摘要
目的研究一株多重耐药鲍曼不动杆菌(Multi-drug-resistant Acinetobacter baumannii,MDR-ABA)J65可能存在的β-内酰胺类药物耐药机制。方法 MDR-ABA J65株分离自2011年12月某三甲医院住院患者痰标本,用gyrA和parC基因PCR扩增、测序和BLASTn比对确认菌种。用PCR法分析该菌株的PBP1a、PBP2、CarO和33种A^D类β-内酰胺酶编码基因,并对检出的β-内酰胺酶编码基因作了插入序列与β-内酰胺酶编码基因连锁检测。结果 MDR-ABA J65检出β-内酰胺酶编码基因bla TEM-1、bla ADC-62、bla OXA-23、bla OXA-66,插入序列与β-内酰胺酶编码基因连锁检测显示ISaba1-ADC-62和ISaba1-OXA-23为阳性。PBP1a、PBP2和CarO编码基因序列与鲍曼不动杆菌敏感株(SDF)相比均存在有义突变,且三维结构同源建模显示,与SDF株PBP1a、PBP2和CarO蛋白分子立体结构有明显差别。结论 MDR-ABA J65对β-内酰胺类耐药机制为PBPs和孔蛋白CarO变异及可移动遗传元件介异的β-内酰胺酶编码基因。
Objective To investigate resistant mechanisms to β-lactams of a strain of multi-drug-resistant Acinetobacter baumannii Strain J65 （MDR-ABA J65）. Methods In December 2011, MDR-ABA J65 was isolated from sputum sample of an inpatient from a hospital in China. Then the strain was confirmed as A. baumannii by PCR amplifying and sequencing ofgyrA and parC, and aligning with BLASTn. The PBP1A, PBP2, CarO, 33 kinds of β-lactamase genes and linkage detection of insertion sequences and β-lactamase genes were amplified by PCR methods. Results Four kinds of β-lactamase genes（TEM-1, ADC-62, OXA-23 and OXA-66） were positive in MDR- ABA J65. ISabal-ADC-62 and ISabal-OXA-23 were positive by linkage detection of insertion sequences and 13-1actamase genes. When compared with sensitive strain （SDF） of A. baumannii, missense mutations were found in carO gene, pbplA gene and pbp2 gene of MDR-ABA J65, and the three-dimensional molecular structure of PBP1A and PBP2 shows significant difference between MDR-ABA J65 and SDF. Conclusion In MDR-ABA J65, mutations of housekeeping genes（PBP1A, PBP2 and carO）, producing β-lactamase genes mediated by mobile genetic elements, played a key role in resistance to β-lactams.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2014年第1期58-64,共7页
Chinese Journal of Antibiotics
基金
无锡市医院管理中心科技发展基金项目(YGM1001)
无锡市医院管理中心医学技术联合攻关项目(YGZX1212)
南京医科大学科技发展基金重点项目(2012NJMU171)
关键词
鲍曼不动杆菌
Β-内酰胺酶基因
膜孔蛋白
外排泵蛋白
青霉素结合蛋白
多重耐药
Acinetobacter baumannii
β-lactamase genes
Outer membrane protein
Effiux pump protein
Penicillin-binding protein
Multi-drug-resistant
