A study on erm(B)-mediated MLS resistance in Streptococcus pyogenes clinical isolates

ICE Sp1116 , the Genetic Element Responsible for erm (B)-Mediated, Inducible Erythromycin Resistance in Streptococcus pyogenes, Belongs to the Tn GBS Family of Integrative and Conjugative Elements

“…In fact, ICESp1116-harboring isolates are a major subpopulation within the erythromycin-resistant S. pyogenes populations circulating in Italy (10,12,13). ICESp1116 has never been described in other Streptococcus species, including viridans group streptococci, which harbor a wide assortment of varied erythromycin resistance elements (14).…”

ICE Sp1116 , the Genetic Element Responsible for erm (B)-Mediated, Inducible Resistance to Erythromycin in Streptococcus pyogenes

“…Within the erythromycin-resistant S. pyogenes population circulating in Italy, isolates bearing inducible erm(B) represent a major subpopulation (13,21,27,34) clearly prevailing among erm(B)-positive isolates (7,24) and typically characterized by uniform susceptibility to tetracycline (7,13,21). In this study, Tn1116, renamed ICESp1116 (23), was comprehensively characterized (accession no.…”

“…IS1216 cuts off the coding sequence of tet(M), resulting in loss of the 5= end of the gene (besides, of course, the remaining upstream portion of Tn5397) and in a silent tet(M). A subpopulation harboring ICESp1116, sharing a number of typing characters, is highly prevalent in Italy among erythromycin-resistant S. pyogenes isolates (7,13,21,24,27,34). The success of this subpopulation may have been favored by the acquisition of specific genetic traits, such as orf6, whose product, the cell wall-anchored adhesin SspB, may have provided ICESp1116-harboring isolates with an adaptive advantage and enhanced their survival through a greater ability to compete with indigenous commensal streptococci in colonizing host surfaces (6).…”