BACTERIAL ANTIBIOTIC RESISTANCE IN AGRICULTURE

农业中的细菌抗生素耐药性

• 批准号: 7610357
• 负责人: MANUEL F VARELA
• 金额: $ 6.16万
• 依托单位: NEW MEXICO STATE UNIVERSITY LAS CRUCES
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7610357
• 关键词: Abdominal Infection; Acute suppurative arthritis due to bacteria; Agriculture; Amino Acids; Amoxicillin; Ampicillin; Antibiotics; Antimicrobial Resistance; Bacteremia; Bacterial Antibiotic Resistance; Benzalkonium Chloride; Binding; Cells; Clinical; Cloaca Chamber; Cloning; Computer Retrieval of Information on Scientific Projects Database; Condition; DNA; DNA Sequence Analysis; Data; Endocarditis; Enterobacter cloacae; Erythromycin; Escherichia coli; Ethidium; Family; Family member; Fosfomycin; Frequencies; Funding; Genes; Grant; Guns; Homidium Bromide; Infection; Institution; Intra-abdominal; Knowledge; Lower Respiratory Tract Infection; Mediating; Membrane; Multi-Drug Resistance; Open Reading Frames; Organism; Osteomyelitis; Pharmaceutical Preparations; Poison; Proteins; Reporting; Research; Research Personnel; Resistance; Resources; Rifampin; Skin; Soft Tissue Infections; Source; United States National Institutes of Health; Urinary tract infection; Vesicle; antimicrobial drug; antiporter; bacterial resistance; beta-Lactam Resistance; efflux pump; infectious disease treatment; member; novel; pathogen; resistance mechanism

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Enterobacter cloacae is an important nosocomial pathogen which causes a variety of infections including bacteremia, lower respiratory tract infections, skin and soft tissue infections, urinary tract infections, endocarditis, intra-abdominal infections, septic arthritis, osteomyelitis, and ophthalmic infections. Recently, multidrug resistant E. cloacae have been reported with increasing frequency in clinical and environmental settings. These resistant bacteria circumvent toxic compounds, resulting in reduced efficacy in the treatment of infectious disease by antimicrobial agents. Thus, understanding the multidrug resistance mechanisms of this organism is very important in the efforts to reduce the conditions that make bacterial resistance to antimicrobial agents possible. To understand the resistance mechanisms in E. cloacae, we cloned a gene, designated emrF, which is responsible for multidrug resistance in Enterobacter cloacae using shot-gun cloning of chromosomal DNA. Host cells of E. coli KAM32 possessing the emrF gene showed elevated resistances to fosfomycin, rifampicin, ampicillin, amoxicilline, erythromycin and ethidium bromide. DNA sequencing and analysis revealed one open reading frame (ORF) encoding a novel protein of 120 amino acids. The deduced protein, EmrF, was predicted to have four transmembrane segments and found to be similar to the SMR family of multidrug efflux pumps using TMHMM and GenomeNet TBLASTN analyses. Furthermore, EmrF showed some conserved amino acid residues such as Tyr-40 and Tyr-60, and Tyr-40 which have previously been reported to mediate binding of some substrates. We found that EmrF mediated low level resistances to beta-lactams and ethidium, similar to the Qac subfamily; but EmrF did not show resistance to benzalkonium chloride. EmrF showed high resistance to fosfomycin and rifampicin. These antibiotics have not been reported as substrates of other SMR family members. We detected energy-dependent efflux of fosfomycin with everted membrane vesicles harboring EmrF, and found that EmrF is an H+-drug antiporter. We also observed ethidium efflux activity by comparing ethidium bromide accumulation in cells with and without EmrF. Our data indicate that EmrF is a novel H+-drug antiporter and a member of the SMR family of transporters. To our knowledge, this is the first report of a multidrug efflux pump in E. cloacae.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 阴沟肠杆菌是一种重要的医院病原体，其引起多种感染，包括菌血症、下呼吸道感染、皮肤和软组织感染、尿路感染、心内膜炎、腹腔内感染、脓毒性关节炎、骨髓炎和眼部感染。近年来，多药耐药大肠杆菌（E.在临床和环境环境中，已报告了越来越频繁的Clobacteria。 这些耐药细菌避开有毒化合物，导致抗微生物剂治疗感染性疾病的功效降低。因此，了解这种微生物的多药耐药机制是非常重要的，努力减少的条件下，使细菌耐药性的抗菌剂成为可能。 了解大肠杆菌的耐药机制。在大肠杆菌中，我们克隆了一个基因，命名为emrF，这是负责多药耐药的大肠杆菌染色体DNA的鸟枪克隆。 大肠杆菌的宿主细胞。大肠杆菌KAM 32对磷霉素、利福平、氨苄西林、阿莫西林、红霉素和溴化乙锭的耐药性均升高。 DNA序列分析表明，该基因含有一个开放阅读框（ORF），编码120个氨基酸的蛋白质。 推测的蛋白质EmrF具有四个跨膜片段，并使用TMHMM和GenomeNet TBLANDIX分析发现其与SMR家族的多药外排泵相似。此外，EmrF显示了一些保守的氨基酸残基，如Tyr-40和Tyr-60，以及先前已报道介导某些底物结合的Tyr-40。 我们发现，EmrF介导的低水平的耐药性β-内酰胺类和乙锭，类似于Qac亚家族，但EmrF没有表现出耐药性苯扎氯铵。EmrF对磷霉素和利福平高度耐药。这些抗生素尚未报告为其他SMR家族成员的底物。我们检测到能量依赖性外排磷霉素与外翻膜囊泡窝藏EmrF，并发现EmrF是一个H+-药物逆向转运。 我们还观察了乙锭外排活性，通过比较溴化乙锭在细胞中的积累与EmrF。 我们的数据表明，EmrF是一种新的H+-药物反向转运蛋白和SMR家族的转运蛋白的成员。 据我们所知，这是第一次在大肠杆菌中发现多药外排泵。clothing.