Genotype profiles of Mycobacterium avium subspecies paratuberculosis isolates recovered from animals, commercial milk, and human beings in North India

Abstract

To understand the genetic diversity of Mycobacterium avium subspecies paratuberculosis (MAP) isolates recovered from domestic and wild ruminants, commercial milk, and human beings in North India. Genotyping of MAP isolates (N=117) recovered from animals, commercial milk, and human beings in different regions of North India between 1998 and 2007 was carried out using IS1311 PCR-restriction enzyme analysis (REA) and short sequence repeat (SSR) typing (G and GGT repeat loci). Of the 117 MAP isolates recovered from North India, bison-type was the predominant (83.8%) genotype followed by cattle-type (16.2%). Bison-type was the exclusive genotype recovered from goats, sheep, buffaloes, and blue bulls. However, both bison-type and cattle-type genotypes were recovered from cattle, humans, and commercial bovine milk samples. The relative distribution of the two genotypes was different in the different regions. Bison-type was the major genotype at the Central Institute for Research on Goats (CIRG), Akos, Ajmer, and Mathura, whereas, cattle-type was the major genotype from New Delhi and Agra. SSR typing of these isolates revealed that all MAP bison-type isolates had an identical profile (7g4ggt) with respect to G and GGT repeat SSR loci. In this study the sheep-type genotype was not found in North India. This study is the first from India to report the presence of two kinds of MAP genotypes (cattle-type and bison-type). However, non-reporting of the sheep-type genotype may not mean that it is absent in North India; the use of multiple culture media to recover MAP from clinical samples for future investigations is advised.