Genome-wide identification of virulence genes in Acinetobacter baumannii in vivo

鲍曼不动杆菌体内毒力基因的全基因组鉴定

基本信息

批准号：
8699488
负责人：
HARRY L. MOBLEY
金额：
$ 19.44万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-03-20 至 2016-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8699488
关键词：
Acinetobacter baumannii Address Afghanistan Animal Model Antibiotic Resistance Area Bacteremia Bacteria Bacterial Genes Blood Circulation Burn Trauma Chronic lung disease Communities Community Hospitals Convalescence Development Essential Genes Fostering Frequencies Genes Genetic Determinism Genetic Screening Genomic DNA Goals Gram-Negative Bacteria Health High Prevalence High-Throughput DNA Sequencing High-Throughput Nucleotide Sequencing Hospitals Immune response Immune system Immunocompromised Host In Vitro Individual Infection Injury Intensive Care Units Investigation Iraq Knowledge Laboratories Libraries Medical Meningitis Mission Modeling Molecular Models Mus Mutagenesis Mutation Organism Output Pathogenesis Patients Peritoneum Public Health Rehabilitation Centers Research Respiratory System Respiratory tract structure Risk Scourge Site Surface Time Tissues United States Urinary tract Vaccinated Virulence Virulence Factors War Work antimicrobial bacterial genetics base combat deep sequencing diabetic patient fitness genome sequencing genome wide association study genome-wide improved in vivo innovation molecular modeling mutant pathogen public health relevance research study respiratory trauma care

项目摘要

DESCRIPTION (provided by applicant): Acinetobacter baumannii, a Gram-negative bacterium, has emerged as an important opportunistic pathogen that poses a significant public health risk in the United States. Clinically, A. baumannii is emerging as a leading nosocomial pathogen, particularly in intensive care units specializing in respiratory care, trauma and burns. Despite having the complete genome sequences for three strains of A. baumannii, the identity of most genes that are essential for pathogenesis in a mammalian host is not known. We propose to identify which of the nearly 4000 bacterial genes are essential for survival in a mammalian host and to demonstrate the necessity for each gene during experimentally induced bacteremia. The result will represent a major step forward in understanding the pathobiology of A. baumannii infections and for devising strategies to treat these infections or vaccinate against their occurrence. Our long-term goal is to systematically establish a molecular model of pathogenesis for A. baumannii infection. The objective of this application is to identify all genes essential to establish infection within a mammalian host. Based on a successful pilot experiment with 109,000 mutant of A. baumannii ATCC17978 in a murine model of bacteremia, our central hypothesis is that genes of A. baumannii essential for development of bacteremia can be determined by combining global transposon mutagenesis, a murine model of infection, and high throughput sequencing. Our rationale for conducting this work is to establish a framework that will direct detailed mechanistic investigations of A. baumannii pathogenesis in compromised patients. Using a saturating transposon library of A. baumannii mutants, the animal model of bacteremia, and high- throughput DNA sequencing, we will accomplish the following specific aims: 1) identify virulence genes essential for A. baumannii to colonize and disseminate within a mammalian host; and 2) confirm A. baumannii virulence genes that contribute most significantly to colonization and dissemination in the murine model using defined mutations. This contribution will be significant because, in these comprehensive and unbiased experiments, we will determine for the first time the complete A. baumannii virulence gene set for two strains during a mammalian infection. This proposal should be considered innovative as it applies transposon-directed insertion-site sequencing (TraDIS) for genome-wide identification of A. baumannii virulence genes using a forward-genetic screen in a relevant animal model of infection.

描述（由申请人提供）：鲍曼不动杆菌是一种革兰氏阴性细菌，已成为一种重要的机会性病原体，对美国构成重大的公共卫生风险。在临床上，鲍曼不动杆菌正在成为一种主要的医院病原体，特别是在专门从事呼吸护理、创伤和烧伤的重症监护病房中。尽管拥有鲍曼不动杆菌三种菌株的完整基因组序列，但哺乳动物宿主发病机制所必需的大多数基因的身份尚不清楚。我们打算鉴定近 4000 个细菌基因中的哪些对于哺乳动物宿主的生存至关重要，并证明每个基因在实验诱导的菌血症期间的必要性。该结果将代表着在了解鲍曼不动杆菌感染的病理学以及制定治疗这些感染或针对其发生进行疫苗接种的策略方面向前迈出的重要一步。我们的长期目标是系统地建立鲍曼不动杆菌感染发病机制的分子模型。该应用程序的目的是识别所有基因对于在哺乳动物宿主内建立感染至关重要。基于在鼠菌血症模型中对 109,000 个鲍曼不动杆菌 ATCC17978 突变体进行的成功试点实验，我们的中心假设是，可以通过结合全局转座子诱变（鼠感染模型）来确定鲍曼不动杆菌对菌血症发生至关重要的基因，以及高通量测序。我们进行这项工作的理由是建立一个框架，指导对受损患者的鲍曼不动杆菌发病机制进行详细的机制研究。利用鲍曼不动杆菌突变体的饱和转座子文库、菌血症动物模型和高通量DNA测序，我们将实现以下具体目标：1）鉴定鲍曼不动杆菌在哺乳动物宿主内定植和传播所必需的毒力基因; 2) 使用确定的突变确认对小鼠模型中定植和传播贡献最大的鲍曼不动杆菌毒力基因。这一贡献将是意义重大的，因为在这些全面且公正的实验中，我们将首次确定哺乳动物感染过程中两种菌株的完整鲍曼不动杆菌毒力基因集。该提案应被认为是创新的，因为它应用转座子定向插入位点测序（TraDIS）在相关动物感染模型中使用正向遗传筛选来全基因组鉴定鲍曼不动杆菌毒力基因。