growth. Inoculated agar can be placed into a loosely closed plastic
bag to increase the humidity inside the container and still allow
some gas exchange. Commercial media is readily available and
includes sufficient quality controls and lowers lot-to-lot variability
than media made in the laboratory. For this reason, this option is
recommended.
1.3 Liquid Media
Mycobacteria grow more readily in broth than on solid media.
Middlebrook 7H9 with ADC and Dubos Tween albumin broths
are commonly used (see Table 1). Isolation rates from clinical
samples are higher for broth than solid media, although it is
recommended that laboratories inoculate both. Solid media can
serve as a backup if broth growth fails. Turbid broths should be
plated on solid media to determine if the culture is mixed or
Table 1
Description of most important media used to isolate and grow mycobacteria
Organism
Recommended media
Temperature
(
C)
Time
(days)
M. tuberculosis var.
tuberculosis
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
28
M. tuberculosis var.
bovis
Middlebrook 7H9 broth with ADC and 40 mM
sodium pyruvate
Middlebrook 7H10 agar with OADC and 40 mM
sodium pyruvate
37
28
M. avium
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
14–28
M. smegmatis
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
2–3
M. ulcerans
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
30
30–90
M. abscessus
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
3–5
M. kansasii
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
7–42
M. marinum
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
30
7–9
L-J Lowenstein–Jensen, OADC oleic albumin dextrose catalase supplement, ADC Middlebrook albumin dextrose
catalase supplement. (Other liquid media such as Sauton’s, Glycine Alanine Salt (GAS) and Proskauer-Beck are commonly used for research purposes. Tween is usually added when dispersion of cell clumps is needed)
Culturing Mycobacteria
5
bag to increase the humidity inside the container and still allow
some gas exchange. Commercial media is readily available and
includes sufficient quality controls and lowers lot-to-lot variability
than media made in the laboratory. For this reason, this option is
recommended.
1.3 Liquid Media
Mycobacteria grow more readily in broth than on solid media.
Middlebrook 7H9 with ADC and Dubos Tween albumin broths
are commonly used (see Table 1). Isolation rates from clinical
samples are higher for broth than solid media, although it is
recommended that laboratories inoculate both. Solid media can
serve as a backup if broth growth fails. Turbid broths should be
plated on solid media to determine if the culture is mixed or
Table 1
Description of most important media used to isolate and grow mycobacteria
Organism
Recommended media
Temperature
(
C)
Time
(days)
M. tuberculosis var.
tuberculosis
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
28
M. tuberculosis var.
bovis
Middlebrook 7H9 broth with ADC and 40 mM
sodium pyruvate
Middlebrook 7H10 agar with OADC and 40 mM
sodium pyruvate
37
28
M. avium
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
14–28
M. smegmatis
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
2–3
M. ulcerans
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
30
30–90
M. abscessus
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
3–5
M. kansasii
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
L-J
37
7–42
M. marinum
Middlebrook 7H9 broth with ADC
Middlebrook 7H10 agar with OADC
30
7–9
L-J Lowenstein–Jensen, OADC oleic albumin dextrose catalase supplement, ADC Middlebrook albumin dextrose
catalase supplement. (Other liquid media such as Sauton’s, Glycine Alanine Salt (GAS) and Proskauer-Beck are commonly used for research purposes. Tween is usually added when dispersion of cell clumps is needed)
Culturing Mycobacteria
5