Comparison of Minitek Anaerobe II®, API An-Ident®, and RapID ANA® Systems for Identification of Clostridium difficile

Abstract

Three commercial anaerobic systems, Minitek^® (BBL Microbiology Systems, Cockeysville, MD), API An-Ident^® (Ahalytab Products, Plainview, NY), and. RapID ANA^® (Innovative Diagnostic Systems, Decatur, GA) were evaluated for ability to identify 45 Clostridium difficile isolates accurately. Minitek correctly identified 66% of C. difficile isolates to species, 27% were incompletely identified, and 7% were misidentitied. Most of the discrepancies with Minitek were due to false negative biochemical results. API An-Ident correctly identified 9% C. difficile isolates to species, 89% were incompletely identified, and 2% were misidentificd. Most of the API An-Ident discrepancies were due to the data base, which distinguished poorly between C. difficile, Clostridium hastiforme, and Clostridium sporogenes. RapID ANA correctly identified 100% of C. difficile isolates.