摘要
目的观察多重耐药鲍曼不动杆菌(MDR-AB)中青霉素结合蛋白1a(PBP1a)基因ponA表达情况,以及ponA对碳青霉烯类抗生素诱导的反应。方法收集MDR-AB菌株19株,采用PCR法检测ponA基因表达情况并进行测序。将MDR-AB与SDF ponA基因翻译的氨基酸序列进行同源建模,用分子可视化工具软件作结构相似性分析,并与鲍曼不动杆菌抗生素敏感株(SDF)进行比较。分别用三种碳青霉烯类抗生素(亚胺培南、美罗培南、多尼培南)对MDR-AB进行诱导,qRT-PCR检测ponA表达情况并进行测序。结果19株MDR-AB均表达ponA基因,测序结果与Genbank中ATCC 17978标准菌株ponA序列显示98%同源。MDR-AB株与SDF株的ponA基因翻译氨基酸序列存在4处氨基酸变异,为第23位丝氨酸>丙氨酸、第47位丙氨酸>天冬氨酸、第110位异亮氨酸>亮氨酸、第128位谷氨酸>天冬氨酸;MDR-AB株与SDF株的ponA基因编码蛋白构象存在明显差异。亚胺培南组、美罗培南组、多尼培南组ponA基因相对表达量均低于未处理组(P均<0.05);抗生素诱导后的菌株未发现ponA基因突变。结论MDR-AB中存在ponA基因表达,其翻译氨基酸序列及编码PBP1a蛋白构象均不同于SDF;碳青霉烯类抗生素诱导可导致MDR-AB中ponA基因表达下调。
Objective To observe the penicillin-binding protein 1a(PBP1a)gene ponA expression in the multi-drug resistant acinetobacter baumannii(MDR-AB),and ponA reaction induced by carbapenems antibiotics.Methods Nineteen MDR-AB strains were collected.We detected ponA gene expression by PCR.The ponA gene of MDR-AB and the sensitive strains of acinetobacter baumannii antibiotics(SDF)were translated into the amino acid sequence,and we carried on the homologous modeling,and used molecular visualization tool software for structural similarity analysis and compared with SDF.We used three kinds of carbapenem antibiotics(imipenem,meropenem,doripenem)to induce MDR-AB,and detected ponA expression by qRT-PCR and sequencing.Results PonA gene expression was found in all 19 strains of MDR-AB.The sequencing results showed 98%homology with the ponA sequence of the ATCC 17978 standard strain in Genbank.There were four amino acid mutations,23rd serine>alanine,47th alanine>aspartic acid,110th isoleucine>leucine,and 128th glutamic acid>aspartic acid.There were significant difference in the protein conformation encoded by ponA gene between the MDR-AB and SDF strains.The relative expression of ponA in the imipenem,meropenem,doripenem groups was lower than that of the untreated group(all P<0.05).But the mutation of ponA was not found after induction.Conclusion PonA gene expression exists in MDR-AB strain,its amino acid sequence and coding PBP1a protein conformation are different from those of SDF;carbapenems antibiotics could lead to down-regulation of ponA gene expression in MDR-AB strain.
作者
魏星
游德红
郑兰
庞博
余爽
陈思
龚大彩
徐革
WEI Xing;YOU Dehong;ZHENG Lan;PANG Bo;YU Shuang;CHEN Si;GONG Dacai;XU Ge(Pidu District People′s Hospital,Chengdu 611730,China;不详)
出处
《山东医药》
CAS
2020年第20期24-28,共5页
Shandong Medical Journal
基金
四川省卫计委科研课题项目(18PJ108)。
关键词
鲍曼不动杆菌
多重耐药
ponA基因
PBP1a蛋白
碳青霉烯类抗生素
Acinetobacter baumannii
multi-drug resistance
ponA gene
penicillin-binding protein 1a(PBP1a)protein
carbapenems antibiotics
