Pneumologie 2011; 65 - P358
DOI: 10.1055/s-0031-1272163

Identification of pathogens directly from respiratory specimens from patients with HAP within 40 minutes

E Blömecke 1, V Krauter 1, I Thrippleton 2, W von Stein 2, M Stange 2, K Pfeffer 1, C Mackenzie 3
  • 1Universitätsklinikum Düsseldorf, Heinrich Heine Universität
  • 2miacom diagnostics GmbH – Düsseldorf
  • 3Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Universitätsklinikum Düsseldorf, Heinrich Heine Universität

Background:

Hospital acquired pneumonia (HAP) is a leading cause of mortality, morbidity and increased hospital costs. Treatment of HAP mandates initiation of generally broad spectrum antibiotics after establishing the diagnosis with deescalation after pathogen identification. Classical microbiological culture and identification requires 24 to 48 hours. We have developed and tested a rapid method of identifying pathogens using a beacon-based fluorescent insitu hybridisation (bbFISH) method to identify the major pathogens causing HAP.

Methods:

The often high viscosity of sputum has hitherto prevented the direct application of fluorescence-based assays. The novel bbFISH method allows application of this technology. Respiratory specimens obtained from an interdisciplinary surgical intensive care unit were examined and high quality specimens as judged by the number of leukocytes were included in the study and subjected to additional bbFISH analysis. The results of bbFISH were compared to culture.

Results:

In a proof of principal pilot study 53 specimens were analysed. Out of twelve anticipated pathogens included in this panel, eleven were detected in this study. E. coli and P. aeruginosa were identified with a high- and P. vulgaris with a low frequency. The method showed a sensitivity of 97% and a specificity of 93%. Respiratory specimens were then analysed in a five month period and compared to culture.

Conclusions:

The technology enables correct identification of pathogens directly from respiratory specimen such as sputa or aspirates, without cultivation or amplification, within 40 minutes. The method allows the rapid identification of potential pathogens and in conjunction with the local resistance data could lead to a more rational targeted antibitotic therapy until the results of the susceptibility tests are available. We believe that this method may impact on patient mortality, morbidity, hospital costs and in addition lead to reduced use of broad-spectrum antibiotics.