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Comparative evaluation of Vitek 2 identification and susceptibility testing of Gram-negative rods directly and isolated from BacT/ALERT-positive blood culture bottles

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Abstract

The performance of Vitek 2 was evaluated for the identification and susceptibility testing of Gram-negative bacilli directly from positive blood cultures bottles. Direct inoculation of the positive blood cultures with the Vitek cards ID-GN and AST-NO58 was compared with the standard inoculation method based on the sub-culture of the positive blood culture to agar. A total of 142 blood cultures were included in the study; of those, 119 were from patients’ clinical samples, while 23 were artificially prepared with strains showing different mechanisms of resistance. A total of 136 (95.8%) strains were correctly identified to the species level, only 2 (1.4%) were mis-identified and 4 (2.8%) were not identified. Susceptibility results were available for all isolates tested against 17 antibiotics, thus, resulting in a total of 2,414 isolate/anti-microbial combinations. The error rate was 2.8% (67/2,414) overall; 0.6% (14/2,414) very major errors, 0.1% (3/2,414) major errors and 2.1% (50/2,414) minor errors. The direct method detected 88.5% (22/25) of the strains producing extended-spectrum beta-lactamases (ESBLs). The susceptibility agreement among the added strains with ESBL, AMPc hyperproduction, resistance to ceftazidime, carbapenems and cefepime was very high. Direct identification and susceptibility testing gave rapid and reliable results, reducing by 24 h the turnaround time of the microbiology laboratory.

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References

  1. Barenfanger J, Drake C, Kacich G (1999) Clinical and financial benefits of rapid bacterial identification and antimicrobial susceptibility testing. J Clin Microbiol 37:1415–1418

    PubMed  CAS  Google Scholar 

  2. Doern GV, Vautour R, Gaudet M, Levy B (1994) Clinical impact of rapid in vitro susceptibility testing and bacterial identification. J Clin Microbiol 32:1757–1762

    PubMed  CAS  Google Scholar 

  3. Kerremans JJ, Verboom P, Stijnen T, Hakkaart-van Roijen L, Goessens W, Verbrugh HA, Vos MC (2008) Rapid identification and antimicrobial susceptibility testing reduce antibiotic use and accelerate pathogen-directed antibiotic use. J Antimicrob Chemother 61:428–435

    Article  PubMed  CAS  Google Scholar 

  4. Murray PR, Baron EJ, Pfaller MA, Tenover FC, Yolken RH (eds) (1999) Manual of clinical microbiology, 7th edn. American Society for Microbiology, Washington, D.C.

    Google Scholar 

  5. Christner M, Rohde H, Wolters M, Sobottka I, Wegscheider K, Aepfelbacher M (2010) Rapid identification of bacteria from positive blood culture bottles by use of matrix-assisted laser desorption–ionization time of flight mass spectrometry fingerprint. J Clin Microbiol 48:1584–1591

    Article  PubMed  CAS  Google Scholar 

  6. Ferroni A, Suarez S, Beretti JL, Dauphin B, Bille E, Meyer J, Bougnoux ME, Alanio A, Berche P, Nassif X (2010) Real-time identification of bacteria and Candida species in positive blood culture broths by matrix-assisted laser desorption ionization–time of flight mass spectrometry. J Clin Microbiol 48:1542–1548

    Article  PubMed  CAS  Google Scholar 

  7. Prod’hom G, Bizzini A, Durussel C, Bille J, Greub G (2010) Matrix-assisted laser desorption ionization–time of flight mass spectrometry for direct bacterial identification from positive blood culture pellets. J Clin Microbiol 48:1481–1483

    Article  PubMed  Google Scholar 

  8. Stevenson LG, Drake SK, Murray PR (2010) Rapid identification of bacteria in positive blood culture broths by matrix-assisted laser desorption ionization–time of flight mass spectrometry. J Clin Microbiol 48:444–447

    Article  PubMed  CAS  Google Scholar 

  9. Hyle EP, Lipworth AD, Zaoutis TE, Nachamkin I, Bilker WB, Lautenbach E (2005) Impact of inadequate initial antimicrobial therapy on mortality in infections due to extended-spectrum beta-lactamase-producing enterobacteriaceae: variability by site of infection. Arch Intern Med 165:1375–1380

    Article  PubMed  Google Scholar 

  10. Calvo J, Cantón R, Fernández-Cuenca F, Mirelis B, Navarro F (2011) Detección fenotípica de mecanismos de resistencia en gramnegativos. Procedimientos en Microbiología Clínica. Recomendaciones de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. Available online at: http://www.seimc.org/documentos/protocolos/microbiologia/cap38indice.htm

  11. Bruins MJ, Bloembergen P, Ruijs GJ, Wolfhagen MJ (2004) Identification and susceptibility testing of Enterobacteriaceae and Pseudomonas aeruginosa by direct inoculation from positive BACTEC blood culture bottles into Vitek 2. J Clin Microbiol 42:7–11

    Article  PubMed  Google Scholar 

  12. de Cueto M, Ceballos E, Martínez-Martínez L, Perea EJ, Pascual A (2004) Use of positive blood cultures for direct identification and susceptibility testing with the Vitek 2 system. J Clin Microbiol 42:3734–3738

    Article  PubMed  Google Scholar 

  13. Hansen DS, Jensen AG, Nørskov-Lauritsen N, Skov R, Bruun B (2002) Direct identification and susceptibility testing of enteric bacilli from positive blood cultures using VITEK (GNI+/GNS-GA). Clin Microbiol Infect 8:38–44

    Article  PubMed  CAS  Google Scholar 

  14. Ling TK, Tam PC, Liu ZK, Cheng AF (2001) Evaluation of VITEK 2 rapid identification and susceptibility testing system against gram-negative clinical isolates. J Clin Microbiol 39:2964–2966

    Article  PubMed  CAS  Google Scholar 

  15. Ling TK, Liu ZK, Cheng AF (2003) Evaluation of the VITEK 2 system for rapid direct identification and susceptibility testing of gram-negative bacilli from positive blood cultures. J Clin Microbiol 41:4705–4707

    Article  PubMed  Google Scholar 

  16. Quesada MD, Giménez M, Molinos S, Fernández G, Sánchez MD, Rivelo R, Ramírez A, Banqué G, Ausina V (2010) Performance of VITEK-2 Compact and overnight MicroScan panels for direct identification and susceptibility testing of Gram-negative bacilli from positive FAN BacT/ALERT blood culture bottles. Clin Microbiol Infect 16:137–140

    Article  PubMed  CAS  Google Scholar 

  17. Chen JR, Lee SY, Yang BH, Lu JJ (2008) Rapid identification and susceptibility testing using the VITEK 2 system using culture fluids from positive BacT/ALERT blood cultures. J Microbiol Immunol Infect 41:259–264

    PubMed  CAS  Google Scholar 

  18. Joyanes P, del Carmen Conejo M, Martínez-Martínez L, Perea EJ (2001) Evaluation of the VITEK 2 system for the identification and susceptibility testing of three species of nonfermenting gram-negative rods frequently isolated from clinical samples. J Clin Microbiol 39(9):3247–3253

    Article  PubMed  CAS  Google Scholar 

  19. Gavin PJ, Warren JR, Obias AA, Collins SM, Peterson LR (2002) Evaluation of the Vitek 2 system for rapid identification of clinical isolates of gram-negative bacilli and members of the family Streptococcaceae. Eur J Clin Microbiol Infect Dis 21:869–874

    PubMed  CAS  Google Scholar 

  20. Wiegand I, Geiss HK, Mack D, Stürenburg E, Seifert H (2007) Detection of extended-spectrum beta-lactamases among Enterobacteriaceae by use of semiautomated microbiology systems and manual detection procedures. J Clin Microbiol 45:1167–1174

    Article  PubMed  CAS  Google Scholar 

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Acknowledgements

We thank Dr. Joaquín Ruíz for his helpful comments on the manuscript.

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Correspondence to G. Yagüe.

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Munoz-Dávila, M.J., Yagüe, G., Albert, M. et al. Comparative evaluation of Vitek 2 identification and susceptibility testing of Gram-negative rods directly and isolated from BacT/ALERT-positive blood culture bottles. Eur J Clin Microbiol Infect Dis 31, 663–669 (2012). https://doi.org/10.1007/s10096-011-1356-1

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