Hasenbein Meredith E, Warner John E, Lambert Kathleen G, Cole Sarah E, Onderdonk Andrew B, McAdam Alexander J
Department of Laboratory Medicine, Children's Hospital Boston and Harvard Medical School, Massachusetts 02115, USA.
J Clin Microbiol. 2004 Apr;42(4):1559-63. doi: 10.1128/JCM.42.4.1559-1563.2004.
Macrolide (including erythromycin and azithromycin) and lincosamide (including clindamycin) antibiotics are recommended for treatment of penicillin-allergic patients with Streptococcus pyogenes pharyngitis. Resistance to erythromycin in S. pyogenes can be as high as 48% in specific populations in the United States. Macrolide and lincosamide resistance in S. pyogenes is mediated by several different genes. Expression of the erm(A) or erm(B) genes causes resistance to erythromycin and inducible or constitutive resistance to clindamycin, respectively, whereas expression of the mef(A) gene leads to resistance to erythromycin but not clindamycin. We studied the resistance of S. pyogenes to erythromycin and clindamycin at an urban tertiary-care hospital. Of 196 sequential isolates from throat cultures, 15 (7.7%) were resistant to erythromycin. Three of these were also constitutively resistant to clindamycin and had the erm(B) gene. Five of the erythromycin-resistant isolates were resistant to clindamycin upon induction with erythromycin and had the erm(A) gene. The remaining seven erythromycin-resistant isolates were susceptible to clindamycin even upon induction with erythromycin and had the mef(A) gene. Pulsed-field gel electrophoresis analysis and emm typing demonstrated that the erythromycin-resistant S. pyogenes comprised multiple strains. These results demonstrate that multiple mechanisms of resistance to macrolide and lincosamide antibiotics are present in S. pyogenes strains in the United States.
对于青霉素过敏的化脓性链球菌咽炎患者，推荐使用大环内酯类抗生素（包括红霉素和阿奇霉素）和林可酰胺类抗生素（包括克林霉素）进行治疗。在美国特定人群中，化脓性链球菌对红霉素的耐药率可高达48%。化脓性链球菌对大环内酯类和林可酰胺类抗生素的耐药性由几种不同的基因介导。erm(A)或erm(B)基因的表达分别导致对红霉素的耐药以及对克林霉素的诱导型或组成型耐药，而mef(A)基因的表达则导致对红霉素耐药但对克林霉素不耐药。我们在一家城市三级医疗中心医院研究了化脓性链球菌对红霉素和克林霉素的耐药情况。在196份连续的咽拭子培养分离株中，15株（7.7%）对红霉素耐药。其中3株对克林霉素也呈组成型耐药，且具有erm(B)基因。5株红霉素耐药分离株在用红霉素诱导后对克林霉素耐药，且具有erm(A)基因。其余7株红霉素耐药分离株即使在用红霉素诱导后对克林霉素仍敏感，且具有mef(A)基因。脉冲场凝胶电泳分析和emm分型表明，红霉素耐药的化脓性链球菌包含多个菌株。这些结果表明，在美国化脓性链球菌菌株中存在对大环内酯类和林可酰胺类抗生素的多种耐药机制。
