ICU患者感染泛耐药鲍氏不动杆菌携带OXA酶与AmpC酶的研究
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摘要
目的了解ICU患者感染泛耐药鲍氏不动杆菌携带碳青霉烯酶基因、头孢菌素酶(AmpC酶)基因,从而分析其耐药机制。方法常规细菌培养方法分离细菌,用VITEK-2全自动微生物鉴定/药敏测试系统进行菌种鉴定及体外敏感测定;采用多重PCR检测25株鲍氏不动杆菌携带的碳青霉烯酶、AmpC酶相关耐药基因(16S rRNA、OXA-23、OXA-24、OXA-51、OXA-58、ADC、DHA、ISAba1),并对耐药基因扩增的阳性产物进行DNA序列分析。结果 ICU患者感染泛耐药鲍氏不动杆菌均携带OXA-23、OXA-51、ADC基因,21株携带插入序列ISAba1;DNA序列分析结果显示,OXA-23、OXA-51、ADC分别与NCBI的序列同源性均为99.0%。结论产OXA-23型碳青霉烯酶可能是ICU患者感染鲍氏不动杆菌对碳青霉烯酶类抗菌药物耐药的主要原因,且为同一克隆株传播。
OBJECTIVE To investigate carbapenemase related resistant genes OXA and AmpC of pan-resistant Acinetobacter baumannii(PDRAB)in ICU and to further analyze the resistance mechanism.METHODS A.baumannii were isolated from specimens of patients by conventional culture method and the VITEK-II automated microbial system was used for strain identification and in vitro susceptibility test.Multiplex PCR detection method was used to identify 25 A.baumannii strains carrying carbapenemase and AmpCrelated resistant genes OXA-23,OXA-24,OXA-51,OXA-58,ADC,DHA and ISAba1,and the positive amplified products of resistant genes were subjected to DNA sequence analysis.RESULTS The selected PDA samples showed all strains carried OXA-51,OXA-23 and ADCgenes.Out of 23 PDA strains,21 carried ISAba1genes.DNA sequence analysis of OXA-23,OXA-51 and ADC with the NCBI sequence showed 99% homology.CONCLUSION OXA-23 producing gene which spread by the same clone may be the main cause of resistance of A.baumannii to carbapenem antimicrobial agents.
OBJECTIVE To investigate carbapenemase related resistant genes OXA and AmpC of pan-resistant Acinetobacter baumannii(PDRAB)in ICU and to further analyze the resistance mechanism.METHODS A.baumannii were isolated from specimens of patients by conventional culture method and the VITEK-II automated microbial system was used for strain identification and in vitro susceptibility test.Multiplex PCR detection method was used to identify 25 A.baumannii strains carrying carbapenemase and AmpCrelated resistant genes OXA-23,OXA-24,OXA-51,OXA-58,ADC,DHA and ISAba1,and the positive amplified products of resistant genes were subjected to DNA sequence analysis.RESULTS The selected PDA samples showed all strains carried OXA-51,OXA-23 and ADCgenes.Out of 23 PDA strains,21 carried ISAba1genes.DNA sequence analysis of OXA-23,OXA-51 and ADC with the NCBI sequence showed 99% homology.CONCLUSION OXA-23 producing gene which spread by the same clone may be the main cause of resistance of A.baumannii to carbapenem antimicrobial agents.
引文
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[6]Higgins PG,Dammhayn C,Hackel M,et al.Global spread of carbapenem-resistant Acinetobacter baumannii[J].J Antimicrob Chemother,2010,65(2):233-238.
[7]Wang H,Guo P,Sun H,et al.Molecular epidemiology of clinical isolates of carbapenem-resistant Acinetobacter spp.from Chinese hospitals[J].Antimicrob Agents Chemother,2007,51(11):4022-4028.