Identification and evolution of an IS6110 low-copy-number Mycobacterium tuberculosis cluster.
A cohort of 56 patients infected with related strains of Mycobacterium tuberculosis, the S75 group, was identified in a New Jersey population-based study of all isolates with a low number of copies of the insertion element IS6110. Genotyping was combined with surveillance data to identify the S75 group and to elucidate its recent evolution. The S75 group had similar demographic and geographic characteristics. Seventeen persons (30%) were linked epidemiologically. The S75 group was segregated from other low-copy-number isolates on the basis of several independent molecular methods. This group included 3 IS6110 genotype variants: BE, H6, and C28, containing 1, 2, and 3 IS6110 insertions, respectively. IS6110 insertion site mapping and comparative sequence analysis strongly suggest a stepwise acquisition of IS6110 elements from BE to H6 to C28. S75 represents a locally produced strain cluster that has recently evolved. The combination of multiple molecular tools with traditional epidemiology provides novel insights into dissemination, local transmission, and evolution of M. tuberculosis.
Mathema
Barun
B
Public Health Research Institute Tuberculosis Center, 455 First Ave., New York, NY 10016, USA. barun@phri.org
Bifani
Pablo J
PJ
Driscoll
Jeffrey
J
Steinlein
Lauren
L
Kurepina
Natalia
N
Moghazeh
Soraya L
SL
Shashkina
Elena
E
Marras
Salvatore A
SA
Campbell
Shannon
S
Mangura
Bonita
B
Shilkret
Kenneth
K
Crawford
Jack T
JT
Frothingham
Richard
R
Kreiswirth
Barry N
BN
D004251:DNA Transposable Elements / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D018628:Gene Dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics; D016133:Polymerase Chain Reaction; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000382:microbiology
D004251:DNA Transposable Elements