碳青霉烯类耐药肺炎克雷伯菌由于具有广泛耐药特征使临床抗感染治疗面临无药可用困境。产生碳青霉烯酶（包括A、B和D类）是细菌对碳青霉烯类药物最主要的耐药机制。与A和B类碳青霉烯酶不同的是，以OXA-232为代表的D类OXA-48家族碳青霉烯酶在水解底物谱上有明显差别，且其在我国临床分离菌株中的流行分布特征未明。课题组前期研究发现，近年肺炎克雷伯菌中OXA-232型碳青霉烯酶的检出率快速上升。本研究①通过多中心样本研究，分析产OXA-232型酶肺炎克雷伯菌在我国的流行和分布；②通过酶切克隆方法获得OXA-232基因及其周边调控基因序列，RT-PCR及测序阐明调控基因序列及结构改变对OXA-232基因表达水平及耐药表型的影响，揭示表达调控机制；③通过质粒携带OXA-232基因遗传环境生物信息学分析，探索耐药基因起源和传播机制；通过本课题研究，可进一步揭示并丰富细菌对碳青霉烯类的耐药机理。

Carbapenem-resistant Klebsiella pneumoniae with the extensively drug-resistant characteristic developed the great challenge for public health. Production of carbapenemase (class A, B and D) is the predominant resistance mechanism of K. pneumoniae to carbapenem. Compared with class A and B carbapenemase, class D carbapenemase OXA-48 like carbapenemase especiall OXA-232 is difference for both Hydrolysis substrate and the distribution among clinical strains. Our previous study indicated the prevalence of OXA-232 producing K. pneumoniae was rapidly increasing. In this study, we want to clarify the epidemiology, function of surrounding regulators and the gene expression of blaOXA-232 among K. pneumoniae. We try to clone different OXA-232-containing DNA fragments into a vector via restriction enzyme double-digestion technique. Then we try to analyze the horizontal transmissibility and evolution of OXA-232-harboring plasmids by bioinformatics software. The project may help to reveal the carbapenem-resistant mechanism in K. pneumoniae and might provide the basis for prevention and control of carbapenem-resistant strains.