[Quantitative cultures in diagnosis of pneumonia--a method for routine practice?]

Quantitative cultures of respiratory secretions represent a valid technique for the diagnosis of ventilator-associated pneumonia. Contamination, colonization and true infection can be differentiated with a reasonable specificity using established cut-offs of bacterial colony counts. Quantitative investigations provide local epidemiological databases as a framework for empirical antimicrobial policies and may also prove helpful in the guidance of individual antimicrobial therapy. Another reasonable indication is HIV-associated pneumonia. However, the use of this technique in routine practice is hampered by the high expertise and experience that will be necessary to be successfully used. Nevertheless, in view of the need to identify bacterial susceptibility patterns, at least large treatment centers should routinely use this most powerful diagnostic technique.