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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†Comments to Author 
Author affiliations: *University of Maryland, College Park, Maryland, USA; †US Food and Drug Administration, College Park, Maryland, USA; ‡US Food and Drug Administration, Laurel, Maryland, USA;

Main Article

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).

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References
  1. Rodrigue  DC, Tauxe  RV, Rowe  B. International increase in Salmonella Enteritidis: a new pandemic? Epidemiol Infect. 1990;105:21–7. DOIPubMedGoogle Scholar
  2. Mead  PS, Slutsker  L, Dietz  V, McCaig  LF, Bresee  JS, Shapiro  C, Food-related illness and death in the United States. Emerg Infect Dis. 1999;5:607–12. DOIPubMedGoogle Scholar
  3. Olsen  JE, Skov  MN, Threlfall  EJ, Brown  DJ. Clonal lines of Salmonella enterica serotype Enteritidis documented by IS200-, ribo-, pulsed-field gel electrophoresis and RFLP typing. J Med Microbiol. 1994;40:15–22. DOIPubMedGoogle Scholar
  4. Saeed  AM, Walk  ST, Arshad  M, Whittam  TS. Clonal structure and variation in virulence of Salmonella Enteritidis isolated from mice, chickens, and humans. J AOAC Int. 2006;89:504–11.PubMedGoogle Scholar
  5. Swaminathan  B, Barrett  TJ, Hunter  SB, Tauxe  RV. PulseNet: the molecular subtyping network for foodborne bacterial disease surveillance, United States. Emerg Infect Dis. 2001;7:382–9.PubMedGoogle Scholar
  6. Thong  KL, Ngeow  YF, Altwegg  M, Navaratnam  P, Pang  T. Molecular analysis of Salmonella Enteritidis by pulsed-field gel electrophoresis and ribotyping. J Clin Microbiol. 1995;33:1070–4.PubMedGoogle Scholar
  7. Landeras  E, Gonzalez-Hevia  MA, Alzugaray  R, Mendoza  MC. Epidemiological differentiation of pathogenic strains of Salmonella Enteritidis by ribotyping. J Clin Microbiol. 1996;34:2294–6.PubMedGoogle Scholar
  8. Davis  MA, Hancock  DD, Besser  TE, Call  DR. Evaluation of pulsed-field gel electrophoresis as a tool for determining the degree of genetic relatedness between strains of Escherichia coli O157:H7. J Clin Microbiol. 2003;41:1843–9. DOIPubMedGoogle Scholar
  9. Davis  MA, Hancock  DD, Besser  TE, Rice  DH, Hovde  CJ, Digiacomo  R, Correlation between geographic distance and genetic similarity in an international collection of bovine fecal Escherichia coli O157:H7 isolates. Epidemiol Infect. 2003;131:923–30. DOIPubMedGoogle Scholar
  10. Roberts  RJ, Vincze  T, Posfai  J, Macelis  D. REBASE–restriction enzymes and DNA methyltransferases. Nucleic Acids Res. 2005;33:D230–2. DOIPubMedGoogle Scholar
  11. Ribot  EM, Fair  MA, Gautom  R, Cameron  DN, Hunter  SB, Swaminathan  B, Standardization of pulsed-field gel electrophoresis protocols for the subtyping of Escherichia coli O157:H7, Salmonella, and Shigella for PulseNet. Foodborne Pathog Dis. 2006;3:59–67. DOIPubMedGoogle Scholar
  12. Centers for Disease Control and Prevention. Standardized molecular subtyping of foodborne bacterial pathogens by pulsed-field gel electrophoresis. Atlanta: The Centers; 1998 [cited 2007 Sep 20]. Available from http://www.cdc.gov/pulsenet/protocols.htm
  13. Hunter  PR, Gaston  MA. Numerical index of the discriminatory ability of typing systems: an application of Simpson’s index of diversity. J Clin Microbiol. 1988;26:2465–6.PubMedGoogle Scholar
  14. Struelens  MJ. Consensus guidelines for appropriate use and evaluation of microbial epidemiologic typing systems. Clin Microbiol Infect. 1996;2:2–11.PubMedGoogle Scholar
  15. Schmid  D, Luckner-Hornischer  A, Holzhammer  G, Rokita  D, Federspeil  M, Lassnig  H, Lessons learned from a Salmonella Enteritidis phage type 4 outbreak in Austria, 2005. J Food Prot. 2007;70:35–9.PubMedGoogle Scholar

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