High prevalence of OXA-51-type class D beta-lactamases among ceftazidime-resistant clinical isolates of Acinetobacter spp.: co-existence with OXA-58 in multiple centres.
High prevalence of OXA-51-type class D beta-lactamases among ceftazidime-resistant clinical isolates of Acinetobacter spp.: co-existence with OXA-58 in multiple centres.
复制标题
不动杆菌属耐头孢他啶临床分离株中 OXA-51 型 D 类 β-内酰胺酶的患病率较高：在多个中心与 OXA-58 共存。
DOI：
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发表时间：
2006
影响因子：
5.2
通讯作者：
C. Eroğlu
中科院分区：
文献类型：
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作者：
H. Vahaboğlu;F. Budak;M. Kasap;GÜLÇİN GÖYMEN GACAR;S. Torol;A. Karadenizli;F. Kolaylı;C. Eroğlu
目标
本研究旨在证明新发现的碳青霉烯水解D类酶OXA-51型和OXA-58在不动杆菌属临床分离株中的流行率。
方法
共研究了来自6个中心的72株分离株。用bla（OXA-51型）和bla（OXA-58型）特异性引物通过PCR筛选分离株。PCR产物进行序列分析。用EcoRV消化质粒，用PvuII消化基因组DNA。用地高辛标记的特异性探针进行杂交实验。对SmaI消化的基因组DNA进行宏观限制性分析。
结果
共有56株（77.8%）分离株为bla（OXA-51型）基因阳性。从23个选定的分离株的产物的序列分析显示，在所有贡献中心的多个等位基因的发生。在5个中心的10株分离株中检测到bla（OXA-58）基因。所有患者的bla（OXA-51型）基因也呈阳性。在bla（OXA-58）阳性分离株中，来自同一中心的2株分离株对新型OXA-51等位基因（OXA-86）呈阳性。质粒和基因组DNA的Southern杂交表明，bla（OXA-51型）基因位于染色体上，而bla（OXA-58型）基因是质粒携带的。质粒图谱和脉冲场凝胶电泳图谱表明bla（OXA-58）基因在多个克隆中传播。bla（OXA-51型）和bla（OXA-58型）共携带菌株大多与泛耐药表型相关。
结论
本研究表明，携带bla（OXA-58）的质粒容易在携带bla（OXA-51型）的不动杆菌属临床分离株的多个克隆中传播。由于这些分离株对抗生素具有高度耐药性，这一发现表明土耳其医院存在重大问题。
OBJECTIVES
This study was designed to demonstrate the prevalence of the newly discovered carbapenem-hydrolysing class D enzymes, OXA-51-type and OXA-58, among clinical isolates of Acinetobacter spp.
METHODS
A total of 72 isolates from six centres were studied. Isolates were screened by PCR with specific primers for bla(OXA-51-type) and bla(OXA-58). PCR products were sequence-analysed. Plasmids were digested with EcoRV and genomic DNAs were digested with PvuII. Hybridization experiments were done with digoxigenin-labelled specific probes. Macro-restriction analysis was done on SmaI-digested genomic DNAs.
RESULTS
A total of 56 (77.8%) isolates were positive for bla(OXA-51-type) genes. Sequence analysis of the products from 23 selected isolates revealed the occurrence of multiple alleles in all contributing centres. The bla(OXA-58) gene was detected among 10 isolates from five centres. All were also positive for bla(OXA-51-type) genes. Among the bla(OXA-58)-positive isolates, two from the same centre were positive for a novel OXA-51 allele (OXA-86). Southern hybridization of plasmids and of genomic DNAs suggested that bla(OXA-51-type) genes are located on chromosomes whereas bla(OXA-58) genes are plasmid borne in these 10 isolates. Plasmid profiles and pulsed-field gel electrophoresis patterns indicated the spread of the bla(OXA-58) gene among multiple clones. The bla(OXA-51-type) and bla(OXA-58) co-carrier strains were mostly associated with a pandrug-resistant phenotype.
CONCLUSIONS
This study indicated that bla(OXA-58)-bearing plasmids are readily spreading among multiple clones of the bla(OXA-51-type)-bearing clinical isolates of Acinetobacter spp. Since these isolates are highly resistant to antibiotics this finding indicates the existence of a significant problem in Turkish hospitals.