Volume 13, Number 12—December 2007
Dispatch
Enhanced Subtyping Scheme for Salmonella Enteritidis
Jie Zheng*, Christine E. Keys†, Shaohua Zhao‡, Jianghong Meng*, and Eric W. Brown†
Table 2
PFGE diversity indices for various combinations of restriction enzymes in Salmonella Enteritidis
| Enzyme/combination | PFGE patterns* | Mean no. strains/ polytomy† | % polytomous strains‡ | Node:strain ratio§ | Simpson diversity index |
|---|---|---|---|---|---|
| XbaI | 19 | 9.1 | 84 | 0.30 | 0.83 |
| BlnI | 15 | 16.3 | 85 | 0.22 | 0.76 |
| SpeI | 16 | 9.6 | 88 | 0.28 | 0.80 |
| SfiI | 15 | 13.2 | 87 | 0.24 | 0.67 |
| PacI | 20 | 9.0 | 83 | 0.32 | 0.74 |
| NotI | 26 | 5.2 | 82 | 0.47 | 0.92 |
| XbaI/BlnI | 24 | 9.7 | 76 | 0.37 | 0.84 |
| XbaI/SpeI | 26 | 6.6 | 78 | 0.43 | 0.88 |
| XbaI/SfiI | 30 | 5.2 | 75 | 0.51 | 0.92 |
| XbaI/PacI | 30 | 5.6 | 74 | 0.50 | 0.91 |
| XbaI/NotI | 38 | 4.2 | 66 | 0.63 | 0.95 |
| BlnI/SpeI | 22 | 8.6 | 79 | 0.36 | 0.84 |
| BlnI/SfiI | 26 | 6.6 | 78 | 0.43 | 0.89 |
| BlnI/PacI | 28 | 6.3 | 75 | 0.46 | 0.88 |
| BlnI/NotI | 36 | 4.3 | 68 | 0.61 | 0.94 |
| SpeI/SfiI | 27 | 5.9 | 78 | 0.46 | 0.90 |
| SpeI/PacI | 30 | 6.8 | 71 | 0.46 | 0.89 |
| SpeI/NotI | 35 | 3.9 | 72 | 0.61 | 0.96 |
| SfiI/PacI | 30 | 5.2 | 75 | 0.51 | 0.87 |
| SfiI/NotI | 43 | 4.0 | 58 | 0.67 | 0.96 |
| PacI/NotI | 42 | 3.6 | 62 | 0.70 | 0.96 |
| SpeI/SfiI/NotI | 48 | 3.8 | 50 | 0.64 | 0.97 |
| SpeI/PacI/NotI | 47 | 3.6 | 53 | 0.72 | 0.97 |
| SfiI/PacI/NotI | 51 | 3.3 | 47 | 0.79 | 0.98 |
| 6 enzymes | 57 | 3.6 | 38 | 0.78 | 0.98 |
*PFGE, pulsed-field gel electrophoresis. Absolute tally of unique PFGE fingerprints or fingerprint combinations derived from the corresponding enzyme or group of enzymes.
†Total no. polytomous strains/no. polytomies in the dendrogram.
‡No. polytomous strains/76 (total S. Enteritidis strains in the analysis).
§Total no. nodes in the dendrogram/76 S.Enteritidis strains.
¶Derived from the formula for assessing discriminatory capability of a subtyping method (13).
