文档介绍：3株耐碳青霉烯鲍曼不动杆菌临床株耐药机制的研究
作者:钱洁宋诗铎祁伟王玉宝
【摘要】目的研究鲍曼不动杆菌(obacter baumannii)对碳青霉烯耐药的分子机制。方法采用琼脂纸片扩散法(KB法)及微量肉汤法筛选出3株对碳青霉烯耐药的鲍曼不动杆菌临床株,PCR扩增blaOXA23基因和测序、提取外膜蛋白及进行聚丙烯酰胺凝胶电泳(SDSPAGE)。结果 3株耐碳青霉烯的鲍曼不动杆菌具有多重耐药性;耐药基因PCR扩增和测序证实3株耐药菌均有blaOXA23基因;,其余2株耐药菌在该条带处与敏感菌相比较无明显差异。结论本次试验中对碳青霉烯耐药的鲍曼不动杆菌全部含有blaOXA23基因,其中一株耐药菌还出现了外膜蛋白孔道的缺失可能与其多重耐药性有关。
【关键词】鲍曼不动杆菌多重耐药 blaOXA 23基因外膜蛋白聚合酶链反应
The mechanism of three carbapenemresistant clinical isolates
of obacter baumannii
ABSTRACT Objective To study the molecular mechanism of carbapenemresistant obacter baumannnii. Methods The carbapenemresistant strains were detected from clinical obacter baumannii by disk diffusion and microdiluted broth method. The blaOXA23 gene was amplified by PCR method and then sequenced. Their out membrane proteins (OMP) were extracted and analyzed by using SDSpolyacrylamide gel electrophoresis and a carbapenemsusceptible obacter baumannnii strain as control. Results The PCR amplification and sequencing results showed that the three multiresiltant obacter baumannii isolates were multiresistant and all carried blaOXA23 gene. The SDSPAGE electrophoresis result showed that band deficiency was found in AB173, whereas other two resistant isolates showed the same electrophoresis profiles with the control. Conclusions In this experiment, all three carbapenemresistant obacter baumannii strains carried blaOXA23 gene and one of them lacked a OMP, which were probably attributed to the multiresistance anisms.
KEY WORDS obacter baumannii; Multiresistance; blaOXA23 gene; Outer membrane protein; Polymerase chain reaction (PCR)
在过去的几十年内,ICU病房中有创性检查及治疗的增加使得不动杆菌成为重要的条件致病菌,它可以导致广泛的临床并发症,例如肺炎、败血症、泌尿系感染、伤口感染、脑膜炎,尤其易发生在免疫功能低下的患者身上[1]。由于不动杆菌对氨基糖苷类、β内酰胺类等多种抗生素耐药,因此限制了治疗时对敏感药物的选择,给临床治疗带来了巨大的压力。研究显示鲍曼不动杆菌对碳青霉烯类抗生素耐药机制涉及产碳青霉烯酶、外膜蛋白(outermembrane prothin,OMP)缺失、外排泵系统表达亢进和青霉素结合蛋白突变等诸多方面。本试验收集了近期3株耐碳青霉烯鲍曼不动杆菌临床株并对其产OXA23型碳青霉烯酶和外膜蛋白的情况进行研究。
1 材料与方法