TABLE 2.
Southern blotting of representative Salmonella serotype Typhimurium isolates and probe hybridization using selected gene cassettesa
| Phage type | R type | Presence (+) or absence (−) of 10-kb XbaI fragment | IP type | Probe hybridization
|
||
|---|---|---|---|---|---|---|
| ant(3")-1a | pseI | dhfrI | ||||
| DT104 | ||||||
| CIT-V38 | ACSSuT | + | I | + | + | − |
| CIT-F45 | ACSSuT | + | I | + | + | − |
| CIT-H164 | ACSSuT | + | I | + | + | − |
| CIT-H176 | ACSSuTTp | + | I | + | + | − |
| CIT-H183 | SSu | − | VII | − | − | − |
| CIT-V115 | ACSSuT | + | I | + | + | − |
| CIT-F44 | ASu | − | III | − | − | − |
| DT104 related | ||||||
| CIT-F107 (104b) | ACSSuTK | + | I | + | + | − |
| CIT-H144 (104b) | ACSSuTTp | + | I | + | + | + |
| CIT-V37 (U302) | ACSSuTTp | + | I | + | + | − |
| DT193 | ||||||
| CIT-F34 | ASSuTN | − | IV | + | + | + |
| CIT-F41 | ASSuTTp | − | II | + | + | + |
| DT195, CIT-V60 | SuTTp | − | IV | − | − | − |
| DT208, CIT-V75 | T | − | IV | − | − | − |
| DT170a | ||||||
| CIT-V127 | ASSuTTp | − | II | + | + | + |
| CIT-V129 | SuTTp | − | IV | − | − | − |
| NT | ||||||
| CIT-F40 | Sensitive | − | V | − | − | − |
| CIT-F105 | SuTp | − | V | − | − | − |
| CIT-H195 | SuTp | − | IV | + | + | − |
| Controls | ||||||
| E. coli R100.1 | − | a | + | + | + | |
| E. coli R751 | − | b | + | + | − | |
a
ant(3")-1a, aminoglycoside-modifying enzyme coding gene; pseI, β-lactamase gene; dhfrI, dihydrofolate reductase gene. R type, antimicrobial resistance pattern. IP types a and b were previously defined (6). A, ampicillin; C, chloramphenicol; S, streptomycin; Su, sulfonamides; T, tetracycline; N, nalidixic acid; K, kanamycin. In the phage types, the letters V, H, and F refer to veterinary, human, and food origins, respectively.