Table 2.
Molecular characterization of the 41 ETEC, STEC, and STEC/ETEC mcr-1-positive isolates.
| Pathotype (No. isolates) | Serotypea-PG-ST | CHb | No. isolates | ESBL typing (No. isolates) | Virulence gene profile (No. isolates) | Resistance profilec (isolates with mcr co-occurrence and type) |
|---|---|---|---|---|---|---|
| ETEC (33) | O141:H4-A-ST10 | 11-24 | 2 | – | STa, STb, F18ac, HlyA (1) | AMP AMP/SAM CHL COL GEN TI TMP/SMX TOB |
| STa, STb (1) | AMP AMP/SAM CHL COL GEN TI TMP/SMX TOB | |||||
| O157:HNM-A-ST10 | 11-24 | 10 | CTX-M-14 (3) | LT, STb, K88ac, HlyA (5) | AMP AMP/SAM ATM COL CTX FEP MI NAL TI | |
| AMP AMP/SAM CHL COL CTX FEP MI NAL TI TMP/SMX | ||||||
| AMP AMP/SAM COL CTX FEP GEN MI NAL TI TMP/SMX TOB | ||||||
| AMP AMP/SAM COL GEN MI NAL TI TMP/SMX TOB | ||||||
| CIP COL LEV MI NAL | ||||||
| LT, STb, K88ac (2) | AMP AMP/SAM COL GEN MI NAL TI TMP/SMX TOB (mcr-1/mcr-5) | |||||
| COL MI NAL TMP/SMX | ||||||
| LT, STb, HlyA (1) | AMP COL GEN MI NAL TI TMP/SMX TOB (mcr-1/mcr-5) | |||||
| LT, K88ac, HlyA (1) | AMP AMP/SAM COL GEN MI NAL TI TMP/SMX TOB | |||||
| LT, STb, K88ac, HlyA (1) | AMP COL GEN MI NAL TI TMP/SMX TOB | |||||
| 11-0 | 1 | LT, STb, K88ac, HlyA (1) | AMP AMP/SAM COL GEN NAL TI TMP/SMX TOB | |||
| O45:HNM-A-ST10 | 11-24 | 1 | – | LT, F18ac, HlyA (1) | AMP AMP/SAM CIP COL GEN LEV NAL TI TMP/SMX TOB (mcr-1/mcr-4) | |
| ONT:HNM-A-ST10 | 11-24 | 1 | – | LT, F18ac, HlyA (1) | AMP AMP/SAM CIP COL GEN LEV NAL TI TMP/SMX TOB (mcr-1/mcr-4) | |
| 11-94 | 2 | CTX-M-14 (1) | STa, STb (1) | AMP AMP/SAM CHL COL GEN NAL TI TMP/SMX TOB | ||
| STa, STb, F18ac, HlyA (1) | AMP AMP/SAM ATM CHL CIP COL CTX FEP GEN LEV NAL TI TMP/SMX TOB | |||||
| O35:H6-A-ST10 | 11-45 | 1 | – | STb (1) | AMP COL NAL TI (mcr-1/mcr-4) | |
| O141:H4-A-ST5786 | 11-24 | 5 | CTX-M-14 (1) | STa, STb, F18ac, HlyA (2) | AMP COL TMP/SMX | |
| COL FOS MI TMP/SMX NAL | ||||||
| STa, F18ac, HlyA (1) | AMP AMP/SAM ATM CHL COL CTX FEP MI NAL TI | |||||
| STa, STb, F18ac, HlyA (1) | AMP CHL COL GEN NAL TI TMP/SMX TOB | |||||
| STa, STb, F18ac, HlyA (1) | CHL COL FOS TMP/SMX | |||||
| O7:H4-A-ST93 | 11-27 | 1 | SHV-12 (1) | STb (1) | AMP AMP/SAM ATM CAZ CHL COL CTX TI | |
| O138:H10-A-ST100 | 27-0 | 2 | – | LT, STb, K88ac, HlyA (1) | AMP AMP/SAM COL GEN MI NAL TI TOB | |
| STb, K88ac, HlyA (1) | COL MI TMP/SMX | |||||
| O8:HNM-A-ST398 | 7-171 | 1 | – | STb (1) | CHL COL | |
| O157:HNM-B1-ST156 | 29-38 | 1 | – | STb (1) | AMP AMP/SAM CHL CIP COL LEV MI NAL TI TMP/SMX TOB | |
| O138:H14-E-ST42 | 28-65 | 3 | – | LT, STa, STb, F18ac, HlyA (1) | AMP AMP/SAM CIP COL ∗FOS LEV MI NAL TI | |
| LT, STb, F18ac, HlyA (1) | AMP AMP/SAM CHL COL ∗FOS TI TMP/SMX NAL | |||||
| LT, STa, STb, F18ac, HlyA (1) | CHL COL ∗FOS GEN TOB NAL | |||||
| O15:H45-E-ST118 | 4-331 | 1 | – | STb (1) | AMP AMP/SAM CHL COL GEN MI NAL TI TOB | |
| O45:H45-E-ST4247 | 550-400 | 1 | – | STb (1) | COL NAL | |
| STEC/ETEC (5) | O141:H4-A-ST10 | 11-24 | 5 | – | STa, STb, Stx2e, F18ac, HlyA (3) | AMP AMP/SAM CHL COL ∗FOS GEN TI TMP/SMX TOB (2) |
| AMP AMP/SAM CHL COL TI TMP/SMX | ||||||
| STa, STb, Stx2e, F18ac HlyA (2) | AMP AMP/SAM CHL COL GEN TI TMP/SMX TOB (2) | |||||
| STEC (3) | O2:HNM-A-ST10 | 11-23 | 1 | – | Stx2e, HlyA (1) | AMP AMP/SAM CHL COL FOS MI NAL TI TMP/SMX |
| O141:HNM-A-ST10 | 11-24 | 1 | CTX-M-14 (1) | Stx2e (1) | AMP AMP/SAM ATM CHL COL CTX FEP GEN TI TMP/SMX TOB | |
| O139:H1-E-ST1 | 2-54 | 1 | – | Stx2e, F18ab, HlyA (1) | AMP COL MI TI TMP/SMX |
aIsolates that did not react with any O antisera were classified as non-typeable (ONT) and non-motile isolates were designated as HNM. PG, phylogroup; ST, sequence type. bCH, clonotype (fumC-fimH alleles); 0 = fimH negative by PCR. cAMP, ampicillin; AMP/SAM, ampicillin-sulbactam; ATM, aztreonam; CAZ, ceftazidime; CHL, chloramphenicol; CIP, ciprofloxacin; COL, colistin; CTX, cefotaxime; FEP, cefepime; FOS, fosfomycin; GEN, gentamicin; LEV, levofloxacin, MI, minocycline; NAL, nalidixic acid; TI, ticarcillin; TMP/SMX, trimethoprim-sulfamethoxazole; TOB, tobramycin. ∗Isolates with a MIC value for FOS = 64 (according to EUCAST, the cutoff point is 32 mg/L and higher values are considered resistant, while for CLSI it is 64).