In vitro activity of ketolides telithromycin and HMR 3004 against Italian isolates of Streptococcus pyogenes and Streptococcus pneumoniae with different erythromycin susceptibility
In vitro activity of ketolides telithromycin and HMR 3004 against Italian isolates of Streptococcus pyogenes and Streptococcus pneumoniae with different erythromycin susceptibility
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DOI：
10.1093/jac/46.6.905
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发表时间：
2000-12-01
影响因子：
5.2
通讯作者：
Varaldo, PE
中科院分区：
文献类型：
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作者：
Giovanetti, E;Montanari, MP;Varaldo, PE
两种酮内酯，特利霉素和HMR 3004，在体外对红霉素敏感和耐药的化脓性链球菌和肺炎链球菌的活性进行了评价。根据红霉素耐药株对大环内酯类、林可酰胺和链霉素类抗生素的耐药性，将其分为构成耐药(CMLS)表型、诱导耐药(IMLS)表型和Rn表型。化脓性IMLS菌株进一步分为IMLS-A、-B和-C三个亚型。泰利霉素和HMR3004对肺炎球菌(无论对红霉素和/或青霉素的敏感性或耐药性)、对红霉素敏感的S、化脓性肺炎链球菌和M表型(耐药性由外排系统介导)或IMLS-B或-C表型(耐药性由ermtr基因编码的甲基酶介导)的化脓性链球菌均具有高度的活性。这两种酮内酯对具有CMLS表型或IMLS-A亚型(耐药性由ermAM基因编码的甲基酶介导)的红霉素耐药化脓性链球菌活性较低，这些菌株的表型范围从敏感度上限到低水平耐药。
Two ketolides, telithromycin and HMR 3004, were evaluated for their in vitro activity against erythromycin-susceptible and -resistant strains of Streptococcus pyogenes and Streptococcus pneumoniae. On the basis of their resistance to macrolide, lincosamide and streptogramin (MLS) antibiotics, erythromycin-resistant test strains were assigned to the constitutive resistance (cMLS) phenotype, the inducible resistance (iMLS) phenotype or the Rn phenotype. iMLS S. pyogenes strains were further subdivided into the three recently described subtypes iMLS-A, -B and -C. Telithromycin and HMR 3004 were uniformly and highly active against pneumococci (regardless of their susceptibility or resistance to erythromycin and/or penicillin), erythromycin-susceptible S, pyogenes and erythromycin-resistant S. pyogenes strains of the M phenotype (in which resistance is mediated by an efflux system) or iMLS-B or -C phenotype (in which resistance is mediated by a methylase encoded by the ermTR gene). Both ketolides were less active against erythromycin-resistant S. pyogenes strains with the cMLS phenotype or the iMLS-A subtype (where resistance is mediated by a methylase encoded by the ermAM gene), these strains ranging in phenotype from the upper limits of susceptibility to low-level resistant.