凝固酶阴性葡萄球菌中新的夫西地酸耐药决定簇 fusF。
A novel fusidic acid resistance determinant, fusF, in Staphylococcus cohnii.
机构信息
Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
Center for Optoelectronic Medicine, National Taiwan University College of Medicine, Taipei, Taiwan Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
出版信息
J Antimicrob Chemother. 2015 Feb;70(2):416-9. doi: 10.1093/jac/dku408. Epub 2014 Oct 13.
OBJECTIVES
To determine MICs of fusidic acid for and identify genetic determinants of resistance in Staphylococcus cohnii isolates.
METHODS
Susceptibility to fusidic acid was determined by the standard agar dilution method in 24 S. cohnii subsp. urealyticus clinical isolates, 7 S. cohnii subsp. cohnii clinical isolates and 2 reference strains. Sequencing of a novel resistance determinant, fusF, and its flanking regions was performed by long and accurate PCR and inverse PCR. To evaluate the function of fusF, the MIC of fusidic acid was determined for recombinant Staphylococcus aureus carrying a plasmid expressing fusF.
RESULTS
A total of 25 S. cohnii subsp. urealyticus (24 clinical isolates and 1 reference strain) and 2 S. cohnii subsp. cohnii displayed low-level resistance to fusidic acid (MICs 2-16 mg/L). Sequencing of a 4259 bp fragment from S. cohnii subsp. urealyticus ATCC 49330 revealed a novel resistance gene, designated fusF, which displayed 70.5% nucleotide and 67.3% amino acid identity to fusD. Expression of fusF in S. aureus confers resistance to fusidic acid.
CONCLUSIONS
A novel FusB-family gene, fusF, was identified as a major resistance determinant in S. cohnii clinical isolates resistant to fusidic acid.
目的
确定凝固酶阴性葡萄球菌（CNS）分离株中夫西地酸的 MIC 值并鉴定其耐药的遗传决定因素。
方法
采用琼脂稀释法检测 24 株解脲亚种 CNS 临床分离株、7 株 C 亚种 CNS 临床分离株和 2 株参考株对夫西地酸的敏感性。通过长而准确的 PCR 和反向 PCR 对新型耐药决定因子 fusF 及其侧翼区进行测序。为评估 fusF 的功能，测定了表达 fusF 的质粒携带的重组金黄色葡萄球菌对夫西地酸的 MIC 值。
结果
25 株解脲亚种 CNS（24 株临床分离株和 1 株参考株）和 2 株 C 亚种 CNS 对夫西地酸表现出低度耐药（MIC 2-16mg/L）。对解脲亚种 CNS ATCC 49330 的 4259bp 片段进行测序，发现了一个新的耐药基因，命名为 fusF，其核苷酸和氨基酸序列与 fusD 的同源性分别为 70.5%和 67.3%。fusF 在金黄色葡萄球菌中的表达赋予其对夫西地酸的耐药性。
结论
在对夫西地酸耐药的 CNS 临床分离株中，鉴定出一种新型 FusB 家族基因 fusF 作为主要的耐药决定因子。
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