Table 3. Characteristics of the carbapenemase-producing Escherichia coli isolates, Switzerland, May–August 2018 (n = 24).
| Strains | STa | Resistance phenotypeb | Resistance genesc and mutationsd | Localisatione |
|---|---|---|---|---|
| AR8.2b; AR10.2b; AR17.2b; AR22.1; AR22.2; AR24.2b; AR25.2; AR26.2c; AR31.2a; AR33.2a; AR44.2; AR46.2b; AR62.2; AR76.2; AR76.3; AR81.2; AR94.2b; AR96.2a; AR96.3; AR135.2a; AR145.2; AR148.2 (n = 22) | 410 | AMP-CIP-ETP-FEP-FOT-NAL-TAZ | bla CMY-42, sugE | Plasmid IncI1, 47-kb |
| bla OXA-181, qnrS1 | Plasmid IncX3, 51-kb | |||
| GyrA (Ser83Leu, Asp87Asn); ParC (Ser80Ile) | Chromosome | |||
| AR89.2b (n = 1) | 410 | AMP-CIP-ETP-FOT-NAL | bla OXA-181, qnrS1 | Plasmid IncX3, 51-kb |
| None | Plasmid IncI1, 88-kbf | |||
| GyrA (Ser83Leu, Asp87Asn); ParC (Ser80Ile) | Chromosome | |||
| AR144.2 (n = 1) | 410 | AMP-CIP-ETP-FOT-NAL-TET | bla OXA-181, qnrS1 | Plasmid IncX3, 51-kb |
| bla TEM-1B, tet(A) | Plasmid IncI1, 98-kbf | |||
| GyrA (Ser83Leu, Asp87Asn); ParC (Ser80Ile) | Chromosome |
AMP: ampicillin; CHL: chloramphenicol; CIP: ciprofloxacin; COL: colistin; ETP: ertapenem; FEP: cefepime; FOT: cefotaxime; GEN: gentamicin; IMI: imipenem; MERO: meropenem; NAL: nalidixic acid; SMX: sulfamethoxazole; ST: sequence type; TAZ: ceftazidime; TET: tetracycline; TGC: tigecycline; TMP: trimethoprim.
a Sequence type based on multilocus sequence typing was determined with MLSTtool 2.0.
b Results interpreted according to the EUCAST and CLSI criteria (see Table 1).
c Resistance genes were detected with ResFinder 3.0: bla CMY-42, cephalosporinase CMY-42 gene (resistance to FEP, TAZ); bla OXA-181, carbapenemase OXA-181 gene (resistance to AMP, ETP, FOT); qnrS1, DNA gyrase protection gene to fluoroquinolones (low-level resistance to fluoroquinolones); bla TEM-1b, β-lactamase TEM-1b gene (resistance to AMP); tet(A), tetracycline efflux gene (resistance to TET); sugE, quaternary ammonium compound resistance gene.
d Chromosomal mutations were detected with ResFinder 3.0. GyrA (Ser83Leu and Asp87Asn), combined with ParC (Ser80Ile), mutations in the topoisomerase II and IV (high-level resistance to fluoroquinolones).
e Incompatibility groups (Inc) were determined with PlasmidFinder 1.3.
f As determined using plasmid SPAdes (v3.12.0).