TABLE 2.
Salmonella isolates used in this study
| Isolate | State | Sourcea | Serovar | % Invasionb | Antibiotic resistancec | Antibiotic resistance-associated gened
|
Virulence-associated genee
|
Genetic typef
|
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| intI1 | merA | aadA1 | invA | spvB | pef | PFGE (BlnI) | PFGE (XbaI) | RAPD (1254) | ||||||
| 98A-6836 | Wy. | Pheasant (C) | Infantis | ND | − | − | − | + | − | − | A | B | BB | |
| 98A-7582 | Wy. | English sparrow (F) | Typhimurium | ND | + | − | − | + | + | + | B1-A | A1-A | DD | |
| 98A-12202 | Wy. | English sparrow (F) | Typhimurium | ND | − | − | − | + | + | + | B1-A | A1-A | FF | |
| 98W-12198 | Wy. | English sparrow (F) | Typhimurium | ND | − | − | − | + | + | + | B1-A | A1-A | DD | |
| 96A-29192 | W.V. | Wild turkey (F) | Java | 100 | + | − | − | + | − | − | C | C | CC | |
| 96A-37518 | Ga. | Cowbird (F) | Typhimurium | ND | − | − | − | + | + | + | B1-B | A1-B | DD | |
| 96A-38567 | Ga. | Owl (F) | 4,5,12:I-monophasic | 8 | Su Tc | + | + | − | + | + | + | B3 | A3 | EE |
| 97-9746 | Ga. | Quail | Typhimurium (Copenhagen) | ND | Ap Kn Sm Su Tc | + | + | + | + | + | − | D | D | DD |
| 97A-9840 | Ga. | Parakeet (C) | Typhimurium | 25 | − | − | − | + | + | + | H | A2 | DD | |
| 97A-11201 | Ga. | Heron (F) | 4,5,12:I-monophasic | 125 | − | − | − | + | + | + | E | A3 | DD | |
| 97A-17868 | Fla. | Emu (C) | Typhimurium | 175 | − | − | − | + | − | − | B2 | A2 | DD | |
| 97A-47510 | N.C. | African grey parrot (C) | Typhimurium | ND | Su | − | − | − | + | + | + | H | A3 | DD |
| 98A-9551 | Ga. | Coturnix quail (F) | Typhimurium (Copenhagen) | 105 | Ap Kn Sm Su | + | − | + | + | + | − | D | D | DD |
| 98A-17535 | Fla. | Laughing gull (F) | Typhimurium | 140 | − | − | − | + | + | + | B2 | A1-B | AA | |
| 98A-24966-2 | Ga. | Cowbird (F) | Typhimurium | 50 | + | − | − | + | + | + | B1-B | A1-B | DD | |
| 98A-28238 | Ga. | Cowbird (F) | Typhimurium | 65 | + | − | − | + | + | + | B1-B | A1-B | DD | |
| 98A-33516 | Ky. | Goldfinch (F) | Typhimurium (Copenhagen) | ND | Su | − | − | − | + | − | − | B3 | A2 | DD |
| 98A-3397 | Ga. | Senegal parrot (C) | Typhimurium (Copenhagen) DT104 | ND | Ap Cm Sm Su Tc | + | − | + | + | + | + | F | F | DD |
| 98A-3398 | Ga. | Lorikeet (C) | Typhimurium (Copenhagen) DT104 | ND | Ap Cm Sm Su Tc | + | − | + | + | + | + | F | F | DD |
| 7992 | Ga. | Hawk (F) | Alabama | ND | − | − | − | + | − | − | G | G | GG | |
| 98A-31777 | Ga. | Emu (C) | Anatum | ND | − | − | − | + | − | − | I | E | HH | |
| 97A-26782 | N.J. | Pigeon (F) | Typhimurium (Copenhagen) | ND | − | − | − | + | + | + | B3 | H | DD | |
Salmonella isolates were from diseased birds. These nondomestic birds, examined at the Athens Diagnostic Laboratory, represent either free-ranging (F) or captive (C) birds.
Invasion is presented as a percentage relative to levels obtained with Salmonella enterica serovar Typhimurium SR11. E. coli K-12 strain HB101 was included as an invasion-negative control for BATCs (21).
Abbreviations: Ap, ampicillin; Cm, chloramphenicol; Kn, kanamycin; Sm, streptomycin; Su, sulfamethoxazole; Tc, tetracycline. All isolates were sensitive to amikacin, apramycin, ceftiofur, ceftriaxone, cephalothin, ciprofloxacin, gentamicin, nalidixic acid, and trimethoprim.
Salmonella isolates were screened by DNA-DNA hybridization for the presence of class 1 integrons and resistance genes associated with them. intI1, class 1 integrase; merA, mercury reductase; aadA1, streptomycin and spectinomycin resistance gene.
Salmonella isolates were screened by DNA-DNA hybridization for the presence of invasion gene invA and virulence plasmid-associated genes spvC and pef.
We chose PFGE and RAPD PCR for typing of Salmonella isolates. For PFGE, the restriction enzymes XbaI and BlnI were selected for typing of bacterial isolates. RAPD involved using a 10-mer oligonucleotide, 1254, as the typing primer. An alphabetical designation was assigned to each distinct DNA fingerprint.