Skip to content


  • Meeting abstract
  • Open Access

Specific multigenotypic diagnosis of nosocomial pneumonia in ICU

  • 1,
  • 2,
  • 3,
  • 2 and
  • 1, 3
Critical Care20015(Suppl 1):P047

Received: 15 January 2001

Published: 2 March 2001


  • Pneumonia
  • Critical Care
  • Current Result
  • Bronchoalveolar Lavage
  • Molecular Identification

Mortality rate of nosocomial pneumonia in ventilated ICU patients (pts) is about 20-25%. Despite advances in critical care, standard criteria for pneumonia are still inaccurate. Antibiotherapy is often started on a 'best guess' basis to anticipate frequently negative bacteriological results (Ba-cul). Main etiological pathogens are staphylococci, streptococci, pseudomonads and enterobacteriaceae. A multigenotypic and sequential molecular identification (Mol-id) was applied on bronchoalveolar lavages (BAL) from 12 pts with clinical-radiological evidence of infection with (n = 9)/without (n = 3) positive Ba-cul. DNA extraction and duplicate specific amplification of 16S rDNA from BAL was first used to identify signals corresponding to the presence of Gram + (G+), Gram - (G-), or mixed G+/G-. Any G+ signal was followed by femA and mecA multiplex (mpx)-PCR for species-specific identification of staphylococci and methicillin resistance, and by mpx-PCR for S. pneumoniae. Any G- signal was followed by mpx-PCR for species-specific identification of Pseudomonads (aeruginosa, cepacia, maltophilia) vs other G- for which the 16S rDNA amplicon was sequenced.

Mol-id identified mixed G+/G- in 2/3 negative Ba-cul. Ba-cul gave G+ or G- only in 3 and 4/12 pts, respectively. Among these, Mol-id confirmed either G+ (2/3) or G- (2/4), and found a mixed signal in 3/7 pts. Mixed G+/G- was found by Ba-cul and Mol-id in 2/12 BAL, but in one case, S. epidermidis was found by Mol-id and enterococci by Ba-cul. Staphylococci (MRSA, other) and Ps. aeruginosa were found by Ba-cul and Mol-id in 2 and 3 pts, respectively.

Current results suggest that Mol-id is a useful adjunct bringing more insight to standard criteria of nosocomial pneumoniae in ICU and can be a timely relevant guide for antibiotherapy.

Authors’ Affiliations

Laboratory of Applied Molecular Technology, Université Catholique de Louvain, Belgium
Department of Intensive Care, St. Luc University Hospital, Belgium
Section MSW, Operational Epidemiology and Infections Diseases, Queen Astrid Military Hospital, Brussels, Belgium


© The Author(s) 2001