| 1. |
- Andersson, Dan I, et al.
(författare)
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Mechanisms and clinical relevance of bacterial heteroresistance
- 2019
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Ingår i: Nature Reviews Microbiology. - : Nature Publishing Group. - 1740-1526 .- 1740-1534. ; 17:8, s. 479-496
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Forskningsöversikt (refereegranskat)abstract
- Antibiotic heteroresistance is a phenotype in which a bacterial isolate contains subpopulations of cells that show a substantial reduction in antibiotic susceptibility compared with the main population. Recent work indicates that heteroresistance is very common for several different bacterial species and antibiotic classes. The resistance phenotype is often unstable, and in the absence of antibiotic pressure it rapidly reverts to susceptibility. A common mechanistic explanation for the instability is the occurrence of genetically unstable tandem amplifications of genes that cause resistance. Due to their instability, low frequency and transient character, it is challenging to detect and study these subpopulations, which often leads to difficulties in unambiguously classifying bacteria as susceptible or resistant. Finally, in vitro experiments, mathematical modelling, animal infection models and clinical studies show that the resistant subpopulations can be enriched during antibiotic exposure, and increasing evidence suggests that heteroresistance can lead to treatment failure.
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| 2. |
- Balaban, Nathalie Q., et al.
(författare)
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Definitions and guidelines for research on antibiotic persistence
- 2019
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Ingår i: Nature Reviews Microbiology. - : Nature Publishing Group. - 1740-1526 .- 1740-1534. ; 17:7, s. 441-448
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Forskningsöversikt (refereegranskat)abstract
- Increasing concerns about the rising rates of antibiotic therapy failure and advances in single-cell analyses have inspired a surge of research into antibiotic persistence. Bacterial persister cells represent a subpopulation of cells that can survive intensive antibiotic treatment without being resistant. Several approaches have emerged to define and measure persistence, and it is now time to agree on the basic definition of persistence and its relation to the other mechanisms by which bacteria survive exposure to bactericidal antibiotic treatments, such as antibiotic resistance, heteroresistance or tolerance. In this Consensus Statement, we provide definitions of persistence phenomena, distinguish between triggered and spontaneous persistence and provide a guide to measuring persistence. Antibiotic persistence is not only an interesting example of non-genetic single-cell heterogeneity, it may also have a role in the failure of antibiotic treatments. Therefore, it is our hope that the guidelines outlined in this article will pave the way for better characterization of antibiotic persistence and for understanding its relevance to clinical outcomes.
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| 3. |
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| 4. |
- Bush, Matthew J, et al.
(författare)
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c-di-GMP signalling and the regulation of developmental transitions in streptomycetes.
- 2015
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Ingår i: Nature Reviews. Microbiology. - : Springer Science and Business Media LLC. - 1740-1534 .- 1740-1526. ; 13:12, s. 749-760
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Forskningsöversikt (refereegranskat)abstract
- The complex life cycle of streptomycetes involves two distinct filamentous cell forms: the growing (or vegetative) hyphae and the reproductive (or aerial) hyphae, which differentiate into long chains of spores. Until recently, little was known about the signalling pathways that regulate the developmental transitions leading to sporulation. In this Review, we discuss important new insights into these pathways that have led to the emergence of a coherent regulatory network, focusing on the erection of aerial hyphae and the synchronous cell division event that produces dozens of unigenomic spores. In particular, we highlight the role of cyclic di-GMP (c-di-GMP) in controlling the initiation of development, and the role of the master regulator BldD in mediating c-di-GMP signalling.
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| 5. |
- Eme, Laura, et al.
(författare)
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Archaea and the origin of eukaryotes
- 2018
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Ingår i: Nature Reviews Microbiology. - : Springer Nature. - 1740-1526 .- 1740-1534. ; 16:2
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Tidskriftsartikel (refereegranskat)abstract
- This corrects the article DOI: 10.1038/nrmicro.2017.133.
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| 6. |
- Eme, Laura, et al.
(författare)
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Archaea and the origin of eukaryotes
- 2017
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Ingår i: Nature Reviews Microbiology. - : Springer Science and Business Media LLC. - 1740-1526 .- 1740-1534. ; 15:12, s. 711-723
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Forskningsöversikt (refereegranskat)abstract
- Woese and Fox's 1977 paper on the discovery of the Archaea triggered a revolution in the field of evolutionary biology by showing that life was divided into not only prokaryotes and eukaryotes. Rather, they revealed that prokaryotes comprise two distinct types of organisms, the Bacteria and the Archaea. In subsequent years, molecular phylogenetic analyses indicated that eukaryotes and the Archaea represent sister groups in the tree of life. During the genomic era, it became evident that eukaryotic cells possess a mixture of archaeal and bacterial features in addition to eukaryotic-specific features. Although it has been generally accepted for some time that mitochondria descend from endosymbiotic alphaproteobacteria, the precise evolutionary relationship between eukaryotes and archaea has continued to be a subject of debate. In this Review, we outline a brief history of the changing shape of the tree of life and examine how the recent discovery of a myriad of diverse archaeal lineages has changed our understanding of the evolutionary relationships between the three domains of life and the origin of eukaryotes. Furthermore, we revisit central questions regarding the process of eukaryogenesis and discuss what can currently be inferred about the evolutionary transition from the first to the last eukaryotic common ancestor.
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| 7. |
- Hauryliuk, Vasili, 1980-, et al.
(författare)
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Recent functional insights into the role of (p)ppGpp in bacterial physiology
- 2015
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Ingår i: Nature Reviews Microbiology. - : Macmillan Publishers Ltd.. - 1740-1526 .- 1740-1534. ; 13:5, s. 298-309
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Forskningsöversikt (refereegranskat)abstract
- The alarmones guanosine tetraphosphate and guanosine pentaphosphate (collectively referred to as (p) ppGpp) are involved in regulating growth and several different stress responses in bacteria. In recent years, substantial progress has been made in our understanding of the molecular mechanisms of (p) ppGpp metabolism and (p) ppGpp-mediated regulation. In this Review, we summarize these recent insights, with a focus on the molecular mechanisms governing the activity of the RelA/SpoT homologue (RSH) proteins, which are key players that regulate the cellular levels of (p) ppGpp. We also discuss the structural basis of transcriptional regulation by (p) ppGpp and the role of (p) ppGpp in GTP metabolism and in the emergence of bacterial persisters.
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| 8. |
- Holmqvist, Erik, 1977-, et al.
(författare)
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RNA-binding proteins in bacteria
- 2018
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Ingår i: Nature Reviews Microbiology. - : Nature Publishing Group. - 1740-1526 .- 1740-1534. ; 16:10, s. 601-615
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Forskningsöversikt (refereegranskat)abstract
- RNA-binding proteins (RBPs) are central to most if not all cellular processes, dictating the fate of virtually all RNA molecules in the cell. Starting with pioneering work on ribosomal proteins, studies of bacterial RBPs have paved the way for molecular studies of RNA-protein interactions. Work over the years has identified major RBPs that act on cellular transcripts at the various stages of bacterial gene expression and that enable their integration into post-transcriptional networks that also comprise small non-coding RNAs. Bacterial RBP research has now entered a new era in which RNA sequencing-based methods permit mapping of RBP activity in a truly global manner in vivo. Moreover, the soaring interest in understudied members of host-associated microbiota and environmental communities is likely to unveil new RBPs and to greatly expand our knowledge of RNA-protein interactions in bacteria.
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| 9. |
- Macek, B., et al.
(författare)
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Protein post-translational modifications in bacteria
- 2019
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Ingår i: Nature Reviews Microbiology. - : Springer Science and Business Media LLC. - 1740-1526 .- 1740-1534. ; 17:11, s. 651-664
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Forskningsöversikt (refereegranskat)abstract
- Over the past decade the number and variety of protein post-translational modifications that have been detected and characterized in bacteria have rapidly increased. Most post-translational protein modifications occur in a relatively low number of bacterial proteins in comparison with eukaryotic proteins, and most of the modified proteins carry low, substoichiometric levels of modification; therefore, their structural and functional analysis is particularly challenging. The number of modifying enzymes differs greatly among bacterial species, and the extent of the modified proteome strongly depends on environmental conditions. Nevertheless, evidence is rapidly accumulating that protein post-translational modifications have vital roles in various cellular processes such as protein synthesis and turnover, nitrogen metabolism, the cell cycle, dormancy, sporulation, spore germination, persistence and virulence. Further research of protein post-translational modifications will fill current gaps in the understanding of bacterial physiology and open new avenues for treatment of infectious diseases.
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| 10. |
- Makarova, Kira S, et al.
(författare)
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An updated evolutionary classification of CRISPR-Cas systems
- 2015
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Ingår i: Nature Reviews Microbiology. - : Springer Science and Business Media LLC. - 1740-1526 .- 1740-1534. ; 13:11, s. 722-736
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of CRISPR-cas loci, which encode adaptive immune systems in archaea and bacteria, involves rapid changes, in particular numerous rearrangements of the locus architecture and horizontal transfer of complete loci or individual modules. These dynamics complicate straightforward phylogenetic classification, but here we present an approach combining the analysis of signature protein families and features of the architecture of cas loci that unambiguously partitions most CRISPR-cas loci into distinct classes, types and subtypes. The new classification retains the overall structure of the previous version but is expanded to now encompass two classes, five types and 16 subtypes. The relative stability of the classification suggests that the most prevalent variants of CRISPR-Cas systems are already known. However, the existence of rare, currently unclassifiable variants implies that additional types and subtypes remain to be characterized.
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