OBJECTIVES: The objective of this study was to investigate @entity7646 -resistant @entity5967 isolates harbouring erm(TR), an erm(A) gene subclass, with emphasis on their erm(TR)-carrying genetic elements. Four erm(TR)-carrying elements have been described to date: three closely related (ICE10750-RD.2, Tn1806 and ICESp1108) in @entity4195 , @entity328 and @entity4195 , respectively; and one completely different (IMESp2907, embedded in ICESp2906 to form ICESp2905) in @entity4195 . METHODS: Seventeen @entity7646 -resistant erm(TR)-positive @entity5967 isolates were phenotypically and genotypically characterized. Their erm(TR)-carrying elements were explored by analysing the distinctive recombination genes of known erm(TR)-carrying integrative and conjugative elements (ICEs) and by PCR mapping. The new genetic context and organization of IMESp2907 in @entity5967 were explored using several experimental procedures and in silico analyses. RESULTS: Five isolates harboured ICE10750-RD.2/Tn1806, five isolates harboured ICESp1108 and five isolates bore unknown erm(TR)-carrying elements. The remaining two isolates, exhibiting identical serotypes and pulsotypes, harboured IMESp2907 in a new genetic environment, which was further investigated in one of the two isolates, SagTR7. IMESp2907 was circularizable in @entity5967 , as described in @entity4195 . The new IMESp2907 junctions were identified based on its site-specific integration; the att sites were almost identical to those in @entity4195 . In strain SagTR7, erm(TR)-carrying IMESp2907 was embedded in an erm(TR)-less internal element related to ICE10750-RD.2/Tn1806, which, in turn, was embedded in an ICESde3396-like element. The resulting whole ICE, ICESagTR7 (   129 kb), was integrated into the chromosome downstream of the rplL gene, and was excisable in circular form and transferable by conjugation. CONCLUSIONS: This is the first study exploring erm(TR)-carrying genetic elements in @entity5967 .

XXXX resistance gene erm(TR) and erm(TR)-carrying genetic elements in @entity5967 : characterization of ICESagTR7, a new composite element containing IMESp2907.

@entity4195 :: ('1314', 'Species') :: ['Streptococcus pyogenes', 'S. pyogenes'] @entity328 :: ('1313', 'Species') :: ['Streptococcus pneumoniae'] @entity5967 :: ('1311', 'Species') :: ['Streptococcus agalactiae', 'S. agalactiae'] @entity7646 :: ('CHEBI:25106', 'Chemical') :: ['macrolide']
@entity7646 :: (CHEBI:25106,Chemical) :: ['Macrolide']
