Table 2.

The number of colonies of different strains surviving exposures to CTMB, DBLAB or glutaraldehyde

	M. abscessus						M. chelonae				M. smegmatis
Exposure	2.0 WT ∼102 cfu plated	2.1 Select. CTAB ∼102 cfu plated	2.2 Select. DBLAB ∼102 cfu plated	2.3 Select. GTA ∼102 cfu plated	2.0 WT ∼105 cfu plated	2.3 Select. GTA ∼105 cfu plated	2.0 WT ∼102 cfu plated	2.1 Select. CTAB ∼102 cfu plated	2.2 Select. DBLAB ∼102 cfu plated	2.0 WT ∼105 cfu plated	mc2155 WT ∼105 cfu plated
5 min
2% GTA	0	0	0	0	1	4	0	0	0	2	0
20 min
9% CTAB	12	72	61	78	NT	NT	14	86	76	NT	0
9% DBLAB	15	68	58	92	NT	NT	4	NT	NT	NT	0
2% GTA	0	0	0	0	1	2	0	NT	NT	0	0
60 min
9% CTAB	6	47	57	52	NT	NT	8	53	73	NT	0
9% DBLAB	6	63	48	70	NT	NT	3	NT	NT	NT	0
2% GTA	0	0	0	0	0	0	0	NT	NT	0	0
24 h
9% CTAB	1	0	0	0	NT	NT	0	0	0	NT	0
9% DBLAB	0	0	1	0	NT	NT	0	0	0	NT	0

The strains tested were the parental isolates and their resistant derivatives, selected as survivors of previous exposures to the indicated disinfectants. NT, not tested; GTA, glutaraldehyde; Select., the strain was selected as a survivor after exposure to the indicated disinfectant.