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

• Published in: 2012; 6. Journées des Microbiologistes de l'INRA 2012, L'Isle-sur-la-Sorgue, FRA, 2012-11-13-2012-11-15, 156
• Main Authors: Biet, Franck, Sevilla, Iker A, Cochard, Thierry, Lefrançois, Louise, Garrido, Joseba M, heron, Ian, Juste, Ramon A, McLukie, Joyce, Thibault, Virginie, Supply, Philip, Collins, Desmond M, Behr, Marcel A, Stevenson, Karen
• Format: Conference Proceeding
• Language: English
• Published: 2012
• Subjects: analyse génétique; Bacteriology; Bactériologie; genotyping; génotypage; Mycobacterium; Mycobacterium avium subsp. paratuberculosis; paratuberculosis; S type; typage moléculaire

Background : Mycobacterium 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. Results : The 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. Fifteen 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 member of Mycobacterium avium Complex, and Map S-type from C-type but not type I from III. Pigmented Map isolates were found to be either type I or III. Conclusion : This is the largest panel of S-type strains investigated to date and the results concur with the division of Map strains into two major lineages comprising S-type and C-type strains. 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). Pigmentation is not exclusively associated with type I strains.