TABLE 3.
Distribution of selected antimicrobial resistance genes in Streptococcus suis isolated from pigs in Korea
| Resistance phenotype/gene | No. (%) of isolates with specific resistance phenotype/gene from: |
||
|---|---|---|---|
| Diseased pigs | Healthy pigs | Total | |
| Tetracycline resistance phenotype | 53 (94.6) | 150 (87.7) | 203 (89.4) |
| tet(L) | 1 (1.9) | 3 (2.0) | 4 (2.0) |
| tet(M) | 3 (5.7) | 1 (0.7) | 4 (2.0) |
| tet(O) | 41 (77.4) | 125 (83.3) | 166 (81.8) |
| tet(L) and tet(O) | 2 (3.8) | 9 (6.0) | 11 (5.4) |
| None of the tested genes | 6 (11.3) | 12 (8.0) | 18 (8.9) |
| Macrolide resistance phenotype | 53 (94.6) | 163 (95.3) | 216 (95.2) |
| erm(B) | 5 (9.4) | 8 (4.9) | 13 (6.0) |
| erm(C) | 0 (0.0) | 1 (0.6) | 1 (0.5) |
| mef(A) and/or mef(E) | 10 (18.9) | 27 (16.6) | 37 (17.1) |
| mph(C) | 0 (0.0) | 1 (0.6) | 1 (0.5) |
| erm(B) and mef(A) and/or mef(E) | 0 (0.0) | 2 (1.2) | 2 (0.9) |
| None of the tested genes | 38 (71.7) | 124 (76.1) | 162 (75.0) |
| Aminoglycoside resistance phenotype | 40 (71.4) | 146 (85.4) | 186 (81.9) |
| aph(3′)-IIIa | 4 (10.0) | 38 (26.0) | 42 (22.6) |
| aac(6′)-Ie-aph(2″)-Ia | 0 (0.0) | 19 (13.0) | 19 (10.2) |
| aph(3′)-IIIa and aac(6′)-Ie-aph(2″)-Ia | 0 (0.0) | 33 (22.6) | 33 (17.7) |
| None of the tested genes | 36 (90.0) | 56 (38.4) | 92 (49.5) |