African 2, a clonal complex of Mycobacterium bovis epidemiologically important in East Africa
Berg, Stefan; Garcia-Pelayo, M. Carmen; Muller, Borna; Hailu, Elena; Asiimwe, Benon; Kremer, Kristin; Dale, James; Boniotti, M. Beatrice; Rodriguez, Sabrina; Hilty, Markus; Rigouts, Leen; Firdessa, Rebuma; Machado, Adelina; Mucavele, Custodia; Ngandolo, Bongo Nare Richard; Bruchfeld, Judith; Boschiroli, Laura; Muller, Annelle; Sahraoui, Naima; Pacciarini, Maria; Cadmus, Simeon I.B.; Joloba, Moses; Van Soolingen, Dick; Michel, Anita Luise; Djønne, Berit; Aranaz, Alicia; Zinsstag, Jakob; Van Helden, Paul David; Portaels, Francoise; Kazwala, Rudovick R.; Kallenius, Gunilla; Hewinson, R. Glyn; Aseffa, Abraham; Gordon, Stephen V.; Smith, Noel H.
We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda,
Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2)
clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be
identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates
from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of
the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific
spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the
few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex
is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of M. bovis have, in general,
four or more copies of the insertion sequence IS6110, in contrast to the majority of M. bovis strains isolated
from cattle, which are thought to carry only one or a few copies.