A Pseudomonas aeruginosa isolate producing the GES-5 extended-spectrum beta-lactamase.
A Pseudomonas aeruginosa isolate producing the GES-5 extended-spectrum beta-lactamase.
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产生 GES-5 超广谱 β-内酰胺酶的铜绿假单胞菌分离株。
DOI：
10.1093/jac/dkl116
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发表时间：
2006
影响因子：
5.2
通讯作者：
Z. Mi
中科院分区：
文献类型：
--
作者：
Chun;P. Cai;D. Chang;Z. Mi
先生，绿脓杆菌是一种常见的医院病原体，它有一种可诱导的，天然存在的头孢菌素酶，这种酶能抵抗氨基青霉素和窄谱头孢菌素，如头孢噻吩和头孢西丁。对超广谱头孢菌素类抗生素的耐药可能是由于这种头孢菌素酶、获得性β-内酰胺酶或两者的过度表达。自20世纪80年代初以来，在肠杆菌科成员中经常报告所谓的克拉维酸抑制超广谱β-内酰胺酶（ESBLs），最近才在铜绿假单胞菌中描述。目前，铜绿假单胞菌中已检出5种A类（TEM、SHV、PER、VEB和IBC/GES）和D类（OXA）ESBLs。目前已知有9种GES型ESBLs。到目前为止，在铜绿假单胞菌中发现了四种GES类型（GES-1，-2，-8和-9）。6我们在这篇文章中报告了在中国的头孢他啶耐药铜绿假单胞菌分离株中发现的GES-5。铜绿假单胞菌PK 1278于2004年7月在中国北京解放军第304医院从一名右腿烧伤并发生伤口感染的35岁患者的血液中分离。他首先用头孢噻肟和阿米卡星治疗。停用这些抗生素，并给予亚胺培南。患者病情好转，30天后出院。入院前未接受抗生素治疗，也未出国旅行。通过Vitek革兰氏阴性鉴定卡（bioMérieux-Vitek，Inc.，哈泽尔伍德，密苏里州，美国）。根据NCCLS，使用纸片扩散和琼脂稀释法测定铜绿假单胞菌PK 1278的抗菌药物敏感性特征。将通过快速碱裂解程序制备的来自铜绿假单胞菌PK 1278的全细胞DNA用作PCR测定中的模板。采用表1所列的blaTEM、blaSHV、blaGES、blaPER、blaVEB和blaOXA引物进行PCR，这些引物是根据GenBank中发表的所有6种ESBL基因型设计的。PCR条件为：93 ℃ 3分钟; 93 ℃ 1分钟、55 ℃ 1分钟和72 ℃ 1分钟的40个循环;最后，72 ℃ 7分钟。用PCR Clean Up试剂盒（Roche Molecular Biochemicals，曼海姆，德国）纯化扩增子，并在ABI PRISM 377测序仪分析仪（Applied Biosystems，Foster City，CA，USA）上测序。纸片扩散法药敏试验结果显示，铜绿假单胞菌PK 1278仅对亚胺培南和美罗培南敏感，对头孢他啶、头孢曲松、头孢吡肟、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、环丙沙星和阿米卡星耐药。对头孢他啶（MIC > 256 mg/L）、头孢曲松（MIC > 256 mg/L）、头孢吡肟（MIC 64 mg/L）、头孢哌酮/舒巴坦（MIC 64 mg/L）、哌拉西林/他唑巴坦（MIC 128 mg/L）、环丙沙星（MIC 2 mg/L）和阿米卡星（MIC 256 mg/L）耐药，对亚胺培南（MIC 8 mg/L）和美罗培南（MIC 8 mg/L）中度耐药。铜绿假单胞菌PK 1278在PCR测定中仅对blaGES呈阳性。将来自blaGES扩增子（GenBank登录号AY 953375）的核苷酸序列提交至BLAST 2.0，发现与blaGES 5相同，blaGES 5在核苷酸位置117（C！A），435（G！513（G！T）与大肠杆菌的blaGES-5（GenBank登录号AY 494717）进行比较。这是全球首例铜绿假单胞菌GES-5的报告。
Sir, Pseudomonas aeruginosa is a common nosocomial pathogen, and has an inducible, naturally occurring cephalosporinase that confers resistance to aminopenicillins and narrow-spectrum cephalosporins such as cefalotin and cefoxitin. Resistance to extended-spectrum cephalosporins may arise from the overexpression of this cephalosporinase, acquired b-lactamases or both. The so-called clavulanic acid-inhibited extended-spectrum b-lactamases (ESBLs) have been frequently reported in members of the family Enterobacteriaceae since the early 1980s, and have been described in P. aeruginosa only more recently. To date, five types of class A (TEM, SHV, PER, VEB and IBC/GES) and class D (OXA) ESBLs have been detected in P. aeruginosa. There are currently nine known GES-type ESBLs. So far, four of these GES types (GES-1, -2, -8 and -9) have been found in P. aeruginosa. 6 We report in this article the discovery of GES-5 in a ceftazidime-resistant P. aeruginosa isolate in China. P. aeruginosa PK1278 was isolated in July 2004 at the PLA 304th Hospital in Beijing, China, from the blood of a 35-year-old patient who suffered from a burn on his right leg and developed a wound infection. He was first treated with cefotaxime and amikacin. These antibiotics were discontinued and he was given imipenem. He improved and was discharged 30 days later. He had not received antibiotic therapy prior to the admission or travelled outside China. The isolate was identified by Vitek Gram-negative identification cards (bioMérieux-Vitek, Inc., Hazelwood, MO, USA). The antimicrobial susceptibility profile of P. aeruginosa PK1278 was determined using the disc diffusion and agar dilution methods according to the NCCLS. Whole cell DNA from P. aeruginosa PK1278, prepared by a rapid alkaline lysis procedure, was used as a template in PCR assays. PCR was performed using the primers for blaTEM, blaSHV, blaGES, blaPER, blaVEB and blaOXA listed in Table 1, which were designed based on all six genotypes of ESBL genes published in GenBank. PCR conditions were: 3 min at 93 C; 40 cycles of 1 min at 93 C, 1 min at 55 C and 1 min at 72 C; and, finally, 7 min at 72 C. The amplicons were purified with PCR Clean Up Kits (Roche Molecular Biochemicals, Mannheim, Germany) and were sequenced on an ABI PRISM377 sequencer analyser (Applied Biosystems, Foster City, CA, USA). According to antibiotic susceptibility testing by disc diffusion, P. aeruginosa PK1278 was only susceptible to imipenem and meropenem and resistant to ceftazidime, ceftriaxone, cefepime, cefoperazone/sulbactam, piperacillin/tazobactam, ciprofloxacin and amikacin. The isolate showed resistance to ceftazidime (MIC > 256 mg/L), ceftriaxone (MIC > 256 mg/L), cefepime (MIC 64 mg/L), cefoperazone/sulbactam (MIC 64 mg/L), piperacillin/tazobactam (MIC 128 mg/L), ciprofloxacin (MIC 2 mg/L) and amikacin (MIC 256 mg/L), and intermediate resistance to imipenem (MIC 8 mg/L) and meropenem (MIC 8 mg/L). P. aeruginosa PK1278 was only positive for blaGES in PCR assays. The nucleotide sequence derived from the blaGES amplicon (GenBank accession number AY953375) was submitted to BLAST 2.0 and found to be identical with blaGES5 which contained three silent mutations at nucleotide positions 117 (C!A), 435 (G!C) and 513 (G!T) compared with blaGES-5 from Escherichia coli (GenBank accession number AY494717). This is the first report of GES-5 in P. aeruginosa worldwide.