950. Evaluation of the performance of the Target Enriched Multiplex Polymerase Chain Reaction (TEM-PCR) Gastrointestinal (GI) Panel vs the Cepheid Xpert C. difficile/Epi assay for the detection of toxigenic Clostridium difficile
Session: Poster Abstract Session: Clostridium difficile Infections: Epidemiology and Diagnostics
Friday, October 9, 2015
Room: Poster Hall

Background: Clostridium difficile (CD) is one of the most common healthcare associated infections (HAIs). While the gold standard for diagnosis of CD is cytotoxicity assay and toxigenic culture, there are a number of molecular assays for rapid CD detection. This study evaluated the performance of an in-house TEM-PCR GI panel with the Cepheid Xpert C. difficile/Epi assay using clinical samples collected in hospital setting.

Methods: Stool samples of patients with suspected CD infections were tested by TEM-PCR GI panel and with Cepheid Xpert assay. CD detection is the part of the Diatherix multiplex GI panel which can simultaneously detect 3 viral, 7 bacterial, 2 protozoan, and 3 toxins in a single specimen. The Cepheid assay detects the toxin B gene and the O27/NAP1/B1 strain. Two TaqMan assays targeting the toxin B and tpi gene were developed as an alternative approach for confirmation of discrepant results. Demographics data, risk factors, and other clinically relevant information was obtained for this study.

Results: We enrolled 36 patients with mean age of 67 years (TaqMan assays done in 31). 53% females. Known risk factors included: recurrent CD infection (17%), recent antibiotic use (56%), recent hospitalization (53%), proton pump inhibitor use (44%), gastrointestinal disorders (31%) and immunosuppression (19%). 22% of specimens were not tested by Cepheid PCR as stool was formed.  There was 100% concordance between TEM-PCR CD toxin B, Taqman tpi gene, and Cepheid Xpert. Cepheid NAP1/B1 was positive in 8% of patients. TEM-PCR detected positive binary toxin in 38% of patients. All NAP1/B1 positive specimens were positive for binary toxin with TEM-PCR. 13% of patients with positive CD by TEM-PCR had co-detection of other targets (25% Norovirus, 50% Rotavirus and 25% EPEC). Those patients with co-detection, 80% were female and more than 55 years old. Other stool studies done in 67% of patients, 42% had occult blood with 87% positive, 42% had cultures with 7% positive for Gram positive cocci and 22% had O&P (All were negative)

Conclusion: The performance of TEM-PCR GI panel was comparable to Cepheid assay for CD detection.  Further studies are needed to asses the clinical utility of TEM-PCR GI panel to detect multiple pathogens and how this information can be used to improve patient care.

 

Khushdeep Chahal, MD1, Esmeralda Gutierrez-Asis, MD1, Farrah Ibrahim, MD FACP2, Elena Grigorenko, PhD3, Stefan Brzezinski, MBA, BS4, Donald Stalons, PhD, D(ABMM), MPH4 and Ali Hassoun, MD FIDSA FACP5, (1)Internal Medicine, UAB Huntsville Regional Medical Campus, Huntsville, AL, (2)Internal Medicine, UAB-Huntsville campus, Huntsville, AL, (3)Diatherix Laboratories, Inc, Huntsville, AL, (4)Diatherix Laboratories, Inc., Huntsville, AL, (5)University of Alabama School of Medicine - Huntsville campus, Huntsville, AL

Disclosures:

K. Chahal, None

E. Gutierrez-Asis, None

F. Ibrahim, None

E. Grigorenko, Diatherix lab: Investigator , Salary

S. Brzezinski, Diatherix lab: Employee , Salary

D. Stalons, Diatherix Lab: Investigator , Salary

A. Hassoun, None

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