDI (usually ampicillin, cefotaxime, levofloxacin, meropenem, and others)

The MICs for selected antimicrobials are provided for each sample, including a summary table of MIC50, MIC90, and geometric mean MIC.

Culture for MDROs from stool

Stool samples are screened for multidrug-resistant organims (MDROs) including MRSA, VRE, ESBL-E/CRE and Candida. After enrichment in brain heart infusion (BHI), samples are sub-cultured onto highly selective agar plates (usually HardyCHROM plate).  Species and resistant determinants are then confirmed by PCR and/or MALDI-TOF.  Other species than the ones names above can be grown. For each sample, presence or absence of each MDRO requested along with confirmation of species and resistant determinant. All isolates identified can also be further analyzed using whole genome sequencing.