The LEPVOR project achieved substantial results in all work packages and three objectives.
The most important results are the linkage of mutations in two genes with dapsone resistance, including one gene involved in a compensatory mechanism and another involved directly in dapsone resistance. The results suggest a new mechanism of resistance for dapsone previously unknown. The characterization of this new mechanism is now performed, and the development of a PCR assay to efficiently detect mutations in these genes in clinical isolates.
In parallel, a total of 193 new M. leprae genomes from Brazil were sequenced, and we identified a drug resistance cluster of strains circulating in Para state, Brazil. Several SNPs are associated with this cluster and require functional characterization. The genotypes and molecular drug resistance results were communicated to the clinician, and patient treatment was adjusted accordingly. These data were also transmitted to the leprosy national program head in Brazil for further action to interrupt the transmission of drug-resistant strain in the state of Para.
The data are now used to write a publication describing the distribution of M. leprae strains in the state.
In the frame of the WP2/3, the M. leprae ML0411 and the mutated protein versions were successfully purified. The antibody response to these antigens is currently tested in Brazil.
The work performed, the knowledge acquired and methods developed during during the LEPVOR project have led to the publication of 12 peer-reviewed articles, including reviews and original research. The work performed in objective 1 led to the collection of solid preliminary data that are now used to write a grant application to characterize further the new mechanism of resistance identified in objective 1.
