identification of legionella pneumophila in intubated patients with taqman real time pcr

Background: legionellaceae contains legionella genus with over 52 species and 64 serogroups. it is one of the most important causes of respiratory disease in human. more than 30% of hospital-acquired pneumonia is caused by legionella. ventilator-associated pneumonia (vap) is an infection acquired in hospital wards, particularly in intensive care unit (icu). this disease approximately affects 9% to 20% of intubated patients. mortality in these patients varies between 8% and 76%. legionella is one of the important factors for infection in intubated patients. objectives: the present study was aimed to investigate the use of molecular methods in diagnosis of infection caused by legionella pneumophila. materials and methods: in this study, 109 samples of lung secretions collected from intubated patients admitted to icu wards of four university hospitals in a three-month period were examined. cultivation and real time polymerase chain reaction (pcr) methods were used to assess l. pneumophila colonization in these samples. results: eleven samples had positive results using real time pcr analysis of 16s rrna gene fragments specific for l. pneumophila, but according to culture method on specific buffered charcoal-yeast extract medium (bcye), no positive cases were detected. of the total positive cases, six were males, one female and four infants. the seven adults aged 40-65 years. conclusions: using molecular methods in diagnosis of infection caused by l. pneumophila has a great value because of its high specificity and rapid diagnosis potency.