Mycobacterium genotypes in pulmonary tuberculosis infections and their detection by trained African giant pouched rats
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Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Science+Business
Abstract
Tuberculosis (TB) diagnosis in low-income
countries is mainly done by microscopy. Hence, little is
known about the diversity of Mycobacterium spp. in TB
infections. Different genotypes or lineages of Mycobacte-
rium tuberculosis vary in virulence and induce different
inflammatory and immune responses. Trained Cricetomys
rats show a potential for rapid diagnosis of TB. They detect
over 28 % of smear-negative, culture-positive TB. How-
ever, it is unknown whether these rats can equally detect
sputa from patients infected with different genotypes of M.
tuberculosis. A 4-month prospective study on diversity of Mycobacterium spp. was conducted in Dar es Salaam,
Tanzania. 252 sputa from 161 subjects were cultured on
Lowenstein-Jensen medium and thereafter tested by rats.
Mycobacterial isolates were subjected to molecular iden-
tification and multispacer sequence typing (MST) to
determine species and genotypes. A total of 34 Mycobac-
terium spp. isolates consisting of 32 M. tuberculosis, 1
M. avium subsp. hominissuis and 1 M. intracellulare were
obtained. MST analyses of 26 M. tuberculosis isolates
yielded 10 distinct MST genotypes, including 3 new
genotypes with two clusters of related patterns not grouped
by geographic areas. Genotype MST-67, shared by one-
third of M. tuberculosis isolates, was associated with the
Mwananyamala clinic. This study shows that diverse M.
tuberculosis genotypes (n = 10) occur in Dar es Salaam
and trained rats detect 80 % of the genotypes. Sputa with
two M. tuberculosis genotypes (20 %), M. avium homin-
issuis and M. intracellulare were not detected. Therefore,
rats detect sputa with different M. tuberculosis genotypes
and can be used to detect TB in resource-poor countries.
Description
Article of Curr Microbiol (2015) 70:212–218
Keywords
Mycobacterium genotypes, Pulmonary tuberculosis infections, Trained African Giant, Pouched Rats