鲍曼不动杆菌多位点序列分型及 blaOXA-51-like基因的基因型分析

摘要

目的：对广州地区3家教学医院的鲍曼不动杆菌菌株进行分子流行病学分型及blaOXA-51-like基因的基因型分析，以了解鲍曼不动杆菌菌群结构及流行菌株。方法收集非重复鲍曼不动杆菌52株，多位点序列分型（MLST）进行分子分型，eBURST分析菌株亲缘性，将序列型（STs）归类为克隆复合体（CC）， PCR扩增blaOXA-51-like基因全长并测序确定blaOXA-51-like基因型。结果 MLST将52株鲍曼不动杆菌分为5个已有ST型及7个新ST型，其中STn4包含新发现的gpi位点的等位基因G1，其与gpi 111的差别在于第3个碱基的T→C突变，STn5包含新发现的gltA的等位基因A1，其与gltA 1的差别在于第156位碱基的A→C突变及159位碱基的A→C突变。 ST195及ST208最常见，占到了总数的69．2％， eBURST分析显示其属于CC92。52株菌株中只有1株携带OXA-199，其余51株菌株均携带OXA-66。结论鲍曼不动杆菌CC92在广州地区广泛流行，携带OXA-66基因。%Objective To investigate the distribution of blaOXA-51-like genes and the clonal relation-ship among Acinetobacter baumannii strains isolated from three teaching hospitals in Guangzhou , China. Methods Fifty-two Acinetobacter baumannii isolates were genotyped by multilocus sequence typing (MLST).eBURST algorithm was performed to define clonal complexes (CCs).blaOXA-51-like genes were am-plified by using polymerase chain reaction ( PCR) and sequenced .Results MLST grouped the A.bauman-nii isolates into 5 existing sequence types (STs) and 7 new STs.STn4 carried allele G1 with a T→C muta-tion at the 3rd nucleotide site (nt3) on the gpi111 locus.STn5 carried allele A1, possessing A→C muta-tions at nt156 and nt159 on the gltA1 locus.ST195 and ST208 accounted for 69.2%of all isolates.Clonal relationship analysis showed that ST 195 and ST208 belonged to CC92.Fifty-one A.baumannii isolates car-ried OXA-66 and the rest one carried OXA-199.Conclusion A.baumannii strains that belonged to CC92 and carried OXA-66 were the predominant genotype circulating in Guangzhou , China.