Table 1. Genetic and phenotypic characteristics of ceftriaxone and ciprofloxacin-resistant Salmonella strains and their corresponding transconjugants.
| Strain ID | Species | ESBL/PMQR genes | Plasmids(∼kb) | Mutation | MIC (µg/ml) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AZI | AMK | CTX | CIP | KAN | OLA | STR | CRO | TET | CHL | NAL | MRP | AMP | STX | |||||
| Sa44 | S. London | qnrB6-aac(6’)-Ib-cr blaCTX-M130 | 202, 108 and 90 | - | >32 | 4 | >16 | 4 | 64 | 16 | >128 | >16 | >32 | >64 | 16 | 0.03 | >64 | >32 |
| Sa44-TC1 | E. coli J53 | qnrB6-aac(6’)-Ib-cr blaCTX-M130 | 202, 108 and 90 | - | 1 | 2 | >16 | 1 | 16 | 8 | >128 | >16 | >32 | 2 | 16 | 0.03 | >64 | >32 |
| Sa44-TC2 | E. coli J53 | blaCTX-M130 | 90 | - | 1 | ≤0.5 | 16 | 0.015 | ≤0.5 | 4 | 2 | 16 | 0.5 | 2 | 2 | 0.03 | >64 | 4 |
| J53 | E. coli | - | - | - | 1 | ≤0.5 | ≤0.015 | 0.015 | ≤0.5 | 4 | 2 | ≤0.015 | 0.5 | 1 | 2 | 0.03 | 2 | 4 |
| Sa48 | S. London | - | - | - | 2 | 1 | 0.03 | 0.06 | 8 | 16 | >128 | 0.03 | >32 | 64 | 8 | 0.03 | 16 | 8 |
| Sa48-TC | S. London | qnrB6-aac(6’)-Ib-cr blaCTX-M130 | 202, 108 and 90 | - | 2 | 4 | >16 | 4 | >128 | 32 | 16 | >16 | 16 | 2 | 8 | 0.03 | >64 | 16 |
Notes: ND, not determined; ESBL, extended spectrum β-lactamase; PMQR, plasmid mediated quinolone resistance AMK, amikacin; AZI, azithromycin; CTX, cefotaxime; CIP, ciprofloxacin; KAN, kanamycin; OLA, olaquidox; STR, streptomycin; CRO, ceftriaxone; TET, tetracycline; CHL, chloramphenicol; NAL, nalidixic acid; AMP, ampicillin; MRP, meropenem; SXT, trimethoprim/sulfamethoxazole. Sa48-TC refers to Salmonella conjugant generated through conjugation of Sa44-TC1 to Salmonella strain, Sa48, to conjugate the conjugative plasmid back to Salmonella.