MOLECULAR ANALYSIS BY PULSED-FIELD GEL-ELECTROPHORESIS OF PENICILLIN-RESISTANT STREPTOCOCCUS-PNEUMONIAE FROM TOULOUSE, FRANCE

A sample of 28 penicillin-resistant Streptococcus pneumoniae strains i solated between 1991 and 1993 in a large hospital in Toulouse, France, was characterized by pulsed-field gel electrophoresis of genomic DNA. Also included were 6 penicillin-susceptible clinical isolates from To ulouse and 12 penicillin-resistant strains from different parts of the world. The restriction endonucleases Apal and Smal were used to diges t intact chromosomes, and the fragments were resolved by field-inversi on gel electrophoresis. Seven major pattern types could be recognized among the penicillin-resistant isolates from Toulouse. Nine of these i solates could be assigned to two clones that were also found in Spain and were associated with serotypes 6B and 9V. A third clone was isolat ed in South Africa and in Spain and contained se retype 23F isolates. The profiles obtained by field-inversion gel electrophoresis suggested that 15 of the 16 penicillin-resistant serogroup 23 isolates from Tou louse belonged to the same Spanish 23F clone. The molecular test profi les of penicillin-susceptible strains differed from those of resistant strains of the same serotype except those of 9V strains. These data u nderline the importance of the geographic spread of resistant clones f rom Spain in the emergence of penicillin-resistant pneumococci in Fran ce.