Evaluation of the FilmArray® Respiratory Panel for clinical use in a large children's hospital.

BACKGROUND: Respiratory pathogens are a leading cause of hospital admission and traditional detection methods are time consuming and insensitive. Multiplex molecular detection methods have recently been investigated in hope of replacing these traditional techniques with rapid panel-based testing. OBJECTIVES: This study evaluated the FilmArray(®) Respiratory Panel ([FARP], Idaho Technology Inc., Salt Lake City, UT) as a replacement for direct fluorescent antibody (DFA) testing in a pediatric hospital. METHODS: Eleven of the 21 FARP analytes (Adenovirus, Bordetella pertussis, human Metapneumovirus, Influenza A, Influenza A H1N1 2009, Influenza B, Parainfluenza [1, 2, & 3], Respiratory Syncytial Virus, and rhinovirus) were evaluated using nasopharyngeal specimens. Positive samples were pooled in groups of 5. Samples identified by reference methods as positive for respiratory pathogens were used for the majority of positive samples. DFA was the reference method for ten analytes; Luminex™ xTAG Respiratory Virus Panel (RVP) was the reference method for rhinovirus. Discrepant results were resolved by positive culture and fluorescent antibody stain and/or laboratory-developed real-time polymerase chain reaction (PCR) assays (LDT). RESULTS: The agreement for most analytes was in concordance with the established reference methods with the exception of Adenovirus. Additionally, the FARP detected several pathogens not previously detected by DFA, and most were confirmed by LDT. Several DFA-positive analytes were confirmed as true-negatives by the FARP and LDT. CONCLUSION: FARP overall performed better than DFA with the exception of Adenovirus, making the FARP an attractive alternative to laboratories looking to replace DFA with a rapid, user-friendly, multiplex molecular assay.

Multicenter clinical evaluation of the portrait toxigenic C. difficile assay for detection of toxigenic Clostridium difficile strains in clinical stool specimens.

We compared the Portrait Toxigenic C. difficile Assay, a new semiautomated sample-to-result molecular test, to a toxigenic bacterial culture/cell cytotoxin neutralization assay (TBC/CCNA) for the detection of toxigenic Clostridium difficile in 549 stool specimens. Stool specimens were also tested by one of three alternative FDA-cleared molecular tests for toxigenic C. difficile (Xpert C. difficile, Illumigene C. difficile, or GeneOhm Cdiff). The sensitivities and specificities of the molecular tests compared to TBC/CCNA were as follows: 98.2% and 92.8% for the Portrait assay, 100% and 91.7% for the Xpert assay, 93.3% and 95.1% for the Illumigene assay, and 97.4% and 98.5% for the GeneOhm assay, respectively. The majority of Portrait false-positive results (20/31; 64.5%) were also positive for C. difficile by an alternative molecular test, suggesting an increased sensitivity compared to the culture-based "gold standard" method. The Portrait test detected an assay input of 30 CFU in 100% of spiked samples and detected an input of 10 CFU in 96.7% of samples tested.

Rapid identification of pathogens from positive blood cultures by multiplex polymerase chain reaction using the FilmArray system.

Sepsis is a leading cause of death. Rapid and accurate identification of pathogens and antimicrobial resistance directly from blood culture could improve patient outcomes. The FilmArray® (FA; Idaho Technology, Salt Lake City, UT, USA) Blood Culture (BC) panel can identify >25 pathogens and 4 antibiotic resistance genes from positive blood cultures in 1 h. We compared a development version of the panel to conventional culture and susceptibility testing on 102 archived blood cultures from adults and children with bacteremia. Of 109 pathogens identified by culture, 95% were identified by FA. Among 111 prospectively collected blood cultures, the FA identified 84 (91%) of 92 pathogens covered by the panel. Among 25 Staphylococcus aureus and 21 Enterococcus species detected, FA identified all culture-proven methicillin-resistant S. aureus and vancomycin-resistant enterococci. The FA BC panel is an accurate method for the rapid identification of pathogens and resistance genes from blood culture.