In vitro activities of new ketolide, telithromycin, and eight other macrolide antibiotics against Streptococcus pneumoniae having mefA and ermB genes that mediate macrolide resistance.
In vitro activities of new ketolide, telithromycin, and eight other macrolide antibiotics against Streptococcus pneumoniae having mefA and ermB genes that mediate macrolide resistance.
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DOI：
10.1007/s10156-003-0258-2
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发表时间：
2003-09-01
影响因子：
2.2
通讯作者：
Sunakawa, Keisuke
中科院分区：
文献类型：
--
作者：
Ubukata, Kimiko;Iwata, Satoshi;Sunakawa, Keisuke
用琼脂稀释法测定了一种新的酮内酯、泰利霉素（TEL）和其他8种大环内酯林可酰胺类抗生素（MLS）对215株肺炎链球菌（包括青霉素耐药株（PRSP））的体外活性。这些菌株分离自1995年至1997年期间的肺炎、中耳炎和化脓性脑膜炎患者。通过聚合酶链反应（PCR）鉴定了两个编码MLS抗性的基因，mefA和ermB。其中mefA基因阳性率为30.2%（n=65），ermB基因阳性率为37.7%（n=81），两种耐药基因阳性率为1.4%（n=3）。对于具有mefA基因的菌株，TEL和16元环MLS的最小抑制浓度（MIC 90）为0.063-0.25 μ g/ml，这与MLS敏感菌株的水平相同。另一方面，具有mefA基因的菌株对14-和15-元环MLS表现出低水平的抗性，MIC 90范围为1至4 μ g/ml。对于具有ermB基因的菌株，只有0.5 μ g/ml的TEL的MIC 90上级14-、15-和16-元环MLS的MIC 90（≥ 64 μ g/ml）。TEL还显示出针对具有异常pbp 1a、pbp 2x和pbp 2b基因的PRSP的优异活性。具有mefA和ermB基因的大多数菌株被血清分型为3、6、14、19和23。上述结果提示，TEL可能是治疗呼吸道感染的有效化疗药物。肺炎。
The comparative in vitro activity of a new ketolide, telithromycin (TEL), and eight other macrolidelincosamide antibiotics (MLS) against 215 strains, of Streptococcus pneumoniae including penicillin-resistant isolates (PRSP), was determined by the agar dilution method. These strains were isolated from patients with pneumonia, otitis media, and purulent meningitis between 1995 and 1997. Two genes, mefA and ermB, that encode MLS resistance in the strains were identified by polymerase chain reaction (PCR). Of the strains, 30.2% (n=65) had the mefA gene, 37.7% (n=81) had the ermB gene, and 1.4% (n=3) had both resistant genes. The minimum inhibitory concentration (MIC90s) of TEL and 16-membered ring MLS for strains having the mefA gene were 0.063-0.25 mug/ml, which were the same level as those for MLS-susceptible strains. On the other hand, the strains with the mefA gene showed low-level resistance to 14- and 15-membered ring MLS, with MIC90s ranging from 1 to 4 mug/ml. Only the MIC90 of TEL at 0.5 mug/ml, for strains having the ermB gene was superior to that of the 14-, 15-, and 16-membered ring MLS (MIC90, gtoreq64 mug/ml). TEL also showed excellent activity against PRSP having abnormal pbp1a, pbp2x, and pbp2b genes. Most strains having the mefA and ermB genes were serotyped to 3, 6, 14, 19, and 23. These results suggest that TEL may be a useful chemotherapeutic agent for respiratory tract infections caused by S. pneumoniae.