Identification and characterisation of novel antigenic
proteins of Leptospira are necessary to unravel the secrets of the Leptospiral disease biology. Besides, the current scenario of
Leptospirosis demands the development of advanced diagnostics with the potential of an early and specific diagnosis. This work reports the diagnostic efficacy of a PI-PLC (LA_1375) of Leptospira interrogans serovar Lai strain 56601.
Phospholipases are
enzymes that catalyse the degradation of membrane
phospholipids, with the after effects of pathophysiological consequences through the impairment of cellular signalling mechanisms. The immunoblotting analysis allows to identify the
Leptospirosis positive serum samples demonstrated the expression and exposure of the
protein to the immune system and confirmed the antigenic nature of the
protein. Furthermore, evaluation of diagnostic efficacy of an ELISA to detect
antibodies against recombinant PI-PLC has tested in indirect
IgM ELISA using the purified 50 kDa
recombinant protein as the coating
antigen. A cut-off value of 0.218 at mean + 2SD and a sensitivity value of 100% and a specificity value of 95.65% explored for the rPI-PLC
IgM ELISA. The PPV and NPV of ELISA for the
Leptospirosis confirmed acute phase samples were 95.87% and 100% respectively. Comparison of the ELISA assay with MAT for the detection of Leptospiral
antibodies showed a positive correlation (r value 0.345, p < 0.05), and signified the diagnostic efficacy of rPI-PLC for the definitive diagnosis of the
Leptospirosis. In addition, the revealed conservation nature of PI-PLC among different Leptospira species highlights the diagnostic and
vaccine candidate potential. Thus, the study emphasises the Leptospiral PI-PLC as a potential
antigen still the importance as a novel
biomarker candidate for the serodiagnosis and pathogenesis of
Leptospirosis have to be investigated.