Skip to main content
. 2022 Dec 8;11(1):e03582-22. doi: 10.1128/spectrum.03582-22

TABLE 2.

Antimicrobial susceptibility data for C. difficile isolates by ribotypea

RT Antimicrobial MIC (mg/L)
 GM Breakpoint (mg/L)
 Isolate resistance
S
 I
 R
Range MIC50/MIC90 S I R % n % n % n
All (n = 284) FDX 0.03 to 0.5 0.25/0.25 0.16 ≥1 100.0 284
VAN 1 to 4 2/2 1.45 ≤2 >2 98.2 279 1.8 5
MTZ 0.125 to 1 0.25/0.5 0.26 ≤2 >2 100.0 284
RFX 0.015 to >64 0.03/0.03 0.03 ≥32 98.6 280 1.4 4
CLI 0.125 to >256 8/32 6.75 ≤2 4 ≥8 12.3 35 31.0 88 56.7 161
ERY 0.25 to >256 2/>256 1.51 >8 85.6 243 14.4 41
AMC 0.125 to 2 0.5/1 0.61 ≤4 8 ≥16 100.0 284
MEM 1 to 16 2/4 2.34 ≤4 8 ≥16 98.6 280 1.1 3 0.35 1
MXF 1 to 32 2/2 2.06 ≤2 4 ≥8 94.7 269 2.8 8 2.5 7
TET 0.125 to 64 0.25/16 0.56 ≤4 8 ≥16 83.8 238 2.5 7 13.7 39
 
RT014/020 (n = 42) FDX 0.03 to 0.5 0.25/0.25 1.70 ≥1 100.0 42
VAN 1 to 2 1/2 1.37 ≤2 >2 100.0 42
MTZ 0.125 to 0.5 0.25/0.25 0.25 ≤2 >2 100.0 42
RFX 0.015 to 16 0.03/0.03 0.03 ≥32 100.0 42
CLI 0.5 to >256 8/16 6.61 ≤2 4 ≥8 9.5 4 23.8 10 66.7 28
ERY 0.25 to >256 2/4 1.58 >8 90.5 38 9.5 4
AMC 0.25 to 1 0.5/0.5 0.51 ≤4 8 ≥16 100.0 42
MEM 1 to 4 2/2 2.07 ≤4 8 ≥16 100.0 42
MXF 2 to 2 2/2 2.00 ≤2 4 ≥8 100.0 42
TET 0.125 to 64 0.25/1 0.42 ≤4 8 ≥16 90.5 38 9.5 4
 
RT010 (n = 41) FDX 0.03 to 0.5 0.25/0.5 0.21 ≥1 100.0 41
VAN 1 to 2 1/2 1.31 ≤2 >2 100.0 41
MTZ 0.25 to 0.5 0.25/0.25 0.26 ≤2 >2 100.0 41
RFX 0.015 to 0.03 0.03/0.03 0.03 ≥32 100.0 41
CLI 1 to 64 8/16 6.42 ≤2 4 ≥8 9.8 4 36.6 15 53.7 22
ERY 1 to >256 2/2 1.74 >8 97.6 40 2.4 1
AMC 0.5 to 1 1/1 0.95 ≤4 8 ≥16 100.0 41
MEM 2 to 4 2/4 2.76 ≤4 8 ≥16 100.0 41
MXF 2 to 4 2/2 2.07 ≤2 4 ≥8 95.1 39 4.9 2
TET 0.125 to 32 0.25/0.5 0.31 ≤4 8 ≥16 95.1 39 4.9 2
 
RT039 (n = 12) FDX 0.125 to 0.5 0.25/0.25 0.22 ≥1 100.0 12
VAN 1 to 2 1/2 1.33 ≤2 >2 100.0 12
MTZ 0.25 to 0.5 0.5/0.5 0.42 ≤2 >2 100.0 12
RFX 0.015 to 0.03 0.03/0.03 0.03 ≥32 100.0 12
CLI 4 to >256 16/>256 27.43 ≤2 4 ≥8 8.3 1 91.7 11
ERY 2 to >256 2/>256 2.00 >8 50.0 6 50.0 6
AMC 0.5 to 1 1/1 0.94 ≤4 8 ≥16 100.0 12
MEM 2 to 4 2/4 2.67 ≤4 8 ≥16 100.0 12
MXF 2 to 2 2/2 2.00 ≤2 4 ≥8 100.0 12
TET 0.25 to 16 2/16 3.36 ≤4 8 ≥16 66.7 8 33.3 4
 
88 “other” RTs (n = 189) FDX 0.03 to 0.5 0.25/0.25 0.15 ≥1 100.0 189
VAN 1 to 4 2/2 1.51 ≤2 >2 97.4 184 2.6 5
MTZ 0.125 to 1 0.25/0.5 0.25 ≤2 >2 100.0 189
RFX 0.015 to >64 0.03/0.03 0.03 ≥32 97.9 185 2.1 4
CLI 0.125 to >256 8/32 6.40 ≤2 4 ≥8 14.3 27 32.8 62 52.9 100
ERY 0.25 to >256 2/>256 1.43 >8 84.1 159 15.9 30
AMC 0.125 to 2 0.5/1 0.57 ≤4 8 ≥16 100.0 189
MEM 1 to 16 2/4 2.31 ≤4 8 ≥16 97.9 185 1.6 3 0.5 1
MXF 1 to 32 2/2 2.07 ≤2 4 ≥8 93.1 176 3.2 6 3.7 7
TET 0.125 to 64 0.25/16 0.61 ≤4 8 ≥16 81.0 153 3.7 7 15.3 29
a

RT, ribotype; FDX, fidaxomicin; VAN, vancomycin; MTZ, metronidazole; RFX, rifaximin; CLI, clindamycin; ERY, erythromycin; AMC, amoxicillin-clavulanic acid; MEM, meropenem; MXF, moxifloxacin; TET, tetracycline; GM, geometric mean; S, susceptible; I, intermediate; R, resistant.