肠道菌群耐药基因组与肝硬化并发自发性腹膜炎的致病菌耐药性之间的关联研究

项目名称： 肠道菌群耐药基因组与肝硬化并发自发性腹膜炎的致病菌耐药性之间的关联研究

项目编号： No.81501795

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 刘琳

作者单位： 浙江大学

项目金额： 18万元

中文摘要： 细菌感染并发症是导致肝硬化患者病死率增加的主要原因之一，细菌耐药是抗感染治疗中的重要问题。肠道细菌移位在肝硬化并发自发性腹膜炎（SBP）的发生发展中起重要作用，但是人们对肠道菌群这一“抗生素耐药基因的巨大贮存库”的了解甚少，对人体腹水菌群及耐药基因也需要通过最新的宏基因学进行全面的再认识。本项目在已找到肝硬化患者肠道菌群失衡规律的基础上，计划通过采集肝硬化并发SBP患者的大便和腹水样品，采用宏基因组生物信息和多元分析技术，揭示其菌群组成和耐药基因组特征；并首次建立肝硬化SBP腹水菌群数据库，通过与肠道菌群耐药基因组的同源、聚类、差异和进化关系的关联分析，结合临床表型及对腹水分离菌耐药性和耐药基因功能的研究，阐明腹水致病菌耐药基因肠道产生、进化和体内转移途径及致病机理，为临床抗生素使用指导及肠道微生态干预改善预后奠定研究基础。

中文关键词： 细菌性自发性腹膜炎；耐药基因；微生态；宏基因组学；高通量测序

英文摘要： China has a highest incidence of cirrhosis, usually resulting from chronic infection of HBV virus. The cirrhosis is often complicated by bacterial infection leading to a high percentage of death. Bacterial antibiotic resistance (AR) is one of the most important threats in bacterial infection therapy. The human gut microbiota is a great reservoir of antibiotic resistance genes, and intestinal bacterial translocation (BT) probably play an important role in the progress of bacterial infection in cirrhosis, but little is known about AR gene diversity and richness within the gut，and none has done in the comparison in spontaneous bacteria peritonitis (SBP) ascitic bacteria and their AR genes with gut microbial AR genes. Taking advantages in quick advances in the next-generation sequencing (NGS) and metagenomic technologies, our lab has successfully found gut microbial markers for cirrhosis development (N Qin, et al. 2014, Nature), and it also provided basic database for this study. In this project, we aim to collect 20 ascites and feces samples from SBP-complicated liver cirrhosis patients, and use Illumina-based metagenomic sequencing and most updated bioinformatics tools to achieve the following goals: reveal and compare the bacterial communcity structure and AR genes in the gut and ascites microbiota; assembly, gene annotation and homologous analysis of AR genes in both sample types, to reveal ascitic AR gene (bacteria) origin, evolution and migration; functional studies of AR genes by construction of BAC library and drug-screen for new AR genes, and knock-out experiment of target gene-containing ascites-isolated bacterial strain, for confirmation of the gene's AR function and AR mechanism; Compare metagenomic and gene function data with clinical examination results and prognosis for potential methods to improve diagnosis and therapy.

英文关键词： Spontaneous bacterial peritonitis;antibiotic resistance genes;microecology;metagenomics;high-throughput sequencing