Genetic basis of metabolite production against clinically-derived pathogens

多药耐药(MDR)细菌感染的死亡率预计每年导致1000万人死亡。 到2050年在全球范围内，使抗生素耐药性成为对社会的重大威胁。进一步加剧这场危机的是 45%-97%的新冠肺炎患者增加了抗生素的使用，这可能会增加对 MDR表型。不幸的是，随着这些化合物的滥用和过度使用，病原体 进化出几种机制来抵抗目前使用的所有抗感染药物。世界卫生组织 最近，耐碳青霉烯类铜绿假单胞菌被认为是最难治疗的感染之一， 因此，未来对该物种和其他革兰氏阴性病原体的管理将需要新的、尚未发现的、 抗生素。作为细菌群，环境假单胞菌(env-Ps)以其广泛性而著称 基因组内容和多样性。由于它们的遗传复杂性，它们产生了一系列 次生代谢物已被证明可以防止病原真菌的生长，分解复合体 顽固性化合物，表现出抗肿瘤活性，并抑制广泛的细菌病原体，包括 耐甲氧西林金黄色葡萄球菌和结核分枝杆菌。此外，土壤和淡水 世界各地的环境都由假单胞菌主导，它们在全球范围内的丰富表明 某些对生态生存有利的特征。相比之下，铜绿假单胞菌在 生态环境。可能对环境蛋白的这种健康效应有贡献的一个特征是能够对抗 附近的竞争对手通过生产抗菌化合物。先前的研究表明，水衍生的 Env-Ps能够抑制囊性纤维化(CF)病原体，包括铜绿假单胞菌、伯克霍尔德氏菌、 Achromobacter和Steno营养性单胞菌，并随后确定了参与 环境菌株内的拮抗活性。作为该项目的延续，来自营养丰富的环境污染物 水系统被认为是强大的抗菌活性的来源。事实上，初步数据显示 来自受污染河流的环境蛋白显示出显著的抑制CF来源的广泛耐药性的能力 (XDR)病原体，包括碳青霉烯类耐药铜绿假单胞菌。在本研究中，一种创新的方法使用 可培养细菌将用于将拮抗活性(表型)与不同的生物合成基因簇联系起来。 (基因)参与抗菌活性。通过研究环境蛋白和环境蛋白之间的直接竞争相互作用 XDR病原菌、新的拮抗因子有望被发现。这将通过以下方式实现：(I)隔离 和测定污染水柱中环氧氯丙烷的抗菌活性；(Ii)生物合成产物的鉴定 参与活性的基因簇；以及(Iii)编码的未发现化合物的初步特征。 合并后的结果将用于鉴定为未来选择有效拮抗菌株的指标 有针对性的新型抗菌化合物的发现。

Mortality from multi-drug resistant (MDR) bacterial infections is projected to cause 10 million deaths per year worldwide by 2050, making antibiotic resistance a vital threat to society. Fueling this crisis even further is the increased use of antibiotics among 45-97% of COVID-19 patients, which will likely boost selective pressure for MDR phenotypes. Unfortunately, with the misuse and overuse of these chemical compounds, pathogens have evolved several mechanisms to resist all currently used anti-infective agents. The World Health Organization recently deemed carbapenem resistant Pseudomonas aeruginosa as one of the most difficult infections to treat, so future management of this species and other Gram-negative pathogens will require novel, yet undiscovered, antibiotics. As a bacterial group, environemtnal Pseudomonas strains (env-Ps) are well known for their extensive genomic content and diversity. Owed to their genetic complexity is the production of an assorted repertoire of secondary metabolites that have been shown to prevent the growth of pathogenic fungi, breakdown complex recalcitrant compounds, exhibit anti-tumor activity, and inhibit a wide range of bacterial pathogens including methicillin-resistant Staphylococcus aureus and Mycobacterium tuberculosis. Moreover, soil and freshwater environments are dominated worldwide by pseudomonads, whose global abundance suggest the expression of certain traits that are advantageous to ecological survival. In contrast, P. aeruginosa is observed infrequently in ecological settings. One trait that is likely to contribute to such fitness effects of env-Ps is the ability to antagonize nearby competitors through production of antimicrobial compounds. Previous work showed that water-derived env-Ps were able to inhibit cystic fibrosis (CF) derived pathogens including P. aeruginosa, Burkholderia, Achromobacter, and Stenotrophomonas species, and subsequently identified gene clusters involved in antagonistic activity within the environmental strains. As a continuation of this project, env-Ps from nutrient-rich water systems are hypothesized to be sources of potent antimicrobial activity. Indeed, preliminary data shows that env-Ps from a polluted river exhibited the remarkable ability to inhibit CF-derived extensively drug resistant (XDR) pathogens, including carbapenem resistant P. aeruginosa. In this study, an innovation approach using culturable bacteria will be utilized to link antagonistic activity (phenotype) to diverse biosynthetic gene clusters (genotype) involved in antimicrobial activity. By investigating direct competitive interactions between env-Ps and XDR pathogens, novel antagonistic factors are expected to be identified. This will be achieved by (i) isolating and determining the antimicrobial activity of env-Ps from polluted water columns; (ii) identification of biosynthetic gene clusters involved in the activity; and (iii) initial characterization of encoded undiscovered compounds. Combined results will be used to identify metrics that select for potent antagonistic strains for the future of targeted novel antimicrobial compound discovery.