TABLE 3.
Antimicrobial resistance mechanisms detected in 1,195 C. coli isolatesa
| Antimicrobial class | Genetic AMR determinant | Description | No. (%) of positive isolates |
|---|---|---|---|
| Tetracyclines | tet(O) | Acquired AMR gene | 460 (38.49) |
| tet(L) | Acquired AMR gene | 20 (1.67) | |
| tet(O/32/O) | Acquired AMR gene | 19 (1.59) | |
| tet(W) | Acquired AMR gene | 12 (1.00) | |
| tet(O/W/32/O) | Acquired AMR gene | 1 (0.08) | |
| Fluoroquinolones | gyrA T86I | Point mutation | 445 (37.24) |
| Aminoglycoside | aph(3′)-III | Acquired AMR gene | 223 (18.66) |
| ant(6)-Ia | Acquired AMR gene | 168 (14.06) | |
| aadE-Cc | Acquired AMR gene | 161 (13.47) | |
| aac(6′)-aph(2′') | Acquired AMR gene | 94 (7.87) | |
| aph(2′')-If | Acquired AMR gene | 49 (4.10) | |
| aph(2′')-Ig | Acquired AMR gene | 39 (3.26) | |
| aph(2′')-Ic | Acquired AMR gene | 14 (1.17) | |
| aph(3′)-VIIa | Acquired AMR gene | 11 (0.92) | |
| aph(2′')-Ib | Acquired AMR gene | 5 (0.42) | |
| aac(6′)-Im | Acquired AMR gene | 5 (0.42) | |
| β-Lactams | bla OXA-489 | Acquired AMR gene | 676 (56.57) |
| bla OXA-193 | Acquired AMR gene | 407 (34.06) | |
| bla OXA-450 | Acquired AMR gene | 387 (32.38) | |
| bla OXA-453 | Acquired AMR gene | 387 (32.38) | |
| bla OXA-61 | Acquired AMR gene | 382 (31.97) | |
| bla OXA-452 | Acquired AMR gene | 378 (31.63) | |
| bla OXA-451 | Acquired AMR gene | 371 (31.05) | |
| bla OXA-460 | Acquired AMR gene | 84 (7.03) | |
| bla OXA-461 | Acquired AMR gene | 42 (3.51) | |
| bla OXA-465 | Acquired AMR gene | 1 (0.08) | |
| bla TEM-116 | Acquired AMR gene | 1 (0.08) | |
| bla TEM-229 | Acquired AMR gene | 1 (0.08) | |
| Macrolides | 23S rRNA A2075G | Point mutation | 204 (17.07) |
| 23S rRNA A2074G | Point mutation | 2 (0.17) | |
| erm(A) | Acquired AMR gene | 8 (0.67) | |
| erm(B) | Acquired AMR gene | 72 (6.03) | |
| Lincosamides | lnu(B) | Acquired AMR gene | 1 (0.08) |
| lnu(C) | Acquired AMR gene | 14 (1.17) | |
| lsa(E) | Acquired AMR gene | 1 (0.08) | |
| Phenicols | cat | Acquired AMR gene | 30 (2.51) |
| cat(pC194) | Acquired AMR gene | 12 (1.00) | |
| optrA | Acquired AMR gene | 12 (1.00) | |
| fexA | Acquired AMR gene | 7 (0.59) | |
| Multidrug efflux transporter | cmeABC | Acquired AMR gene | 1181 (98.83) |
| RE-cmeABC | Acquired AMR gene | 11 (0.92) |
a
Mutation reference isolates were gyrA-like ATCC 33559 and 23S rRNA-like NCTC 11168.