271. Evaluation of the Comparative Performance of Verigene Blood Culture Nucleic Acid System to Conventional Techniques in a Tertiary-Care Hospital in Kuwait
Session: Poster Abstract Session: Diagnostic Microbiology; Novel Molecular Methods
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • IDSA Poster October 2013.pdf (987.4 kB)
  • Background:

    Rapid bacterial identification directly from positive blood culture bottles is of great value in the early initiation of appropriate antibiotics in patients with septicemia.The objectives of the study is to evaluate the performance of Verigene Blood Culture nucleic acid system  (Nanosphere, USA) in comparison to conventional culture technique for  the identification of both Gram-positive and Gram-negative bacteria and their resistance markers mecA, vanA, vanB for Gram-positive and  CTX-M, KPC, NDM, VIM, IMP, OXA for Gram-negative bacteria  directly from positive blood culture bottles.

    Methods: A total of 40 patients with positive blood culture for Gram-positive and 12 for Gram-negative bacteria were included in the evaluation. All positive blood culture bottles were tested with verigene BC  as well as plated on blood agar plates both aerobically and anaerobically and Mac Conkey  agar plates.  Identification and antimicrobial susceptibility testing of bacteria were done using Vitek II ( Biomerieux , France).

    Results: The Verigene BC-Gram-positive  correctly identified methicillin-sensitive  S.aureus ( MSSA)(8), S.epidermidis (12), Enterococcus  faecalis (4), Enterococcus faecium (2), S.pyogenes (3), S.agalactiae (4) and S.pneumoniae (3).  MecA was absent in all the 8 MSSA’s, and present in all the 12 S.epidermidis which showed resistance to cloxacillin. VanA was detected only in the  E.faecium that was resistant to vancomycin.  The Verigene BC-Gram-negative correctly identified  Escheracia coli (6),  Klepsiella pneumoniae (2) and Acinitobacter baumanii, Pseudomonas aeruginosa and Serratia marcescens one each. It failed to detect Stenotrophomonas maltophilia as it is not in the data base. It correctly detected CTX-M for 3 and 1 of the ESBL-producing  E.coli  and Klebsiella pneumoniae, respectively. It failed to detect carbapenem resistance in Pseudomonas aeruginosa. The  average turn around time for Verigene was 1 hr and 50 min compared to and 48-72 hr for the conventional culture. Modification of empirical therapy was made accordingly with excellent clinical outcome.

    Conclusion: Verigene BC  is a rapid and accurate system for the identification of both Gram-positive and Gram-negative  bacteria directly from a positive blood culture together with their resistance markers.

    Eiman Mokaddas, Professor of Clinical Microbiology, Microbiology, Faculty of Medicine, Kuwait University, Dasma, Kuwait


    E. Mokaddas, None

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