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细菌耐多药外排泵的研究进展 总被引:1,自引:0,他引:1
近年来,由于抗生素的不合理及广泛使用,全球多重耐药菌和广泛耐药菌不断出现。关于细菌耐药机制中外排泵及生物膜形成的研究越来越受关注。研究发现,外排泵与生物膜形成有密切联系,不同细菌的不同外排泵对生物膜形成的影响各异,而生物膜形成又影响外排泵基因表达。本文就细菌耐多药外排泵的研究进展进行综述。 相似文献
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Jose Luis Martinez María Blanca Sánchez Laura Martínez-Solano Alvaro Hernandez Leonor Garmendia Alicia Fajardo & Carolina Alvarez-Ortega 《FEMS microbiology reviews》2009,33(2):430-449
Multidrug efflux pumps have emerged as relevant elements in the intrinsic and acquired antibiotic resistance of bacterial pathogens. In contrast with other antibiotic resistance genes that have been obtained by virulent bacteria through horizontal gene transfer, genes coding for multidrug efflux pumps are present in the chromosomes of all living organisms. In addition, these genes are highly conserved (all members of the same species contain the same efflux pumps) and their expression is tightly regulated. Together, these characteristics suggest that the main function of these systems is not resisting the antibiotics used in therapy and that they should have other roles relevant to the behavior of bacteria in their natural ecosystems. Among the potential roles, it has been demonstrated that efflux pumps are important for processes of detoxification of intracellular metabolites, bacterial virulence in both animal and plant hosts, cell homeostasis and intercellular signal trafficking. 相似文献
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Marquez B 《Biochimie》2005,87(12):1137-1147
It is now well established that bacterial resistance to antibiotics has become a serious problem of public health that concerns almost all antibacterial agents and that manifests in all fields of their application. Among the three main mechanisms involved in bacterial resistance (target modification, antibiotic inactivation or default of its accumulation within the cell), efflux pumps, responsible for the extrusion of the antibiotic outside the cell, have recently received a particular attention. Actually, these systems, classified into five families, can confer resistance to a specific class of antibiotics or to a large number of drugs, thus conferring a multi-drug resistance (MDR) phenotype to bacteria. To face this issue, it is urgent to find new molecules active against resistant bacteria. Among the strategies employed, the search for inhibitors of resistance mechanisms seems to be attractive because such molecules could restore antibiotic activity. In the case of efflux systems, efflux pump inhibitors (EPIs) are expected to block the pumps and such EPIs, if active against MDR pumps, would be of great interest. This review will focus on the families of bacterial efflux systems conferring drug resistance, and on the EPIs that have been identified to restore antibiotic activity. 相似文献
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Large-scale production of renewable biofuels through microbiological processes has drawn significant attention in recent years, mostly due to the increasing concerns on the petroleum fuel shortages and the environmental consequences of the over-utilization of petroleum-based fuels. In addition to native biofuel-producing microbes that have been employed for biofuel production for decades, recent advances in metabolic engineering and synthetic biology have made it possible to produce biofuels in several non-native biofuel-producing microorganisms. Compared to native producers, these non-native systems carry the advantages of fast growth, simple nutrient requirements, readiness for genetic modifications, and even the capability to assimilate CO2 and solar energy, making them competitive alternative systems to further decrease the biofuel production cost. However, the tolerance of these non-native microorganisms to toxic biofuels is naturally low, which has restricted the potentials of their application for high-efficiency biofuel production. To address the issues, researches have been recently conducted to explore the biofuel tolerance mechanisms and to construct robust high-tolerance strains for non-native biofuel-producing microorganisms. In this review, we critically summarize the recent progress in this area, focusing on three popular non-native biofuel-producing systems, i.e. Escherichia coli, Lactobacillus and photosynthetic cyanobacteria. 相似文献
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Inhibitors of drug efflux pumps have great potential as pharmacological agents that restore the drug susceptibility of multidrug resistant bacterial pathogens. Most attention has been focused on the discovery of small molecules that inhibit the resistance nodulation division (RND) family drug efflux pumps in Gram-negative bacteria. The prototypical inhibitor of RND-family efflux pumps in Gram-negative bacteria is MC-207,110 (Phe-Arg-β-naphthylamide), a C-capped dipeptide. Here, we report that C-capped dipeptides inhibit two chloramphenicol-specific efflux pumps in Streptomyces coelicolor, a Gram-positive bacterium that is a relative of the human pathogen Mycobacterium tuberculosis. Diversity-oriented synthesis of a library of structurally related C-capped dipeptides via an Ugi four component reaction and screening of the resulting compounds resulted in the discovery of a compound that is threefold more potent as a suppressor of chloramphenicol resistance in S. coelicolor than MC-207,110. Since chloramphenicol resistance in S. coelicolor is mediated by major facilitator superfamily drug efflux pumps, our findings provide the first evidence that C-capped dipeptides can inhibit drug efflux pumps outside of the RND superfamily. 相似文献
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合成生物学是一个快速发展的研究领域,其重要性体现在科学研究和应用开发两方面。它不但加深了我们对复杂的生物过程与机理的理解,而且使得基础生物研究向实际应用的快速转化成为可能。将介绍一些新型高效的合成生物学工具以及如何利用它们开发能从可再生原料生产药物和燃料的上程菌株。 相似文献
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T. E. HUMPHREYS 《Plant, cell & environment》1987,10(3):259-266
Abstract During incubation of maize scutellum slices in fructose, there was an efflux of sucrose. Efflux was constant for at least 4 h at fructose concentrations of 70 or 100 mol m?3. Efflux was increased by EDTA, and decreased by Ca2+. Efflux was independent of pH after EDTA treatment, but increased from untreated slices when the pH was lowered from 7 to 4. Uranyl ion and PCMBS (p-chloro-mercuribenzenesulfonic acid) abolished sucrose uptake, but were only weak inhibitors of sucrose efflux. These results are consistent with efflux occurring by simple diffusion through aqueous pores, but they do not rule out facilitated diffusion. Rates of sucrose export from the scutellum to the root shoot axis were estimated from measurements of axis respiration and dry weight gain. Sucrose efflux from scutellum slices was only 14-22% of the export rate. Sucrose efflux from the whole scutellum was only 3-4% of the export rate. It is concluded that the observed efflux is from leaky cells and does not represent sucrose on the way to the phloem along a path that includes the apoplast. These results support the idea that the path for sucrose from parenchyma cell to sieve tube in the maize scutellum is entirely symplastic. 相似文献
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Mary J. Dunlop Jay D. Keasling Aindrila Mukhopadhyay 《Systems and synthetic biology》2010,4(2):95-104
Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield
insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation,
and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic
control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels,
the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects
may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel
production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show
that controlling efflux pump expression directly with a biofuel-responsive promoter is a straightforward way of improving
biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel
production rates. 相似文献
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