Applications of Legionella Pneumophila Protein FLA and PILE in Serological Diagnosis

Background: Serological testing for antibody against Legionella pnewnophila (LP) is often the primary method of screening for possible Lp infections. Methods: This study is an attempt to use the Lp protein FLA and PILE as coating antigen for ELISA. First, the coding sequences of the two proteins were cloned into the pET32a(+) vectors. Then the two proteins were produced and purified. The best working concentration of the two proteins as coating antigen was screened separately by criss-cross serial-dilution analysis. Then an ELISA method was developed for Lp antibody detection. The Lp antibody level of 120 serums was detected by both this new ELISA method and the DRG ELISA kit. Results: The results suggest that protein FLA and PILE as coating antigen of ELISA to detect Lp antibody in serum shows better specificity and positive rate (5%, 3.4%) than the DRG ELISA kit. Conclusions: The new ELISA has a high referential value for Legionnaires' disease (LD) diagnosis and provided valuable information for the development of a serodiagnosis Kit for LD.