Clinical and microbiological aspects of linezolid resistance mediated by the cfr gene encoding a 23S rRNA methyltransferase
Clinical and microbiological aspects of linezolid resistance mediated by the cfr gene encoding a 23S rRNA methyltransferase
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DOI：
10.1128/jcm.01886-07
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发表时间：
2008-03-01
影响因子：
9.4
通讯作者：
Quinn, John P.
中科院分区：
文献类型：
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作者：
Arias, Cesar A.;Vallejo, Martha;Quinn, John P.
cfr（氯霉素-氟苯尼考耐药）基因编码23S rRNA甲基转移酶，使其对利奈唑胺产生耐药性。采用稀释和扩散法（包括Etest）对首次携带cfr的人医院利奈唑胺和耐甲氧西林金黄色葡萄球菌（MRSA CM-05）进行耐药性检测。在患者的家庭接触者中定植的葡萄球菌分离株和从分离MRSA CM-05的同一单位的患者中回收的临床分离株中调查了cfr的存在。此外，对2001年至2004年间从医院回收的68株哥伦比亚耐氯霉素MRSA分离株进行了cfr基因筛选。除erm(B)外，CM-05中还检测到erm(A)基因。该分离物属于序列5型，携带葡萄球菌染色体盒型mec i型。我们无法在任何筛选的人类葡萄球菌（临床或定殖分离株）中检测到cfr基因。琼脂稀释法和肉汤稀释法检测CM-05对利奈唑胺的耐药性。但经24h孵育后，Etest法和纸片扩散法均未检测出抗性。由cfr基因介导的恶唑烷酮耐药是罕见的，由人类分离株获得似乎是最近在哥伦比亚发生的事件。氟氯化碳介导的利奈唑胺耐药检测可能会受到纸片扩散或测试方法的影响。
The cfr (chloramphenicol-florfenicol resistance) gene encodes a 23S rRNA methyltransferase that confers resistance to linezolid. Detection of linezolid resistance was evaluated in the first cfr-carrying human hospital isolate of linezolid and methicillin-resistant Staphylococcus aureus (designated MRSA CM-05) by dilution and diffusion methods (including Etest). The presence of cfr was investigated in isolates of staphylococci colonizing the patient's household contacts and clinical isolates recovered from patients in the same unit where MRSA CM-05 was isolated. Additionally, 68 chloramphenicol-resistant Colombian MRSA isolates recovered from hospitals between 2001 and 2004 were screened for the presence of the cfr gene. In addition to erm(B), the erm(A) gene was also detected in CM-05. The isolate belonged to sequence type 5 and carried staphylococcal chromosomal cassette mec type I. We were unable to detect the cfr gene in any of the human staphylococci screened (either clinical or colonizing isolates). Agar and broth dilution methods detected linezolid resistance in CM-05. However, the Etest and disk diffusion methods failed to detect resistance after 24 h of incubation. Oxazolidinone resistance mediated by the cfr gene is rare, and acquisition by a human isolate appears to be a recent event in Colombia. The detection of cft-mediated linezolid resistance might be compromised by the use of the disk diffusion or Etest method.