The diagnosis of gram-negative bacillary pneumonia in an animal model using a competitive ELISA technique to detect the presence of lipid A.

Gram-negative bacillary pneumonias represent a major problem in hospitalized patients. A major research interest has been towards the development of rapid and accurate diagnostic procedures for these infections. An ELISA procedure for the detection of lipid A in pulmonary lavage fluid has been developed. Using the quantitation of lipid A, an antigen common to all clinically important gram-negative bacilli, as a marker for gram-negative bacilli, the presence or absence of pneumonia caused by these organisms could be demonstrated in laboratory animals. Additionally, by quantitating the lipid A associated with the lavageable pulmonary cell population, a measure of bacterial lung clearance could be obtained.