BACKGROUND: The illumigene® (Meridian Bioscience, Inc., Cincinnati, OH) and GeneOhm® (BD Diagnostics, La Jolla, CA) Clostridium difficile assays target the tcdA gene and tcdB gene, respectively. We assessed the use of tcdA as the molecular target in the illumigene® C. difficile loop-mediated amplification assay in detecting a wide variety of C. difficile strains including those with tcdA deletions. METHODS: We tested 38 C. difficile strains and 108 patient stool specimens using the illumigene® assay. The GeneOhm® real-time polymerase chain reaction (PCR) assay served as the reference method. Discordant results were resolved by repeat testing, anaerobic culture, and a laboratory-developed real-time PCR targeting tcdA and tcdB. RESULTS: Both illumigene® and GeneOhm® assays detected all 37 C. difficile toxin B(+) strains representing seven toxinotypes and including four toxin A(-) B(+) isolates. No cross-reactivity with 20 other Clostridium species or toxin-negative C. difficile was observed in either assay. Among patient stool specimens, agreement was 94.4% (102/108). After discordant result resolution, agreement was 96.3% (104/108). Specimens with initially discordant results had target concentrations approaching the limit of detection for the two commercial assays. Discordance appeared unrelated to whether tcdA or tcdB was the amplification target. CONCLUSION: The tcdA 5' region used by the illumigene® assay is a practical target for toxigenic C. difficile detection.
BACKGROUND: The illumigene® (Meridian Bioscience, Inc., Cincinnati, OH) and GeneOhm® (BD Diagnostics, La Jolla, CA) Clostridium difficile assays target the tcdA gene and tcdB gene, respectively. We assessed the use of tcdA as the molecular target in the illumigene® C. difficile loop-mediated amplification assay in detecting a wide variety of C. difficile strains including those with tcdA deletions. METHODS: We tested 38 C. difficile strains and 108 patient stool specimens using the illumigene® assay. The GeneOhm® real-time polymerase chain reaction (PCR) assay served as the reference method. Discordant results were resolved by repeat testing, anaerobic culture, and a laboratory-developed real-time PCR targeting tcdA and tcdB. RESULTS: Both illumigene® and GeneOhm® assays detected all 37 C. difficile toxin B(+) strains representing seven toxinotypes and including four toxin A(-) B(+) isolates. No cross-reactivity with 20 other Clostridium species or toxin-negative C. difficile was observed in either assay. Among patient stool specimens, agreement was 94.4% (102/108). After discordant result resolution, agreement was 96.3% (104/108). Specimens with initially discordant results had target concentrations approaching the limit of detection for the two commercial assays. Discordance appeared unrelated to whether tcdA or tcdB was the amplification target. CONCLUSION: The tcdA 5' region used by the illumigene® assay is a practical target for toxigenic C. difficile detection.
Authors: Briony Elliott; Michelle M Squire; Sara Thean; Barbara J Chang; Jon S Brazier; Maja Rupnik; Thomas V Riley Journal: J Med Microbiol Date: 2011-03-10 Impact factor: 2.472
Authors: H Kato; H Kita; T Karasawa; T Maegawa; Y Koino; H Takakuwa; T Saikai; K Kobayashi; T Yamagishi; S Nakamura Journal: J Med Microbiol Date: 2001-08 Impact factor: 2.472
Authors: Erik R Dubberke; Zhuolin Han; Linda Bobo; Tiffany Hink; Brenda Lawrence; Susan Copper; Joan Hoppe-Bauer; Carey-Ann D Burnham; William Michael Dunne Journal: J Clin Microbiol Date: 2011-06-22 Impact factor: 5.948
Authors: Hanna Pituch; Willem van Leeuwen; Kees Maquelin; Dorota Wultańska; Piotr Obuch-Woszczatyński; Grazyna Nurzyńska; Haru Kato; Martin Reijans; Felicja Meisel-Mikołajczyk; Mirosław Łuczak; Alex van Belkum Journal: J Clin Microbiol Date: 2007-02-21 Impact factor: 5.948
Authors: Grace O Androga; Alan M McGovern; Briony Elliott; Barbara J Chang; Timothy T Perkins; Niki F Foster; Thomas V Riley Journal: J Clin Microbiol Date: 2014-12-17 Impact factor: 5.948