Table 4. Characteristics of ESBL-producing E. coli isolates from wastewater chains.
| Sampling location | Variant ID | No. resistances | AMR profile* | ESBL | Extra β-lacamases | Phylo-genetic subgroup | No. of isolates (%) | ST (no. of isolates tested) |
|---|---|---|---|---|---|---|---|---|
| Wastewater chain 1 | ||||||||
| HCI-4 (n = 9) | 1A | 9 | AmCxCzTeStCiNaSuTr | CTX-M-1 | TEM-1 | A 1 | 9 (100%) | ST23 (3) |
| HCI-2 (n = 10) | 1B | 8 | AmCxCzTeCiNaSuTr | CTX-M-1 | TEM-1 | B1 | 1 (10%) | n.t. |
| 1C | 9 | AmCxCzTeStCiNaSuTr | CTX-M-15 | OXA-1 | B2 3 | 9 (90%) | ST131 (3) | |
| mWWTP-2 | 1D | 7 | AmCxCzTeStSuTr | CTX-M-1 | TEM-1 | A1 | 1 (50%) | n.t. |
| Influent (n = 2) | 1C | 9 | AmCxCzTeStCiNaSuTr | CTX-M-15 | - | B2 3 | 1 (50%) | ST131 (1) |
| mWWTP-2 | 1E | 5 | AmCxCzCiNa | CTX-M-14 | - | A1 | 1 (16.7%) | n.t. |
| Effluent (n = 6) | 1F | 5 | AmCxCzTeSu | CTX-M-1 | - | B1 | 1 (16.7%) | n.t. |
| 1G | 7 | AmCxCzStCiNaTr | CTX-M-1 | - | A1 | 1 (16.7%) | n.t. | |
| 1H | 7 | AmCxCzTeStSuTr | CTX-M-1 | - | A1 | 1 (16.7%) | n.t. | |
| 1I | 7 | AmCxCzTeStSuTr | CTX-M-1 | - | B1 | 1 (16.7%) | n.t. | |
| 1A | 9 | AmCxCzTeStCiNaSuTr | CTX-M-1 | TEM-1 | A 1 | 1 (16.7%) | ST23 (1) | |
| Wastewater chain 2 | ||||||||
| HCI-5 (n = 8) | 2A | 5 | AmCxCzCiNa | CTX-M-15 | TEM-1 | B23 | 2 (25%) | n.t. |
| 2B | 6 | AmCxCzStCiSu | SHV-12 | - | D2 | 1 (12.5%) | n.t. | |
| 2C | 6 | AmCxCzTeCiNa | CTX-M-15 | OXA-1 | D 2 | 1 (12.5%) | ST405 (1) | |
| 2D | 7 | AmCxCzTeStSuTr | CTX-M-14 | TEM-1 | D2 | 1 (12.5%) | n.t. | |
| 2E | 9 | AmCxCzTeStCiNaSuTr | CTX-M-15 | TEM-1, OXA-1 | B23 | 2 (25%) | n.t. | |
| 2F | 9 | AmCxCzTeStCiNaSuTr | CTX-M-15, SHV-12 | TEM-1, OXA-1 | A0 | 1 (12/5%) | n.t. | |
| mWWTP-3 | 2G | 4 | AmCxCzCh | CTX-M-14 | - | B23 | 1 (12.5%) | n.t. |
| Influent (n = 8) | 2C | 6 | AmCxCzTeCiNa | CTX-M-15 | OXA-1 | D 2 | 1 (12.5%) | ST405 (1) |
| 2H | 8 | AmCxCzTeCiNaSuTr | CTX-M-15 | - | A1 | 1 (12.5%) | n.t. | |
| 2I | 9 | AmCxCzTeStCiNaSuTr | CTX-M-27 | - | B23 | 1 (12.5%) | n.t. | |
| 2J | 10 | AmCxCzTeStCiNaSuTrCh | CTX-M-1 | TEM-1 | A0 | 4 (50%) | n.t. | |
| mWWTP-3 | 2K | 5 | AmCxCzSuTr | CTX-M-1 | - | A0 | 2 (20%) | n.t. |
| Effluent (n = 10) | 2L | 5 | AmCxCzSuTr | CTX-M-1 | - | B22 | 1 (10%) | n.t. |
| 2M | 6 | AmCxCzStTrSuTr | CTX-M-1 | - | B22 | 1 (10%) | n.t. | |
| 2N | 7 | AmCxCzCiNaSuTr | CTX-M-15 | - | B23 | 1 (10%) | n.t. | |
| 2O | 7 | AmCxCzStCiSuTr | CTX-M-9, SHV-12 | - | D2 | 1 (10%) | n.t. | |
| 2P | 8 | AmCxCzTeStCiSuTr | CTX-M-15 | TEM-1 | D1 | 1 (10%) | n.t. | |
| 2I | 9 | AmCxCzTeStCiNaSuTr | CTX-M-27 | - | B23 | 1 (10%) | n.t. | |
| 2J | 10 | AmCxCzTeStCiNaSuTrCh | CTX-M-1 | TEM-1 | A0 | 2 (20%) | n.t. | |
* Am = ampicillin
Cx = cefotaxime
Cz = ceftazidime
Te = tetracyclin
St = streptomycin
Ci = ciprofloxacine
Na = nalidixic acid
Su = sulfamethoxazole
Tr = trimethoprim
Ch = chloramphenicol.
MICs were determined with Etests (Cz, Na, Su, Ch) and microbroth dilution (remainder of antimicrobials), resistance defined as MIC greater than or equal to the epidemiological cut-off (EUCAST).
Indicated in bold are pheno-/genotypes present in HCI and municipal wastewater.