Molecular diagnosis in HAP/VAP

Purpose of review This review describes recent findings related to molecular-based methods of potential application in the diagnosis of bacterial hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP). It focuses on methods capable of providing organism identification and keys of bacterial resistance necessary in clinical and epidemiological management of patients and on their ability to provide quantitative results. Recent findings Significant advances have been made in recent years in the field of molecular diagnosis of bacterial pathogens. Real-time PCR, hybridization and mass spectrometry-based platforms dominate the scene. Some of the new technologies provide high sensitivity and specificity in the identification of single or multiple pathogens or a combination of etiological identification and antimicrobial resistance determinants in Staphylococcus aureus, nonfermenter Gram-negative bacilli and Enterobacteriaceae that are often associated with the cause of bacterial HAP/VAP in the late onset of the disease. In diagnosis made directly from clinical specimens and quantification of targets for bacterial load, some of them are promising. Summary Despite some limitations, current molecular diagnostic methods have a great potential to include bacterial targets useful in the identification of microorganisms and antimicrobial resistance, to analyze directly unprocessed samples and to obtain quantitative results in bacterial HAP/VAP, an entity of complex microbiological diagnosis due to the features of the pathogens commonly implicated.