Program Schedule

Clinical and molecular characteristics of NDM-1 harboring Multi-Drug Resistant Gram Negative Bacteria at Carilion Medical Center

Session: Poster Abstract Session: Multidrug-resistant Organisms: Epidemiology and Prevention
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • NDM-1 upload.jpg (198.8 kB)
  • Background: Carbapenem (C) resistant gram negative bacteria (GNB) have emerged as an important concern as infections by these organisms spread rapidly in hospital settings, are difficult to treat and carry high mortality rates.  Among several different types of carbepenemase producing genes, New Delhi Metallo β-lactamase-1 (NDM-1) is a new gene that causes resistance to C antibiotics;  GNB also commonly co-harbor Aminoglycoside (A) resistance genes. Both resistance genes can be found commonly on the same plasmid. Infections by NDM-1 harboring GNB are increasingly being reported in US. We are observing an increasing number of multi-drug resistant (MDR) GNB at Carilion Medical Center (CMC) which are resistant to C and A.

    Methods: A retrospective study was conducted on a small number of banked specimens (n=15) of MDR-GNB collected at CMC in 2011-2012. We isolated plasmids of these organisms using Qiagen kits as per the manufacturer’s protocol, characterized plasmid profile and performed screening with NDM-1 gene specific primers by using polymerase chain reaction (PCR). Retrospective chart analysis was performed and demographic, clinical and outcome data were collected.

    Results: Among 15 MDR-GNB specimens, 10 were Pseudomonas aeruginosa, 1 Enterobacter cloacae, 1 Burkholderia cepacia, 1 Proteus mirablis, 1 Achromobacter xylosoxidans, 1 Kleibsiella pneumonia. Nine of 15 organisms were resistant or intermediate to Amikacin and 13/15 were resistant to C. These plasmids were larger in size (>23kbp in size) and multiple (2-3) in 5/15 bacteria. NDM-1 gene specific primer PCR with 813 kbp band was positive in 8 of 15 MDR-GNB. Chart analysis was available for 14 patients (pts) only (7 NDM-1 +ve and 7 NDM-1 -ve). Mean age of NDM-1 +ve pts was 65.4 yrs and NDM-1 -ve pts was 60.8 yrs. Six of 7 NDM-1 +ve and 3/7 NDM-1 -ve pts were admitted from a healthcare facility. Information regarding foreign travel or contact with foreign pts was unavailable. Five of 7 NDM-1 +ve pts were admitted with acute respiratory failure and 4/7 patients died; 2/7 NDM-1 -ve pts died.

    Conclusion: C resistant GNB remain a threat to pts in healthcare settings. NDM-1 gene-present pts have 2.33 times higher relative risk of death than non NDM-1 carrying pts in our study. Resistance to A and C should arouse suspicion to the presence of NDM-1 gene with need for early detection and intervention.

    Ekta Bansal, MD1, Thomas Kerkering, MD1, Charles Schleupner, MD2, Ritesh Kohli, MD3, Anthony Baffoe, MBCh.B1, Endang Purwantini, PhD4, Biswarup Mukhopadhyay, PhD5 and Jayasimha Rao, PhD6, (1)Virginia Tech Carilion School of Medicine, Roanoke, VA, (2)Infectious Diseases, Carilion Clinic - Virginia Tech Carilion School of Medicine, Roanoke, VA, (3)Internal Medicine, Virginia Tech/Carilion School of Medicine, Roanoke, VA, (4)Biochemistry, Virginia Tech, Blacksburg, VA, (5)Biochemisstry, Virginia Tech, Blacksburg, VA, (6)Internal Medicine/Section of Infectious Diseases, Virginia Tech Carilion School of Medicine, Roanoke, VA


    E. Bansal, None

    T. Kerkering, None

    C. Schleupner, None

    R. Kohli, None

    A. Baffoe, None

    E. Purwantini, None

    B. Mukhopadhyay, None

    J. Rao, None

    Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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