Cloning and physical characterization of chromosomal conjugative elements in streptococci.

摘要: We used a directed insertion method to introduce nonreplicating vector plasmid into the large conjugative cat-tet element found in chromosome of Streptococcus pneumoniae BM6001 and derivatives. To direct preferentially element, we transferred it by conjugation faecalis then DNA from this strain as source restriction nuclease fragments for ligation digests pVA891, which can replicate Escherichia coli but not streptococci. This mix was transform pneumococcal cells carrying with selection erythromycin resistance carried pVA891. Eight such isolates were found, transformation tests showed that each case had inserted expected. these strains generated variety E. plasmids provide tools obtaining detailed map defining other structural features streptococcal element.