The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis.
The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis.
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DOI：
10.1590/0074-02760150356
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发表时间：
2016-03
影响因子：
2.8
通讯作者：
Malm A
中科院分区：
文献类型：
--
作者：
Juda M;Chudzik-Rzad B;Malm A
凝固酶阴性葡萄球菌，特别是表皮葡萄球菌，可被视为致病菌株（例如金黄色葡萄球菌）抗性基因的潜在储存库。本研究的目的是评估红霉素耐药性表皮葡萄球菌对大环内酯类、林可酰胺类和链阳菌素 B (MLSB) 抗生素的不同耐药表型的流行情况，并评估促进以下不同类型 MLSB 耐药性的基因：ermA、ermB、ermC、msrA、mphC 和 linA/A’。还检查了对螺旋霉素的敏感性。其中 75 名红霉素耐药者。表皮分离菌株中，最常见的表型是大环内酯类和链阳菌素 B (MSB) 以及组成型 MLSB (cMLSB)。此外，所有具有 cMLSB 表型的菌株和大多数诱导型 MLSB (iMLSB) 分离株都对螺旋霉素具有耐药性，而具有 MSB 表型的菌株对此抗生素敏感。对于一些具有 iMLSB 表型的螺旋霉素耐药菌株，在靠近螺旋霉素盘的克林霉素盘周围发现了 D 形抑制区，表明这种 16 元大环内酯诱导了对克林霉素的耐药性。最常见的分离基因是 ermC，无论 MLSB 抗性表型如何，而最常见的基因组合是ermC、mphC、linA/A’。获得的结果表明，表皮葡萄球菌中负责不同MLSB抗性机制的基因通常共存，但通常没有各自的表型表达。
Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A’. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A’. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.