Spoligotype diversity of Mycobacterium bovis strains isolated in France from 1979 to 2000

The molecular fingerprints of 1,349 isolates of Mycobacterium bovis receive d between 1979 and August 2000 at Agence Francaise de Securite Sanitaire de s Aliments (Afssa) have been obtained by spoligotyping. The majority of the isolates (1,266) were obtained from cattle living in France. An apparently high level of heterogeneity was observed between isolates. One hundred six ty-one spoligotypes were observed in total, of which 153 were from French i solates. The two predominant spoligotypes, designated BCG-like and GB54, ac counted for 26 and 12% of the isolates, respectively.. In addition, 84% of the spoligotypes were found fewer than 10 times. Analysis of the results by clustering and parsimony-based algorithms revealed that the majority of th e spoligotypes were closely related. The predominant spoligotype was identi cal to that of the vaccine strain Mycobacterium bovis BCG, which was isolat ed in France at the end of the 19th century. Some spoligotypes were closely associated with restricted geographical areas. Interestingly, some spoligo types, which were frequently observed in France, were also observed in neig hboring countries. Conversely, few spoligotypes were common to France and E ngland, and those that were shared were observed at very different frequenc ies. This last point illustrates the potential role for an international da ta bank which could help trace the spread of M. bovis across national borde rs.