ⅲ. Escherichia coli
Monitoring of antimicrobial resistance on 12 agents was carried out between 2012 and 2018. In 2018,
antimicrobial resistance in excess of 50% was observed among strains isolated from food-producing animals as
follows: ABPC, SM and TC resistance among cattle, pigs, and chickens; and CP and ST resistance among pigs.
Resistance rates to 8 out of 12 antimicrobials were observed to be higher in strains isolated from pigs than in those
derived from cattle and chickens. Resistance to CTX, CPFX, and CL, which are critically important antimicrobials
for human medicine, was in the ranges 3.3-11.8%, 11.8-22.3%, and 2.0-35.5%, respectively. It must be noted that
the BPs of CEZ and CL are the CLSI’s revised figures. As the BP of CL has changed, resistance rates in strains
isolated from pigs have been above 50% since 2016, but no upward trend has been observed in resistance rates
using the pre-revision BP. As CL was positioned as a second-line veterinary drug in 2018, its designation as a feed
additive was revoked and its use prohibited. Accordingly, it will be necessary to check trends in resistance rates
resulting from these risk management measures going forward.
Table 48. The proportion (%) of antimicrobial-resistant Escherichia coli isolated from diseased animals
Animal
2012†
2013†
2014†
2015
2016
2017
2018
Cattle
61.4
57.8
63.8
37.7
50.0
51.7
ABPC
32*
Pigs
65.2
50.4
57.4
74.5
70.7
62.8
Chickens
75.6
54.2
60.4
43.5
33.3
52.9
Cattle
21.1
6.7
14.9
15.6
15.6
17.2
32 (8* from
CEZ
Pigs
10.1
6.1
9.3
34.3
35.0
21.5
2016)
Chickens
40.2
16.7
14.6
15.2
11.1
17.6
Cattle
10.5
6.7
8.5
7.8
8.9
9.2
CTX
4*
Pigs
2.5
0.0
3.7
2.9
3.3
3.3
Chickens
37.8
14.6
10.4
6.5
5.6
11.8
Cattle
68.9
78.7
49.4
61.1
57.5
SM
32
Pigs
64.3
66.7
74.5
72.4
54.5
Chickens
60.4
56.5
38.9
51.0
Cattle
17.5
6.7
12.8
10.4
8.9
10.3
GM
16*
Pigs
24.1
8.7
19.4
21.6
22.8
13.2
Chickens
6.1
3.1
2.1
10.9
5.6
2.0
Cattle
38.6
26.7
29.8
16.9
26.7
28.7
KM
64*
Pigs
34.2
33.9
31.5
46.1
39.0
32.2
Chickens
51.2
35.4
39.6
50.0
36.1
27.5
Cattle
50.9
66.7
66.0
54.5
62.2
58.6
TC
16*
Pigs
79.1
75.7
75.9
87.3
78.9
70.2
Chickens
74.4
61.5
70.8
78.3
55.6
72.5
Cattle
29.8
33.3
36.2
18.2
33.3
33.3
NA
32*
Pigs
60.1
52.2
50.0
48.0
50.4
33.1
Chickens
73.2
59.4
52.1
56.5
55.6
35.3
Cattle
19.3
24.4
34.0
11.7
17.8
21.8
CPFX
4*
Pigs
36.1
23.5
32.4
24.5
28.5
22.3
Chickens
22.0
25.0
8.3
8.7
11.1
11.8
Cattle
5.3
6.7
0.0
10.4
20.0
11.5
16 (4* from
CL
Pigs
3.2
0.0
2.8
56.9§1
52.0§1
35.5§1
2016)
Chickens
2.4
1.0
0.0
8.7
0.0
2.0
Cattle
21.1
28.9
46.8
19.5
28.9
31.0
CP
32*
Pigs
64.6
64.3
61.1
69.6
59.3
57.0
Chickens
22
25
16.7
21.7
11.1
21.6
ST (TMP
Cattle
22.8
33.3
44.7
23.4
35.6
42.5
ST is 76/4*
from 2012
Pigs
49.4
59.1
64.8
62.7
56.9
52.9
(TMP is 16*)
to 2017)
Chickens
31.7
33.3
33.3
23.9
13.9
19.6
Cattle
57
45
47
77
90
87
Strains tested (n)
Pigs
158
115
108
102
123
121
Chickens
82
96
48
46
36
51
The unit of BP is μg/mL. * BP follows CLSI Criteria.
†-: Not under surveillance.
§1
If the BP of 16 used until 2015 is applied, CL resistance rate in pig-derived strains was 2.9% in 2016, 1.6% in 2017, and 0.8% in 2018.
Agent

BP

38