Molecular analysis of a composite chromosomal conjugative element (Tn3701) of Streptococcus pyogenes.
AUTOR(ES)
Le Bouguénec, C
RESUMO
The plasmid-free Streptococcus pyogenes A454 contains a conjugative element, Tn3701, encoding resistance to erythromycin (Emr), tetracycline (Tcr), and minocycline (Mnr). We have mapped a 50-kilobase (kb) chromosomal region of A454 corresponding to the internal part of Tn3701. Tn3701 includes a 19.7-kb structure, designated Tn3703, on which the Emr Tcr Mnr determinants were localized. Tn3703 was very similar in structure to Tn916. Translocation of the Emr Tcr Mnr markers from A454 onto pIP964, an Enterococcus faecalis hemolysin plasmid, yielded different pIP964 derivatives. When the inserts of four of these derivatives were aligned with the 50-kb region of Tn3701, three of them were found to result from the transposition of Tn3703 and one resulted from the insertion of a 44.0-kb portion of Tn3701, including Tn3703. Tn3701 inserted, apparently without changing its structure, in the chromosomes of various streptococcal transconjugants, as well as in one of the 12 E. faecalis transconjugants studied. Tn3703 inserted at different chromosomal sites in four E. faecalis transconjugants, and one copy of Tn3701 plus an additional copy of Tn3703 were detected in the chromosomes of seven transconjugants.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=211392Documentos Relacionados
- Presence of chromosomal elements resembling the composite structure Tn3701 in streptococci.
- Genetic analysis of antibiotic resistance in Streptococcus pyogenes.
- Hemolytic mutants of group A Streptococcus pyogenes.
- Physical and genetic chromosomal map of an M type 1 strain of Streptococcus pyogenes.
- Platelet aggregation by Streptococcus pyogenes.