TY - JOUR
T1 - An enhanced discriminatory pulsed-field gel electrophoresis scheme for subtyping Salmonella serotypes heidelberg, Kentucky, SaintPaul, and Hadar
AU - Xi, Meili
AU - Zheng, J. I.E.
AU - Zhao, Shaohua
AU - Brown, Eric W.
AU - Meng, Jianghong
PY - 2008/10
Y1 - 2008/10
N2 - Conventional pulsed-field gel electrophoresis (PFGE) protocols, used extensively as a successful approach for subtyping many salmonellae, may be inadequate for discriminating strains sharing levels of homogeneity within the same serotype. Four additional restriction enzymes (SpeI, PacI, SfiI, and NotI), in addition to XbaI and BlnI, were used in PFGE typing of 33 Salmonella Heidelberg, 27 Salmonella Kentucky, 27 Salmonella SaintPaul, and 27 Salmonella Hadar isolates that were recovered from poultry and porcine retail meats from different states of the United States. A dendrogram derived from the combined analysis of six enzymes was highly discriminatory with a Simpson index of diversity value of over 0.950. The ratio of nodes to isolates was more than 0.75 with an average of fewer than three isolates in each polytomy for all four serotypes. Two three-enzyme combinations, SpeI/NotI/SfiI for Salmonella Heidelberg and Salmonella Hadar, and SpeI/BlnI/SfiI for Salmonella Kentucky and Salmonella SaintPaul, were found to have comparable discriminatory abilities of differentiating isolates of these Salmonella serotypes with the six-enzyme combination. The enhanced discriminatory PFGE-based subtyping scheme can be used effectively for the differentiation of strains of the four Salmonella serotypes. The findings also highlight PFGE analysis as a continued essential and informative subtyping method for source tracking and outbreak investigations of these and other Salmonella pathogens.
AB - Conventional pulsed-field gel electrophoresis (PFGE) protocols, used extensively as a successful approach for subtyping many salmonellae, may be inadequate for discriminating strains sharing levels of homogeneity within the same serotype. Four additional restriction enzymes (SpeI, PacI, SfiI, and NotI), in addition to XbaI and BlnI, were used in PFGE typing of 33 Salmonella Heidelberg, 27 Salmonella Kentucky, 27 Salmonella SaintPaul, and 27 Salmonella Hadar isolates that were recovered from poultry and porcine retail meats from different states of the United States. A dendrogram derived from the combined analysis of six enzymes was highly discriminatory with a Simpson index of diversity value of over 0.950. The ratio of nodes to isolates was more than 0.75 with an average of fewer than three isolates in each polytomy for all four serotypes. Two three-enzyme combinations, SpeI/NotI/SfiI for Salmonella Heidelberg and Salmonella Hadar, and SpeI/BlnI/SfiI for Salmonella Kentucky and Salmonella SaintPaul, were found to have comparable discriminatory abilities of differentiating isolates of these Salmonella serotypes with the six-enzyme combination. The enhanced discriminatory PFGE-based subtyping scheme can be used effectively for the differentiation of strains of the four Salmonella serotypes. The findings also highlight PFGE analysis as a continued essential and informative subtyping method for source tracking and outbreak investigations of these and other Salmonella pathogens.
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U2 - 10.4315/0362-028X-71.10.2067
DO - 10.4315/0362-028X-71.10.2067
M3 - Article
C2 - 18939754
AN - SCOPUS:53749101695
SN - 0362-028X
VL - 71
SP - 2067
EP - 2072
JO - Journal of food protection
JF - Journal of food protection
IS - 10
ER -