Table 2.

Drug-resistant phenotypes of S. Derby ST40 strains (n = 314).

Antibacterial drug types	Antimicrobial agent	R		I		S
		No. of isolates	Rate (%)	No. of isolates	Rate (%)	No. of isolates	Rate (%)
Penicillin	AMP	215	68.5	2	0.63	97	30.9
	AMS	44	14	161	51.3	109	34.7
Tetracycline	TET	287	90.54	0	0	27	8.6
	TGC	0	0	0	0	314	100
Polymyxins	CT	1	0.32	313	99.68	0	0
Carbapenems	ETP	1	0.32	0	0	313	99.68
	MEM	1	0.32	0	0	313	99.68
Cephalosporins	CZA	1	0.32	0	0	313	99.68
	CTX	5	1.6	0	0	309	98.4
	CAZ	4	1.3	0	0	313	99.7
Quinolones	CIP	122	38.9	16	5.1	176	56.1
	NAL	132	42	0	0	182	58
Aminoglycosides	AMK	1	0.32	0	0	313	99.7
	STR	107	34.1	0	0	207	65.9
Macrolides	AZI	2	0.63	0	0	312	99.36
Amido alcohols	CHL	237	75.4	0	6.31	57	18.2
Sulfonamides	SXT	196	62.4	0	0	118	37.6

R, antibiotic resistance; I, antibiotic intermediary; S, antibiotic sensitivity; AMP, ampicillin; AMS, ampicillin-sulbactam; AZI, azithromycin; AMK, Amikacin; CT, Polymyxin E; CZA, ceftazidime/avibactam; CTX, cefotaxime; CAZ, Ceftazidime; CIP, ciprofloxacin; CHL, chloramphenicol; ETP, ertapenem; MEM, meropenem; NAL, nalidixic acid; STR, Streptomycin; SXT, trimethoprim/sulfamethoxazole; TET, tetracycline; TGC, tigecycline; Breakpoints (in milligrams per liter) are as follows: AMP, S ≤ 8, I = 16, and R ≥ 32; AMS, S ≤ 8, I = 16, and R ≥ 32; AZI, S ≤ 16 and R ≥ 32; AMK, S ≤ 16, I = 32, and R ≥ 64; CT, S = 2, I ≤ 4, and R ≥ 8; CZA, S ≤ 2 and R ≥ 4; CTX, S ≤ 1, I = 2, and R ≥ 4; CAZ, S ≤ 4, I = 8, and R ≥ 16; CIP, S ≤ 1, I = 2, and R ≥ 4; CHL, S ≤ 8, I = 16, and R ≥ 32; ETP, S ≤ 0.5, I = 1, and R ≥ 2; MEM, S ≤ 1, I = 2, and R ≥ 4; NAL, S ≤ 16 and R ≥ 32; STR, S ≤ 8, I = 16, and R ≥ 32; SXT, S ≤ 2/38 and R ≥ 4/76; TET, S ≤ 4, I = 8, and R ≥ 16; TGC, S ≤ 2, I = 4, and R ≥ 8.