TABLE 2.

Resistance phenotypes conferred by CTX-M-15 Ω loop variants in E. coli TOP10

CTX-M-15 variant	MIC (μg/ml)a
	CAZ	CAZ-AVI	AMX	AMC	CF	FOX	CTX	ATM	FEP	ETP	IPM
Noneb	0.25	0.25	2	2	16	4	0.06	0.25	0.023	0.003	0.25
M-15	16	0.5	>256	4	>256	8	>32	16	1.5	0.006	0.38
M-15 R164G	4	0.5	>256	6	256	8	1	0.75	0.25	0.003	0.19
M-15 P167L	4	0.5	>256	4	>256	8	0.38	0.75	0.19	0.012	0.25
M-15 P174Q	4	0.5	>256	4	256	12	0.75	0.75	0.75	0.008	0.25
M-15 P167Q	8	0.5	>256	4	>256	8	0.75	0.75	0.25	0.008	0.38
M-15 P167A	8	0.5	>256	4	>256	12	2	1.5	0.38	0.012	0.25
M-15 P167T	16	0.5	>256	6	>256	8	1	2	0.38	0.008	0.25
M-15 T171S	16	0.5	>256	4	>256	8	>32	12	2	0.006	0.38
M-15 P167S	64	2	>256	6	>256	12	8	3	2	0.032	0.25
M-15 L169Q	256	0.5	16	4	32	8	32	6	3	0.023	0.25
M-15 L169Q G240D	64	1	32	4	64	8	6	>32	4	0.032	0.19
M-15 L169Q S130G	32	16	24	12	32	8	0.25	0.25	0.75	0.004	0.25
M-15 L169Q S130G G240D	8	4	32	24	8	8	0.38	0.38	0.38	0.004	0.19
M-15 S130G	1	0.5	>256	24	32	3	0.023	0.047	0.016	0.003	0.094

^aCAZ, ceftazidime; AVI, avibactam (4 μg/ml); AMX, amoxicillin; AMC, amoxicillin combined with clavulanate (2 μg/ml); CF, cephalothin; FOX, cefoxitin; CTX, cefotaxime; ATM, aztreonam; FEP, cefepime; ETP, ertapenem; IPM, imipenem.

^bNone, plasmid control without bla_CTX-M-15.