Mycoplasma Pneumoniae in the ICU
Joel B. Baseman, PhD

This project is a multicenter study investigating the role of Mycoplasma pneumoniae, a frequent cause of community-acquired pneumonia, in ICU patients with suspected pneumonia developed while on a ventilator. Our objectives are to determine how frequently M. pneumoniae infection occurs among patients on a ventilator, and to evaluate the impact of this infection on ICUvrecovery. To achieve these goals, we will use new diagnostic tests targeting a unique toxinvfrom M. pneumoniae, the Community Acquired Respiratory Distress Syndrome (CARDS) toxin.

Eligible subjects will be undergoing the routine suctioning of fluid from the lungs (bronchoalveolar lavage) to confirm the diagnosis of pneumonia. A sample of the lung fluid will be collected along with a blood sample at that time. We will test these samples for CARDS toxin DNA in lung fluid and blood; CARDS toxin proteins in lung fluid; and antibodies against CARDS toxin in blood. Additional blood samples will be collected every two weeks while subjects remain in the ICU, and these will also be tested for anti-toxin antibodies. These tests will allow us to determine the frequency of M. pneumoniae infection in this setting.

We will also collect data on the clinical outcomes for each subject in order to determine the impact of M. pneumoniae infection in the ICU. Our preliminary data show that M. pneumoniae is common in ventilator-dependent patients with suspected pneumonia, and is associated with longer ventilator times and worse oxygenation in patients with severe respiratory disease. This study will expand upon these findings from a single ICU by the inclusion of multiple sites around the country. This study is the first to use these tests for the rapid diagnosis of M. pneumonia infection in the ICU, and the first to evaluate the contribution of this organism to lung disease in critically ill patients.