Volume 19 Supplement 1

35th International Symposium on Intensive Care and Emergency Medicine

Open Access

Concordance between a new molecular real-time approach and traditional culture in suspected VAP patients

  • M Clavel1,
  • O Barraud2,
  • V Moucadel3,
  • MC Ploy2,
  • E Karam4,
  • F Meynier3 and
  • Study Group François for Valibi B5
Critical Care201519(Suppl 1):P107

https://doi.org/10.1186/cc14187

Published: 16 March 2015

Introduction

Early microbiological documentation may reduce attributable mortality and excessive use of broad-spectrum antibiotics in ventilator-associated pneumonia (VAP). Using bronchoalveolar lavage (BAL) and endotracheal aspirates (ETA), we studied a new molecular biology-based approach to detect and quantify bacteria in less than 3 hours. This prospective multicenter trial aimed at comparing the microbiological results obtained using this molecular protocol (easyMAG® system) and semiquantitative culture in suspected VAP.

Methods

ETA and BAL samples were consecutively collected during 10 months in adult patients in four ICUs of France. The molecular method includes a preprocessing liquefaction for ETA before DNA extraction. DNAs were extracted using the easyMAG® system. Real-time PCR (qPCR) was run using the ABI7500FastDx PCR instrument. The results presented here concern: Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacteriaceae. Quantification was performed using qPCR standard curves, by converting the cycle threshold to CFU/ ml.

Results

A total of 125 suspected VAP were included from 122 patients. In total, 125 BAL and 107 ETA were collected. Sex ratio (M/F) was 76%, and CPIS ≥6 was calculated in 74.6% of the suspected VAP patients. Mean ventilation duration before sampling was 6 days. Seventy-eight percent and 65% of the BAL and ETA culture were positive respectively. Correlations between molecular method and culture on BAL and ETA are reported in Table 1.
Table 1

Concordance between qPCR and culture on BAL/ETA in VAP patients.

 

Positive culture

qPCR

Agreement (%)

Sensitivity (%)

Specificity (%)

S. aureus(BAL/ETA)

28/20

31/25

96.7/89.7

96.6/76.9

96.8/93.8

P. aeruginosa(BAL/ETA)

23/20

20/23

97.6/93.5

100/100

97.1/92.4

Enterobacteriaceae (BAL/ETA)

27/7

36/18

90.3/85.0

90.0/58.3

90.4/88.4

Conclusion

Sensitivity and specificity of the new molecular approach for these main bacteria found in VAP could enable targeted first-line antibiotic therapy. In the future, the development of this approach will aim at obtaining a bedside diagnostic in only a few hours.

Authors’ Affiliations

(1)
Hopital Dupuytren
(2)
UMRS-1092, Hopital Dupuytren
(3)
Biomérieux SA
(4)
Service de Réanimation
(5)
Inserm

Copyright

© Clavel et al.; licensee BioMed Central Ltd. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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