258. Whole Genome Sequencing in Tracking Intergenus Klebsiella pneumoniae Carbapenemase (KPC) Gene Transmission in a Tertiary Care Center
Session: Poster Abstract Session: Diagnostics: Typing and Sequencing
Thursday, October 8, 2015
Room: Poster Hall
  • Popiel-Haraoui.pdf (214.6 kB)
  • Background: An outbreak is traditionally suspected when a cluster of cases associated with a common organism is observed. Outbreaks due to carbapenemase-producing organisms challenge traditional infection control approaches as the focus shifts to resistance genes transmitted between different genera and species. Whole genome sequencing (WGS) is a new tool that allows for the genetic typing of isolates and for tracking of mobile resistance elements.

    Methods: In a 637-bed university teaching hospital in Montréal, Canada, detection of a new case of a nosocomially acquired KPC-producing Enterobacter cloacae (Ec1) prompted the application of WGS analysis to epidemiologically-linked clinical and surveillance samples harbouring the KPC gene (n=9). blaKPC gene presence was confirmed by PCR. Pulsed-field gel electrophoresis using XbaI, plasmid fingerprinting (pRFLP) using Bgl II and PCR to detect plasmid incompatibility groups (Inc) was conducted. Whole genome sequencing (WGS) was conducted using Illumina technology on a Miseq with assembly using Spades. Analysis of the genomes was conducted by single variant polymorphisms (SVP), MLST and mapping of Tn4401 to a referencing using Bowtie.

    Results: In all, 9 isolates from 5 subjects were sequenced: 5 K. pneumoniae, 1 E.coli, 1 K. oxytoca and 2 E. cloacae (Ec1 and the only other known KPC-producing E. cloacae detected at the hospital in the previous year). SNP analysis of Tn4401 and pRFLP revealed 3 transposon types (Tn4401-type1-3), incorporated into 6 distinct plasmids (A1, A2, B1, C1, D1, E1), belonging to IncN, IncP,L/M, IncFllk or IncFIA(H1). Tn4401-type1 was identified in 3 plasmids (A2,D1,E1), found in 3 species, K. pneumoniae, E. cloacae and K. oxytoca. A2, an IncN plasmid, associated with Tn4401-type1 was identified in Ec1 and in a K.pneumoniae suggesting that the isolates are linked.

    Conclusion: WGS is a promising tool to aid in investigating and tracking transmission of both organisms and their highly mobile genetic determinants of resistance. As demonstrated here, its application in the setting of nosocomial transmission supports re-thinking of when and how to implement infection control practices and endorses WGS on a larger scale to optimize the management of nosocomial outbreaks.

    Kristin Popiel, MD1, Yves Longtin, MD2, Laura Mataseje, M.Sc.3, Michael Mulvey, PhD3, Chand Mangat, PhD4, Mark Miller, MD, MSc2, Brigitte Lefebvre, PhD5 and Louis-Patrick Haraoui, MD1, (1)Infectious Diseases & Microbiology, McGill University, Montreal, QC, Canada, (2)Infectious Diseases & Microbiology, Jewish General Hospital, Montreal, QC, Canada, (3)Nosocomial Infections, National Microbiology Laboratory, Winnipeg, MB, Canada, (4)National Microbiology Laboratory, Winnipeg, MB, Canada, (5)Laboratoire De Sante Publique Du Quebec, Ste-Anne-de-Bellevue, QC, Canada


    K. Popiel, None

    Y. Longtin, None

    L. Mataseje, None

    M. Mulvey, None

    C. Mangat, None

    M. Miller, None

    B. Lefebvre, None

    L. P. Haraoui, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.