Molecular detection of mutations in rpoB gene involved in rifampin resistance in leprosy patients from Côte d'Ivoire

The control measures recommended for treatment of leprosy with multidrug therapy should limit spread of drug-resistant strains; however, rifampicin resistance continues to be reported in several countries. Resistance to anti-infectious used in multidrug therapy has not yet been molecularly established in Côte d'Ivoire. This preliminary study presents results of evaluation of level rifampicin resistance in Côte d'Ivoire. For each case of clinically confirmed multibacillary leprosy (new or relapsed cases) a dermal juice sample was examined by microscopy after Ziehl-Neelsen staining and a specific PCR targeting RLEP repeat sequence. 48 isolates were used to perform amplification of the rpoB gene involved in rifampicin resistance. The origin of the resistance was then investigated after sequencing and mutations analysis. Thus, 24 isolates (50 %) had mutations, 11 (22. 91 %) of which had mutations conferring rifampicin resistance. The mutations correlated with resistance were as follows: Gln438Val (9. 09 %), Asp441Asn (18. 18 %), Ser456Leu (45. 50 %) and Ser456Phe (27. 27 %) in 9 health districts in Côte d'Ivoire. These mutations were observed in both relapsed and new cases. In conclusion, cases of rifampicin resistance exist in Côte d'Ivoire and an active surveillance should be carried out to monitor the evolution of this resistance. In addition, this information can be used to control the spread of drug-resistant M. leprae strains.