title: Detection of viable Mycobacterium leprae in soil samples: insights into possible sources of transmission of leprosy.
abstract: Leprosy has ceased to be a public health problem world wide, after the successful implementation of effective chemotherapy (MDT) and use of control measures. However, new cases of leprosy continue to occur. Mycobacterium leprae cannot be grown in any acceptable culture medium and besides the wild armadillos, there is no known animal reservoir for leprosy. The transmission of leprosy is believed to be due to a large extent by droplet discharge of bacilli through nose and mouth and to a lesser extent by direct contact of susceptible host with a patient for long duration. The exact role of the environment in the transmission dynamics is still speculative. In the present study, we have tried to detect viable M. leprae from soil samples in endemic areas by using molecular methods. Eighty soil samples were collected from villages of this area, DNA and RNA of M. leprae extracted and identified using specific M. leprae primers. PCR amplification was done and real-time RT-PCR was used to detect viable M. leprae. DNA targeting the 16S region of M. leprae was detected in 37.5%, whereas M. leprae RNA targeting the same region was detected in 35% of these samples. Of the total 80 samples, 40 were collected from residential areas of leprosy patients whereas 40 samples were from no-patient areas. Fifty-five percent positivity for 16S rRNA of M. leprae was observed from the "patient" area in comparison to 15% positivity from the "no-patient" area (p < 0.001). This study thus provides valuable information of presence of viable M. leprae in soil specimens, which would be of use in investigating the transmission dynamics in leprosy.
authors.affiliation: National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra 282001, India.
authors.forename: Mallika
authors.initials: M
authors.lastname: Lavania
authors.forename: Kiran
authors.initials: K
authors.lastname: Katoch
authors.forename: Vishwa Mohan
authors.initials: VM
authors.lastname: Katoch
authors.forename: Anuj Kumar
authors.initials: AK
authors.lastname: Gupta
authors.forename: Devendra Singh
authors.initials: DS
authors.lastname: Chauhan
authors.forename: Rahul
authors.initials: R
authors.lastname: Sharma
authors.forename: Rashi
authors.initials: R
authors.lastname: Gandhi
authors.forename: Varsha
authors.initials: V
authors.lastname: Chauhan
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Bansal
authors.forename: Pawan
authors.initials: P
authors.lastname: Sachan
authors.forename: Shailendra
authors.initials: S
authors.lastname: Sachan
authors.forename: V S
authors.initials: VS
authors.lastname: Yadav
authors.forename: Rupendra
authors.initials: R
authors.lastname: Jadhav
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D004784:Environmental Monitoring; D007918:Leprosy / Q000382:microbiology* / Q000635:transmission*; D009166:Mycobacterium leprae / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S