TABLE 3.
Antimicrobial susceptibilities profiles and MIC values to 15 antibiotics of the major Nocardia species/complex in clinical infections in China from 2009 to 2021a
| Drugs | Breakpoint | Species/complex, no. of strains (%)b |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N. farcinica, 176 (39.9) | N. cyriacigeorgica, 126 (28.6) | N. abscessus complex, 54 (12.2)c | N. otitidiscaviarum, 26 (5.9) | N. brasiliensis, 18 (4.1) | N. transvalensis complex, 11 (2.5)d | N. nova complex, 11 (2.5)e | N. puris, 7 (1.6) | N. pseudobrasiliensis, 2 (0.5) | Other Nocardia, 10 (2.3)f | All Nocardia, 441 (100) | |||
| TMP-SMX | S ≤ 2/38, R ≥ 4/76 | MIC50 | ≤0.25/4.75 | ≤0.25/4.75 | ≤0.25/4.75 | 0.5/9.5 | ≤0.25/4.75 | ≤0.25/4.75 | ≤0.25/4.75 | ≤0.25/4.75 | ≤0.25/4.75 | ≤0.25/4.75 | |
| MIC90 | 1/19 | 0.5/9.5 | 0.5/9.5 | 2/38 | ≤0.25/4.75 | 0.5/9.5 | 0.5/9.5 | 0.5/9.5 | 1/19 | 1/19 | |||
| Range | ≤0.25/4.75 to >8/152 | ≤0.25/4.75 to 1/19 | ≤0.25/4.75 to 1/19 | ≤0.25/4.75 to 2/38 | ≤0.25/4.75 to 0.5/9.5 | ≤0.25/4.75 to 1/19 | ≤0.25/4.75 to 0.5/9.5 | ≤0.25/4.75 to 0.5/9.5 | ≤0.25/4.75 to 2/38 | ≤0.25/4.75 to >8/152 | |||
| S/R (%) | 97.7/2.3 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 99.1/0.9 | ||
| Linezolid | S ≤ 8 | MIC50 | 2 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | |
| MIC90 | 2 | 2 | ≤1 | 2 | 2 | ≤1 | 2 | 2 | 2 | 2 | |||
| Range | ≤1 to 4 | ≤1 to 4 | ≤1 to 2 | ≤1 to 2 | ≤1 to 2 | ≤1 to 2 | ≤1 to 2 | ≤1 to 2 | ≤1 to 2 | ≤1 to 4 | |||
| S/NS (%) | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | ||
| Ciprofloxacin | S ≤ 1, R ≥ 4 | MIC50 | 0.5 | >4 | 4 | 2 | 4 | 0.5 | >4 | 4 | 4 | 4 | |
| MIC90 | 2 | >4 | >4 | >4 | >4 | 2 | >4 | >4 | >4 | >4 | |||
| Range | ≤0.12 to >4 | 0.5 to >4 | 0.5 to >4 | 0.5 to >4 | 4 to >4 | ≤0.12 to >4 | 2 to >4 | 4 to >4 | 0.25 to >4 | ≤0.12 to >4 | |||
| S/I/R (%) | 68.8/22.2/9.1 | 2.4/1.6/96 | 18.5/16.7/64.8 | 7.7/42.3/50 | 0/0/100 | 72.7/18.2/9.1 | 0/18.2/81.8 | 0/0/100 | 50/0/50 | 30/10/60 | 33.6/15/51.5 | ||
| Imipenem | S ≤ 4, R ≥ 16 | MIC50 | 8 | 4 | 8 | >64 | >64 | 16 | ≤2 | 4 | 16 | 8 | |
| MIC90 | 32 | 32 | >64 | >64 | >64 | 32 | 4 | 32 | 64 | 64 | |||
| Range | ≤2 to >64 | ≤2 to >64 | ≤2 to >64 | 4 to >64 | 16 to >64 | ≤2 to >64 | ≤2 to 16 | ≤2 to 32 | ≤2 to >64 | ≤2 to >64 | |||
| S/I/R (%) | 39.8/19.9/40.3 | 58.7/19/22.2 | 46.3/18.5/35.2 | 3.8/0/96.2 | 0/0/100 | 36.4/0/63.6 | 90.9/0/9.1 | 57.1/14.3/28.6 | 0/0/100 | 30/10/60 | 43.3/16.1/40.6 | ||
| Moxifloxacin | S ≤ 1, R ≥ 4 | MIC50 | ≤0.25 | 2 | 2 | 2 | 1 | ≤0.25 | 2 | 2 | 1 | 1 | |
| MIC90 | 1 | 4 | >8 | 4 | 1 | 0.5 | 4 | 4 | 4 | 4 | |||
| Range | ≤0.25 to >8 | ≤0.25 to >8 | ≤0.25 to >8 | ≤0.25 to 4 | 0.5 to 2 | ≤0.25 to 2 | 1 to 4 | 1 to 4 | ≤0.25 to >8 | ≤0.25 to >8 | |||
| S/I/R (%) | 90.3/8/1.7 | 18.3/48.4/33.3 | 29.6/25.9/44.4 | 46.2/42.3/11.5 | 94.4/5.6/0 | 90.9/9.1/0 | 27.3/54.5/18.2 | 42.9/42.9/14.3 | 100/0/0 | 70/10/20 | 57.1/25.4/17.5 | ||
| Cefepimec | MIC50 | >32 | 16 | 4 | >32 | >32 | 8 | 8 | >32 | 32 | >32 | ||
| MIC90 | >32 | >32 | 32 | >32 | >32 | >32 | 16 | >32 | >32 | >32 | |||
| Range | 2 to >32 | ≤1 to >32 | ≤1 to >32 | 2 to >32 | 8 to >32 | 4 to >32 | ≤1 to >32 | 32 to >32 | 2 to >32 | ≤1 to >32 | |||
| Cefoxitinc | MIC50 | 128 | 128 | 8 | >128 | 128 | 128 | 64 | 32 | 64 | 128 | ||
| MIC90 | >128 | >128 | 128 | >128 | >128 | >128 | 64 | 64 | >128 | >128 | |||
| Range | ≤4 to >128 | ≤4 to >128 | ≤4 to >128 | 128 to >128 | 64 to >128 | 32 to >128 | ≤4 to 128 | 16 to 64 | 8 to >128 | ≤4 to >128 | |||
| Amoxicillin-clavulanic acid | S ≤ 8/4, R ≥ 32/16 | MIC50 | 8/4 | 32/16 | 16/8 | >64/32 | 8/4 | 4/2 | 64/32 | 32/16 | 64/32 | 16/8 | |
| MIC90 | 32/16 | 64/32 | >64/32 | >64/32 | 8/4 | 16/8 | >64/32 | 64/32 | >64/32 | >64/32 | |||
| Range | ≤2/1 to >64/32 | ≤2/1 to >64/32 | ≤2/1 to >64/32 | ≤2/1 to >64/32 | ≤2/1 to 16/8 | 4/2 to 32/16 | 4/2 to >64/32 | 16/8 to 64/32 | 8/4 to >64/32 | ≤2/1 to >64/32 | |||
| S/I/R (%) | 61.9/22.7/15.3 | 6.3/27/66.7 | 48.1/7.4/44.4 | 11.5/0/88.5 | 94.4/5.6/0 | 63.6/27.3/9.1 | 18.2/18.2/63.6 | 0/28.6/71.4 | 50/50/0 | 10/10/80 | 39.5/20/40.6 | ||
| Amikacin | S ≤ 8, R ≥ 16 | MIC50 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | ≤1 | |
| MIC90 | 2 | ≤1 | ≤1 | ≤1 | ≤1 | 16 | ≤1 | ≤1 | ≤1 | ≤1 | |||
| Range | ≤1 to 4 | ≤1 to 8 | ≤1 to 2 | ≤1 to 2 | to ≤1 | ≤1 to 16 | ∼≤1 | ∼≤1 | ≤1 to 8 | ≤1 to 16 | |||
| S/R (%) | 100/0 | 100/0 | 100/0 | 100/0 | 100/0 | 72.7/27.3 | 100/0 | 100/0 | 100/0 | 100/0 | 99.3/0.7 | ||
| Ceftriaxone | S ≤ 8, R ≥ 64 | MIC50 | 64 | ≤4 | ≤4 | >64 | 16 | ≤4 | 8 | 32 | 8 | 32 | |
| MIC90 | >64 | 64 | 8 | >64 | >64 | 64 | 16 | >64 | >64 | >64 | |||
| Range | ≤4 to >64 | ≤4 to >64 | ≤4 to >64 | 8 to >64 | ≤4 to >64 | ≤4 to 64 | ≤4 to 32 | ≤4 to >64 | ≤4 to >64 | ≤4 to >64 | |||
| S/I/R (%) | 8.5/25.6/65.9 | 66.7/17.5/15.9 | 90.7/7.4/1.9 | 3.8/3.8/92.3 | 27.8/27.8/44.4 | 63.6/18.2/18.2 | 72.7/27.3/0 | 42.9/14.3/42.9 | 50/50/0 | 60/10/30 | 40.6/19.3/40.1 | ||
| Doxycycline | S ≤ 1, R ≥ 8 | MIC50 | 2 | 2 | 0.25 | 1 | 2 | 2 | 4 | 1 | 1 | 2 | |
| MIC90 | 4 | 2 | 2 | 2 | 4 | 4 | 8 | 2 | 4 | 4 | |||
| Range | ≤0.12 to 16 | ≤0.12 to 4 | ≤0.12 to 4 | ≤0.12 to 4 | 0.5 to 4 | 1 to 4 | 0.25 to 8 | ≤0.12 to 2 | ≤0.12 to 8 | ≤0.12 to 16 | |||
| S/I/R (%) | 18.8/78.4/2.8 | 47.6/52.4/0 | 83.3/16.7/0 | 53.8/46.2/0 | 22.2/77.8/0 | 18.2/81.8/0 | 27.3/45.5/27.3 | 57.1/42.9/0 | 50/50/0 | 50/40/10 | 38.8/59.2/2 | ||
| Minocycline | S ≤ 1, R ≥ 8 | MIC50 | 2 | 2 | ≤1 | ≤1 | ≤1 | 2 | 2 | ≤1 | 2 | 2 | |
| MIC90 | 4 | 2 | 2 | 2 | 2 | 2 | 4 | 2 | 8 | 4 | |||
| Range | ≤1 to 8 | ≤1 to 4 | ≤1 to 4 | ≤1 to 4 | ≤1 to 2 | ≤1 to 4 | ≤1 to 8 | ≤1 to 2 | ≤1 to 8 | ≤1 to 8 | |||
| S/I/R (%) | 26.1/73.3/0.6 | 42.9/57.1/0 | 79.6/20.4/0 | 61.5/38.5/0 | 83.3/16.7/0 | 27.3/72.7/0 | 36.4/54.5/9.1 | 85.7/14.3/0 | 50/50/0 | 40/40/20 | 43.5/55.6/0.9 | ||
| Tigecyclinec | MIC50 | 1 | 0.5 | 0.25 | 0.12 | 0.12 | 0.5 | 0.5 | 0.25 | 0.5 | 0.5 | ||
| MIC90 | 2 | 1 | 1 | 1 | 0.25 | 2 | 2 | 1 | 1 | 2 | |||
| Range | 0.03 to 4 | ≤0.015 to 4 | ≤0.015 to 4 | ≤0.015 to 2 | 0.03 to 0.5 | 0.12 to 2 | 0.06 to 2 | 0.06 to 1 | 0.06 to 2 | ≤0.015 to 4 | |||
| Tobramycin | S ≤ 4, R ≥ 16 | MIC50 | 16 | ≤1 | ≤1 | 2 | ≤1 | >16 | 8 | ≤1 | ≤1 | ≤1 | |
| MIC90 | >16 | ≤1 | 8 | 16 | ≤1 | >16 | >16 | ≤1 | 8 | 16 | |||
| Range | ≤1 to >16 | ≤1 to 16 | ≤1 to >16 | ≤1 to >16 | ∼≤1 | 4 to >16 | ≤1 to >16 | ∼≤1 | ≤1 to 16 | ≤1 to >16 | |||
| S/I/R (%) | 14.2/13.6/72.2 | 96/0.8/3.2 | 87/7.4/5.6 | 57.7/23.1/19.2 | 100/0/0 | 9.1/18.2/72.7 | 45.5/27.3/27.3 | 100/0/0 | 100/0/0 | 80/10/10 | 56.5/9.3/34.2 | ||
| Clarithromycin | S ≤ 2, R ≥ 8 | MIC50 | >16 | 16 | 2 | >16 | 8 | 8 | 0.25 | >16 | 1 | >16 | |
| MIC90 | >16 | >16 | >16 | >16 | >16 | >16 | >16 | >16 | >16 | >16 | |||
| Range | 0.5 to >16 | 0.12 to >16 | ≤0.06 to >16 | ≤0.06 to >16 | 2 to >16 | 0.25 to >16 | ≤0.06 to >16 | ∼>16 | ≤0.06 to >16 | ≤0.06 to >16 | |||
| S/I/R (%) | 4/1.7/94.3 | 19.8/15.9/64.3 | 53.7/9.3/37 | 3.8/0/96.2 | 11.1/16.7/72.2 | 27.3/9.1/63.6 | 72.7/0/27.3 | 0/0/100 | 50/50/0 | 60/0/40 | 18.6/7.5/73.9 | ||
a
The table shows the antimicrobial susceptibilities profiles and MIC values (in μg/mL) (as determined by the broth microdilution method) to 15 antibiotics of the major Nocardia species/complex responsible for clinical infections in China from 2009 to 2021. TMP-SMX, trimethoprim-sulfamethoxazole. S, susceptible; I, intermediate; R, resistant; NS, nonsusceptible; MIC50 and MIC90, MICs at which 50% and 90% of the strains were inhibited, respectively.
b
Percentage with respect to the total number of identified Nocardia strains (n = 441).
c
N. abscessus complex (54) includes N. abscessus (29), N. asiatica (12), and N. beijingensis (13).
d
N. transvalensis complex (11) includes N. wallacei (7), N. blacklockiae (2), and N. transvalensis (2).
e
N. nova complex (11) includes N. africana (1), N. elegans (3), N. nova (5), N. vermiculata (1), and N. veterana (1).
f
Other Nocardia species (10) includes N. terpenica (1), N. niigatensis (1), N. carnea (1), N. asteroides (1), N. concava (1), N. neocaledoniensis (1), and unidentified Nocardia (4).