Direct identification of major Gram-negative pathogens in respiratory specimens by respiFISH® HAP Gram (-) Panel, a...

Rapid detection of microorganisms in respiratory specimens is of paramount importance to drive the proper antibiotic regimen to prevent complications and transmission of infections. In the present study, the respiFISH® HAP Gram (-) Panel (miacom diagnostics GmbH, Duesseldorf, Germany) for the etiological diagnosis of hospital-acquired pneumonia was compared with the traditional culture method for the detection of major Gram-negative pathogens in respiratory specimens. respiFISH® combined the classical fluorescence in situ hybridization (FISH) technology with fluorescence-labeled DNA molecular beacons as probes. From September 2011 to January 2012, 165 samples were analyzed: the sensitivity and specificity were 94.39 and 87.93%, respectively. Only six pathogens (3.6%) were not identified with respiFISH®, while seven specimens (3%) provided false-positive results. This beacon-based identification shortens the time to result by at least one work day, providing species-level identification within half an hour. Considering the high sensitivity and specificity and the significant time saving, the introduction of bbFISH® assays could effectively complement traditional systems in microbiology laboratories.