African 1, an epidemiologically important clonal complex of Mycobacterium bovis dominant in Mali, Nigeria, Cameroon, and Chad.
We have identified a clonal complex of Mycobacterium bovis present at high frequency in cattle in population samples from several sub-Saharan west-central African countries. This closely related group of bacteria is defined by a specific chromosomal deletion (RDAf1) and can be identified by the absence of spacer 30 in the standard spoligotype typing scheme. We have named this group of strains the African 1 (Af1) clonal complex and have defined the spoligotype signature of this clonal complex as being the same as the M. bovis BCG vaccine strain but with the deletion of spacer 30. Strains of the Af1 clonal complex were found at high frequency in population samples of M. bovis from cattle in Mali, Cameroon, Nigeria, and Chad, and using a combination of variable-number tandem repeat typing and spoligotyping, we show that the population of M. bovis in each of these countries is distinct, suggesting that the recent mixing of strains between countries is not common in this area of Africa. Strains with the Af1-specific deletion (RDAf1) were not identified in M. bovis isolates from Algeria, Burundi, Ethiopia, Madagascar, Mozambique, South Africa, Tanzania, and Uganda. Furthermore, the spoligotype signature of the Af1 clonal complex has not been identified in population samples of bovine tuberculosis from Europe, Iran, and South America. These observations suggest that the Af1 clonal complex is geographically localized, albeit to several African countries, and we suggest that the dominance of the clonal complex in this region is the result of an original introduction into cows naïve to bovine tuberculosis.
Müller
Borna
B
Swiss Tropical Institute, Socinstrasse 57, 4002 Basel, Switzerland.
Hilty
Markus
M
Berg
Stefan
S
Garcia-Pelayo
M Carmen
MC
Dale
James
J
Boschiroli
M Laura
ML
Cadmus
Simeon
S
Ngandolo
Bongo Naré Richard
BN
Godreuil
Sylvain
S
Diguimbaye-Djaibé
Colette
C
Kazwala
Rudovick
R
Bonfoh
Bassirou
B
Njanpop-Lafourcade
Betty M
BM
Sahraoui
Naima
N
Guetarni
Djamel
D
Aseffa
Abraham
A
Mekonnen
Meseret H
MH
Razanamparany
Voahangy Rasolofo
VR
Ramarokoto
Herimanana
H
Djønne
Berit
B
Oloya
James
J
Machado
Adelina
A
Mucavele
Custodia
C
Skjerve
Eystein
E
Portaels
Francoise
F
Rigouts
Leen
L
Michel
Anita
A
Müller
Annélle
A
Källenius
Gunilla
G
van Helden
Paul D
PD
Hewinson
R Glyn
RG
Zinsstag
Jakob
J
Gordon
Stephen V
SV
Smith
Noel H
NH
D000349:Africa / Q000453:epidemiology; D000818:Animals; D015373:Bacterial Typing Techniques; D002417:Cattle; D002872:Chromosome Deletion; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014380:Tuberculosis, Bovine / Q000453:epidemiology* / Q000382:microbiology*