Table 3.
Mutations in erythromycin-resistant C. coli isolated from pigs and chickens from 2010 to 2018 in Korea.
| Source | ERY a MIC Range (µg/mL) |
Nucleotide/Amino Acid Substitution | Sequence Types | |||
|---|---|---|---|---|---|---|
| 23s rRNA b | L4c | L22 c | No. of Isolates | |||
| Pigs (n = 87) |
≥64 | A2075G | WT | WT | 38 | 7 ST854, 7 ST1016, 2 ST2715, 2 ST2733, 2 ST11050, 2 ST1556, 2 ST4172, 2 ST828, and each of ST860, ST900, ST1062, ST1068, ST1104, ST1142, ST1446, ST11056, ST11049, ST11061, ST2716, and ST890 |
| >64 | A2075G | WT | A103V | 1 | ST854 | |
| >64 | A2075G | WT | no band | 1 | ST10826 | |
| ≥64 | A2075G | M192I | WT | 13 | 4 ST829, 2 ST1055, and each of ST828, ST872, ST1142, ST2715, ST7168, and ST11054, ST11062 | |
| 64 | A2075G | M192I | A103V | 3 | ST1131, ST1450, and ST2715 | |
| >64 | A2075G | P28S | WT | 6 | 2 ST854, 2 ST9575, and each of ST1556 and ST11050 | |
| >64 | A2075G | V121A | WT | 2 | ST1096 and ST11054 | |
| >64 | A2075G | V121A, V176I, T177S, V184I, M192I | WT | 4 | ST1016, ST1096, ST7123, and ST11054 | |
| >64 | A2075G | V121A, V176I, T177S, V184I, M192I | A103V | 4 | ST1417, ST1450, ST1556, and ST11054 | |
| >64 | A2075G | V176I, T177S | WT | 2 | ST1058 and ST1117 | |
| >64 | A2075G | V176I, T177S, V184I | WT | 1 | ST2715 | |
| >64 | A2075G | V176I, T177S, V184I, M192I | WT | 2 | ST854 and ST2715 | |
| >64 | A2075G | V176I, T177S, V184I, M192I | A103V | 1 | ST1131 | |
| >64 | A2075G | V184I, M192I | WT | 2 | ST829 and ST2715 | |
| >64 | A2075G | no band | no band | 1 | ST829 | |
| >64 | A2075Y | WT | WT | 1 | ST4809 | |
| >64 | A2075G, C2097T | V121A, V176I, T177S, V184I, M192I | A103V | 2 | ST890 | |
| >64 | WT | V121A, A140T | WT | 1 | ST2718 | |
| >64 | WT | V121A | WT | 1 | ST1055 | |
| >64 | WT | P28S | WT | 1 | ST854 | |
| Chickens (n = 50) |
≥64 | A2075G | WT | WT | 32 | 10 ST860, 7 ST9867, 4 ST9201, 2 ST5675, 2 ST6148, 2 ST11051, 2ST1016, and each of ST828, ST1587, and ST1556 |
| >64 | A2075G | WT | Q24R, V65I, G74A, T109A | 2 | ST11052 and ST860 | |
| 64 | A2075G | WT | V65I, G74A, T109A | 1 | ST5675 | |
| >64 | A2075G | M192I | G74A, T109A | 1 | ST2711 | |
| >64 | A2075G | P28S | WT | 1 | ST854 | |
| >64 | A2075G | V184I | WT | 1 | ST1096 | |
| 64 | A2075G | V121A, M192I | V65M | 1 | ST11051 | |
| >64 | A2075G | V121A, M192I | V65I, G74A, T109S | 1 | ST6148 | |
| 64 | A2075G | V184I, M192I | WT | 1 | ST2715 | |
| >64 | A2075G | no band | WT | 1 | ST860 | |
| ≥32 | A2075G, T2114C | WT | WT | 4 | ST860 | |
| >64 | A2074M, A2075Y | WT | WT | 1 | ST6148 | |
| ≥32 | WT | WT | WT | 3 | 2 ST9867 and an ST829 | |
a Abbreviations: ERY, erythromycin; WT, wild type; ST, b position according to Escherichia Coli numbering. c Position of amino acids changes. DNA sequences of rplD and rplV genes coding L4 and L22 ribosomal proteins, respectively, were compared with the sequence in the C. coli JV20 genome.