Regulation of stress resistance and virulence genes in Acinetobacter baumannii

鲍曼不动杆菌抗逆性和毒力基因的调控

• 批准号: 9098590
• 负责人: HOWARD A SHUMAN
• 金额: $ 19.19万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9098590
• 关键词: Acinetobacter baumannii; Aerobic; Bacteria; Bacterial Outer Membrane Proteins; Cessation of life; Community-Acquired Infections; Complement; DNA Insertion Elements; DNA-Binding Proteins; Deletion Mutation; Disease; Endocarditis; Environment; Exhibits; Frequencies; Gene Deletion; Gene Expression; Genes; Genetic; Genetic Screening; Genome; Growth; Health; Healthcare; Hemolymph; Hospitals; Human; Infection; Infectious Agent; Insecta; Insertion Mutation; Intervention; Iron; Knowledge; Larva; Ligase; Measures; Membrane Proteins; Microbial Biofilms; Modeling; Molecular; Moths; Multi-Drug Resistance; Nosocomial Infections; Nutrient; Organism; Osteomyelitis; Oxidative Stress; Pain; Pathogenesis; Phenotype; Pneumonia; Polysaccharides; Potassium Channel; Prevalence; Production; Protein Secretion; Proteins; Regulation; Regulator Genes; Regulatory Pathway; Reporting; Resistance; Sepsis; Siderophores; Site; Skin Tissue; Soft Tissue Infections; Source; Stress; System; Testing; Toxin; Transcriptional Regulation; Trehalose; Urinary tract infection; Virulence; Virulence Factors; Waxes; Work; Zinc; base; biological adaptation to stress; genetic regulatory protein; mutant; pathogen; resistant strain; transcriptome; transcriptome sequencing

 DESCRIPTION (provided by applicant): Acinetobacter baumannii is a strictly aerobic, gram-negative coccobacillus that has recently emerged as a significant opportunistic human pathogen. This organism is most commonly associated with nosocomial infections and is generally considered to be an opportunistic human pathogen, although some community acquired infections are reported. Diseases caused by A. baumannii include skin and soft tissue infections, infections of the urinary tract, as well as more invasive diseases such as endocarditis, sepsis, osteomyelitis and pneumonia. A. baumannii infections are further complicated by the increasing prevalence of multidrug resistant (MDR) strains. At present, little is known about A. baumannii virulence mechanisms. Currently proposed virulence determinants include the production of siderophores, elaboration of capsular polysaccharides, biofilm production, the bacterial outer membrane protein A (OmpA), as well as several other candidate proteins of unknown function. There is even less information about how virulence-related genes are regulated. To discover A. baumannii virulence genes, we took advantage of an invertebrate insect model that has been used to study a variety of infectious agents, the larva of the wax moth, Galleria mellonella. We conducted a forward genetic screen using a large pool of transposon insertion mutations in the genome of a MDR pathogenic strain of A. baumannii, AB5075. By sequencing the insertion sites of the transposons in bacteria grown in rich media and from infected larvae, we identified more than 180 genes that appear to be specifically required for survival in larvae and dispensable for survival and growth in rich media. Seventeen of the genes encode products that are annotated as either DNA binding proteins or other types of regulatory proteins. In addition, 11 genes predicted to encode proteins related to resistance to osmotic stress were found. We created deletions of the genes annotated as trehalose synthetase (otsB), potassium channels (trkAH), and a mechanosensitive channel (mscS). These mutants also exhibited decreased survival in larva hemolymph compared to wild-type A. baumannii AB5075. This proposed work includes construction of deletion mutations of the 28 genes (17 regulators and 11 stress resistance) and testing their phenotypes in the Galleria model. The ability of the corresponding wild-type genes to complement mutants that exhibit a phenotype will be evaluated. Transcriptional profiling by RNAseq will be performed on several mutants that exhibit decreased virulence in the Galleria larva model. This work will result in important new knowledge about the genetic basis of virulence in an emerging human pathogen.

 描述（由申请人提供）：鲍曼不动杆菌是一种严格需氧的革兰氏阴性球杆菌，最近已成为一种重要的机会性人类病原体。这种微生物最常与医院感染相关，并且通常被认为是机会性人类病原体，尽管有一些社区获得性感染的报道。鲍曼不动杆菌引起的疾病包括皮肤和软组织感染、尿路感染，以及更具侵袭性的疾病，如心内膜炎、败血症、骨髓炎和肺炎。由于多重耐药 (MDR) 菌株的流行，鲍曼不动杆菌感染变得更加复杂。目前，人们对鲍曼不动杆菌的毒力机制知之甚少。目前提出的毒力决定因素包括铁载体的产生、荚膜多糖的加工、生物膜的产生、细菌外膜蛋白 A (OmpA) 以及其他几种功能未知的候选蛋白。 There is even less information about how virulence-related genes are regulated.为了发现鲍曼不动杆菌的毒力基因，我们利用了无脊椎动物模型，该模型已用于研究多种传染源，即大蜡螟的幼虫。我们利用鲍曼不动杆菌 MDR 致病菌株 AB5075 基因组中的大量转座子插入突变进行了正向遗传筛选。通过对在丰富培养基中生长的细菌和受感染幼虫中转座子的插入位点进行测序，我们鉴定了 180 多个基因，这些基因似乎是幼虫生存所特别需要的，并且对于在丰富培养基中生存和生长是必不可少的。 Seventeen of the genes encode products that are annotated as either DNA binding proteins or other types of regulatory proteins.此外，预计有 11 个基因编码与耐药性相关的蛋白质。 发现渗透压。我们删除了注释为海藻糖合成酶 (otsB)、钾通道 (trkAH) 和机械敏感通道 (mscS) 的基因。与野生型鲍曼不动杆菌 AB5075 相比，这些突变体还表现出幼虫血淋巴存活率降低。这项拟议的工作包括构建 28 个基因（17 个调节基因和 11 个抗应激基因）的缺失突变，并在 Galleria 模型中测试它们的表型。将评估相应野生型基因补充表现出表型的突变体的能力。将通过 RNAseq 对几种在 Galleria 幼虫模型中表现出毒力降低的突变体进行转录分析。 This work will result in important new knowledge about the genetic basis of virulence in an emerging human pathogen.

项目成果

Joint Transcriptional Control of Virulence and Resistance to Antibiotic and Environmental Stress in Acinetobacter baumannii.

• DOI: 10.1128/mbio.01660-15
• 发表时间: 2015-11-10
• 期刊: mBio
• 影响因子: 6.4
• 作者: Gebhardt MJ;Gallagher LA;Jacobson RK;Usacheva EA;Peterson LR;Zurawski DV;Shuman HA
• 通讯作者: Shuman HA

Leishmania major-Infected Phlebotomus duboscqi Sand Fly Bites Enhance Mast Cell Degranulation.

• DOI: 10.3390/pathogens12020207
• 发表时间: 2023-01-28
• 期刊: Pathogens (Basel, Switzerland)

Optimizing tick artificial membrane feeding for Ixodes scapularis.

优化为ixodes capularis的壁虱人造膜喂养。

• DOI: 10.1038/s41598-023-43200-z
• 发表时间: 2023-09-27
• 期刊: SCIENTIFIC REPORTS
• 影响因子: 4.6
• 作者: Guizzo, Melina Garcia;Meneses, Claudio;Cecilio, Pedro Amado;Alvarenga, Patricia Hessab;Sonenshine, Daniel;Ribeiro, Jose M.
• 通讯作者: Ribeiro, Jose M.

Molecular Diversity between Salivary Proteins from New World and Old World Sand Flies with Emphasis on Bichromomyia olmeca, the Sand Fly Vector of Leishmania mexicana in Mesoamerica.

• DOI: 10.1371/journal.pntd.0004771
• 发表时间: 2016-07
• 期刊: PLoS neglected tropical diseases
• 影响因子: 3.8
• 作者: Abdeladhim M;V Coutinho-Abreu I;Townsend S;Pasos-Pinto S;Sanchez L;Rasouli M;B Guimaraes-Costa A;Aslan H;Francischetti IM;Oliveira F;Becker I;Kamhawi S;Ribeiro JM;Jochim RC;Valenzuela JG
• 通讯作者: Valenzuela JG