1999. Rapid detection and genotyping of antimicrobial resistance determinants with the BioFire FilmArray® System
Session: Poster Abstract Session: Antimicrobial Resistance Mechanisms
Saturday, October 29, 2016
Room: Poster Hall
Posters
  • Montgomery_IDWeek 2016.pdf (1.1 MB)
  • Background: Antimicrobial resistance is increasing in prevalence and complexity. Infection mortality rates are an estimated five-fold higher for resistant organisms. Timely therapy requires rapid identification of antimicrobial susceptibility. Standard testing methods require several days to perform. Nucleic acid-based detection of resistance determinants is a potential rapid alternative. The heterogeneity of determinants necessitates a multiplexed system with the ability to genotype specific variants that impact resistance phenotype. As a proof of concept, we have developed a research use only antimicrobial resistance panel for the FilmArray System covering a range of resistance mechanisms in Gram-negative bacteria.

    Methods: Clinical isolates of Escherichia coli and Klebsiella pneumoniae (n=50) were obtained from internal repositories and the FDA-CDC Antimicrobial Resistance Isolate Bank. Five minutes of hands on time was required and comprehensive results were returned in about one hour. This panel contained assays for twenty-two resistance determinants including extended-spectrum β-lactamases (CTX-M, TEM, SHV), plasmid-mediated AmpCs (CMY, DHA, FOX), carbapenamases (KPC, NDM, VIM, IMP, OXA), and quinolone resistance determinants (gyrA, parC, QnrA/B/S/D, QepA). Specific variants of gyrA, parC, TEM, and SHV were identified with genotyping assays. Detected resistance determinants not previously identified were confirmed with sequencing.

    Results: The following resistance determinants were detected and were in 100% agreement with expected resistance: CTX-M, TEM, SHV, CMY, DHA, KPC, NDM, VIM, IMP, OXA-181. Genotyping assays detected variants of TEM (E104K, R164H/S, G238S, E240K), SHV (D179G/N, G238S, E240K), gyrA (S83L/F/I, D87A/N), and parC (S80I, E84G/K/V) and were 95% concordant with sequencing. Disagreements were due to similar missense mutations (e.g. the gyrA D87A assay detected D87G).

    Conclusion: The FilmArray System is amenable to rapid identification and genotyping of antimicrobial resistance determinants in an easy-to-use format. Additional studies are required to evaluate the relationship between resistance determinant typing and standard susceptibility testing.

    This abstract contains information regarding assays that have not been reviewed by regulatory agencies for in vitro diagnostic use.

    Jesse Montgomery, PhD, Neil Draper, MS, Andrew Hemmert, PhD and Robert Crisp, PhD, BioFire Diagnostics, LLC, Salt Lake City, UT

    Disclosures:

    J. Montgomery, BioFire Diagnostics, LLC: Employee , Salary

    N. Draper, BioFire Diagnostics, LLC: Employee , Salary

    A. Hemmert, BioFire Diagnostics, LLC: Employee , Salary

    R. Crisp, BioFire Diagnostics, LLC: Employee , Salary

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.