TABLE 1.
Susceptibility to antimicrobials in multidrug-resistant isolates of non-typhoidal Salmonella recovered from patients in Armenia (54 isolates) and Georgia (3 isolates).
| Antimicrobial agent | AM class/subclass (CLSI) | Total MDR isolates (N = 57), % (N) | S. Typhimurium isolates (N = 48), % (N) | Isolates with other serotypes (N = 9), % (N) | ESBL-producer isolates (N = 37), % (N) | ESBL-negative isolates (N = 20), % (N) | ||||||||||
| S | I | R | S | I | R | S | I | R | S | I | R | S | I | R | ||
| Ampicillin (AMP) | Penicillins/Aminopenicillin | 8.77 (5) | 3.51 (2) | 87.72 (50) | 6.25 (3) | 0.00 (0) | 93.75 (45) | 22.22 (2) | 22.22 (2) | 55.56 (5) | 0.00 (0) | 0.00 (0) | 100 (37) | 25.00 (5) ↑b | 10.00 (2) | 65.00 (13) |
| Amoxicillin- Clavulanic acid (AUG) | β-Lactam/ β-lactamase inhibitor combinations | 28.07 (16) | 52.63 (30) | 19.30 (11) | 18.75 (9) | 58.33 (28) | 22.92 (11) | 77.78 (7) ↑a | 22.22 (2) | 0.00 (0) | 13.51 (5) | 70.27 (26) | 16.22 (6) | 55.00 (11) ↑b | 20.00 (4) | 25.00 (5) |
| Ceftriaxone (CRO) | Cephems/Cephalosporin III | 26.32 (15) | 1.75 (1) | 71.93 (41) | 16.67 (8) | 0.00 (0) | 83.33 (40) | 77.78 (7) ↑a | 11.11 (1) | 11.11 (1) | 0.00 (0) | 0.00 (0) | 100 (37) | 75.00 (15) ↑b | 5.00 (1) | 20.00 (4) |
| Ceftazidime (TZ) | Cephems/Cephalosporin III | 38.60 (22) | 47.37 (27) | 14.04 (8) | 29.17 (14) | 56.25 (27) | 14.58 (7) | 88.89 (8) ↑a | 0.00 (0) | 11.11 (1) | 10.81 (4) | 70.27 (26) | 18.92 (7) | 90.00 (18) ↑b | 5.00 (1) | 5.00 (1) |
| Imipenem (IMI) | Penems/Carbapenem | 98.25 (56) | 1.75 (1) | 0.00 (0) | 97.92 (47) | 2.08 (1) | 0.00 (0) | 100 (9) | 0.00 (0) | 0.00 (0) | 100 (37) | 0.00 (0) | 0.00 (0) | 95.00 (19) | 5.00 (1) | 0.00 (0) |
| Ciprofloxacin (CIP) | Fluoroquinolones | 56.14 (32) | 38.60 (22) | 5.26 (3) | 58.33 (28) | 41.67 (20) | 0.00 (0) | 44.44 (4) | 22.22 (2) | 33.33 (3) | 56.76 (21) | 43.24 (16) | 0.00 (0) | 55.00 (11) | 30.00 (6) | 15.00 (3) |
| Nalidixic acid (NAL) | Quinolone | 10.53 (6) | 0.00 (0) | 89.47 (51) | 8.33 (4) | 0.00 (0) | 91.67 (44) | 22.22 (2) | 0.00 (0) | 77.78 (7) | 0.00 (0) | 0.00 (0) | 100 (37) | 30.00 (6) ↑b | 0.00 (0) | 70.00 (14) |
| Gentamicin (G) | Aminoglycosides | 98.25 (56) | 0.00 (0) | 1.75 (1) | 97.92 (47) | 0.00 (0) | 2.08 (1) | 100 (9) | 0.00 (0) | 0.00 (0) | 97.30 (36) | 0.00 (0) | 2.70 (1) | 100 (20) | 0.00 (0) | 0.00 (0) |
| Streptomycin (SM) | Aminoglycosides | 75.44 (43) | 10.53 (6) | 14.04 (8) | 79.17 (38) | 8.33 (4) | 12.50 (6) | 55.56 (5) | 22.22 (2) | 22.22 (2) | 89.19 (33) | 5.40 (2) | 5.40 (2) | 50.00 (10) ↓c | 20.00 (4) | 30.00 (6) |
| Sulfonamide (S3) | Folate pathway inhibitors | 63.16 (36) | 0.00 (0) | 36.84 (21) | 66.67 (32) | 0.00 (0) | 33.33 (16) | 44.44 (4) | 0.00 (0) | 55.56 (5) | 78.38 (29) | 0.00 (0) | 21.62 (8) | 35.00 (7) ↓c | 0.00 (0) | 65.00 (13) |
| Trimethoprim- Sulfamethoxazole (T/S) | Folate pathway inhibitors | 82.46 (47) | 3.51 (2) | 14.04 (8) | 83.33 (40) | 4.17 (2) | 12.50 (6) | 77.78 (7) | 0.00 (0) | 22.22 (2) | 86.49 (32) | 5.40 (2) | 8.11 (3) | 75.00 (15) | 0.00 (0) | 25.00 (5) |
| Chloramphenicol (C) | Phenicols | 78.95 (45) | 0.00 (0) | 21.05 (12) | 79.17 (38) | 0.00 (0) | 20.83 (10) | 77.78 (7) | 0.00 (0) | 22.22 (2) | 89.19 (33) | 0.00 (0) | 10.81 (4) | 60.00 (12) ↓c | 0.00 (0) | 40.00 (8) |
| Tetracycline (TE) | Tetracyclines | 77.19 (44) | 0.00 (0) | 22.81 (13) | 81.25 (39) | 0.00 (0) | 18.75 (9) | 55.56 (5) | 0.00 (0) | 44.44 (4) | 89.19 (33) | 0.00 (0) | 10.81 (4) | 55.00 (11) ↓c | 0.00 (0) | 45.00 (9) |
AM, antimicrobial; CLSI, Clinical and Laboratory Standards Institute; MDR, multidrug-resistant; ESBL, extended-spectrum beta-lactamase; interpretive categories: S, susceptible; I, intermediate; R, resistant. aStatistically significant differences between S. Typhimurium isolates and isolates belonging to other serotypes of non-typhoidal Salmonella, two-tailed Fisher’s exact test P-value < 0.005. bStatistically significant differences between ESBL-positive and ESBL-negative isolates, two-tailed Fisher’s exact test P-value < 0.005. cStatistically significant differences between ESBL-positive and ESBL-negative isolates, two-tailed Fisher’s exact test P-value < 0.05.