TABLE 1.
Phenotypic characteristics of Salmonella isolated from swine feed, barn floor swabs, and feces from the same barns, farms, and production systemsd
| Farmb | Stagec | Replicatea | Phenotypic characteristics of Salmonella isolates (no. of samples)e |
|||||
|---|---|---|---|---|---|---|---|---|
| Feed (30) |
Swabs (71) |
Feces (179) |
||||||
| Serogroup(s) | R type | Serogroup(s) | R type | Serogroup(s) | R type | |||
| RW7 | F1 | R1 | C | Su Te (3) | E | Te (3) | C | St Su Te (1) |
| C | Su Te (36) | |||||||
| A to I | Am Te (6) | |||||||
| B | Te (2) | |||||||
| RW6 | F2 | R1 | E | Te (3) | A to I | Te (1) | E | Te (15) |
| E | Su Te (3), St Su Te (1) | |||||||
| D | St Su Te (2), Te (1) | |||||||
| C | Te (2), St Su (2), Su (6) | |||||||
| C | Am St Su Te Km (1) | |||||||
| B | Am Cl St Su Te (4), Su (1) | |||||||
| B | Am Su Te Km (3) | |||||||
| RW4 | F1 | R1 | A to E | Am St Te (3) | B | Am Cl St Su Te (4) | E | Te (5) |
| B | Am Cl St Su Te/Ax (5) | |||||||
| C | Su Te (3) | |||||||
| A to I | Te (1), Am Te (2) | |||||||
| A to I | Am Su Te (1) | |||||||
| TT2A | R1 | A to I | Pansusceptible (3) | B | St Su Te (14) | |||
| B | Am Cl St Su Te (3) | |||||||
| C | St Su Te (1) | |||||||
| BH3 | R1 | A to I | Te (3) | B | St Su Te (4) | |||
| B | Am St Te Km (4) | |||||||
| Am St Su Te Km (1) | ||||||||
| RW4 | F1 | R3 | B | Te (3) | E | Te (1) | B | Te (20) |
| B | St Su Te (2) | C | Su Te (1) | |||||
| C | St Su Te (2) | |||||||
| E | Am Te (2) | |||||||
| E | Am Su Te (1) | |||||||
| RW6 | F1 | R3 | B | Te (3) | A to I | St Su Te (4) | B | Te (5) |
| B | St Su Te (6) | |||||||
| A to E | St Su Te (1) | |||||||
| GO2A | F2 | R3 | B | Am Cl St Su Te (3) | C | St Su Te (12) | A to I | Su Te (7) |
| C | Su Te (4) | A to I | Te (1) | |||||
| C | St Su (1) | E | Am St Su Te (1) | |||||
| G | Te (3) | |||||||
| E | Te (6) | |||||||
| FF12 | F2 | R3 | B | Am St Te Km (3) | B | Am St Te Km (23) | ||
| TE6A | F2 | R4 | B | Am St Te Km (3) | E | Te (1) | B (F2) | St Su Te (3) |
| B | Pansusceptible (3) | |||||||
Each replicate consists of sampling of designated barn floors before and after disinfection, sampling of pigs at early and late finishing stages per treatment group, and pooled feed sampling. We made a total of four replicate visits (R1 to R4) to each farm (n = 9) during the study period.
Includes the farm code (RW, TT, BH, FF, GO, or TE) and barn number (7, 6, 6A, 3, 4, 2A, or 12).
F1 = early finishing stage (6 to 9 weeks of age); F2 = late finishing stage (market age).
Salmonella isolates sharing similar serogrouping and antimicrobial resistance patterns are indicated in boldface.
Am, ampicillin; Ax, amoxicillin-clavulanic acid; Cl, chloramphenicol (30 μg); Km, kanamycin; St, streptomycin; Su, sulfisoxazole; Te, tetracycline.