TABLE 2.
Phenotypic and genomic antibiogram of NDM isolatesa
| Drug class | Drug | AST method and call | ECO-222 | ECO-165 | ECC-174 | ECO-190 | ECO-219 |
|---|---|---|---|---|---|---|---|
| Beta-lactams | Aztreonam | KB resistance | R | S | R | R | R |
| Cefoxitin | MIC (μg/ml), resistance | 64, R | 64, R | 64, R | 64, R | 64, R | |
| Ceftriaxone | KB resistance | R | R | R | R | R | |
| Cefepime | KB resistance | R | R | R | R | R | |
| Ertapenem | KB resistance | R | R | R | R | R | |
| Imipenem | KB resistance | R | R | R | I | R | |
| Meropenem | KB resistance | R | R | R | R | R | |
| All beta-lactams | Genotype | blaTEM-1 blaCTX-M-15 blaNDM-5 blaOXA-1 | blaTEM-1 (2 copies) blaNDM-5 | blaACT25 blaTEM-1 blaSHV-7 blaSHV-12 (2 copies) blaNDM-1 | blaCTX-M-15 blaCMY-6 blaTEM-1b blaOXA-1 blaNDM-1 | blaCTX-M-15 blaTEM-1 blaOXA-1 blaNDM-5 | |
| Glycylcyclines | Tigecyclineb | Etest (μg/ml) | 0.25 | 0.75 | 0.75 | 0.125 | 0.38 |
| Tetracyclines | Tetracycline | KB resistance | R | Not done | Not done | Not done | S |
| Tetracycline | MIC (μg/ml), resistance | Not done | 16, R | 4, S | 2, S | Not done | |
| All tetracyclines | Genotype | tetB tetD | tetA | None detected | None detected | None detected | |
| Aminoglycosides | Gentamicin | MIC (μg/ml), resistance | 16, R | 4, R | 16, R | 16, R | 16, R |
| All aminoglycosides | Genotype | aac(3)-Id aac(6′)-Ib-cr ant(3″)-Ia (2 copies) | rmtB aac(6′)Ib-cr ant(3″)-Ia family aph(3″) family aph(6)-I family aac(3)-Id | aph(3′)-Ia ant(3″) family ant(3″)-Ia aph(6)-Id aph(3″) family ant(2″)-Ia aac(6)-Ib | rmtC aph(6)-Id aph(3″)-Ib aac(6′)Ib-cr aph(3′)-Ia aph(3′)-VI | rmtB ant(3)-Ia aac(6′)-Ib-cr | |
| Folate antagonists | Trimethoprim-sulfamethoxazole | MIC (μg/ml), resistance | 16/304, R | 16/304, R | 16/304, R | 16/304, R | 16/304, R |
| All folate antagonists | Genotype | sul1 (2 copies) dfrA17 dfrA12 | sul1 sul2 dfrA14 (2 copies) | sul1 (3 copies) dfrA8 dfrA19 | sul1 sul2 dfrA14 | sul1 dfrA12 | |
| Fluoroquinolones | Ciprofloxacin | MIC (μg/ml), resistance | 4, R | 64, R | 4, R | 4, R | 4, R |
| All fluoroquinolones | Genotype | aac(6′)Ib-cr qnrS1 | aac(6′)Ib-cr | qnrS1 qnrB2 | aac(6′)Ib-cr qnrB1 | aac(6′)-Ib-cr | |
| Phenicol | Chloramphenicol | KB resistance | I | R | R | R | I |
| All phenicols | Genotype | None detected | catA1 | catA1 | cm/family | None detected | |
| Polymyxins | Colistinc | MIC (μg/ml) resistance | 0.06 wild type | 0.06 wild type | 0.06 wild type | 0.12 wild type | 0.12 wild type |
| All polymyxins | Genotype | None detected | None detected | None detected | None detected | None detected |
a
AST, antimicrobial susceptibility testing method; KB, Kirby-Bauer disk diffusion testing. MICs are by concentration cutoff for growth. Genotype indicates resistance genes identified by next-generation sequencing and gene annotation. R, resistant; I, intermediate; S, susceptible.
b
Tigecycline Etest does not have CLSI guidelines for reporting resistance or susceptibility.
c
Colistin MICs were assessed by broth microdilution as described in the CLSI guidelines (M100-ED28 [37]). Results are reported as epidemiological cutoff values (ECVs).