Transformation as a tool for studying the epidemiology of tet determinants in Streptococcus pneumoniae.

Transformation of pneumococcus was used to detect homology among tetracycline resistance determinants of clinical isolates of Streptococcus pneumoniae. A strain of pneumococcus containing a mutated tet determinant (tet-3), of class M, integrated into the chromosome was used as a recipient in transformation experiments, where donor DNA was from the tetracycline resistant isolates. 34/34 strains appeared to have tet determinants homologous to tet-3 (i.e. tet M). Still using transformation it was possible to determine that the tet-3 transforming activity of DNA from Tn916 and S. pneumoniae BM6001 was contained in a 5 kb HincII fragment. For this purpose a transformation technique where donor DNA was directly taken from low melting point agarose gels was standardized and used.