Table 1.
Resistance genes identified and associated with plasmids in the retrospective isolates (n = 193).
| Antibiotic resistance gene | Antibiotic Class to which resistance is conferred | Number of genes identified in n = 193 isolates | Predicted resistance conferred∗ | Number of genes associated with plasmids |
|---|---|---|---|---|
| aac(6′)-I | Aminoglycosides | 189 | Gen | 0 |
| strB | Aminoglycosides | 67 | Str | 57 |
| strA | Aminoglycosides | 65 | Str | 56 |
| aadA (ant(3″)Ia) | Aminoglycosides | 54 | Str | 38 |
| aac3-Via | Aminoglycosides | 22 | Gen | 20 |
| aph(3′)Ib | Aminoglycosides | 22 | Kan | 16 |
| aphA (aph(3′)IIa) | Aminoglycosides | 13 | Kan | 13 |
| sph (aph(6)Ic) | Aminoglycosides | 13 | Str | 13 |
| aac3-Iid | Aminoglycosides | 11 | Gen | 11 |
| aadB (ant(2″)Ia) | Aminoglycosides | 7 | Gen | 5 |
| aac-IVa | Aminoglycosides | 4 | Gen | 2 |
| aph(4)Ia | Aminoglycosides | 4 | (Hygromycin) | 1 |
| ant(3″)Ia | Aminoglycosides | 1 | Str | 0 |
| blaCMY -2 | β-lactams | 44 | Amp, Fox, Axo Amo, Tio | 44 |
| blaTEM-1 | β-lactams | 37 | Amp | 27 |
| blaCARB-3 | β-lactams | 3 | Amp | 0 |
| tetA | Tetracyclines | 61 | Tet | 49 |
| tetR∗∗ | Tetracyclines | 64 | Tet | 50 |
| tetB | Tetracyclines | 35 | Tet | 30 |
| tetC | Tetracyclines | 7 | Tet | 7 |
| tetG | Tetracyclines | 2 | Tet | 7 |
| tetM | Tetracyclines | 2 | Tet | 0 |
| sul1 | Sulfonamides | 48 | Sul | 41 |
| sul2 | Sulfonamides | 41 | Sul | 36 |
| sul3 | Sulfonamides | 2 | Sul | 0 |
| floR | Phenicols | 27 | Chl | 24 |
| cmlA | Phenicols | 11 | Chl | 8 |
| catA | Phenicols | 4 | Chl | 0 |
| fosA2 | Fosfomycin | 48 | (Fosfomycin) | 0 |
| mphA | Macrolides | 2 | Azi | 2 |
| ereA | Macrolides | 2 | (Erythromycin) | 0 |
| mefB | Macrolides | 1 | Azi | 0 |
| dfrA | Trimethoprim | 8 | Trimethoprim | 5 |
| arr2 | Rifampicin | 2 | (Rifampicin) | 0 |
∗For drugs which phenotypic testing was available, only tested drugs are listed. Resistance to other drugs are possible. Drug names in parentheses were not tested. Antibiotic abbreviations are as follows: Gen, gentamicin; Kan, kanamycin; Str, streptomycin; Amp, ampicillin; Fox, cefoxitin; Axo, ceftriaxone; Amo, amoxicillin; Tio, ceftiofur; Tet, tetracycline; Sul, sulfonamide; Chl, chloramphenicol; Azi, azithromycin. ∗∗Indicates regulatory gene usually associated with resistance.