Determination of clonal relationships of Salmonella typhimurium by numerical analysis of macrorestriction profiles.
The use of numerical analysis of macrorestriction profiles resolved by pulsed-field gel electrophoresis (PFGE) for identifying epidemiological and clonal relationships between strains of Salmonella typhimurium was investigated. A cluster analysis based on Xba1 macrorestriction profiles of 40 strains was compared to biotype, phage-type and ribotype data on each isolate to validate the integrity and significance of the results. A significant correlation between these data was noted, suggesting that evolutionary divergence, of both recent and a more distant nature, may be detected. Moreover, two principal clonal lines of Salm. typhimurium appear to be prevalent in Denmark, of which one is comparatively stable with respect to phenotype and genotype, while the other is relatively diverse in these respects. We conclude that numerical analysis of macrorestriction profiles is a useful means of evaluating interstrain relationships between Salm. typhimurium strains and has practical applications for both short- and long-term epidermiological surveillance purposes.
On
S L
SL
Danish Veterinary Laboratory, Copenhagen, Denmark. sto@svs.dk
Baggesen
D L
DL
D015373:Bacterial Typing Techniques; D016521:Electrophoresis, Gel, Pulsed-Field; D012486:Salmonella typhimurium / Q000145:classification*