<span style="font-size:15.0pt;mso-bidi-font-size:11.0pt" lang="EN-GB">A new marker IS<i style="mso-bidi-font-style:normal">1311</i> L2 PCR-REA for identification of ‘Indian Bison’ type <i style="mso-bidi-font-style:normal">Mycobacterium avium </i>subspecies <i style="mso-bidi-font-style:normal">paratuberculosis</i> </span>

Abstract

Previously, a new biotype (Indian Bison type S5) of <i style="mso-bidi-font-style: normal">Mycobacterium avium </i>subspecies <i style="mso-bidi-font-style:normal">paratuberculosis </i>(MAP), genetically different from so far reported MAP genotypes, was identified. This biotype is widely distributed in different geographical regions in India among various host species including humans. Due to deletion of TG at 64^th and 65^th of IS<i style="mso-bidi-font-style:normal">1311</i> element at locus 2 (L2), there is a loss of <i style="mso-bidi-font-style:normal">BsaJ</i>I restriction site in Indian Bison type MAP S5. However, in non-Indian MAP (cattle type/sheep type/US Bison type), the site was intact. Taking advantages of these variations in the genome, authors optimized a new marker IS<i style="mso-bidi-font-style:normal">1311 </i>L2 PCR-REA (Restriction Endonuclease Assay), capable of distinguishing Indian Bison type MAP S5 from other biotypes. To test the field applicability, newly optimized assay was applied on 66 DNA samples (27 from cultural isolates and 39 from clinical specimens) where it successfully distinguished the MAP of Indian Bison type from other MAPs. Hence, this assay can be used to characterize MAP isolates in future molecular epidemiology investigations. Also the applicability of this assay on clinical DNA samples gives us freedom to have knowledge of the infecting MAP genotype prior to culture.