. 2023 Apr 20;11(3):e04261-22. doi: 10.1128/spectrum.04261-22

TABLE 1.

Genetic characteristics and antimicrobial susceptibility of CRPA strains tested in this study

Antibiotics	No. of isolates at an MIC (mg/L)^a of:											Breakpoint(s)^b	MIC (mg/L)		R (%)	Genetic resistance determinant(s)
	No. of isolates at an MIC (mg/L)^a of:												MIC₅₀	MIC₉₀
	0.12	0.25	0.5	1	2	4	8	16	32	64	128		MIC₅₀	MIC₉₀
Imipenem		3*		9	26	6	34	337†				≤2/≥8	≥16	≥16	89.40	Inactivation of oprD
Meropenem			4	19	17	67	54	254†				≤2/≥8	≥16	≥16	73.98	MexAB-OprM, mexCD-OprJ, bla_GES, bla_KPC, bla_AIM, bla_GIM, bla_IMP, bla_SPM, bla_VIM, and bla_OXA-198
Ceftazidime		1		2	129	15	61	46	53	108†		≤8/≥32	2	≥64	38.80	bla _AmpC
Cefepime				8*	43	18	155	106	85†			≤8/≥32	8	≥32	25.54	Overexpression of MexCD-OprJ
Piperacillin-tazobactam						30*	57	36	107	50	135†	(≤16/4)/ (≥128/4)	32	≥128	32.53	bla _AmpC
Colistin			390*	10	11	4						≤2/≥4	≤0.5	≤0.5	0.96
Ciprofloxacin		69*	59	95	76	116†						≤0.5/≥2	1	≥4	46.27	gyrA^T83I, gyrA^D87N, parE^A473V, qnrVC, ampC
Levofloxacin	2	2*	11	62	55	130	153†					≤1/≥4	4	≥8	68.19	MexXY-OprM (mexZ), MexVW-OprM
Tobramycin				315*	14	8	5	73†				≤4/≥16	≤1	≥16	17.59	MexXY-OprM
Amikacin					229*	67	29	32	14	44†		≤16/≥64	≤2	≥64	10.60	aac
Aztreonam					7	55	56	85	61	151†		≤8/≥32	32	≥64	51.08	MexAB-OprM

Boldfacing indicates data for resistant strains. *, MIC ≤ the indicated value; †, MIC ≥ the indicated value.

Breakpoint concentrations—expressed as “susceptibility (mg/L)/resistance (mg/L)”—are presented according to CLSI2022.