[Theory and practice of macrorestriction analysis for the clonal analysis of pathogens].

The macrorestriction analysis of bacterial genomes is a method that is generally applicable to the typing of bacteria. The chromosome is cleaved with a restriction endonuclease that cuts infrequently and subsequently separated by pulsed-field gel electrophoresis. The fragment pattern defines the genotype of the strain. The relatedness of strains is evaluated from the similarity of the fragment patterns. The quantitative comparison of fragment patterns allows the definition of the infrasubspecific rank of a clone. Macrorestriction analysis is a sensitive and specific method to trace the origin and spread of infections and to analyse the clonal structure of bacterial populations.