CAJ | 학술논문

目的研究产超广谱β-内酰胺酶(ESBLs)肠杆菌科细菌中16S rRNA甲基化酶基因的分布及传播机制.方法采用PCR扩增、序列分析确定16S rRNA甲基化酶基因和ESBLs基因,Etest 法检测17种抗菌药物的最小抑菌浓度(MIC),并通过接合试验、质粒抽提等方法对耐药基因的传播机制进行研究.结果 447株产ESBLs菌株中筛选到1株产armA型16S rRNA甲基化酶的产酸克雷伯菌(ZJ157),并在该菌株中同时检出CTX-M-15型ESBLs和TEM-1型β-内酰胺酶基因;该菌株对氨基糖苷类、环丙沙星及大部分β-内酰胺类抗菌药物耐药,但对碳青霉烯类、多黏菌素E和替加环素敏感;对阿米卡星及β-内酰胺类抗菌药物的耐药性可以通过接合试验传递给受体菌,且PCR扩增证实接合子的armA、CTX-M-15及TEM-1基因均为阳性.质粒抽提发现原始菌和接合子均有1个约55 kb的质粒.结论在产酸克雷伯菌中检出armA型16S rRNA甲基化酶基因.介导氨基糖苷类抗菌药物高水平耐药的armA基因可以与CTX-M-15及TEM-1基因同时经质粒传递,协同介导菌株的多药耐药.
목적 연구산초엄보β-내선알매(ESBLs)장간균과세균중16S rRNA갑기화매기인적분포급전파궤제.방법 채용PCR확증、서렬분석학정16S rRNA갑기화매기인화ESBLs기인,Etest 법검측17충항균약물적최소억균농도(MIC),병통과접합시험、질립추제등방법대내약기인적전파궤제진행연구.결과 447주산ESBLs균주중사선도1주산armA형16S rRNA갑기화매적산산극뢰백균(ZJ157),병재해균주중동시검출CTX-M-15형ESBLs화TEM-1형β-내선알매기인;해균주대안기당감류、배병사성급대부분β-내선알류항균약물내약,단대탄청매희류、다점균소E화체가배소민감;대아미잡성급β-내선알류항균약물적내약성가이통과접합시험전체급수체균,차PCR확증증실접합자적armA、CTX-M-15급TEM-1기인균위양성.질립추제발현원시균화접합자균유1개약55 kb적질립.결론 재산산극뢰백균중검출armA형16S rRNA갑기화매기인.개도안기당감류항균약물고수평내약적armA기인가이여CTX-M-15급TEM-1기인동시경질립전체,협동개도균주적다약내약.
Objective To investigate the prevalence and dissemination mechanism of 16S rRNA methylase genes in extended-spectrum beta-lactamases(ESBLs)-producing Enterobacteriaceae in China.Methods PCR amplification and DNA sequencing were used for screening and identifing 16S rRNA methylase genes and ESBLs genes.Minimal inhibitory concentrations(MICs)of the antimicrobial agents were detected by Etest.Conjugation and plasmid extract were performed to study dissemination mechanism of 16S rRNA methylase genes and ESBLs genes.Results Only one strain.Klebsiella oxytoca strain ZJ157 was screened as positive for armA gene from 447 ESBLs-producing isolates,which also contained CTX-M-15 and TEM-1 genes.It was resistant to aminoglycesides,ciprofloxacin,and most β-lactams,except carbapenems,polymyxin E and tigecyeline.Resistance to amikacin and β-lactams was transferred to a recipient Escherichia coli 600 by conjugation experiment.arntA.CTX-M-15 and TEM-1 genes were detected in the transconjugant.A plasmid about 55 kb was extracted from Klebsiella oxytoca ZJl57 and the transconjugant.Conclusions A 16S rRNA methylase gene armA was detected in an isolate of Klebsiella oxytoca.armA,CTX-M-15 and TEM-1 genes can be co-transferred in the same plasmid leading to multi-drug resistance.