R. Warren et al., GENOTYPING OF MYCOBACTERIUM-TUBERCULOSIS WITH ADDITIONAL MARKERS ENHANCES ACCURACY IN EPIDEMIOLOGIC STUDIES, Journal of clinical microbiology, 34(9), 1996, pp. 2219-2224
Two highly polymorphic Mycobacterium tuberculosis genomic domains, cha
racterized by hybridization to the oligonucleotide (GTG)(5), were iden
tified as potential DNA fingerprinting probes. These domains were clon
ed [pMTB484(1) and pMTB484(2K4), respectively] and shown to be useful
for genotype analysis by Southern blotting. These probes were used to
genotype geographically linked strains of M. tuberculosis previously s
hown to have identical IS6110 fingerprints. Subsequent DNA fingerprint
s generated dth MTB484(1) and MTB484(2K4) showed a high degree of poly
morphism, allowing subclassification of IS6110-defined clusters into c
omposites of smaller clusters and unique strains. Correlation of the m
olecular data with patient interviews and clinical records confirmed t
he sensitivity of these probes, as contacts were established only with
in subclusters. These findings demonstrate the requirement for multipl
e probes to accurately classify M. tuberculosis strains, even those wi
th high copy numbers of IS6110. The enhanced accuracy of strain typing
should, in turn, further our understanding of the epidemiology of tub
erculosis.