Inter- and Intra-subtype genotypic differences that differentiate Mycobacterium avium subspecies paratuberculosis strains

Abstract

BackgroundMycobacterium avium subspecies paratuberculosis (Map) is the aetiological agent of Johne’s disease or paratuberculosis and is included within the Mycobacterium avium complex (MAC). Map strains are of two major types often referred to as ‘Sheep’ or ‘S-type’ and ‘Cattle’ or ‘C-type’. With the advent of more discriminatory typing techniques it has been possible to further classify the S-type strains into two groups referred to as Type I and Type III. This study was undertaken to genotype a large panel of S-type small ruminant isolates from different hosts and geographical origins and to compare them with a large panel of well documented C-type isolates to assess the genetic diversity of these strain types. Methods used included Mycobacterial Interspersed Repetitive Units - Variable-Number Tandem Repeat analysis (MIRU-VNTR), analysis of Large Sequence Polymorphisms by PCR (LSP analysis), Single Nucleotide Polymorphism (SNP) analysis of gyr genes, Pulsed-Field Gel Electrophoresis (PFGE) and Restriction Fragment Length Polymorphism analysis coupled with hybridization to IS900 (IS900-RFLP) analysis.ResultsThe presence of LSPA4 and absence of LSPA20 was confirmed in all 24 Map S-type strains analysed. SNPs within the gyr genes divided the S-type strains into types I and III. Twenty four PFGE multiplex profiles and eleven different IS900-RFLP profiles were identified among the S-type isolates, some of them not previously published. Both PFGE and IS900-RFLP segregated the S-type strains into types I and III and the results concurred with those of the gyr SNP analysis. Nine MIRU-VNTR genotypes were identified in these isolates. MIRU-VNTR analysis differentiated Map strains from other members of Mycobacterium avium Complex, and Map S-type from C-type but not type I from III. Pigmented Map isolates were found of type I or III.ConclusionThis is the largest panel of S-type strains investigated to date. The S-type strains could be further divided into two subtypes, I and III by some of the typing techniques (IS900-RFLP, PFGE and SNP analysis of the gyr genes). MIRU-VNTR did not divide the strains into the subtypes I and III but did detect genetic differences between isolates within each of the subtypes. Pigmentation is not exclusively associated with type I strains.

Volatile Emissions from Mycobacterium avium subsp. paratuberculosis Mirror Bacterial Growth and Enable Distinction of Different Strains

“…Based on the comparison of whole genomes of MAP, two major lineages have been distinguished, a sheep lineage and a cattle lineage [39], historically designated “Sheep or S-type” and “Cattle or C-type”, respectively [40]. Using genotyping methods, the S-type strains can be further divided into two subtypes, Type I and Type III [41].…”

Culture phenotypes and molecular characterization of Mycobacterium avium subsp. paratuberculosis isolates from small ruminants

“…http://dx.doi.org/10.1016/j.rvsc.2013.03.010 researchers have used a different nomenclature. The Type S group can be divided into Type I and Type III strains (de Juan et al, 2005;Castellanos et al, 2007aCastellanos et al, , 2007bGriffiths et al, 2008;Stevenson, 2010;Biet et al, 2012). Type C strains are synonymous with Type II strains.…”

Molecular typing of Mycobacterium avium subsp. paratuberculosis (MAP) isolated from dairy goats in Brazil

“…The association of each strain with the host is not exclusive and may cause disease in all types of ruminants (Biet et al, 2012). Although the insertion sequence IS1311 is present in M. avium subsp.…”