Table 3.
Antimicrobial susceptibility data summary.
| Agent | Human RT014 (n = 24)† | Porcine RT014 (n = 16) | P-value‡ | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Range (mg/L) | MIC50/90 (mg/L) | GM | %S | %NS | Range (mg/L) | MIC50/90 (mg/L) | GM | %S | %NS | ||
| VANa | 0.5–1 | 1/1 | 0.94 | 100 | 0 | 0.25–1 | 1/1 | 0.81 | 100 | 0 | p > 0.05 |
| MTZb | 0.12–0.5 | 0.5/0.5 | 0.36 | 100 | 0 | 0.12–0.5 | 0.25/0.5 | 0.28 | 100 | 0 | p > 0.05 |
| FDXc | 0.004–0.12 | 0.03/0.06 | 0.03 | 100 | 0 | 0.004–0.12 | 0.06/0.06 | 0.03 | 100 | 0 | p > 0.05 |
| RFXd | 0.002–0.008 | 0.004/0.008 | 0.004 | 100 | 0 | 0.002–0.015 | 0.004/0.008 | 0.004 | 100 | 0 | p > 0.05 |
| AMCb | 0.12–0.5 | 0.25/0.5 | 0.23 | 100 | 0 | 0.12–0.5 | 0.25/0.5 | 0.25 | 100 | 0 | p > 0.05 |
| CLIb | 0.12–8 | 2/4 | 0.99 | 88 | 12 | 0.25–>32 | >32/>32 | 8.72 | 31 | 69 | p < 0.05 |
| ERYb | 0.06–>256 | 0.5/4 | 0.65 | 96 | 4 | 0.12–>256 | >256/>256 | 24.42 | 31 | 69 | p < 0.05 |
| CROb | 4–>128 | 16/32 | 13.85 | 79 | 21 | 8–32 | 16/32 | 16.71 | 81 | 19 | p > 0.05 |
| MEMb | 0.5–2 | 1/2 | 1.09 | 100 | 0 | 0.5–2 | 1/2 | 1.68 | 100 | 0 | p < 0.05 |
| MXFb | 0.5–2 | 1/2 | 1.22 | 100 | 0 | 0.5/1 | 1/1 | 0.84 | 100 | 0 | p < 0.05 |
| TETb | 0.06–0.25 | 0.06/0.12 | 0.08 | 100 | 0 | 0.06–32 | 32/32 | 5.85 | 31 | 69 | p < 0.0001 |
| TZPb | 0.5–8 | 4/8 | 3.89 | 100 | 0 | 0.5–8 | 4/8 | 4.18 | 100 | 0 | p > 0.05 |
| TMP | 8–64 | 32/64 | 28.51 | NR | NR | 16–64 | 32/64 | 33.42 | NR | NR | p > 0.05 |
| GEN | 16–64 | 16/64 | 20.16 | NR | NR | 16–32 | 16/32 | 19.03 | NR | NR | p > 0.05 |
| TOB | 16–128 | 32/128 | 31.09 | NR | NR | 16–32 | 16/32 | 22.63 | NR | NR | p > 0.05 |
| SPC | 16–128 | 32/128 | 57.02 | NR | NR | 32–128 | 32/128 | 47.26 | NR | NR | p > 0.05 |
VAN, vancomycin; MTZ, metronidazole; FDX, fidaxomicin; RFX, rifaximin; AMC, amoxicillin-clavulanate; CLI, clindamycin; ERY, erythromycin; CRO, ceftriaxone; MEM, meropenem; MXF, moxifloxacin; TET, tetracycline; TZP, piperacillin-tazobactam; TMP, trimethoprim, GEN, gentamicin; TOB, tobramycin; SPC, spectinomycin; S, susceptible; NS non-susceptible (intermediate and resistant breakpoints).
Breakpoint for VAN is recommended by EUCAST and is based on epidemiological cut-off values that distinguish “WT” isolates from those with reduced susceptibility.
Breakpoints are those recommended for anaerobes by CLSI.
Proposed susceptible breakpoint of 1 mg/L as recommended by EMA (report WC500119707, http://www.ema.europa.eu/).
Resistance (≥32 mg/L) is as described by O'Connor et al. (2008).
NR, No breakpoints are currently available for trimethoprim, gentamicin, tobramycin, or spectinomycin.
GM, Geometric mean.
Kruskal-Wallis H-test.
testing not performed on UK isolates.
Values in bold are statistically significant at the 95% confidence level.