Table 5.

Synergy concentrations and FICI values of the teicoplanin + tigecycline combination against 14 clinical M. abscessus isolates.

Isolate code	M. abscessus sub-species	erm41 sequevar	Clarithromycin susceptibility	MIC90 (μM)				FICI
				Teicoplanin		Tigecycline
				Alone	Combined	Alone	Combined
M199	abscessus	T28	Resistant	5	2	6	2	0.56
M337	abscessus	T28	Resistant	5	2	7	2	0.51
M404	abscessus	C28	Sensitive	6	2	4	1	0.53
M421	abscessus	T28	Resistant	17	3	4	0.6	0.37
M422	abscessus	T28	Resistant	6	1	6	1	0.44
M232	bolletii	T28	Resistant	21	5	18	2	0.39
M416	bolletii	N.D	Sensitive	4	2	5	1	0.63
M506	bolletii	C28	Sensitive	10	3	9	1	0.45
M111	massiliense	Deletion	Sensitive	10	2	10	2	0.48
M353	massiliense	Deletion	Sensitive	13	3	8	2	0.43
M357	massiliense	Deletion	Sensitive	12	2	8	1	0.33
M414	massiliense	Deletion	Sensitive	8	1	10	2	0.32
M444	massiliense	Deletion	Sensitive	7	3	6	1	0.48
M505	massiliense	Deletion	Sensitive	13	3	8	1	0.39

Results shown are the mean of two replicates. Standard deviations were ±50% of shown values. Synergy is defined as FICI ≤ 0.5. Indifference is defined as 0.5 < FICI ≤ 4, and antagonism is defined as FICI > 4. N.D, not determined.