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mycobacteria

Mycobacteria are a genus of thin, rod-shaped, slow-growing bacteria in the phylum Actinobacteria. They are characterized by a lipid-rich cell wall containing mycolic acids, which makes them acid-fast and resistant to many common stains and disinfectants.

Most are environmental saprophytes found in soil and water, but several species are human or animal pathogens.

They are obligate aerobes and tend to be slow-growing, with division times measured in hours to days.

Pathogenic species cause chronic granulomatous infections. TB causes pulmonary disease and disseminated disease; leprosy affects skin

TB is primarily airborne; leprosy requires prolonged contact in some settings; NTMs are often environmental. Treatment

Infection control, surveillance, and proper antibiotic stewardship are key.

The
genus
includes
the
Mycobacterium
tuberculosis
complex
(M.
tuberculosis,
M.
bovis,
etc.),
and
non-tuberculous
mycobacteria
(NTM)
such
as
M.
avium
complex,
M.
kansasii,
and
M.
marinum;
M.
leprae
is
the
etiologic
agent
of
leprosy.
They
require
specialized
culture
media
(Lowenstein-Jensen,
Middlebrook)
and
often
long
incubation
(weeks).
Acid-fast
staining
(Ziehl-Neelsen
or
auramine-rhodamine)
is
used
for
initial
detection.
and
nerves;
NTMs
cause
lung
disease,
lymphadenitis,
and
disseminated
infections,
especially
in
immunocompromised
individuals.
is
long-term
multi-drug
regimens;
drug
resistance
is
a
major
issue
(MDR-TB,
XDR-TB).
Laboratory
testing
guides
therapy;
vaccination
with
BCG
is
used
in
some
regions.