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المؤلفون: Forrest Kwong, Robert J. Suchland, P. Scott Hefty, Kevin Hybiske, Katelyn R. Soules, Jacob Stanley, Srishti Baid, Yibing Wang, Scott D. LaBrie, Daniel D. Rockey, Zoe E. Dimond, Steven J. Carrell
المصدر: Mol Microbiol
مصطلحات موضوعية: Chlamydia muridarum, Gene Transfer, Horizontal, Chlamydia trachomatis, Biology, Microbiology, Article, Bacterial Proteins, medicine, Animals, Humans, Molecular Biology, Gene, Tropism, Cytopathic effect, Genetics, Chlamydia, Genetic Variation, Chlamydia Infections, medicine.disease, biology.organism_classification, Phenotype, Mice, Inbred C57BL, Horizontal gene transfer, Female, Host adaptation
الوصف: Chlamydia muridarum actively grows in murine mucosae and is a representative model of human chlamydial genital tract disease. In contrast, C. trachomatis infections in mice are limited and rarely cause disease. The factors that contribute to these differences in host adaptation and specificity remain elusive. Overall genomic similarity leads to challenges in the understanding of these significant differences in tropism. A region of major genetic divergence termed the plasticity zone (PZ) has been hypothesized to contribute to the host specificity. To evaluate this hypothesis, lateral gene transfer was used to generate multiple hetero-genomic strains that are predominately C. trachomatis but have replaced regions of the PZ with those from C. muridarum. In vitro analysis of these chimeras revealed C. trachomatis-like growth as well as poor mouse infection capabilities. Growth-independent cytotoxicity phenotypes have been ascribed to three large putative cytotoxins (LCT) encoded in the C. muridarum PZ. However, analysis of PZ chimeras supported that gene products other than the LCTs are responsible for cytopathic and cytotoxic phenotypes. Growth analysis of associated chimeras also led to the discovery of an inclusion protein, CTL0402 (CT147), and homolog TC0424, which was critical for the integrity of the inclusion and preventing apoptosis.
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المؤلفون: Marika Linsky, Gil Segal
المصدر: Molecular Microbiology. 116:766-782
مصطلحات موضوعية: Gene Transfer, Horizontal, Genomic Islands, Effector, Mutagenesis (molecular biology technique), Repressor, Gene Expression Regulation, Bacterial, Regulatory Sequences, Nucleic Acid, Biology, biology.organism_classification, Microbiology, Legionella pneumophila, Cell biology, Repressor Proteins, Bacterial Proteins, Factor For Inversion Stimulation Protein, Genomic island, Horizontal gene transfer, Gene expression, Trans-Activators, Humans, Legionnaires' Disease, Molecular Biology, Gene, Genome, Bacterial
الوصف: The intracellular pathogen Legionella pneumophila translocates >300 effector proteins into host cells, many of which are regulated at the transcriptional level. Here, we describe a novel L. pneumophila genomic island, which undergoes horizontal gene transfer within the Legionella genus. This island encodes two Icm/Dot effectors: LegK3 and a previously uncharacterized effector which we named CegK3, as well as a LuxR type regulator, which we named RegK3. Analysis of this island in different Legionella species revealed a conserved regulatory element located upstream to the effector-encoding genes in the island. Further analyses, including gene expression analysis, mutagenesis of the RegK3 regulatory element, controlled expression studies, and gel-mobility shift assays, all demonstrate that RegK3 directly activates the expression levels of legK3 and cegK3 effector-encoding genes. Additionally, the expression of all the components of the island is silenced by the Fis repressors. Comparison of expression profiles of these three genes among different Legionella species revealed variability in the activation levels mediated by RegK3, which were positively correlated with the Fis-mediated repression. Furthermore, LegK3 and CegK3 effectors moderately inhibit yeast growth, and importantly, they have a strong synergistic inhibitory effect on yeast growth, suggesting these two effectors are not only co-regulated but also might function together.
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المؤلفون: Bo Duan, William Wiley Navarre, Bin Xia, Jun Liu, Pengfei Ding
المصدر: Molecular Biology and Evolution
مصطلحات موضوعية: DNA, Bacterial, Gene Transfer, Horizontal, Review, Bacterial genome size, Biology, AcademicSubjects/SCI01180, medicine.disease_cause, DNA sequencing, H-NS/MvaT/Lsr2/Rok, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Bacterial Proteins, Transcription (biology), Genetics, medicine, Humans, Gene silencing, Gene Silencing, Molecular Biology, Escherichia coli, Gene, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, bacterial genome evolution, AcademicSubjects/SCI01130, DNA, DNA-Binding Proteins, xenogeneic silencer, DNA-binding mechanism, chemistry, Horizontal gene transfer, bacterial genomic AT content, horizontal gene transfer, Genome, Bacterial, 030217 neurology & neurosurgery
الوصف: Horizontal gene transfer (HGT) is a major driving force for bacterial evolution. To avoid the deleterious effects due to the unregulated expression of newly acquired foreign genes, bacteria have evolved specific proteins named xenogeneic silencers to recognize foreign DNA sequences and suppress their transcription. As there is considerable diversity in genomic base compositions among bacteria, how xenogeneic silencers distinguish self- from nonself DNA in different bacteria remains poorly understood. This review summarizes the progress in studying the DNA binding preferences and the underlying molecular mechanisms of known xenogeneic silencer families, represented by H-NS of Escherichia coli, Lsr2 of Mycobacterium, MvaT of Pseudomonas, and Rok of Bacillus. Comparative analyses of the published data indicate that the differences in DNA recognition mechanisms enable these xenogeneic silencers to have clear characteristics in DNA sequence preferences, which are further correlated with different host genomic features. These correlations provide insights into the mechanisms of how these xenogeneic silencers selectively target foreign DNA in different genomic backgrounds. Furthermore, it is revealed that the genomic AT contents of bacterial species with the same xenogeneic silencer family proteins are distributed in a limited range and are generally lower than those species without any known xenogeneic silencers in the same phylum/class/genus, indicating that xenogeneic silencers have multifaceted roles on bacterial genome evolution. In addition to regulating horizontal gene transfer, xenogeneic silencers also act as a selective force against the GC to AT mutational bias found in bacterial genomes and help the host genomic AT contents maintained at relatively low levels.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b51d6b469d59f4d8535220fcf4915b0e
https://doi.org/10.1093/molbev/msab136 -
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المؤلفون: Moly Ba, Victoria Schmidt, Sophie de Bentzmann, Gaël Chambonnier, Corinne Sebban-Kreuzer, Christophe Bordi, Gauthier Dangla-Pélissier, Caroline Giraud, Nicolas Roux
المساهمون: Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Dynamique cellulaire et moléculaire de la muqueuse respiratoire, Université de Reims Champagne-Ardenne (URCA)-IFR53-Institut National de la Santé et de la Recherche Médicale (INSERM), Unité de Recherche Risques Microbiens (U2RM), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Schmidt, Victoria
المصدر: Nucleic Acids Research
Nucleic Acids Research, 2021, 49 (19), pp.10956-10974. ⟨10.1093/nar/gkab827⟩مصطلحات موضوعية: MESH: Chromosomes, Bacterial, Gene Transfer, Horizontal, Genomic Islands, Transcription, Genetic, AcademicSubjects/SCI00010, Virulence Factors, MESH: Trans-Activators, Virulence, MESH: Biofilms, Biology, medicine.disease_cause, Genome, Regulon, MESH: Gene Expression Profiling, Bacterial Proteins, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Genetics, medicine, MESH: Genomic Islands, Gene, MESH: Bacterial Proteins, MESH: Virulence Factors, MESH: Gene Expression Regulation, Bacterial, Pseudomonas aeruginosa, Gene Expression Profiling, MESH: Transcription, Genetic, Gene regulation, Chromatin and Epigenetics, Biofilm, MESH: Conjugation, Genetic, Gene Expression Regulation, Bacterial, Chromosomes, Bacterial, Pathogenicity island, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, MESH: Gene Transfer, Horizontal, MESH: DNA Transposable Elements, Biofilms, Conjugation, Genetic, Horizontal gene transfer, MESH: Pseudomonas aeruginosa, MESH: Regulon, DNA Transposable Elements, Trans-Activators, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
الوصف: Pseudomonas aeruginosa is a major cause of nosocomial infections, particularly in immunocompromised patients or in individuals with cystic fibrosis. Genome sequences reveal that most P. aeruginosa strains contain a significant number of accessory genes gathered in genomic islands. Those genes are essential for P. aeruginosa to invade new ecological niches with high levels of antibiotic usage, like hospitals, or to survive during host infection by providing pathogenicity determinants. P. aeruginosa pathogenicity island 1 (PAPI-1), one of the largest genomic islands, encodes several putative virulence factors, including toxins, biofilm genes and antibiotic-resistance traits. The integrative and conjugative element (ICE) PAPI-1 is horizontally transferable by conjugation via a specialized GI-T4SS, but the mechanism regulating this transfer is currently unknown. Here, we show that this GI-T4SS conjugative machinery is directly induced by TprA, a regulator encoded within PAPI-1. Our data indicate that the nucleotide associated protein NdpA2 acts in synergy with TprA, removing a repressive mechanism exerted by MvaT. In addition, using a transcriptomic approach, we unravelled the regulon controlled by Ndpa2/TprA and showed that they act as major regulators on the genes belonging to PAPI-1. Moreover, TprA and NdpA2 trigger an atypical biofilm structure and enhance ICE PAPI-1 transfer.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::67bf8d73a0b3a9913cc7c579bbab4728
https://hal-amu.archives-ouvertes.fr/hal-03557636 -
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المؤلفون: Misung Kim, Woojun Park, Jaeeun Park
المصدر: Virulence, Vol 12, Iss 1, Pp 150-164 (2021)
Virulence
article-version (VoR) Version of Recordمصطلحات موضوعية: Microbiology (medical), antibiotic resistance, Gene Transfer, Horizontal, medicine.drug_class, Urinary system, Immunology, Antibiotics, Microbial Sensitivity Tests, Infectious and parasitic diseases, RC109-216, Moths, Microbiology, 03 medical and health sciences, Antibiotic resistance, Bacterial Proteins, Drug Resistance, Multiple, Bacterial, medicine, Animals, Humans, polymyxin b-resistance, 030304 developmental biology, whole-genome analysis, 0303 health sciences, biology, 030306 microbiology, Genomics, biology.organism_classification, carbapenem-resistance, Phenotype, Anti-Bacterial Agents, Acinetobacter baumannii, Infectious Diseases, Biofilms, Larva, Urinary Tract Infections, Horizontal gene transfer, horizontal gene transfer, Parasitology, acinetobacter baumannii, Multidrug resistant Acinetobacter baumannii, Genome, Bacterial, Polymyxin B, Research Article, Research Paper, Acinetobacter Infections, medicine.drug
الوصف: Polymyxin B (PMB) is increasingly used as a last-line antibiotic; however, the emergence of PMB resistance is a serious threat to global health. Here, a total of 40 Acinetobacter baumannii clinical isolates were collected to screen for PMB-resistant strains. Several clinical isolates including NCCP 16007 were far more resistant to PMB (MIC: 128–256 μg/ml) than the ATCC 17978 strain (MIC: 2 μg/ml) and appeared to possess resistance to broad-spectrum antibiotics including meropenem and 12 others. Four highly PMB-resistant strains possessed point mutations in the histidine kinase PmrB, leading to an increased expression of pmrC encoding a phosphoethanolamine transferase. Whole-genome analyses revealed that the NCCP 16007 stain had acquired two additional copies of the pmrC gene with phage integrase and 13 antibiotic resistance genes (ARGs) from other pathogens, including Klebsiella pneumoniae and Pseudomonas aeruginosa. The GC ratios of the ARGs (50–60%) were higher than that of the chromosomal backbone (39.06%), further supporting the horizontal gene transfer of ARGs. Comparative genomics with other multidrug-resistant A. baumannii strains revealed that the NCCP 16007 strain has many additional ARGs and has lost several virulence factors including Csu pili and heme oxygenase but exhibited high pathogenicity in Galleria mellonella-infection models. The observation of condensed biofilm through confocal and scanning electron microscopy suggested that the NCCP 16007 strain may possess high adhesion capacity during urinary tract infection. Therefore, our genomic and phenotypic analyses suggested that the multidrug-resistant A. baumannii NCCP 16007 strain possesses high genome plasticity, natural transformation ability, and pathogenicity.
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المؤلفون: Zachary C. Ruhe, David A. Low, Christopher S. Hayes
المصدر: Annu Rev Microbiol
Annual review of microbiology, vol 74, iss 1مصطلحات موضوعية: Gene Transfer, Horizontal, Bacterial Toxins, Gene Transfer, colicins, type VI secretion system, outer membrane exchange, Biology, Microbiology, Article, Horizontal, 03 medical and health sciences, Bacterial Proteins, Immunity, Esx-like secretion system, Genetics, ESS, OME, Clade, 030304 developmental biology, Type VI secretion system, 0303 health sciences, Bacteria, 030306 microbiology, Effector, Mechanism (biology), contact-dependent growth inhibition, Type VI Secretion Systems, biology.organism_classification, MafB, T6SS, Emerging Infectious Diseases, Infectious Diseases, Medical Microbiology, Colicin, Horizontal gene transfer, Microbial Interactions, CDI, Infection, Biotechnology
الوصف: All bacteria must compete for growth niches and other limited environmental resources. These existential battles are waged at several levels, but one common strategy entails the transfer of growth-inhibitory protein toxins between competing cells. These antibacterial effectors are invariably encoded with immunity proteins that protect cells from intoxication by neighboring siblings. Several effector classes have been described, each designed to breach the cell envelope of target bacteria. Although effector architectures and export pathways tend to be clade specific, phylogenetically distant species often deploy closely related toxin domains. Thus, diverse competition systems are linked through a common reservoir of toxin-immunity pairs that is shared via horizontal gene transfer. These toxin-immunity protein pairs are extraordinarily diverse in sequence, and this polymorphism underpins an important mechanism of self/nonself discrimination in bacteria. This review focuses on the structures, functions, and delivery mechanisms of polymorphic toxin effectors that mediate bacterial competition.
وصف الملف: application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f3c03f823bc7b2660d908c14178a1993
https://doi.org/10.1146/annurev-micro-020518-115638 -
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المؤلفون: Yisong, Li, Ying, Huang
المصدر: Microbiology Spectrum
مصطلحات موضوعية: Gene Transfer, Horizontal, sialic acid catabolism, N-Acetylneuraminic Acid, Actinobacteria, Evolution, Molecular, Bacterial Proteins, Multigene Family, evolution, distribution, Animals, Humans, horizontal gene transfer, environmental adaptation, free-living species, Genome, Bacterial, Phylogeny, Research Article
الوصف: Sialic acids are present in humans and other metazoans, playing essential roles in physiological and pathological processes. Commensal and pathogenic bacteria have evolved the capacity to utilize sialic acids as nutrient and energy sources. However, in some actinobacteria, sialic acid catabolism (SAC) is associated with free-living populations. To unravel the distribution and evolutionary history of SAC in the phylum Actinobacteria, we analyzed the presence and diversity of the putative SAC gene cluster (nan) in 7,180 high-quality, nonredundant actinobacterial genomes that covered 1,969 species. The results showed that ∼13% of actinobacterial species had the potential to utilize sialic acids, with 45 species capable of anhydro-SAC, all except two of them through the canonical pathway. These species belonged to 20 orders and 81 genera, with ∼36% of them from four genera, Actinomyces, Bifidobacterium, Corynebacterium, and Streptomyces. Moreover, ∼40% of the nan-positive species are free living. Phylogenetic analysis of the key nan genes, nanA, nanK, and nanE, revealed a strong signal of horizontal gene transfer (HGT), accompanied with vertical inheritance and gene loss. This evolutionary pattern led to high diversity and differential distribution of nan among actinobacterial taxa and might cause the cluster to spread to some free-living species while losing in some host-associated species. The evolution of SAC in actinobacteria probably represents the evolution of certain kinds of noncore bacterial functions for environmental adaptation and lifestyle switch, in which HGT plays a dominant role. IMPORTANCE Sialic acids play essential roles in the physiology of humans and other metazoan animals, and microbial sialic acid catabolism (SAC) is one of the processes critical for pathogenesis. To date, microbial SAC is studied mainly in commensals and pathogens, while its distribution in free-living microbes and evolutionary pathway remain largely unexplored. Here, by examining all actinobacterial genomes available, we demonstrate that putative SAC is present in a small proportion of actinobacterial species, of which, however, ∼40% are free-living species. We also reveal remarkable difference in the distribution of SAC among actinobacterial taxa and high diversity of the putative SAC gene clusters. HGT plays a significant role in the evolution of SAC, accompanied with vertical inheritance and gene loss. Our results provide a comprehensive and systematic picture of the distribution and evolutionary history of SAC in actinobacteria, expanding the current knowledge on bacterial adaptation and diversification.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=pmid________::8af71ba48ee4874431cefa171d4cb999
https://pubmed.ncbi.nlm.nih.gov/35019771 -
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المؤلفون: Thomas E. Smith, Mijoon Lee, Maria D. Person, Dusan Hesek, Shahriar Mobashery, Nancy A. Moran
المصدر: mBio
mBio, Vol 12, Iss 6 (2021)مصطلحات موضوعية: Gene Transfer, Horizontal, enzyme promiscuity, food and beverages, N-Acetylmuramoyl-L-alanine Amidase, Peptidoglycan, pea aphid, biochemical phenomena, metabolism, and nutrition, Microbiology, QR1-502, symbiosis, carboxypeptidase, Bacterial Proteins, Buchnera, Cell Wall, Virology, Aphids, Animals, Insect Proteins, horizontal gene transfer, multifunctional, endopeptidase, Research Article
الوصف: During evolution, enzymes can undergo shifts in preferred substrates or in catalytic activities. An intriguing question is how enzyme function changes following horizontal gene transfer, especially for bacterial genes that have moved to animal genomes. Some insects have acquired genes that encode enzymes for the biosynthesis of bacterial cell wall components and that appear to function to support or control their obligate endosymbiotic bacteria. In aphids, the bacterial endosymbiont Buchnera aphidicola provides essential amino acids for aphid hosts but lacks most genes for remodeling of the bacterial cell wall. The aphid genome has acquired seven genes with putative functions in cell wall metabolism that are primarily expressed in the aphid cells harboring Buchnera. In analyses of aphid homogenates, we detected peptidoglycan (PGN) muropeptides indicative of the reactions of PGN hydrolases encoded by horizontally acquired aphid genes but not by Buchnera genes. We produced one such host enzyme, ApLdcA, and characterized its activity with both cell wall derived and synthetic PGN. Both ApLdcA and the homologous enzyme in Escherichia coli, which functions as an l,d-carboxypeptidase in the cytoplasmic PGN recycling pathway, exhibit turnover of PGN substrates containing stem pentapeptides and cross-linkages via l,d-endopeptidase activity, consistent with a potential role in cell wall remodeling. Our results suggest that ApLdcA derives its functions from the promiscuous activities of an ancestral LdcA enzyme, whose acquisition by the aphid genome may have enabled hosts to influence Buchnera cell wall metabolism as a means to control symbiont growth and division. IMPORTANCE Most enzymes are capable of performing biologically irrelevant side reactions. During evolution, promiscuous enzyme activities may acquire new biological roles, especially after horizontal gene transfer to new organisms. Pea aphids harbor obligate bacterial symbionts called Buchnera and encode horizontally acquired bacterial genes with putative roles in cell wall metabolism. Though Buchnera lacks cell wall endopeptidase genes, we found evidence of endopeptidase activity among peptidoglycan muropeptides purified from aphids. We characterized a multifunctional, aphid-encoded enzyme, ApLdcA, which displays l,d-endopeptidase activities considered promiscuous for the Escherichia coli homolog, for which these activities do not contribute to its native role in peptidoglycan recycling. These results exemplify the roles of enzyme promiscuity and horizontal gene transfer in enzyme evolution and demonstrate how aphids influence symbiont cell wall metabolism.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c32e17b4dd3f89eda08ee8209c38e183
https://pubmed.ncbi.nlm.nih.gov/34933456 -
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المؤلفون: Paul R. Jensen, Dulce Guillén-Matus, Alexander B. Chase, Douglas Sweeney, Mitchell N. Muskat
المساهمون: Ravel, Jacques
المصدر: mBio
mBio, vol 12, iss 6
mBio, Vol 12, Iss 6 (2021)مصطلحات موضوعية: Gene Transfer, Horizontal, Evolution, Gene Transfer, Secondary Metabolism, homologous recombination, Biology, Diversification (marketing strategy), microbial ecology, Microbiology, Horizontal, Evolution, Molecular, Microbial ecology, Genetic, Bacterial Proteins, Virology, evolution, Genetics, Evolutionary dynamics, Gene, Phylogeny, Salinispora, Recombination, Genetic, Genome, Phylogenetic tree, evolutionary biology, Inheritance (genetic algorithm), Bacterial, Molecular, Micromonosporaceae, QR1-502, Recombination, Biosynthetic Pathways, Evolutionary biology, Multigene Family, Horizontal gene transfer, salinosporamide, Homologous recombination, Genome, Bacterial, Biotechnology, Research Article
الوصف: While specialized metabolites are thought to mediate ecological interactions, the evolutionary processes driving chemical diversification, particularly among closely related lineages, remain poorly understood. Here, we examine the evolutionary dynamics governing the distribution of natural product biosynthetic gene clusters (BGCs) among 118 strains representing all nine currently named species of the marine actinobacterial genus Salinispora. While much attention has been given to the role of horizontal gene transfer (HGT) in structuring BGC distributions, we find that vertical descent facilitates interspecies BGC diversification over evolutionary timescales. Moreover, we identified a distinct phylogenetic signal among Salinispora species at both the BGC and metabolite level, indicating that specialized metabolism represents a conserved phylogenetic trait. Using a combination of genomic analyses and liquid chromatography–high-resolution tandem mass spectrometry (LC-MS/MS) targeting nine experimentally characterized BGCs and their small molecule products, we identified gene gain/loss events, constrained interspecies recombination, and other evolutionary processes associated with vertical inheritance as major contributors to BGC diversification. These evolutionary dynamics had direct consequences for the compounds produced, as exemplified by species-level differences in salinosporamide production. Together, our results support the concept that specialized metabolites, and their cognate BGCs, can represent phylogenetically conserved functional traits with chemical diversification proceeding in species-specific patterns over evolutionary time frames. IMPORTANCE Microbial natural products are traditionally exploited for their pharmaceutical potential, yet our understanding of the evolutionary processes driving BGC evolution and compound diversification remain poorly developed. While HGT is recognized as an integral driver of BGC distributions, we find that the effects of vertical inheritance on BGC diversification had direct implications for species-level specialized metabolite production. As such, understanding the degree of genetic variation that corresponds to species delineations can enhance natural product discovery efforts. Resolving the evolutionary relationships between closely related strains and specialized metabolism can also facilitate our understanding of the ecological roles of small molecules in structuring the environmental distribution of microbes.
وصف الملف: application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a4ec571370636bc7066b7d3270a6b81e
https://pubmed.ncbi.nlm.nih.gov/34809466 -
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المؤلفون: Maria Fernanda Campagnari Bueno, Louise Cerdeira, Gabriela Rodrigues Francisco, Alexandra L. Gerber, Tiago Casella, Ana Tereza Ribeiro de Vasconcelos, Cassia Fernanda Estofolete, Evelin Rodrigues Martins, Nilton Lincopan, Mara Corrêa Lelles Nogueira, Doroti de Oliveira Garcia, Luiz Gonzaga Paula de Almeida
المصدر: Journal of Global Antimicrobial Resistance, Vol 20, Iss, Pp 36-40 (2020)
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USPمصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Transposable element, Gene Transfer, Horizontal, 030106 microbiology, Immunology, Enterobacter, Context (language use), Biology, medicine.disease_cause, Genome, Enterobacter hormaechei, Microbiology, rmtG, 03 medical and health sciences, 0302 clinical medicine, Plasmid, Antibiotic resistance, 16S rRNA methyltransferase, Bacterial Proteins, ENTEROBACTERIACEAE, medicine, Humans, Immunology and Allergy, 030212 general & internal medicine, Aminoglycoside resistance, Gene, Escherichia coli, Genetics, Whole Genome Sequencing, Enterobacteriaceae Infections, High-Throughput Nucleotide Sequencing, Methyltransferases, Chromosomes, Bacterial, QR1-502, Urinary Tract Infections, Horizontal gene transfer, Brazil, Plasmids
الوصف: Objectives Enterobacter hormaechei is an important causative agent of severe infections in critically ill patients. Aminoglycosides are among the main antibiotics for the treatment of E. hormaechei infections, however the development of antimicrobial resistance is an increasing problem. RmtG is a 16S rRNA methyltransferase, a class of enzymes conferring high-level resistance to clinically relevant aminoglycosides. The aim of this study was to characterise the full genetic context of plasmids harbouring the rmtG gene in two aminoglycoside-resistant E. hormaechei isolated in Brazil. Methods ThermtG-harbouring plasmids were transferred to an Escherichia coli J53 recipient strain and were fully sequenced using a MiSeq sequencing system. Complete genome assemblies were accomplished using a combination of Newbler v.3.0, SPAdes 3.10.0 and phrap/cross_match programs. Plasmid sequences were annotated using RAST server and were then manually curated using BLAST databases and ISfinder. Easyfig 2.0 was used to map and compare regions of interest containing rmtG in both plasmids. Results Both isolates carried thermtG gene on an IncA/C plasmid of ˜152 kb and ˜235 kb, respectively, associated with a Tn3 transposon. The plasmids contain a transfer region as well as genes involved in plasmid stability and resistance to β-lactams, sulfonamides and quaternary ammonium compounds. One of the plasmids also carried the mrk operon encoding type 3 fimbriae. Conclusion This first detection ofrmtG in E. hormaechei supports the ability for horizontal transfer. The location in complex genetic platforms carried by Tn3 transposons in IncA/C plasmids may facilitate dissemination to other Gram-negative pathogens, further limiting treatment options.
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