BioMed Research International

Research Article

Truncated Class 1 Integron Gene Cassette Arrays Contribute to Antimicrobial Resistance of Diarrheagenic Escherichia coli

Table 4

Number (%) of antibiotic-resistant diarrheagenic Escherichia coli isolates in Japan, with/without class 1 integrons.


Antibiotics	EAEC			EPEC			STEC			ETEC		Total
Antibiotics	Integron + (n = 20)	Integron − (n = 20)	Total (n = 40)	Integron + (n = 5)	Integron − (n = 32)	Total (n = 37)	Integron + (n = 2)	Integron − (n = 81)	Total (n = 83)	Integron + (n = 0)	Integron − (n = 2)	Integron + (n = 27)	Integron − (n = 135)

Ampicillin	20 (100)^‡	13 (65.0)	33 (82.5)	3 (60.0)^‡	4 (12.5)	7 (18.9)	1 (50.0)	8 (9.9)	9 (10.8)	0	1 (50.0)	24 (88.9)^‡	26 (19.3)
Sulfamethoxazole-trimethoprim	18 (90.0)^‡	3 (15.0)	21 (52.5)	3 (60.0)^‡	1 (3.1)	4 (10.8)	1 (50.0)^‡	1 (1.2)	2 (2.4)	0	1 (50)	22 (81.5)^‡	6 (4.4)
Tetracycline	18 (90.0)^‡	3 (15.0)	21 (52.5)	3 (60.0)^‡	4 (12.5)	7 (18.9)	1 (50.0)	9 (11.1)	10 (12.0)	0	1 (50.0)	22 (81.5)^‡	17 (12.6)
Nalidixic acid	13 (65.0)^‡	3 (15.0)	16 (40.0)	2 (40.0)	3 (9.4)	5 (13.5)	0	0	0	0	2 (100)	15 (55.6)^‡	8 (5.9)
Streptomycin	11 (55.0)^‡	3 (15.0)	14 (35.5)	2 (40.0)	2 (6.3)	4 (10.8)	2 (100)^‡	6 (7.4)	8 (9.6)	0	1 (50.0)	15 (55.6)^‡	12 (8.9)
Chloramphenicol	6 (30.0)	1 (5.0)	7 (17.5)	2 (40.0)	2 (6.3)	4 (10.8)	1 (50.0)^‡	1 (1.2)	2 (2.4)	0	0	9 (33.3)^‡	4 (3.0)
Gentamicin	2 (9.52)	0	2 (5.0)	0	0	0	0	0	0	0	0	2 (7.4)^‡	0
Cefotaxime	1 (10.0)	2 (10.0)	3 (7.5)	0	2 (6.3)	2 (5.4)	0	0	0	0	0	1 (3.7)	4 (3.0)
Norfloxacin	1 (5.0)	0	1 (2.5)	0	0	0	0	0	0	0	0	1 (3.7)	0
Kanamycin	0	0	0	1 (20.0)	1 (3.1)	2 (5.4)	1 (50.0)	2 (2.5)	3 (3.6)	0	0	2 (7.4)	3 (2.2)
Ciprofloxacin, fosfomycin, imipenem, or meropenem	0	0	0	0	0	0	0	0	0	0	0	0	0
Phenotype of multidrug resistance^†	19 (95.0)^‡	2 (10.0)	21 (52.5)	4 (80.0)^‡	3 (9.4)	7 (18.9)	1 (50.0)	2 (2.5)	3 (3.6)	0	1 (50.0)	24 (88.9)^‡	8 (5.9)
β-lactamase genes detected	bla_CTX-M-14 (n = 1), bla_TEM-1 (n = 1)	bla_CTX-M-14 (n = 1), bla_CTX-M-15 (n = 1)	bla_CTX-M-14 (n = 2), bla_CTX-M-15 (n = 1), bla_TEM-1 (n = 1)	bla_OXA-1 (n = 1)	bla_CTX-M-14 (n = 1), bla_TEM-1 (n = 1)	bla_CTX-M-14 (n = 1), bla_TEM-1 (n = 1) bla_OXA-1 (n = 1)						bla_CTX-M-14 (n = 1), bla_TEM-1(n = 1) bla_OXA-1(n = 1)	bla_CTX-M-14 (n = 2), bla_CTX-M-15 (n = 1), bla_TEM-1 (n = 1)

^†Defined as resistance to three or more classes of antimicrobials. ^‡Denotes significantly higher rate of resistance to antibiotics for class 1 integron-positive isolates compared with class 1 integron-negative isolates ().