Real-time PCR-based quantitation of viable Mycobacterium leprae strain from clinical samples and environmental sources and its genotype in multi-case leprosy families of India

AbstractThe potential role of environmentalM. leprae in the transmission of leprosy remains unknown. We investigated role of environment as a possible source of viableM. leprae responsible for transmission of leprosy. The samples were collected from 10 multi-case leprosy families comprising, slit skin smear (SSS) from 9 multibacillary (MB), 16 paucibacillary cases (PB), 22 household contacts, and 38 environmental soil samples. The quantum of viableM. leprae was estimated by qRT-PCR using16S rRNA gene from soil and SSS. Genotypes ofM. leprae were determined by gene sequencing. We could observe presence of viableM. leprae in 11 (44%) leprosy cases (M. leprae 16S rRNA gene copies range from 1.78  × 102 to 8.782  × 109) and 4 (18%) household contacts (M. leprae 16S rRNA gene copies range from 2.54  × 103 and 7.47  × 104). Remarkably, presence of viableM. leprae was also noted in 10 (53%) soil samples where inM. leprae 16S rRNA gene copies ranged from 4.36  × 102 to 7.68  × 102.M leprae subtype 1D was noted in most of the leprosy cases their household contacts and in the surrounding soil samples indicating source of infection in household contacts could be from environment or patients.M. leprae 16S rRNA copies were approximately similar in both PB cases and soil samples along with presence of SNP type 1 subtype 1D in both samples indicating source ofM. leprae from patients to contacts was either from patients or environment or both.
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research