Antibody test for Legionella pneumophila detection.

Legionella pneumophila is responsible for Legionnaires' disease (LD). Its detection in both environmental and clinical samples is mainly performed by culture plate method which requires up to 10days to obtain results. Nowadays, there are commercial antibodies against this bacterium, but they have not been tested against all subgroups of L. pneumophila sg 1 or serogroups 1-16 or their cross-reactions with other non-Legionella bacteria. Indeed, many of these antibodies became available when only 8 serogroups of L. pneumophila had been described. We tested 7 antibodies and found that 2 (Mab 8/5 and OBT) specifically detected all the subgroups of L. pneumophila sg 1, one without cross-reactions (Mab8/5). Moreover, the LP3IIG2 antibody detected almost all serogroups tested with lower rates of cross-reactivity, resulting in a specific sensitive antibody for the detection of L. pneumophila. LP3IIG2 presented higher rate of cross-reactivity against respiratory non-Legionella isolates, thereby contraindicating its clinical applicability.