Proceedings of the 10th International Colloquium on Paratuberculosis

#52 Is ‘Indian Bison Type’ Mycobacterium avium subspecies paratuberculosis represents‘
a new MAP Biotype’?
Jagdeep Singh Sohal, Shoor Vir Singh, Pravin Kumar Singh, Ajay Vir Singh, M C Sharma
Indian Council <strong>of</strong> Agricultural Research, India; Central Institute for Research on Goats, India
Objective: In India, first case <strong>of</strong> Johne’s disease was identified in 1913, but active research was started only
after 1984. Indian MAP has been found to be highly pathogenic and endemic in domestic animals. First time
culture <strong>of</strong> Indian MAP isolates in 1988 by our group, helped in initial characterization using radio-active probes,
protein and lipid pr<strong>of</strong>iles. Genotypic analysis with help <strong>of</strong> Spanish and Australian labs, first time indicated that
‘Indian MAP strains’ were similar to ‘Bison type’ MAP, but possibly represents a new biotype. Present study
aimed to identify <strong>the</strong> genetic variations <strong>of</strong> ‘Indian MAP strains’ and <strong>the</strong>ir evolution compared with o<strong>the</strong>r MAP
strains
Materials and Methods: Different molecular markers (IS elements, LSPs and SSRs) <strong>of</strong> native MAP were
analyzed in order to study above objectives.
Results and Conclusion: Sequencing <strong>of</strong> different markers identified SNPs/indels unique to ‘Indian Bison
Type’ MAP with potential to be used as ‘Molecular Signatures’ for native strains <strong>of</strong> MAP. Positional polymorphism
was also identified in few IS elements. Studies on ‘Phylogenetic Analysis’ indicated that <strong>the</strong> ‘Indian
Bison Type’ MAP may be most recent to evolve in <strong>the</strong> evolutionary ladder, when compared with MAP strains
reported outside India. Molecular phylogeny studies also indicated that <strong>the</strong> o<strong>the</strong>r strains <strong>of</strong> MAP were perhaps
evolutionary intermediates during its’ journey from M. avium to ‘Indian Bison Type’ MAP through ‘Sheep type’,
‘Cattle type’ and ‘US Bison type’ strains. Study also identified genetic rearrangements in <strong>the</strong> genome <strong>of</strong> ‘Indian
Bison Type’ MAP that resulted in duplications <strong>of</strong> LSP regions in it’s genome. These ‘duplicated regions’ encode
for important proteins including virulence factors, antigenic proteins and enzymes. The diagnostic kit (ELISA
based) and ‘indigenous vaccine’ developed using ‘Indian Bison Type’ strain have been reported to be highly
efficacious. Increased gene dosages due to duplicated regions may be responsible for over-production <strong>of</strong> virulence
factors and antigens that may have bearing on over all virulence and efficacy <strong>of</strong> vaccine prepared using
‘Indian Bison Type’ MAP strains Fur<strong>the</strong>r studies at proteome and transcriptome level and complete sequencing
<strong>of</strong> ‘Indian Bison Type’ MAP, will impart novel insights into <strong>the</strong> biology <strong>of</strong> native MAP. Documentation <strong>of</strong> new
‘Indian Bison Type’ MAP strain, (reported to be highly pathogenic) will help initiating efforts towards <strong>the</strong> control
<strong>of</strong> paratuberculosis in <strong>the</strong> country.
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