title: Splitting of a prevalent Mycobacterium bovis spoligotype by variable-number tandem-repeat typing reveals high heterogeneity in an evolving clonal group.
abstract: Mycobacterium bovis populations in countries with persistent bovine tuberculosis usually show a prevalent spoligotype with a wide geographical distribution. This study applied mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing to a random panel of 115 M. bovis isolates that are representative of the most frequent spoligotype in the Iberian Peninsula, SB0121. VNTR typing targeted nine loci: ETR-A (alias VNTR2165), ETR-B (VNTR2461), ETR-D (MIRU4, VNTR580), ETR-E (MIRU31, VNTR3192), MIRU26 (VNTR2996), QUB11a (VNTR2163a), QUB11b (VNTR2163b), QUB26 (VNTR4052), and QUB3232 (VNTR3232). We found a high degree of diversity among the studied isolates (discriminatory index [D] = 0.9856), which were split into 65 different MIRU-VNTR types. An alternative short-format MIRU-VNTR typing targeting only the four loci with the highest variability values was found to offer an equivalent discriminatory index. Minimum spanning trees using the MIRU-VNTR data showed the hypothetical evolution of an apparent clonal group. MIRU-VNTR analysis was also applied to the isolates of 176 animals from 15 farms infected by M. bovis SB0121; in 10 farms, the analysis revealed the coexistence of two to five different MIRU types differing in one to six loci, which highlights the frequency of undetected heterogeneity.
authors.affiliation: Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Rodriguez-Campos
authors.forename: Yurena
authors.initials: Y
authors.lastname: Navarro
authors.forename: Beatriz
authors.initials: B
authors.lastname: Romero
authors.forename: Lucía
authors.initials: L
authors.lastname: de Juan
authors.forename: Javier
authors.initials: J
authors.lastname: Bezos
authors.forename: Ana
authors.initials: A
authors.lastname: Mateos
authors.forename: Paul
authors.initials: P
authors.lastname: Golby
authors.forename: Noel H
authors.initials: NH
authors.lastname: Smith
authors.forename: Glyn R
authors.initials: GR
authors.lastname: Hewinson
authors.forename: Lucas
authors.initials: L
authors.lastname: Domínguez
authors.forename: Darío
authors.initials: D
authors.lastname: García-de-Viedma
authors.forename: Alicia
authors.initials: A
authors.lastname: Aranaz
mesh_terms: D000818:Animals; D002417:Cattle; D016000:Cluster Analysis; D019143:Evolution, Molecular; D014644:Genetic Variation; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D058889:Molecular Typing; D009163:Mycobacterium bovis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D013030:Spain / Q000453:epidemiology; D014380:Tuberculosis, Bovine / Q000453:epidemiology / Q000382:microbiology