In this chapter, the procedures to infect and harvest M. leprae
from athymic nude mice and armadillos will be described.
1.14 Identification
of Mycobacteria
Once a mycobacterial culture is obtained, the genus and species of
the grown organism needs to be identified. This is particularly
important in the case of NTMs, where the identification tools are
less developed than for M. tuberculosis. Species identification of
mycobacteria can be difficult. Phenotypic characteristics have been
used traditionally to identify mycobacteria. These include growth
rate, colony morphology, pigmentation, optimal growth temperature, and reactions in a battery of biochemical tests. However, most
of these are poorly reproducible and require grown cultures before
species-level identification can be done. In addition, some of these
tests cannot differentiate many of the newly described species.
Furthermore, there is a known rate of variability between strains
belonging to the same species, and for these reasons, biochemical
assays are no longer recommended in the diagnostic laboratory. In
other settings, such as research laboratories and production
Fig. 4 Nude mouse with enlarged footpad due to M. leprae inoculation
Fig. 5 Nine-banded armadillo (Dasypus novemcinctus)
Culturing Mycobacteria
13
from athymic nude mice and armadillos will be described.
1.14 Identification
of Mycobacteria
Once a mycobacterial culture is obtained, the genus and species of
the grown organism needs to be identified. This is particularly
important in the case of NTMs, where the identification tools are
less developed than for M. tuberculosis. Species identification of
mycobacteria can be difficult. Phenotypic characteristics have been
used traditionally to identify mycobacteria. These include growth
rate, colony morphology, pigmentation, optimal growth temperature, and reactions in a battery of biochemical tests. However, most
of these are poorly reproducible and require grown cultures before
species-level identification can be done. In addition, some of these
tests cannot differentiate many of the newly described species.
Furthermore, there is a known rate of variability between strains
belonging to the same species, and for these reasons, biochemical
assays are no longer recommended in the diagnostic laboratory. In
other settings, such as research laboratories and production
Fig. 4 Nude mouse with enlarged footpad due to M. leprae inoculation
Fig. 5 Nine-banded armadillo (Dasypus novemcinctus)
Culturing Mycobacteria
13