Multicenter Evaluation of the Quidel Lyra Direct C. difficile Nucleic Acid Amplification Assay

Abstract

dClostridium difficile is a Gram-positive bacterium commonly found in health care and long-term-care facilities and is the most common cause of antibiotic-associated diarrhea. Rapid detection of this bacterium can assist physicians in implementing contact precautions and appropriate antibiotic therapy in a timely manner. The purpose of this study was to compare the clinical performance of the Quidel Lyra Direct C. difficile assay (Lyra assay) (Quidel, San Diego, CA) to that of a direct cell culture cytotoxicity neutralization assay (CCNA) and enhanced toxigenic culture. This study was performed at three geographically diverse laboratories within the United States using residual stool specimens submitted for routine C. difficile testing. Residual samples were tested using the Lyra assay on three real-time PCR platforms, and results were compared to those for direct CCNA and enhanced toxigenic culture. The test results for all platforms were consistent across all three test sites. The sensitivity and specificity of the Lyra assay on the SmartCycler II, ABI 7500 Fast DX, and ABI QuantStudio DX instruments compared to CCNA were 90.0% and 93.3%, 95.0% and 94.2%, and 93.8% and 95.0%, respectively. Compared to enhanced toxigenic culture, the sensitivity and specificity of the Lyra assay on the SmartCycler II, ABI 7500, and QuantStudio instruments were 82.1% and 96.9%, 89.3% and 98.8%, and 85.7% and 99.0%, respectively. Overall, the Lyra assay is easy to use and versatile and compares well to C. difficile culture methods.

Clostridium difficile Infection Diagnosis by Biological Molecular Methods

“…CL, MOX, and RIF resistance levels varied (50, 40, and 13%, respectively) and were evident in many RTs. The most frequent RTs registered were 027 (12%), 001/072 (9%), It is obvious that all articles from previous years that have studied the resistance patterns of C. difficile strains from clinical samples, animal, and environmental sources [108,109,111,112,[120][121][122][123][124][125][126][127][128][129][130][131] from Europe, North America, and South-East Asia were designated not only to describe these patterns and their dynamics but also to classify them as RTs, to have a complete description of spread and risk for CDI, for higher virulent and MDR strains, too. Different studies have tried to describe, by different biological molecular methods, the C. difficile strain resistance mechanisms for cephalosporins, macrolide-lincosamide-streptogramin B (MLS B ) family, fluoroquinolones, including for antibiotics useful in the treatment of CDI t (e.g., metronidazole, vancomycin, rifamycins, and fidaxomicin); excellent syntheses regarding these mechanisms were recently published [61].…”

“…For this short presentation, we have chosen the latest references that offered the most eloquent data regarding sensitivity, specificity, and, if available, positive predictive value and negative predictive value ( Table 3) [101][102][103][104][105][106][107][108][109][110][111].…”

“…The costs, the clinical consequences, and the impact on the nosocomial transmission of treating and/or isolating patients-positive for toxigenic C. difficile by PCR but negative for in vivo toxin production-worth further study. Diagnostic algorithms combining immunoassays and NAATs could also improve the specificity and reduce the global cost of this analysis [108][109][110].…”

Current knowledge on the laboratory diagnosis ofClostridium difficileinfection

“…The Lyra assay may be performed on any of three open-platform, real-time thermocyclers: SmartCycler II (Cepheid, Sunnyvale, CA), ABI 7500 Fast DX (Applied Biosystems, Carlsbad, CA), and ABI QuantStudio DX (Applied Biosystems, Carlsbad, CA). The Lyra assay has a running time of about 3 h[ 96 ]. Depending on the platform used, the sensitivity and specificity may differ; the ABI 7500 instrument is the most sensitive and the ABI QuantStudio DX is the most specific.…”

“…Depending on the platform used, the sensitivity and specificity may differ; the ABI 7500 instrument is the most sensitive and the ABI QuantStudio DX is the most specific. The overall sensitivity is 85.7% and the overall specificity is 98.3% when compared to toxigenic culture[ 96 ].…”