ABSTRACT
Recently, a new rapid assay for the detection of tcdB gene of Clostridioides difficile was developed using the GENECUBE. The assay can directly detect the tcdB gene from stool samples without a purification in approximately 35 minutes with a few minutes of preparation process. We performed a prospective comparative study of the performance of the assay at eight institutions in Japan. Fresh residual stool samples (Bristol stool scale ≥5) were used and comparisons were performed with the BD MAX Cdiff assay and toxigenic cultures. For the evaluation of 383 stool samples compared with the BD MAX Cdiff assay, the sensitivity, and specificity of the two assays was 99.0% (379/383), 98.1% (52/53), 99.1% (327/330), respectively. In the comparison with toxigenic culture, the total, sensitivity, and specificity were 96.6% (370/383), 85.0% (51/60), and 98.8% (319/323), respectively. The current investigation indicated the GENECUBE Clostridioides difficile assay has equivalent performance with the BD MAX Cdiff assay for the detection of tcdB gene of C. difficile.
Subject(s)
Bacterial Proteins/genetics , Bacterial Toxins/genetics , Clostridioides difficile/genetics , Feces/microbiology , Clostridioides difficile/isolation & purification , Clostridium Infections/diagnosis , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Enterotoxins/genetics , Humans , Polymerase Chain Reaction/methods , Reagent Kits, Diagnostic , Repressor Proteins/genetics , Sensitivity and SpecificityABSTRACT
Rapid identification of causative agents from positive blood culture media is a prerequisite for the timely targeted treatment of patients with sepsis. The GENECUBE (TOYOBO Co., Ltd.) is a novel, fully-automated gene analyzer that can purify DNAs and amplify target DNAs. In this study, we evaluated the ability of two newly developed GENECUBE assays to directly detect the nuc and mecA genes in blood culture medium; nuc is specific to Staphylococcus aureus, and mecA indicates methicillin resistance. We examined 263 positive blood culture samples taken at three hospitals from patients suspected of having staphylococcal bacteremia. The results were then compared with those obtained using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, antimicrobial susceptibility testing (Microscan system or Dry-plate EIKEN), and sequencing analysis. The GENECUBE assays had sensitivity and specificity of 100% in detecting both S. aureus and methicillin resistance in positive blood culture. The turnaround time of the examination was evaluated for 36 positive blood culture samples. The time between the initiation of incubation and completion of the GENECUBE examination was 23 h (interquartile range: IQR 21-37 h); the time between reporting of Gram stain examination and completion of the GENECUBE examination was 52 min (IQR 48-62 min). These findings show that the GENECUBE assays significantly reduce the assay time with no loss of sensitivity or specificity.
