Molecular typing of Mycoplasma pneumoniae strains by PCR-based methods andpulsed-field gel electrophoresis. Application to French and Danish isolates

Restriction fragment length polymorphism (RFLP) analysis of the amplified P 1 gene was used to type 153 strains of Mycoplasma pneumoniae isolated in Fr ance between 1977 and 1994, and in Denmark between 1962 and 1994, and an ad ditional group of 28 strains isolated from Belgium and Germany between 1990 and 1993. Random amplified polymorphic DNA (RAPD) analysis was tested on F rench, Belgian and German strains. Both methods separated the strains into two groups corresponding to the two reference strains M129 (group I) and FH (group II), and gave concordant results. When 75 selected strains of diffe rent geographical origin were analysed by pulsed-field gel electrophoresis (PFGE), strains of group II fell into two closely related subgroups, subgro up IIa corresponding to the reference strain FH, and subgroup IIb. Most of the strains isolated in Denmark in the period 1962-86 belonged to group I. Almost all strains isolated in France and Denmark between 1987 and 1988 wer e from group TT, the two subgroups being present. In 1991-3, almost all str ains from France as well as Denmark, Germany and Belgium belonged to group I.