Characterisation of Legionella pneumophila antigen in urine of guinea pigs and humans with Legionnaires' disease.

To study and develop the urinary antigen detection assay, urine was obtained from aerosol infected guinea pigs. The appearance of Legionella pneumophila antigen in guinea pig urine was then compared with that detected in urine from human Legionnaires' Disease (LD) cases. This study demonstrated that the antigen expressed in the experimental model of LD was of identical molecular weight, reacted almost identically in an ELISA based assay and in Western blots with the antigen found in human urine. The guinea pig urine can therefore be used as a reliable, consistent and controllable source of antigen for use in the urinary antigen assay.