title: Presence of viable Mycobacterium leprae in environmental specimens around houses of leprosy patients.
abstract: OBJECTIVE
  Leprosy is a chronic systemic infectious disease caused by Mycobacterium leprae, one of the first organisms to be established as the cause for disease in humans. Because of high prevalence pockets of leprosy in the endemic regions, it is necessary to identify the possible sources of M. leprae in the environment and its mode of transmission.
  
  
  METHODS
  Slit skin smears (SSSs) from lesions were collected in 70% ethanol from 50 leprosy cases staying in the leprosy resettlement village and hospital from a high endemic area. One hundred and sixty soil samples were collected from different areas around the leprosy hospital and from the resettlement village of cured leprosy patients where active cases also resided at the time of sample collection. M. leprae specific gene region (RLEP 129 bp) and 16S rRNA targets were used for polymerase chain reaction (PCR) based detection for the presence and viability of M. leprae. An rpoT region was also amplified to determine presence of numbers of 6 bp tandem repeats.
  
  
  RESULTS
  All the SSS samples collected from patients showed three copies of rpoT region (6 bp tandem repeat, an ancient Indian type). Fifty-two soil samples showed presence of M. leprae DNA whereas M. leprae specific 16S rRNA gene was amplified in sixteen of these samples. PCR amplification and fragment length analysis showed 91 bp, i.e., three copies of the rpoT 6 bp tandem repeats from soil samples and similar three copies observed in patient samples.
  
  
  CONCLUSIONS
  Presence of viable M. leprae in the soil having same rpoT genotype of M. leprae noted in patients suggests that it could be the same strain of M. leprae. M. leprae found in the soil could be the one that is excreted out by the patient. Significance of its viability in the environment and its pathogenicity with respect to transmission needs to be further explored. Findings of this study might provide possible insights for further exploration into understanding transmission patterns in leprosy and also will throw light on identifying potential for existence of extra human source or reservoirs of M. leprae, if any.
authors: Department of Microbiology, Stanley Browne Laboratory, TLM Community Hospital, Nandnagri, New Delhi, India.
authors: R P
authors: RP
authors: Turankar
authors: Department of Microbiology, Stanley Browne Laboratory, TLM Community Hospital, Nandnagri, New Delhi, India.
authors: M
authors: M
authors: Lavania
authors: Department of Molecular Medicine, LRS Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors: M
authors: M
authors: Singh
authors: Department of Microbiology, Stanley Browne Laboratory, TLM Community Hospital, Nandnagri, New Delhi, India.
authors: U
authors: U
authors: Sengupta
authors: Department of Biotechnology, Sreenidhi Institute of Science and Technology, Ghatkesar, Hyderabad, Telangana, India.
authors: Ksr
authors: K
authors: Siva Sai
authors: Department of Microbiology, Government Institute of Science, Mumbai, Maharashtra, India.
authors: R S
authors: RS
authors: Jadhav
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005838:Genotype; D006801:Humans; D007918:Leprosy / Q000382:microbiology*; D009166:Mycobacterium leprae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012808:Sigma Factor / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012808:Sigma Factor; C414706:rpoT protein, Mycobacterium leprae