The prevalence and mechanism of fluoroquinolone resistance in Escherichia coli isolated from swine farms in China

Table 1 Prevalence of resistance to FQs antimicrobials in swine-derived E. coli isolates of different DANO MICs

Antimicrobials	DANO MIC (μg/mL)	HLJ	JL	LN	SD	HN	HB	YN	Resistance (%)	Total
Norfloxacin	≥128	27/34	26/27	24/24		26/27	1/1	1/1	92.11% (105/114)
	64	13/16	11/14	11/11		10/10			88.24% (45/51)
	32	9/15	8/12	10/10	1/2	6/6			75.56% (34/45)
	16	1/10	1/10	1/10	7/10	3/10			26% (13/50)
	8^a	0/7	0/6	2/7		0/7		0/2	6.9% (2/29)
	4–0.5	4/24	0/18	2/20	1/6	0/18	0/15	0/11	6.25% (7/112)
	≤0.25	0/20	0/17	0/14	0/3	0/18	0/4	0/2	0 (0/78)	43.00% (206/479)
Ciprofloxacin	≥128	28/34	26/27	24/24		26/27	1/1	1/1	92.98% (106/114)
	64	13/16	11/14	11/11		10/10			88.24% (45/51)
	32	10/15	8/12	10/10	1/2	6/6			77.78% (35/45)
	16	1/10	5/10	5/10	10/10	7/10			56% (28/50)
	8^a	0/7	1/6	4/7		1/7		0/2	20.69% (6/29)
	4–0.5	4/24	1/18	2/20	1/6	0/18	0/15	0/11	7.14% (8/112)
	≤0.25	0/20	0/17	0/14	0/3	0/18	0/4	0/2	0 (0/78)	47.60% (228/479)
Ofloxacin	≥128	26/34	26/27	24/24		26/27	1/1	1/1	91.23% (104/114)
	64	12/16	12/14	10/11		10/10			86.27% (44/51)
	32	10/15	8/12	9/10	1/2	6/6			75.56% (34/45)
	16	1/10	3/10	4/10	10/10	7/10			50% (25/50)
	8^a	0/7	1/6	3/7		3/7		0/2	24.14% (7/29)
	4–0.5	4/24	1/18	4/20	1/6	1/18	0/15	0/11	9.82% (11/112)
	≤0.25	0/20	0/17	0/14	0/3	0/18	0/4	0/2	0 (0/78)	47.00% (225/479)
Levofloxacin	≥128	24/34	25/27	23/24		26/27	1/1	1/1	87.72% (100/114)
	64	9/16	9/14	9/11		10/10			72.55% (37/51)
	32	3/15	7/12	4/10	1/2	5/6			44.44% (20/45)
	16	1/10	0/10	2/10	9/10	5/10			34% (17/50)
	8^a	0/7	0/6	3/7		2/7		0/2	17.24% (5/29)
	4–0.5	4/24	0/18	2/20	1/6	0/18	0/15	0/11	6.25% (7/112)
	≤0.25	0/20	0/17	0/14	0/3	0/18	0/4	0/2	0 (0/78)	38.83% (186/479)

Note: DANO Danofloxacin, HLJ Heilongjiang, JL Jilin, LN Liaoning, SD Shandong, HN Henan, HB Hubei, YN Yunan; ^a, the susceptibility breakpoint of DANO against swine-derived E. coli [5]

ISSN: 1746-6148