Detection of Mycobacterium leprae DNA in soil: multiple needles in the haystack

Sci Rep. 2019 Feb 28;9(1):3165. doi: 10.1038/s41598-019-39746-6.

Abstract

Leprosy is an infectious disease caused by Mycobacterium leprae affecting the skin and nerves. Despite decades of availability of adequate treatment, transmission is unabated and transmission routes are not completely understood. Despite the general assumption that untreated M. leprae infected humans represent the major source of transmission, scarce reports indicate that environmental sources could also play a role as a reservoir. We investigated whether M. leprae DNA is present in soil of regions where leprosy is endemic or areas with possible animal reservoirs (armadillos and red squirrels). Soil samples (n = 73) were collected in Bangladesh, Suriname and the British Isles. Presence of M. leprae DNA was determined by RLEP PCR and genotypes were further identified by Sanger sequencing. M. leprae DNA was identified in 16.0% of soil from houses of leprosy patients (Bangladesh), in 10.7% from armadillos' holes (Suriname) and in 5% from the habitat of lepromatous red squirrels (British Isles). Genotype 1 was found in Bangladesh whilst in Suriname the genotype was 1 or 2. M. leprae DNA can be detected in soil near human and animal sources, suggesting that environmental sources represent (temporary) reservoirs for M. leprae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bangladesh / epidemiology
  • Ecosystem
  • Genotype
  • Humans
  • Leprosy / epidemiology
  • Leprosy / genetics*
  • Leprosy / microbiology
  • Leprosy / transmission
  • Mycobacterium leprae / genetics
  • Mycobacterium leprae / isolation & purification*
  • Mycobacterium leprae / pathogenicity
  • RNA, Ribosomal, 16S / genetics
  • Soil Microbiology*
  • Suriname / epidemiology

Substances

  • RNA, Ribosomal, 16S