儿童感染碳青霉烯类耐药鲍曼不动杆菌耐药性及耐药基因型分析

Analysis of drug resistance and drug resistance genotype of carbapenemresistant Acetobacter baumannici infection in children

目的研究重庆地区儿童感染鲍曼不动杆菌耐药性及碳青霉烯类耐药鲍曼不动杆菌(CRAb)耐药基因型分析。方法收集2015年1月至2017年12月重庆医科大学附属儿童医院从患者分离的1324株鲍曼不动杆菌,用K-B法检测抗生素的耐药性。回顾性分析155株碳青霉烯类耐药鲍曼不动杆菌,从中随机选出122株复苏提取DNA,PCR扩增B类碳青霉烯酶基因VIM2、SIM1;D类碳青霉烯酶基因blaOXA-23、blaOXA-24、blaOXA-51、blaOXA-58;扩增blaOXA-23-like、blaOXA-51-like上游ISAba1启动元件,所得阳性标本送公司测序,测序结果与Genebank进行对比。结果检出碳青霉烯类耐药鲍曼不动杆菌155株(11.71%)呈现出多重耐药性,对多黏菌素(CL)、阿米卡星(AN)、环丙沙星(CIP)、左氧氟沙星(LEV)、四环素(TE)、复方新诺明(SXT)、氨苄西林/舒巴坦(SAM)、头孢他啶(CAZ)、头孢噻肟(CTX)、哌拉西林/他唑巴坦(TZP)敏感率分别为:98.71%、29.68%、29.03%、29.03%、25.16%、20.00%、13.55%、5.16%、4.52%、2.58%,对其余抗菌药物耐药率均为100.00%。所有碳青霉烯类耐药鲍曼不动杆菌的碳青霉烯酶基因OXA-23、OXA-51、OXA-58检出率分别为:78.69%、65.57%、9.80%,且以OXA-23/OXA-51类基因为主(57.38%),OXA-23/OXA-51(0.82%),OXA-51/OXA-58(0.82%),OXA-23/OXA-51/OXA-58类基因(4.92%)。在blaOXA-23-like、blaOXA-51-like上游连接有ISAba1启动元件(88.50%),未检出OXA-24、VIM2、SIM1碳青霉烯酶基因。结论重庆地区儿童流行对碳青霉烯类耐药的鲍曼不动杆菌产OXA-23、OXA-51、OXA-58型碳青霉烯酶,且以OXA23/OXA51类基因为主,在blaOXA-23-like、blaOXA-51-like上游连接有ISAba1启动元件。

Objective To study the drug resistance of Acinetobacter baumannii infection in children and drug-resistance genotypes of carbapenem resistant Acinetobacter baumannii (CRAb) in Chongqing area. Methods A total of 1 324 strains of Acinetobacter baumannii isolated from the children patients in the Affiliated Children′s Hospital of Chongqing Medical University from January 2015 to December 2017 were collected.Their drug resistance was detected by using the K-B method.The retrospective analysis was performed on 155 strains of carbapenem resistant Acinetobacter bacillus,122 strains were randomly selected among them for conduct the recovery and DND extraction.The class β-carbapenemases gene VIM2 and SIM1 conducted the PCR amplification;in the class D carbapenemase enzyme gene blaOXA-23,blaOXA-24,blaOXA-51,blaOXA-58;blaOXA-23-like,blaOXA-51-like upstream ISAba1 start component were amplified,the obtained positive specimens were sent to the company for conducting the sequencinthen the sequencing results were compared to the Gene bank. Results A total of 155 strains (11.71%) of carbapenem resistant Acinetobacter baumannii were detected out,which showed multiple resistance,their sensitive rates to polymyxin (CL),amikacin (AN),ciprofloxacin (CIP),levofloxacin (LEV),tetracycline (TE),cotrimoxazole (SXT),ampicillin/sulbactam (SAM),ceftazidime (CAZ),cefotaxime (CTX),piperacillin/tazobactam (TZP) were 98.71%,29.68%, 29.03 %, 29.03%,25.16%,20.00%,13.55%,5.16%,4.52%,2.58% respectively,the resistance rate to the rest antibacterial drugs was 100%.The detection rates of carbapenem resistant Acinetobacter baumannii carbapenemases gene OXA and-23,OXA and-51,OXA and-58 were 78.69%,65.57% and 9.80% respectvely,moreover -23/OXA-51 genes OXA (57.38%) were predominant,OXA-23/OXA-51 ( 0.82 %),OXA-51/OXA-58 (0.82%),OXA-23/OXA-51/OXA-58 genes (4.92%).In BlaOXA-23-like,blaOXA-51-like upstream,the ISAba1 start components (88.50%) were connected,the OXA and-24,VIM2.SIM1 carbapenemase genes were not detected. Results Conclusion Chongqing children prevlence was carbapenem resistant Acinetobacter baumannii producing OXA and-23,OXA and-51,OXA and-58-type carbapenemases and mainly OXA23/OXA51 class gene,blaOXA -23-like,blaOXA-51-like upstream is connected by ISAba1 start component.