Table 2.
Proportion of Nontyphoidal Salmonella Isolates From Blood by Antimicrobial Resistance Type, 2003–2013
| Antimicrobial Resistance Typea | Total Isolates, No. | Blood Isolates, No. (%) | OR (95% CI) |
|---|---|---|---|
| Fully susceptible | 16 972 | 868 (5.1) | Referent |
| Agents | |||
| Amoxicillin-clavulanic acid | 1478 | 120 (8.1) | 1.64(1.34–2.00) |
| Ampicillin | 2194 | 201 (9.2) | 1.87 (1.59–2.20) |
| Azithromycinb | 7 | 1 (14.3) | 3.09 (.37–25.71) |
| Cefoxitin | 712 | 59 (8.3) | 1.68(1.27–2.21) |
| Ceftiofur | 686 | 56 (8.2) | 1.65(1.24–2.19) |
| Ceftriaxone | 677 | 55 (8.1) | 1.64 (1.24–2.18) |
| Chloramphenicol | 1423 | 136 (9.6) | 1.96 (1.62–2.37) |
| Ciprofloxacin | 526 | 53 (10.1) | 2.08 (1.55–2.78) |
| Gentamicin | 355 | 34 (9.6) | 1.97 (1.37–2.82) |
| Kanamycin | 493 | 70(14.2) | 3.07 (2.36–3.99) |
| Nalidixic acid | 426 | 48 (11.3) | 2.36 (1.73–3.21) |
| Streptomycin | 2199 | 194 (8.8) | 1.80 (1.53–2.11) |
| Sulfamethoxazole or sulfisoxazolec | 2289 | 192 (8.4) | 1.70(1.44–2.00) |
| Tetracycline | 2695 | 227 (8.4) | 1.71 (1.47–1.99) |
| TMP-SMX | 326 | 34 (10.4) | 2.16 (1.51–3.10) |
| Patterns | |||
| First-line agentd | 2663 | 237 (8.9) | 1.81 (1.56–2.11) |
| ≥1 agent | 3894 | 321 (8.3) | 1.67 (1.46–1.91) |
| ≥3 classes | 2276 | 205 (9.0) | 1.84(1.57–2.15) |
| ≥5 classes | 1378 | 133 (9.7) | 1.98 (1.64–2.40) |
| ACSSuT | 1170 | 105 (9.0) | 1.83 (1.48–2.26) |
| ACSSuTAuCx | 395 | 30 (7.6) | 1.53 (1.04–2.23) |
| ASSuTnoC | 283 | 20 (7.1) | 1.41 (.89–2.24) |
| AAuCx | 647 | 53 (8.2) | 1.66 (1.24–2.21) |
Abbreviations: AAuCx, resistant to at least ampicillin, amoxicillin–clavulanic acid, and ceftriaxone; ACSSuT, resistant to at least ampicillin, chloramphenicol, streptomycin, a sulfonamide, and tetracycline; ACSSuTAuCx, resistant to at least ACSSuT, amoxicillin–clavulanic acid, and ceftriaxone; ASSuTnoC, resistant to at least ampicillin, streptomycin, a sulfonamide, and tetracycline, but not chloramphenicol; CI, confidence interval; OR, odds ratio; TMP-SMX, trimethoprim-sulfamethoxazole.
For single antimicrobials and resistance to ≥1 agent, ≥3 classes, or ≥5 classes, resistance is defined as an intermediate or resistant minimum inhibitory concentration.
Azithromycin was not routinely tested before 2011.
Sulfamethoxazole, which was tested before 2004 to represent sulfonamides, was replaced by sulfisoxazole in 2004.
Resistant to ≥1 of the following agents: ampicillin, ceftriaxone, ciprofloxacin, or TMP-SMX.