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Nohejl T, Palkovicova J, Nesporova K, Valcek A, Lausova J, Dolejska M. Broad-Host Dissemination of Plasmids Coharboring the fos Operon for Fructooligosaccharide Metabolism with Antibiotic Resistance Genes. Appl Environ Microbiol 2023; 89:e0037123. [PMID: 37578374 PMCID: PMC10467340 DOI: 10.1128/aem.00371-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 07/04/2023] [Indexed: 08/15/2023] Open
Abstract
The fos operon encoding short-chain fructooligosaccharide (scFOS) utilization enables bacteria of the family Enterobacteriaceae to grow and be sustained in environments where they would struggle to survive. Despite several cases of the detection of the fos operon in isolates of avian and equine origins, its global distribution in bacterial genomes remains unknown. The presence of the plasmid-harbored fos operon among resistant bacteria may promote the spread of antibiotic resistance. A collection of 11,538 antimicrobial-resistant Enterobacteriaceae isolates from various sources was screened for the fosT gene encoding the scFOS transporter. Out of 307 fosT-positive isolates, 80% of them originated from sources not previously linked to fosT (humans, wastewater, and animals). The chromosomally harbored fos operon was detected in 163/237 isolates subjected to whole-genome sequencing. In the remaining 74 isolates, the operon was carried by plasmids. Further analyses focusing on the isolates with a plasmid-harbored fos operon showed that the operon was linked to various incompatibility (Inc) groups, including the IncHI1, IncF-type, IncK2, IncI1, and IncY families. Long-read sequencing of representative plasmids showed the colocalization of fos genes with antibiotic resistance genes (ARGs) in IncHI1 (containing a multidrug resistance region), IncK2 (blaTEM-1A), IncI1 [sul2 and tet(A)], and IncY [aadA5, dfrA17, sul2, and tet(A)] plasmids, while IncF-type plasmids had no ARGs but coharbored virulence-associated genes. Despite the differences in the locations and structures of the fos operons, all isolates except one were proven to utilize scFOSs. In this study, we show that the fos operon and its spread are not strictly bound to one group of plasmids, and therefore, it should not be overlooked. IMPORTANCE It was believed that members of the family Enterobacteriaceae are unable to grow under conditions with short-chain fructooligosaccharides as the only source of carbon. Nevertheless, the first Escherichia coli isolate from chicken intestine was able to utilize these sugars owing to the chromosomally harbored fos operon. Studies on E. coli isolates from horses discovered the horizontal transfer of the fos operon on IncHI1 plasmids along with genes for antibiotic resistance. The first plasmid detected was pEQ1, originating from the feces of a hospitalized horse in the Czech Republic. Follow-up studies also revealed the dissemination of the IncHI1 plasmid-harbored fos operon in the Netherlands, Germany, Denmark, and France among healthy horses. Despite several cases of detection of the fos operon, its global distribution in bacterial genomes remains unknown. The fos operon possibly plays a role in the adaptation of plasmids among resistant bacteria and therefore may promote the spread of antibiotic resistance.
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Affiliation(s)
- Tomas Nohejl
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic
- CEITEC, University of Veterinary Sciences Brno, Brno, Czech Republic
| | - Jana Palkovicova
- CEITEC, University of Veterinary Sciences Brno, Brno, Czech Republic
| | | | - Adam Valcek
- CEITEC, University of Veterinary Sciences Brno, Brno, Czech Republic
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Jarmila Lausova
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic
- CEITEC, University of Veterinary Sciences Brno, Brno, Czech Republic
| | - Monika Dolejska
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic
- CEITEC, University of Veterinary Sciences Brno, Brno, Czech Republic
- Department of Clinical Microbiology and Immunology, Institute of Laboratory Medicine, The University Hospital Brno, Brno, Czech Republic
- Faculty of Medicine, Biomedical Center, Charles University, Pilsen, Czech Republic
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Rauthan K, Joshi S, Kumar L, Goel D, Kumar S. Functional annotation of uncharacterized proteins from Fusobacterium nucleatum: identification of virulence factors. Genomics Inform 2023; 21:e21. [PMID: 37415454 PMCID: PMC10326533 DOI: 10.5808/gi.22065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 07/08/2023] Open
Abstract
Fusobacterium nucleatum is a gram-negative bacteria associated with diverse infections like appendicitis and colorectal cancer. It mainly attacks the epithelial cells in the oral cavity and throat of the infected individual. It has a single circular genome of 2.7 Mb. Many proteins in F. nucleatum genome are listed as "Uncharacterized." Annotation of these proteins is crucial for obtaining new facts about the pathogen and deciphering the gene regulation, functions, and pathways along with discovery of novel target proteins. In the light of new genomic information, an armoury of bioinformatic tools were used for predicting the physicochemical parameters, domain and motif search, pattern search, and localization of the uncharacterized proteins. The programs such as receiver operating characteristics determine the efficacy of the databases that have been employed for prediction of different parameters at 83.6%. Functions were successfully assigned to 46 uncharacterized proteins which included enzymes, transporter proteins, membrane proteins, binding proteins, etc. Apart from the function prediction, the proteins were also subjected to string analysis to reveal the interacting partners. The annotated proteins were also put through homology-based structure prediction and modeling using Swiss PDB and Phyre2 servers. Two probable virulent factors were also identified which could be investigated further for potential drug-related studies. The assigning of functions to uncharacterized proteins has shown that some of these proteins are important for cell survival inside the host and can act as effective drug targets.
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Affiliation(s)
- Kanchan Rauthan
- Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhnd 246174, India
| | - Saranya Joshi
- Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhnd 246174, India
| | - Lokesh Kumar
- Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhnd 246174, India
| | - Divya Goel
- Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhnd 246174, India
| | - Sudhir Kumar
- Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhnd 246174, India
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Bisaro F, Shuman HA, Feldman MF, Gebhardt MJ, Pukatzki S. Acinetobacter baumannii ATCC 17978 encodes a microcin system with antimicrobial properties for contact-independent competition. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001346. [PMID: 37289493 PMCID: PMC10333792 DOI: 10.1099/mic.0.001346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 05/25/2023] [Indexed: 06/09/2023]
Abstract
Acinetobacter baumannii is a multidrug-resistant opportunistic pathogen that persists in the hospital environment and causes various clinical infections, primarily affecting immunocompromised patients. A. baumannii has evolved a wide range of mechanisms to compete with neighbouring bacteria. One such competition strategy depends on small secreted peptides called microcins, which exert antimicrobial effects in a contact-independent manner. Here, we report that A. baumannii ATCC 17978 (AB17978) encodes the class II microcin 17 978 (Mcc17978) with antimicrobial activity against closely related Acinetobacter, and surprisingly, also Escherichia coli strains. We identified the genetic locus encoding the Mcc17978 system in AB17978. Using classical bacterial genetic approaches, we determined that the molecular receptor of Mcc17978 in E. coli is the iron-catecholate transporter Fiu, and in Acinetobacter is Fiu's homolog, PiuA. In bacteria, the Ferric uptake regulator (Fur) positively regulates siderophore systems and microcin systems under iron-deprived environments. We found that the Mcc17978 system is upregulated under low-iron conditions commonly found in the host environment and identified a putative Fur binding site upstream of the mcc17978 gene. When we tested the antimicrobial activity of Mcc17978 under different levels of iron availability, we observed that low iron levels not only triggered transcriptional induction of the microcin, but also led to enhanced microcin activity. Taken together, our findings suggest that A. baumannii may utilize microcins to compete with other microbes for resources during infection.
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Affiliation(s)
- Fabiana Bisaro
- Department of Biology, The City College, City University of New York, New York, NY 10031, USA
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis MO 63110, USA
| | - Howard A. Shuman
- Department of Microbiology, The University of Chicago, Chicago, IL 60637, USA
- Present address: P.O. Box 1088, Sheffield, MA 01257, USA
| | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis MO 63110, USA
| | - Michael J. Gebhardt
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa 52242, USA
| | - Stefan Pukatzki
- Department of Biology, The City College, City University of New York, New York, NY 10031, USA
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Prevalence of Potential Pathogenic and Antimicrobial Resistant Escherichia coli in Danish Broilers. Antibiotics (Basel) 2023; 12:antibiotics12020344. [PMID: 36830255 PMCID: PMC9952160 DOI: 10.3390/antibiotics12020344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/03/2023] [Accepted: 02/05/2023] [Indexed: 02/10/2023] Open
Abstract
Avian pathogenic Escherichia coli (APEC) are important bacteria in broiler production in terms of economy, welfare, and use of antibiotics. During a previous outbreak of APEC in the Nordic countries, it was suggested that the pathogenic clones of E. coli causing the outbreak originated from grandparent stock and were transmitted to the offspring, causing increased first week mortality. This study investigated whether the pathogenic potential of E. coli at the parent and broiler level differs in relation to pathogenic potential described by the level of virulence-associated genes and pattern of antimicrobial resistance. The hypothesis was that, due to higher biosecurity at the parent level, the E. coli population will show a lower level of antimicrobial resistance and carry fewer virulence-associated genes, as a result of fewer E. coli infections observed. From four parent flocks and eight broiler flocks, 715 E. coli were isolated from cloacal swabs of newly hatched chickens (Ross 308). The isolated E. coli were characterized by eight virulence-associated genes and phenotypic resistance against six antimicrobials. It was found that the prevalence of virulence-associated genes and phenotypic antimicrobial resistance varied significantly between flocks, and the virulence-associated genes papC and irp2 and resistance against ampicillin were significantly more prevalent in breeder flocks compared to broiler flocks.
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Abstract
Microcins are a class of antimicrobial peptides produced by certain Gram-negative bacterial species to kill or inhibit the growth of competing bacteria. Only 10 unique, experimentally validated class II microcins have been identified, and the majority of these come from Escherichia coli. Although the current representation of microcins is sparse, they exhibit a diverse array of molecular functionalities, uptake mechanisms, and target specificities. This broad diversity from such a small representation suggests that microcins may have untapped potential for bioprospecting peptide antibiotics from genomic data sets. We used a systematic bioinformatics approach to search for verified and novel class II microcins in E. coli and other species within its family, Enterobacteriaceae. Nearly one-quarter of the E. coli genome assemblies contained one or more microcins, where the prevalence of hits to specific microcins varied by isolate phylogroup. E. coli isolates from human extraintestinal and poultry meat sources were enriched for microcins, while those from freshwater were depleted. Putative microcins were found in various abundances across all five distinct phylogenetic lineages of Enterobacteriaceae, with a particularly high prevalence in the "Klebsiella" clade. Representative genome assemblies from species across the Enterobacterales order, as well as a few outgroup species, also contained putative microcin sequences. This study suggests that microcins have a complicated evolutionary history, spanning far beyond our limited knowledge of the currently validated microcins. Efforts to functionally characterize these newly identified microcins have great potential to open a new field of peptide antibiotics and microbiome modulators and elucidate the ways in which bacteria compete with each other. IMPORTANCE Class II microcins are small bacteriocins produced by strains of Gram-negative bacteria in the Enterobacteriaceae. They are generally understood to play a role in interbacterial competition, although direct evidence of this is limited, and they could prove informative in developing new peptide antibiotics. However, few examples of verified class II microcins exist, and novel microcins are difficult to identify due to their sequence diversity, making it complicated to study them as a group. Here, we overcome this limitation by developing a bioinformatics pipeline to detect microcins in silico. Using this pipeline, we demonstrate that both verified and novel class II microcins are widespread within and outside the Enterobacteriaceae, which has not been systematically shown previously. The observed prevalence of class II microcins suggests that they are ecologically important, and the elucidation of novel microcins provides a resource that can be used to expand our knowledge of the structure and function of microcins as antibacterials.
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Wang H, Wang X, Wang L, Lu Z. Nutritional stress induced intraspecies competition revealed by transcriptome analysis in Sphingomonas melonis TY. Appl Microbiol Biotechnol 2022; 106:5675-5686. [PMID: 35927333 DOI: 10.1007/s00253-022-12097-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 11/26/2022]
Abstract
Bacteria have developed various mechanisms by which they can compete or cooperate with other bacteria. This study showed that in the cocultures of wild-type Sphingomonas melonis TY and its isogenic mutant TYΔndpD grow with nicotine, the former can outcompete the latter. TYΔndpD undergoes growth arrest after four days when cocultured with wild-type TY, whereas the coculture has just entered a stationary phase and the substrate was nearly depleted, and the interaction between the two related strains was revealed by transcriptomic analysis. Analysis of the differential expression genes indicated that wild-type TY inhibited the growth of TYΔndpD mainly through toxin-antitoxin (TA) systems. The four upregulated antitoxin coding genes belong to type II TA systems in which the bactericidal effect of the cognate toxin was mainly through inhibition of translation or DNA replication, whereas wild-type TY with upregulated antitoxin genes can regenerate cognate immunity protein continuously and thus prevent the lethal action of toxin to itself. In addition, colicin-mediated antibacterial activity against closely related species may also be involved in the competition between wild-type TY and TYΔndpD under nutritional stress. Moreover, upregulation of carbon and nitrogen catabolism related-, stress response related-, DNA repair related-, and DNA replication-related genes in wild-type TY showed that it triggered a series of response mechanisms when facing dual stress of competition from isogenic mutant cells and nutritional limitation. Thus, we proposed that S. melonis TY employed the TA systems and colicin to compete with TYΔndpD under nutritional stress, thereby maximally acquiring and exploiting finite resources. KEY POINTS: • Cross-feeding between isogenic mutants and the wild-type strain. • Nutrition stress caused a shift from cooperation to competition. • TYΔndpD undergo growth arrest by exogenous and endogenous toxins.
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Affiliation(s)
- Haixia Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xiaoyu Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Lvjing Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zhenmei Lu
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.
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7
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Kuhl-Nagel T, Rodriguez PA, Gantner I, Chowdhury SP, Schwehn P, Rosenkranz M, Weber B, Schnitzler JP, Kublik S, Schloter M, Rothballer M, Falter-Braun P. Novel Pseudomonas sp. SCA7 Promotes Plant Growth in Two Plant Families and Induces Systemic Resistance in Arabidopsis thaliana. Front Microbiol 2022; 13:923515. [PMID: 35875540 PMCID: PMC9297469 DOI: 10.3389/fmicb.2022.923515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas sp. SCA7, characterized in this study, was isolated from roots of the bread wheat Triticum aestivum. Sequencing and annotation of the complete SCA7 genome revealed that it represents a potential new Pseudomonas sp. with a remarkable repertoire of plant beneficial functions. In vitro and in planta experiments with the reference dicot plant A. thaliana and the original monocot host T. aestivum were conducted to identify the functional properties of SCA7. The isolate was able to colonize roots, modify root architecture, and promote growth in A. thaliana. Moreover, the isolate increased plant fresh weight in T. aestivum under unchallenged conditions. Gene expression analysis of SCA7-inoculated A. thaliana indicated a role of SCA7 in nutrient uptake and priming of plants. Moreover, confrontational assays of SCA7 with fungal and bacterial plant pathogens revealed growth restriction of the pathogens by SCA7 in direct as well as indirect contact. The latter indicated involvement of microbial volatile organic compounds (mVOCs) in this interaction. Gas chromatography-mass spectrometry (GC-MS) analyses revealed 1-undecene as the major mVOC, and octanal and 1,4-undecadiene as minor abundant compounds in the emission pattern of SCA7. Additionally, SCA7 enhanced resistance of A. thaliana against infection with the plant pathogen Pseudomonas syringae pv. tomato DC3000. In line with these results, SA- and JA/ET-related gene expression in A. thaliana during infection with Pst DC3000 was upregulated upon treatment with SCA7, indicating the ability of SCA7 to induce systemic resistance. The thorough characterization of the novel Pseudomonas sp. SCA7 showed a remarkable genomic and functional potential of plant beneficial traits, rendering it a promising candidate for application as a biocontrol or a biostimulation agent.
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Affiliation(s)
- Theresa Kuhl-Nagel
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Patricia Antonia Rodriguez
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Isabella Gantner
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Microbe-Host Interactions, Faculty of Biology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Soumitra Paul Chowdhury
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Patrick Schwehn
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Maaria Rosenkranz
- Institute of Biochemical Plant Pathology, Research Unit Environmental Simulation, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Baris Weber
- Institute of Biochemical Plant Pathology, Research Unit Environmental Simulation, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Jörg-Peter Schnitzler
- Institute of Biochemical Plant Pathology, Research Unit Environmental Simulation, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Susanne Kublik
- Research Unit for Comparative Microbiome Analysis (COMI), Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis (COMI), Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Michael Rothballer
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Pascal Falter-Braun
- Institute for Network Biology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Microbe-Host Interactions, Faculty of Biology, Ludwig-Maximilians-University of Munich, Munich, Germany
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Parker JK, Davies BW. Microcins reveal natural mechanisms of bacterial manipulation to inform therapeutic development. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001175. [PMID: 35438625 PMCID: PMC10233263 DOI: 10.1099/mic.0.001175] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/17/2022] [Indexed: 12/20/2022]
Abstract
Microcins are an understudied and poorly characterized class of antimicrobial peptides. Despite the existence of only 15 examples, all identified from the Enterobacteriaceae, microcins display diversity in sequence, structure, target cell uptake, cytotoxic mechanism of action and target specificity. Collectively, these features describe some of the unique means nature has contrived for molecules to cross the 'impermeable' barrier of the Gram-negative bacterial outer membrane and inflict cytotoxic effects. Microcins appear to be widely dispersed among different species and in different environments, where they function in regulating microbial communities in diverse ways, including through competition. Growing evidence suggests that microcins may be adapted for therapeutic uses such as antimicrobial drugs, microbiome modulators or facilitators of peptide uptake into cells. Advancing our biological, ecological and biochemical understanding of the roles of microcins in bacterial interactions, and learning how to regulate and modify microcin activity, is essential to enable such therapeutic applications.
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Affiliation(s)
| | - Bryan William Davies
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- John Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, USA
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The conserved serine transporter SdaC moonlights to enable self recognition. J Bacteriol 2021; 204:e0034721. [PMID: 34662238 DOI: 10.1128/jb.00347-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cells can use self recognition to achieve cooperative behaviors. Self-recognition genes are thought to principally evolve in tandem with partner self-recognition alleles. However, other constraints on protein evolution could exist. Here, we have identified an interaction outside of self-recognition loci that could constrain the sequence variation of a self-recognition protein. We show that during collective swarm expansion in Proteus mirabilis, self-recognition signaling co-opts SdaC, a serine transporter. Serine uptake is crucial for bacterial survival and colonization. Single-residue variants of SdaC reveal that self recognition requires an open conformation of the protein; serine transport is dispensable. A distant ortholog from Escherichia coli is sufficient for self recognition; however, a paralogous serine transporter, YhaO, is not. Thus, SdaC couples self recognition and serine transport, likely through a shared molecular interface. Self recognition proteins may follow the framework of a complex interaction network rather than an isolated two-protein system. Understanding molecular and ecological constraints on self-recognition proteins lays the groundwork for insights into the evolution of self recognition and emergent collective behaviors. Importance Bacteria can receive secret messages from kin during migration. For Proteus mirabilis, these messages are necessary for virulence in multi-species infections. We show that a serine transporter-conserved among gamma-enterobacteria- enables self recognition. Molecular co-option of nutrient uptake could limit the sequence variation of these message proteins. SdaC is the primary transporter for L-serine, a vital metabolite for colonization during disease. Unlike many self-recognition receptors, SdaC is sufficiently conserved between species to achieve recognition. The predicted open conformation is shared by transport and recognition. SdaC reveals the interdependence of communication and nutrient acquisition. As the broader interactions of self-recognition proteins are studied, features shared among microbial self-recognition systems, such as Dictyostelium spp. and Neurospora spp., could emerge.
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Alonso-Reyes DG, Galván FS, Portero LR, Alvarado NN, Farías ME, Vazquez MP, Albarracín VH. Genomic insights into an andean multiresistant soil actinobacterium of biotechnological interest. World J Microbiol Biotechnol 2021; 37:166. [PMID: 34463818 PMCID: PMC8405860 DOI: 10.1007/s11274-021-03129-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/14/2021] [Indexed: 12/01/2022]
Abstract
Central-Andean Ecosystems (between 2000 and 6000 m above sea level (masl) are typical arid-to-semiarid environments suffering from the highest total solar and ultraviolet-B radiation on the planet but displaying numerous salt flats and shallow lakes. Andean microbial ecosystems isolated from these environments are of exceptional biodiversity enduring multiple severe conditions. Furthermore, the polyextremophilic nature of the microbes in such ecosystems indicates the potential for biotechnological applications. Within this context, the study undertaken used genome mining, physiological and microscopical characterization to reveal the multiresistant profile of Nesterenkonia sp. Act20, an actinobacterium isolated from the soil surrounding Lake Socompa, Salta, Argentina (3570 masl). Ultravioet-B, desiccation, and copper assays revealed the strain's exceptional resistance to all these conditions. Act20's genome presented coding sequences involving resistance to antibiotics, low temperatures, ultraviolet radiation, arsenic, nutrient-limiting conditions, osmotic stress, low atmospheric-oxygen pressure, heavy-metal stress, and toxic fluoride and chlorite. Act20 can also synthesize proteins and natural products such as an insecticide, bacterial cellulose, ectoine, bacterial hemoglobin, and even antibiotics like colicin V and aurachin C. We also found numerous enzymes for animal- and vegetal-biomass degradation and applications in other industrial processes. The resilience of Act20 and its biotechnologic potential were thoroughly demonstrated in this work.
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Affiliation(s)
- Daniel Gonzalo Alonso-Reyes
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía y Zootecnia, UNT y CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Fátima Silvina Galván
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía y Zootecnia, UNT y CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Luciano Raúl Portero
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía y Zootecnia, UNT y CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Natalia Noelia Alvarado
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía y Zootecnia, UNT y CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - María Eugenia Farías
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Martín P Vazquez
- HERITAS-CONICET, Ocampo 210 bis, Predio CCT, 2000, Rosario, Santa Fe, Argentina
| | - Virginia Helena Albarracín
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía y Zootecnia, UNT y CONICET, San Miguel de Tucumán, Tucumán, Argentina.
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, San Miguel de Tucumán, Tucumán, Argentina.
- Centro Integral de Microscopía Electrónica (CIME, CONICET, UNT), Camino de Sirga s/n. FAZ, Finca El Manantial, 4107, Yerba Buena, Tucumán, Argentina.
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11
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Renoz F, Foray V, Ambroise J, Baa-Puyoulet P, Bearzatto B, Mendez GL, Grigorescu AS, Mahillon J, Mardulyn P, Gala JL, Calevro F, Hance T. At the Gate of Mutualism: Identification of Genomic Traits Predisposing to Insect-Bacterial Symbiosis in Pathogenic Strains of the Aphid Symbiont Serratia symbiotica. Front Cell Infect Microbiol 2021; 11:660007. [PMID: 34268133 PMCID: PMC8275996 DOI: 10.3389/fcimb.2021.660007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/14/2021] [Indexed: 01/10/2023] Open
Abstract
Mutualistic associations between insects and heritable bacterial symbionts are ubiquitous in nature. The aphid symbiont Serratia symbiotica is a valuable candidate for studying the evolution of bacterial symbiosis in insects because it includes a wide diversity of strains that reflect the diverse relationships in which bacteria can be engaged with insects, from pathogenic interactions to obligate intracellular mutualism. The recent discovery of culturable strains, which are hypothesized to resemble the ancestors of intracellular strains, provide an opportunity to study the mechanisms underlying bacterial symbiosis in its early stages. In this study, we analyzed the genomes of three of these culturable strains that are pathogenic to aphid hosts, and performed comparative genomic analyses including mutualistic host-dependent strains. All three genomes are larger than those of the host-restricted S. symbiotica strains described so far, and show significant enrichment in pseudogenes and mobile elements, suggesting that these three pathogenic strains are in the early stages of the adaptation to their host. Compared to their intracellular mutualistic relatives, the three strains harbor a greater diversity of genes coding for virulence factors and metabolic pathways, suggesting that they are likely adapted to infect new hosts and are a potential source of metabolic innovation for insects. The presence in their genomes of secondary metabolism gene clusters associated with the production of antimicrobial compounds and phytotoxins supports the hypothesis that S. symbiotia symbionts evolved from plant-associated strains and that plants may serve as intermediate hosts. Mutualistic associations between insects and bacteria are the result of independent transitions to endosymbiosis initiated by the acquisition of environmental progenitors. In this context, the genomes of free-living S. symbiotica strains provide a rare opportunity to study the inventory of genes held by bacterial associates of insects that are at the gateway to a host-dependent lifestyle.
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Affiliation(s)
- François Renoz
- Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
| | - Vincent Foray
- Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
- Institut de Recherche sur la Biologie de l’insecte, UMR 7261, CNRS, Université de Tours, Tours, France
| | - Jérôme Ambroise
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université catholique de Louvain (UCLouvain), Woluwe-Saint-Lambert, Belgium
| | | | - Bertrand Bearzatto
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université catholique de Louvain (UCLouvain), Woluwe-Saint-Lambert, Belgium
| | - Gipsi Lima Mendez
- Louvain Institute of Biomolecular Science and Technology (LIBST), Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
| | | | - Jacques Mahillon
- Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
| | - Patrick Mardulyn
- Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Luc Gala
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université catholique de Louvain (UCLouvain), Woluwe-Saint-Lambert, Belgium
| | - Federica Calevro
- Univ Lyon, INSA-Lyon, INRAE, BF2i, UMR203, F-69621, Villeurbanne, France
| | - Thierry Hance
- Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
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12
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Warr AR, Giorgio RT, Waldor MK. Genetic analysis of the role of the conserved inner membrane protein CvpA in EHEC resistance to deoxycholate. J Bacteriol 2020; 203:JB.00661-20. [PMID: 33361192 PMCID: PMC8095453 DOI: 10.1128/jb.00661-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 12/15/2020] [Indexed: 12/23/2022] Open
Abstract
The function of cvpA, a bacterial gene predicted to encode an inner membrane protein, is largely unknown. Early studies in E. coli linked cvpA to Colicin V secretion and recent work revealed that it is required for robust intestinal colonization by diverse enteric pathogens. In enterohemorrhagic E. coli (EHEC), cvpA is required for resistance to the bile salt deoxycholate (DOC). Here, we carried out genome-scale transposon-insertion mutagenesis and spontaneous suppressor analysis to uncover cvpA's genetic interactions and identify common pathways that rescue the sensitivity of a ΔcvpA EHEC mutant to DOC. These screens demonstrated that mutations predicted to activate the σE-mediated extracytoplasmic stress response bypass the ΔcvpA mutant's susceptibility to DOC. Consistent with this idea, we found that deletions in rseA and msbB and direct overexpression of rpoE restored DOC resistance to the ΔcvpA mutant. Analysis of the distribution of CvpA homologs revealed that this inner membrane protein is conserved across diverse bacterial phyla, in both enteric and non-enteric bacteria that are not exposed to bile. Together, our findings suggest that CvpA plays a role in cell envelope homeostasis in response to DOC and similar stress stimuli in diverse bacterial species.IMPORTANCE Several enteric pathogens, including Enterohemorrhagic E. coli (EHEC), require CvpA to robustly colonize the intestine. This inner membrane protein is also important for secretion of a colicin and EHEC resistance to the bile salt deoxycholate (DOC), but its function is unknown. Genetic analyses carried out here showed that activation of the σE-mediated extracytoplasmic stress response restored the resistance of a cvpA mutant to DOC, suggesting that CvpA plays a role in cell envelope homeostasis. The conservation of CvpA across diverse bacterial phyla suggests that this membrane protein facilitates cell envelope homeostasis in response to varied cell envelope perturbations.
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Affiliation(s)
- Alyson R Warr
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Disease, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rachel T Giorgio
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Disease, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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13
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Li D, Reid CJ, Kudinha T, Jarocki VM, Djordjevic SP. Genomic analysis of trimethoprim-resistant extraintestinal pathogenic Escherichia coli and recurrent urinary tract infections. Microb Genom 2020; 6:mgen000475. [PMID: 33206038 PMCID: PMC8116683 DOI: 10.1099/mgen.0.000475] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Urinary tract infections (UTIs) are the most common bacterial infections requiring medical attention and a leading justification for antibiotic prescription. Trimethoprim is prescribed empirically for uncomplicated cases. UTIs are primarily caused by extraintestinal pathogenic Escherichia coli (ExPEC) and ExPEC strains play a central role in disseminating antimicrobial-resistance genes worldwide. Here, we describe the whole-genome sequences of trimethoprim-resistant ExPEC and/or ExPEC from recurrent UTIs (67 in total) from patients attending a regional Australian hospital from 2006 to 2008. Twenty-three sequence types (STs) were observed, with ST131 predominating (28 %), then ST69 and ST73 (both 7 %). Co-occurrence of trimethoprim-resistance genes with genes conferring resistance to extended-spectrum β-lactams, heavy metals and quaternary ammonium ions was a feature of the ExPEC described here. Seven trimethoprim-resistance genes were identified, most commonly dfrA17 (38 %) and dfrA12 (18 %). An uncommon dfrB4 variant was also observed. Two blaCTX-M variants were identified - blaCTX-M-15 (16 %) and blaCTX-M-14 (10 %). The former was always associated with dfrA12, the latter with dfrA17, and all blaCTX-M genes co-occurred with chromate-resistance gene chrA. Eighteen class 1 integron structures were characterized, and chrA featured in eight structures; dfrA genes featured in seventeen. ST131 H30Rx isolates possessed distinct antimicrobial gene profiles comprising aac(3)-IIa, aac(6)-Ib-cr, aph(3')-Ia, aadA2, blaCTX-M-15, blaOXA-1 and dfrA12. The most common virulence-associated genes (VAGs) were fimH, fyuA, irp2 and sitA (all 91 %). Virulence profile clustering showed ST131 H30 isolates carried similar VAGs to ST73, ST405, ST550 and ST1193 isolates. The sole ST131 H27 isolate carried molecular predictors of enteroaggregative E. coli/ExPEC hybrid strains (aatA, aggR, fyuA). Seven isolates (10 %) carried VAGs suggesting ColV plasmid carriage. Finally, SNP analysis of serial UTI patients experiencing worsening sequelae demonstrated a high proportion of point mutations in virulence factors.
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Affiliation(s)
- Dmitriy Li
- Ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Cameron J. Reid
- Ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Timothy Kudinha
- NSW Health Pathology, Microbiology, Orange Hospital, Orange, NSW 2800, Australia
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW 2800, Australia
| | - Veronica M. Jarocki
- Ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
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Telhig S, Ben Said L, Zirah S, Fliss I, Rebuffat S. Bacteriocins to Thwart Bacterial Resistance in Gram Negative Bacteria. Front Microbiol 2020; 11:586433. [PMID: 33240239 PMCID: PMC7680869 DOI: 10.3389/fmicb.2020.586433] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/16/2020] [Indexed: 12/16/2022] Open
Abstract
An overuse of antibiotics both in human and animal health and as growth promoters in farming practices has increased the prevalence of antibiotic resistance in bacteria. Antibiotic resistant and multi-resistant bacteria are now considered a major and increasing threat by national health agencies, making the need for novel strategies to fight bugs and super bugs a first priority. In particular, Gram-negative bacteria are responsible for a high proportion of nosocomial infections attributable for a large part to Enterobacteriaceae, such as pathogenic Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. To cope with their highly competitive environments, bacteria have evolved various adaptive strategies, among which the production of narrow spectrum antimicrobial peptides called bacteriocins and specifically microcins in Gram-negative bacteria. They are produced as precursor peptides that further undergo proteolytic cleavage and in many cases more or less complex posttranslational modifications, which contribute to improve their stability and efficiency. Many have a high stability in the gastrointestinal tract where they can target a single pathogen whilst only slightly perturbing the gut microbiota. Several microcins and antibiotics can bind to similar bacterial receptors and use similar pathways to cross the double-membrane of Gram-negative bacteria and reach their intracellular targets, which they also can share. Consequently, bacteria may use common mechanisms of resistance against microcins and antibiotics. This review describes both unmodified and modified microcins [lasso peptides, siderophore peptides, nucleotide peptides, linear azole(in)e-containing peptides], highlighting their potential as weapons to thwart bacterial resistance in Gram-negative pathogens and discusses the possibility of cross-resistance and co-resistance occurrence between antibiotics and microcins in Gram-negative bacteria.
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Affiliation(s)
- Soufiane Telhig
- Institute of Nutrition and Functional Foods, Université Laval, Québec, QC, Canada
- Laboratory Molecules of Communication and Adaptation of Microorganisms, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Laila Ben Said
- Institute of Nutrition and Functional Foods, Université Laval, Québec, QC, Canada
| | - Séverine Zirah
- Laboratory Molecules of Communication and Adaptation of Microorganisms, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Ismail Fliss
- Institute of Nutrition and Functional Foods, Université Laval, Québec, QC, Canada
| | - Sylvie Rebuffat
- Laboratory Molecules of Communication and Adaptation of Microorganisms, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
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15
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Jeckelmann JM, Erni B. The mannose phosphotransferase system (Man-PTS) - Mannose transporter and receptor for bacteriocins and bacteriophages. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183412. [PMID: 32710850 DOI: 10.1016/j.bbamem.2020.183412] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/08/2020] [Accepted: 07/14/2020] [Indexed: 02/06/2023]
Abstract
Mannose transporters constitute a superfamily (Man-PTS) of the Phosphoenolpyruvate Carbohydrate Phosphotransferase System (PTS). The membrane complexes are homotrimers of protomers consisting of two subunits, IIC and IID. The two subunits without recognizable sequence similarity assume the same fold, and in the protomer are structurally related by a two fold pseudosymmetry axis parallel to membrane-plane (Liu et al. (2019) Cell Research 29 680). Two reentrant loops and two transmembrane helices of each subunit together form the N-terminal transport domain. Two three-helix bundles, one of each subunit, form the scaffold domain. The protomer is stabilized by a helix swap between these bundles. The two C-terminal helices of IIC mediate the interprotomer contacts. PTS occur in bacteria and archaea but not in eukaryotes. Man-PTS are abundant in Gram-positive bacteria living on carbohydrate rich mucosal surfaces. A subgroup of IICIID complexes serve as receptors for class IIa bacteriocins and as channel for the penetration of bacteriophage lambda DNA across the inner membrane. Some Man-PTS are associated with host-pathogen and -symbiont processes.
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Affiliation(s)
- Jean-Marc Jeckelmann
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.
| | - Bernhard Erni
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland.
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16
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El Jeni R, Ghedira K, El Bour M, Abdelhak S, Benkahla A, Bouhaouala-Zahar B. High-quality genome sequence assembly of R.A73 Enterococcus faecium isolated from freshwater fish mucus. BMC Microbiol 2020; 20:322. [PMID: 33096980 PMCID: PMC7584074 DOI: 10.1186/s12866-020-01980-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/18/2020] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Whole-genome sequencing using high throughput technologies has revolutionized and speeded up the scientific investigation of bacterial genetics, biochemistry, and molecular biology. Lactic acid bacteria (LABs) have been extensively used in fermentation and more recently as probiotics in food products that promote health. Genome sequencing and functional genomics investigations of LABs varieties provide rapid and important information about their diversity and their evolution, revealing a significant molecular basis. This study investigated the whole genome sequences of the Enterococcus faecium strain (HG937697), isolated from the mucus of freshwater fish in Tunisian dams. Genomic DNA was extracted using the Quick-GDNA kit and sequenced using the Illumina HiSeq2500 system. Sequences quality assessment was performed using FastQC software. The complete genome annotation was carried out with the Rapid Annotation using Subsystem Technology (RAST) web server then NCBI PGAAP. RESULTS The Enterococcus faecium R.A73 assembled in 28 contigs consisting of 2,935,283 bps. The genome annotation revealed 2884 genes in total including 2834 coding sequences and 50 RNAs containing 3 rRNAs (one rRNA 16 s, one rRNA 23 s and one rRNA 5 s) and 47 tRNAs. Twenty-two genes implicated in bacteriocin production are identified within the Enterococcus faecium R.A73 strain. CONCLUSION Data obtained provide insights to further investigate the effective strategy for testing this Enterococcus faecium R.A73 strain in the industrial manufacturing process. Studying their metabolism with bioinformatics tools represents the future challenge and contribution to improving the utilization of the multi-purpose bacteria in food.
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Affiliation(s)
- Rim El Jeni
- Laboratory of Microbiology and Pathology of Aquatic Organisms, Institut National des Sciences et Technologies de la Mer (INSTM), Tunis, Tunisia
- Laboratory of Venoms and Therapeutic Molecules, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Kais Ghedira
- Bioinformatics and Biostatistics Laboratory (LR16IPT09), Pasteur Institute of Tunis, Tunis, Tunisia
| | - Monia El Bour
- Laboratory of Microbiology and Pathology of Aquatic Organisms, Institut National des Sciences et Technologies de la Mer (INSTM), Tunis, Tunisia
| | - Sonia Abdelhak
- Biomedical Genomics and Oncogenetics Laboratory LR16IPT05, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Alia Benkahla
- Bioinformatics and Biostatistics Laboratory (LR16IPT09), Pasteur Institute of Tunis, Tunis, Tunisia
| | - Balkiss Bouhaouala-Zahar
- Laboratory of Venoms and Therapeutic Molecules, Pasteur Institute of Tunis, Tunis, Tunisia
- Medical School of Tunis, University of Tunis El Manar, 1007 Tunis, Tunisia
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17
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Integrated Metabolic Modeling, Culturing, and Transcriptomics Explain Enhanced Virulence of Vibrio cholerae during Coinfection with Enterotoxigenic Escherichia coli. mSystems 2020; 5:5/5/e00491-20. [PMID: 32900868 PMCID: PMC7483508 DOI: 10.1128/msystems.00491-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Most studies proposing new strategies to manage and treat infections have been largely focused on identifying druggable targets that can inhibit a pathogen's growth when it is the single cause of infection. In vivo, however, infections can be caused by multiple species. This is important to take into account when attempting to develop or use current antibacterials since their efficacy can change significantly between single infections and coinfections. In this study, we used genome-scale metabolic models (GEMs) to interrogate the growth capabilities of Vibrio cholerae in single infections and coinfections with enterotoxigenic E. coli (ETEC), which cooccur in a large fraction of diarrheagenic patients. Coinfection model predictions showed that V. cholerae growth capabilities are enhanced in the presence of ETEC relative to V. cholerae single infection, through cross-fed metabolites made available to V. cholerae by ETEC. In vitro, cocultures of the two enteric pathogens further confirmed model predictions showing an increased growth of V. cholerae in coculture relative to V. cholerae single cultures while ETEC growth was suppressed. Dual RNAseq analysis of the cocultures also confirmed that the transcriptome of V. cholerae was distinct during coinfection compared to single-infection scenarios where processes related to metabolism were significantly perturbed. Further, in silico gene-knockout simulations uncovered discrepancies in gene essentiality for V. cholerae growth between single infections and coinfections. Integrative model-guided analysis thus identified druggable targets that would be critical for V. cholerae growth in both single infections and coinfections; thus, designing inhibitors against those targets would provide a broader spectrum of coverage against cholera infections. Gene essentiality is altered during polymicrobial infections. Nevertheless, most studies rely on single-species infections to assess pathogen gene essentiality. Here, we use genome-scale metabolic models (GEMs) to explore the effect of coinfection of the diarrheagenic pathogen Vibrio cholerae with another enteric pathogen, enterotoxigenic Escherichia coli (ETEC). Model predictions showed that V. cholerae metabolic capabilities were increased due to ample cross-feeding opportunities enabled by ETEC. This is in line with increased severity of cholera symptoms known to occur in patients with dual infections by the two pathogens. In vitro coculture systems confirmed that V. cholerae growth is enhanced in cocultures relative to single cultures. Further, expression levels of several V. cholerae metabolic genes were significantly perturbed as shown by dual RNA sequencing (RNAseq) analysis of its cocultures with different ETEC strains. A decrease in ETEC growth was also observed, probably mediated by nonmetabolic factors. Single gene essentiality analysis predicted conditionally independent genes that are essential for the pathogen’s growth in both single-infection and coinfection scenarios. Our results reveal growth differences that are of relevance to drug targeting and efficiency in polymicrobial infections. IMPORTANCE Most studies proposing new strategies to manage and treat infections have been largely focused on identifying druggable targets that can inhibit a pathogen's growth when it is the single cause of infection. In vivo, however, infections can be caused by multiple species. This is important to take into account when attempting to develop or use current antibacterials since their efficacy can change significantly between single infections and coinfections. In this study, we used genome-scale metabolic models (GEMs) to interrogate the growth capabilities of Vibrio cholerae in single infections and coinfections with enterotoxigenic E. coli (ETEC), which cooccur in a large fraction of diarrheagenic patients. Coinfection model predictions showed that V. cholerae growth capabilities are enhanced in the presence of ETEC relative to V. cholerae single infection, through cross-fed metabolites made available to V. cholerae by ETEC. In vitro, cocultures of the two enteric pathogens further confirmed model predictions showing an increased growth of V. cholerae in coculture relative to V. cholerae single cultures while ETEC growth was suppressed. Dual RNAseq analysis of the cocultures also confirmed that the transcriptome of V. cholerae was distinct during coinfection compared to single-infection scenarios where processes related to metabolism were significantly perturbed. Further, in silico gene-knockout simulations uncovered discrepancies in gene essentiality for V. cholerae growth between single infections and coinfections. Integrative model-guided analysis thus identified druggable targets that would be critical for V. cholerae growth in both single infections and coinfections; thus, designing inhibitors against those targets would provide a broader spectrum of coverage against cholera infections.
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18
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Osman N, Ahmed SAM, Shibat El-Hamd DMW, Ahmed AI. Characterization and assessment of naturally mutant non-pathogenic O27 strain Escherichia coli and their potential use as poultry probiotics. J Adv Vet Anim Res 2020; 7:374-383. [PMID: 33005661 PMCID: PMC7521816 DOI: 10.5455/javar.2020.g431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 11/03/2022] Open
Abstract
Objective The purpose of the current study was to evaluate the molecular characteristics of naturally mutant non-pathogenic O27 strain of Escherichia coli and its efficacy as probiotic in broilers and determine the best age at which it can be administered. Materials and methods A total of 24 virulence genes using 24 sets of primers were detected using the polymerase chain reaction technique. For probiotics experiments, 60 chicks (day 1 old) were divided into three groups, 20 per group, and reared for 4 weeks. The first group was considered as a negative control. The second group was treated orally with O27 strain at first day of life for three successive days and repeated at day 21. The third group was administered orally with O27 strain at day 10 old, and repeated at day 21 old. Results The data revealed that type 1 fimbrial adhesion, salmochelin siderophore receptor, and sigma factor-binding protein were detected in O27 strain, but temperature-sensitive hemagglutinin, hemolysin secretion gene, pyelonephritis-associated Pili gene, polysaccharide capsule synthesis gene, Shiga-toxin1 gene, Shiga-toxin2 gene, Brain microvascular endothelial cell invasion, E. coli attaching and effacing gene, heat-stable enterotoxin, heat-labile enterotoxin, east 1 toxin, colicin V, verotoxin type 2, necrotizing cytotoxic factor type 1, colonization factor antigen I, colonization factor antigen III, coli surface 2, coli surface 4, serine protease pic autransporter, vacuolating autotransporter toxin, and serine protease EspP precursor were not detected in O27 strain. Group 2 performance parameters were significantly better (p < 0.01) than groups 3 and 1. Hematological and biochemical parameters did not be influenced (p > 0.05) by the administration of O27 strain. Antibody titers of infectious bursal disease virus and Newcastle disease virus in groups 2 and 3 were improved as compared to group 1. Group 2 had significantly higher titers than group 3. Histopathologically, all groups showed normal histopathological pictures. However, jejunum in groups 2 and 3 showed more tall, intact, and densely packed microvilli and more crypt depth than the control group. Conclusion The O27 strain of E. coli is non-pathogenic bacteria. Its effects on growth performances and enhancement of immunity in broilers match with the same impact of probiotics, and these candidates will fit to be a good probiotic in the future. The results revealed that the effects of O27 strain at the day 1 old of life for three successive days and repeated at day 21 old are better for improving the performance and immunity of the birds. More research works about the characterized non-pathogenic E. coli strain O27 are required for field and commercial use.
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Affiliation(s)
- Nabila Osman
- Department of Poultry Diseases, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Shimaa A M Ahmed
- Department of Poultry Diseases, Agricultural Research Center ARC, Animal Health Research Institute, Qena, Egypt
| | - Dina M W Shibat El-Hamd
- Department of Poultry Diseases, Agricultural Research Center ARC, Animal Health Research Institute, Qena, Egypt
| | - Ahmed I Ahmed
- Department of Poultry Diseases, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
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Navarro SA, Lanza L, Acuña L, Bellomio A, Chalón MC. Features and applications of Ent35-MccV hybrid bacteriocin: current state and perspectives. Appl Microbiol Biotechnol 2020; 104:6067-6077. [PMID: 32418126 DOI: 10.1007/s00253-020-10650-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/22/2020] [Accepted: 04/26/2020] [Indexed: 11/28/2022]
Abstract
Bacteriocins are peptides of ribosomal synthesis that are active against bacteria related to the producing strain. They have been widely used in the food industry as biopreservatives. The generation of hybrid peptides by combining the genes that encode two different bacteriocins has made it possible to study the mechanisms of action of the bacteriocins that compose them and also develop new peptides with improved biotechnological applications. Hybrid bacteriocins may be obtained in several ways. In our laboratory, by combining enterocin CRL35 and microcin V (Ent35-MccV), we obtained a broad-spectrum peptide that is active against both Gram-positive and Gram-negative bacteria. Ent35-MccV is sensitive to the action of intestinal proteases and is heat resistant, which makes it a good candidate for use as a biopreservative. For this reason, the peptide was tested in skim milk and beef burgers as food models. We also obtained more potent variants of the hybrid by modifying the central amino acid of the hinge region that connects the two bacteriocins. This review also discusses future applications and perspectives regarding the Ent35-MccV and other hybrid peptides.Key Points• Ent35-MccV is a new broad-spectrum bacteriocin.• The mechanism of action of bacteriocins can be studied using hybrid peptides.• Genetic engineering allows obtaining improved bacteriocin derivatives.• Hybrid peptides can be used in the food, pharmaceutical, and veterinary applications.
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Affiliation(s)
- S A Navarro
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj," Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - L Lanza
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj," Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - L Acuña
- Instituto de Patología Experimental (IPE, CONICET-UNSa), Universidad Nacional de Salta, Av. Bolivia 5150, Salta, Argentina
| | - A Bellomio
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj," Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - Miriam C Chalón
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj," Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina.
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20
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Zhao S, Wang CL, Chang SK, Tsai YL, Chou CH. Characterization of Escherichia coli Isolated from Day-old Chicken Fluff in Taiwanese Hatcheries. Avian Dis 2020; 63:9-16. [PMID: 31251514 DOI: 10.1637/11935-072318-reg.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 10/31/2018] [Indexed: 11/05/2022]
Abstract
Avian colibacillosis resulting from avian pathogenic Escherichia coli (APEC) seriously disrupts poultry production. Hatcheries are the main source of chickens for commercial farms. To characterize the potential pathogenicity of E. coli strains isolated from hatcheries, 2344 fluff samples from 1-day-old chickens were collected from hatching incubators between October 2016 and November 2017. Among the hatcheries, the incidence of E. coli varied from 0% to 16.9%, with an overall incidence of 2.0%. High incidences reflected inadequate sanitation in some hatcheries. We also compared 20 clinically isolated APEC strains with fluff-originated E. coli in terms of existence of 10 virulence-associated genes (VAGs) and antimicrobial-resistance genes, and antimicrobial resistance using minimum inhibitory concentration (MIC) values. Our results showed that APEC more-frequently possessed most of the assessed VAGs (papC, astA, cvaC, hlyF, fyuA, iroN, iutA, iss, and ompT), suggesting that fluff-originated E. coli is less likely to cause avian colibacillosis. However, fluff-originated E. coli more-frequently expressed the adhesion gene fimC, which could confer higher upper respiratory tract adhesion. Both APEC and fluff-originated E. coli demonstrated multidrug resistance including 100% resistance to ampicillin, amoxicillin, cephalexin, florfenicol, and trimethoprim-sulfamethoxazole. Based on median MIC values, fluff-originated E. coli was more susceptible to antibiotics. However, resistance-gene existence did not significantly differ between groups, suggesting that fluff-originated E. coli should still be a public health concern. Molecular subtyping with XbaI-digested pulsed-field gel electrophoresis revealed that only a few strains showed identical patterns, indicating that a variety of contamination sources were present within individual hatcheries. Identical strains within the same hatchery may indicate vertical transmission from parent flocks. Overall, this is the first study to characterize fluff-originated E. coli. Our results suggest that it has lower pathogenicity than APEC and that thorough sanitation should be performed to reduce the occurrence of fluff-originated E. coli in hatcheries.
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Affiliation(s)
- Shengnan Zhao
- Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, Taipei City 10617, Taiwan
| | - Chia-Lan Wang
- Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, Taipei City 10617, Taiwan
| | - Shao-Kuang Chang
- Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, Taipei City 10617, Taiwan
| | - Yi-Lun Tsai
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung County 91201, Taiwan,
| | - Chung-Hsi Chou
- Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, Taipei City 10617, Taiwan,
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Ugwu IC, Lee-Ching L, Ugwu CC, Okoye JOA, Chah KF. In vitro assessment of pathogenicity and virulence encoding gene profiles of avian pathogenic Escherichia coli strains associated with colibacillosis in chickens. IRANIAN JOURNAL OF VETERINARY RESEARCH 2020; 21:180-187. [PMID: 33178295 PMCID: PMC7608036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 07/04/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Avian pathogenic Escherichia coli (APEC) strains have been associated with various disease conditions in avian species due to virulence attributes associated with the organism. AIMS This study was carried out to determine the in vitro pathogenic characteristics and virulence encoding genes found in E. coli strains associated with colibacillosis in chickens. METHODS Fifty-two stock cultures of E. coli strains isolated from chickens diagnosed of colibacillosis were tested for their ability to produce haemolysis on blood agar and take up Congo red dye. Molecular characterization was carried out by polymerase chain reaction (PCR) amplification of virulence encoding genes associated with APEC. RESULTS Eleven (22%) and 41 (71%) were positive for haemolysis on 5% sheep red blood agar and Congo red agar, respectively. Nine virulence-associated genes were detected as follows: FimH (96%), csgA (52%), iss (48%), iut (33%), tsh (21%), cva (15%), kpsII (10%), pap (2%), and felA (2%). CONCLUSION The APEC strains exhibited virulence properties and harbored virulence encoding genes which could be a threat to the poultry population and public health. The putative virulence genes were diverse and different in almost all isolate implying that pathogenesis was multi-factorial and the infection was multi-faceted which could be a source of concern in the detection and control of APEC infections.
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Affiliation(s)
- I. C. Ugwu
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - L. Lee-Ching
- Department of Bioprocess Technology, School of Industrial Technology, University Sains Malaysia, Penang, Malaysia
| | - C. C. Ugwu
- Department of Animal Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - J. O. A. Okoye
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - K. F. Chah
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
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Navarro SA, Lanza L, Colombo NSR, de Ullivarri MF, Acuña L, Sosa-Padilla B, Picariello G, Bellomio A, Chalón MC. Obtaining an Ent35-MccV derivative with mutated hinge region that exhibits increased activity against Listeria monocytogenes and Escherichia coli. Appl Microbiol Biotechnol 2019; 103:9607-9618. [PMID: 31713671 DOI: 10.1007/s00253-019-10187-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/23/2019] [Accepted: 10/03/2019] [Indexed: 11/29/2022]
Abstract
The present paper describes the generation of derivatives from the hybrid peptide called Ent35-MccV, active against Gram-positive and Gram-negative bacteria. This peptide has a triple glycine hinge region between enterocin CRL35 and microcin V. In order to obtain variants of Ent35-MccV with greater biotechnological potential, a saturation mutagenesis was carried out in the hinge region. As a result, we obtained a bank of E. coli strains expressing different mutated hybrid bacteriocins in the central position of the hinge region. From all these variants, we found that the one bearing a tyrosine in the central region of the hinge (Ent35-GYG-MccV) is 2-fold more active against E. coli and 4-fold more active against Listeria than the original peptide Ent35-MccV. This derivative was purified and characterized. The development and evaluation of alternative hinges for Ent35-MccV represents a step forward in the bioengineering of antimicrobial peptides. This approach fosters the rational design of peptides with enhanced antimicrobial activity.
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Affiliation(s)
- S A Navarro
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - L Lanza
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - N S Ríos Colombo
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - M Fernandez de Ullivarri
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - L Acuña
- Instituto de Patología Experimental (IPE-CONICET-UNSa), Universidad Nacional de Salta, Av. Bolivia, 5150, Salta, Argentina
| | - B Sosa-Padilla
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI-CONICET), Avenida Belgrano y Pasaje Caseros, Tucumán, Argentina
| | - G Picariello
- Istituto di Scienze dell'Alimentazione - Consiglio Nazionale delle Ricerche (CNR), Via Roma, 64 -, 83100, Avellino, Italy
| | - A Bellomio
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - Miriam C Chalón
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina.
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23
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Baquero F, Lanza VF, Baquero MR, Del Campo R, Bravo-Vázquez DA. Microcins in Enterobacteriaceae: Peptide Antimicrobials in the Eco-Active Intestinal Chemosphere. Front Microbiol 2019; 10:2261. [PMID: 31649628 PMCID: PMC6795089 DOI: 10.3389/fmicb.2019.02261] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/17/2019] [Indexed: 12/31/2022] Open
Abstract
Microcins are low-molecular-weight, ribosomally produced, highly stable, bacterial-inhibitory molecules involved in competitive, and amensalistic interactions between Enterobacteriaceae in the intestine. These interactions take place in a highly complex chemical landscape, the intestinal eco-active chemosphere, composed of chemical substances that positively or negatively influence bacterial growth, including those originated from nutrient uptake, and those produced by the action of the human or animal host and the intestinal microbiome. The contribution of bacteria results from their effect on the host generated molecules, on food and digested food, and organic substances from microbial origin, including from bacterial degradation. Here, we comprehensively review the main chemical substances present in the human intestinal chemosphere, particularly of those having inhibitory effects on microorganisms. With this background, and focusing on Enterobacteriaceae, the most relevant human pathogens from the intestinal microbiota, the microcin’s history and classification, mechanisms of action, and mechanisms involved in microcin’s immunity (in microcin producers) and resistance (non-producers) are reviewed. Products from the chemosphere likely modulate the ecological effects of microcin activity. Several cross-resistance mechanisms are shared by microcins, colicins, bacteriophages, and some conventional antibiotics, which are expected to produce cross-effects. Double-microcin-producing strains (such as microcins MccM and MccH47) have been successfully used for decades in the control of pathogenic gut organisms. Microcins are associated with successful gut colonization, facilitating translocation and invasion, leading to bacteremia, and urinary tract infections. In fact, Escherichia coli strains from the more invasive phylogroups (e.g., B2) are frequently microcinogenic. A publicly accessible APD3 database http://aps.unmc.edu/AP/ shows particular genes encoding microcins in 34.1% of E. coli strains (mostly MccV, MccM, MccH47, and MccI47), and much less in Shigella and Salmonella (<2%). Some 4.65% of Klebsiella pneumoniae are microcinogenic (mostly with MccE492), and even less in Enterobacter or Citrobacter (mostly MccS). The high frequency and variety of microcins in some Enterobacteriaceae indicate key ecological functions, a notion supported by their dominance in the intestinal microbiota of biosynthetic gene clusters involved in the synthesis of post-translationally modified peptide microcins.
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Affiliation(s)
- Fernando Baquero
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Val F Lanza
- Bioinformatics Unit, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Maria-Rosario Baquero
- Department of Microbiology, Alfonso X El Sabio University, Villanueva de la Cañada, Spain
| | - Rosa Del Campo
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Daniel A Bravo-Vázquez
- Department of Microbiology, Alfonso X El Sabio University, Villanueva de la Cañada, Spain
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Ríos Colombo NS, Chalón MC, Dupuy FG, Gonzalez CF, Bellomio A. The case for class II bacteriocins: A biophysical approach using "suicide probes" in receptor-free hosts to study their mechanism of action. Biochimie 2019; 165:183-195. [PMID: 31381962 DOI: 10.1016/j.biochi.2019.07.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/26/2019] [Indexed: 11/29/2022]
Abstract
Class II bacteriocins are unmodified membrane-active peptides that act over a narrow spectrum of target bacteria. They bind a specific receptor protein on the membrane to form a pore, leading to membrane permeabilization and cell death. However, little is known about the molecular events triggering the pore formation after the bacteriocin recognizes the receptor. It is not clear yet if the pore is the same receptor forced into an open conformation or if the pore results from the bacteriocin insertion and oligomeric assembly in the lipid bilayer. In order to reveal which model is more suitable to explain the toxicity mechanism, in this work we use chimeric peptides, resulting from the fusion of the bitopic membrane protein EtpM with different class II bacteriocins: enterocin CRL35, pediocin PA-1 and microcin V. E. coli strains lacking the specific receptors for these bacteriocins were chosen as expression hosts. As these constructs display a lethal effect when they are heterologously expressed, they are called "suicide probes". The results suggest that, indeed, the specific receptor would act as a docking molecule more than as a structural piece of the pore, as long as the bacteriocin is somehow anchored to the membrane. These set of chimeric peptides also represent an in vivo system that allows to study the interaction of the bacteriocins with real bacterial membranes, instead of model membranes. Hence, the effects of these suicide probes in membrane fluidity and transmembrane potential were also assessed, using fluorescence spectroscopy. The data show that the different suicide probes are able to increase phospholipid order and depolarize the membranes of receptor-free bacterial cells.
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Affiliation(s)
- N S Ríos Colombo
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - M C Chalón
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - F G Dupuy
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina
| | - C F Gonzalez
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Sciences, University of Florida, 2033 Mowry road, PO Box 103610, Gainesville, FL, 32610-3610, USA
| | - A Bellomio
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, San Miguel de Tucumán, T4000ILI, Argentina.
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25
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Daga AP, Koga VL, Soncini JGM, de Matos CM, Perugini MRE, Pelisson M, Kobayashi RKT, Vespero EC. Escherichia coli Bloodstream Infections in Patients at a University Hospital: Virulence Factors and Clinical Characteristics. Front Cell Infect Microbiol 2019; 9:191. [PMID: 31245301 PMCID: PMC6563721 DOI: 10.3389/fcimb.2019.00191] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/20/2019] [Indexed: 01/24/2023] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) isolates are responsible for many bloodstream infections. The aim of this study was to characterize E. coli isolated from the bloodstreams of patients (n = 48) at the University Hospital in Brazil. Epidemiological data were obtained through the analysis of medical records and laboratory tests. By PCR analysis, we investigated the presence of virulence factors (VFs), pathogenicity islands (PAIs), extended-spectrum β-lactamase (ESBL), phylogenetic classifications (A, B1, B2, C, D, E, and F) and molecular genotype by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The mortality analysis showed that 33.3% of the deaths were associated with bacteraemia due to E. coli infections; in addition, an age between 60 and 75 years (p < 0.001; OR = 6.3[2.1–18.9]) and bacteraemia with an abdominal origin (p = 0.02; OR = 5[1.2–20.5]) were risk factors for the severity of the infection. Additionally, the presence of the afa gene was associated with mortality due to E. coli bacteraemia (p = 0.027; OR = 11.4[1.5–85.7]). Immunosuppression (27.1%), intestinal diseases (25.0%) and diabetes (18.8%), were prevalent among patients, and most of the bacteraemia cases were secondary to urinary tract infections (50.0%). The serum resistance gene traT was present in 77.1% of isolates, group capsular 2 (kpsMT II) was present in 45.8% and the K5 capsule was present in 20.8% of isolates. The isolates also showed a high prevalence for the siderophore yersiniabactina (fyuA) (70.8%) and PAI IV536 (77.1%). Phylogenetic analysis showed that group B2 (45.8%) was the most prevalent, and was the phylogroup that had a higher prevalence of VFs and PAIs. However, in this study, a considerable number of isolated bacteria were classified as group B1 (18.8%) and as group E (14.6%). Eight (16.7%) isolates were resistant to third and fourth generation cephalosporin and group CTX-M-1 (CTX-M-15) was the most prevalent ESBL type. The molecular genotyping showed two clonal lineages and several isolates that were not related to each other. This study provides additional information on the epidemiological and molecular characteristics of E. coli bloodstream infections in Brazil.
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Affiliation(s)
- Ana Paula Daga
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
| | - Vanessa Lumi Koga
- Laboratory of Microbiology, Department of Microbiology, State University of Londrina, Londrina, Brazil
| | - João Gabriel Material Soncini
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
| | - Caroline Martins de Matos
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
| | - Marcia Regina Eches Perugini
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
| | - Marsileni Pelisson
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
| | | | - Eliana Carolina Vespero
- Laboratory of Clinical Microbiology, Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, State University of Londrina, Londrina, Brazil
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Microcin PDI Inhibits Antibiotic-Resistant Strains of Escherichia coli and Shigella through a Mechanism of Membrane Disruption and Protection by Homotrimer Self-Immunity. Appl Environ Microbiol 2019; 85:AEM.00371-19. [PMID: 30902857 DOI: 10.1128/aem.00371-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/15/2019] [Indexed: 11/20/2022] Open
Abstract
Microcin PDI (MccPDI), a class IIa microcin that is produced by Escherichia coli strains 25 and 284, is known to inhibit foodborne pathogenic enterohemorrhagic E. coli serotypes O157:H7 and O26. Here we demonstrate that MccPDI can inhibit Shigella strains and E. coli isolates that are multidrug resistant, the latter including strains known to cause urinary tract infections in people and companion animals. Two exceptions out of 17 strains were identified. One of the two resistant E. coli isolates (AR0349) has a mutation in a critical amino acid residue that was identified in previous work as a requisite for the MccPDI precursor protein (McpM) to interact with outer membrane porin F (OmpF) on susceptible cells. The second resistant E. coli strain (MAD 96) had no mutations in ompF, but it was PCR positive for two antimicrobial peptides, of which colicin Ia/Ib likely inhibits the MccPDI-producing strain during coculture. Recombinant McpM was still effective against strain MAD 96. In an assessment of how MccPDI affects susceptible strains, results from both an extracellular ATP assay and a nucleic acid staining assay were consistent with membrane damage, while the addition of 200- to 600-Da polyethylene glycol (PEG) to cocultures protected against MccPDI (>600-Da PEG did not provide protection). Further studies using a paraformaldehyde cross-linking experiment and a bacterial two-hybrid assay demonstrated that MccPDI immunity protein (McpI) forms a multimeric complex with itself and presumably protects the producer strain from within the periplasm through an unknown mechanism.IMPORTANCE Microcins represent potential alternatives to conventional antibiotics for human and veterinary medicine. For them to be applied in this manner, however, we need to better understand their spectrum of activity, how these proteins interact with susceptible cells, and how producer cells are protected against the antimicrobial properties of the microcins. For microcin PDI (MccPDI), we report that the spectrum of activity likely includes most E. coli strains due to a conserved binding motif found on an outer membrane protein. Shigella has this motif as well and is susceptible to MccPDI killing via damage to the bacterial membrane. Receptor specificity suggests that these proteins could be used without causing large-scale disruptions to a microbiota, but this also increases the likelihood that resistance can evolve via random mutations. As with conventional antibiotics, good stewardship will be needed to preserve the efficacy of microcins should they be deployed for clinical use.
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Sekhon PK, Chander AM, Mayilraj S, Rishi P. Genomic analysis of Indian strains of Salmonella enterica subsp. enterica serovar Typhi indicates novel genetic repertoire for pathogenicity and adaptations. Mol Biol Rep 2019; 46:3967-3989. [DOI: 10.1007/s11033-019-04843-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 04/27/2019] [Indexed: 01/23/2023]
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Jeckelmann JM, Erni B. Carbohydrate Transport by Group Translocation: The Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System. Subcell Biochem 2019; 92:223-274. [PMID: 31214989 DOI: 10.1007/978-3-030-18768-2_8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Bacterial Phosphoenolpyruvate (PEP) : Sugar Phosphotransferase System (PTS) mediates the uptake and phosphorylation of carbohydrates, and controls the carbon- and nitrogen metabolism in response to the availability of sugars. PTS occur in eubacteria and in a few archaebacteria but not in animals and plants. All PTS comprise two cytoplasmic phosphotransferase proteins (EI and HPr) and a species-dependent, variable number of sugar-specific enzyme II complexes (IIA, IIB, IIC, IID). EI and HPr transfer phosphorylgroups from PEP to the IIA units. Cytoplasmic IIA and IIB units sequentially transfer phosphates to the sugar, which is transported by the IIC and IICIID integral membrane protein complexes. Phosphorylation by IIB and translocation by IIC(IID) are tightly coupled. The IIC(IID) sugar transporters of the PTS are in the focus of this review. There are four structurally different PTS transporter superfamilies (glucose, glucitol, ascorbate, mannose) . Crystal structures are available for transporters of two superfamilies: bcIICmal (MalT, 5IWS, 6BVG) and bcIICchb (ChbC, 3QNQ) of B. subtilis from the glucose family, and IICasc (UlaA, 4RP9, 5ZOV) of E. coli from the ascorbate superfamily . They are homodimers and each protomer has an independent transport pathway which functions by an elevator-type alternating-access mechanism. bcIICmal and bcIICchb have the same fold, IICasc has a completely different fold. Biochemical and biophysical data accumulated in the past with the transporters for mannitol (IICBAmtl) and glucose (IICBglc) are reviewed and discussed in the context of the bcIICmal crystal structures. The transporters of the mannose superfamily are dimers of protomers consisting of a IIC and a IID protein chain. The crystal structure is not known and the topology difficult to predict. Biochemical data indicate that the IICIID complex employs a different transport mechanism . Species specific IICIID serve as a gateway for the penetration of bacteriophage lambda DNA across, and insertion of class IIa bacteriocins into the inner membrane. PTS transporters are inserted into the membrane by SecYEG translocon and have specific lipid requirements. Immunoelectron- and fluorescence microscopy indicate a non-random distribution and supramolecular complexes of PTS proteins.
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Affiliation(s)
- Jean-Marc Jeckelmann
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland.
| | - Bernhard Erni
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland
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Breeding for soil-borne pathogen resistance impacts active rhizosphere microbiome of common bean. ISME JOURNAL 2018; 12:3038-3042. [PMID: 30018368 DOI: 10.1038/s41396-018-0234-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 11/08/2022]
Abstract
Over the past century, plant breeding programs have substantially improved plant growth and health, but have not yet considered the potential effects on the plant microbiome. Here, we conducted metatranscriptome analysis to determine if and how breeding for resistance of common bean against the root pathogen Fusarium oxysporum (Fox) affected gene expression in the rhizobacterial community. Our data revealed that the microbiome of the Fox-resistant cultivar presented a significantly higher expression of genes associated with nutrient metabolism, motility, chemotaxis, and the biosynthesis of the antifungal compounds phenazine and colicin V. Network analysis further revealed a more complex community for Fox-resistant cultivar and indicated Paenibacillus as a keystone genus in the rhizosphere microbiome. We suggest that resistance breeding in common bean has unintentionally co-selected for plant traits that strengthen the rhizosphere microbiome network structure and enrich for specific beneficial bacterial genera that express antifungal traits involved in plant protection against infections by root pathogens.
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Cohen LJ, Han S, Huang YH, Brady SF. Identification of the Colicin V Bacteriocin Gene Cluster by Functional Screening of a Human Microbiome Metagenomic Library. ACS Infect Dis 2018; 4:27-32. [PMID: 28810737 DOI: 10.1021/acsinfecdis.7b00081] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The forces that shape human microbial ecology are complex. It is likely that human microbiota, similarly to other microbiomes, use antibiotics as one way to establish an ecological niche. In this study, we use functional metagenomics to identify human microbial gene clusters that encode for antibiotic functions. Screening of a metagenomic library prepared from a healthy patient stool sample led to the identification of a family of clones with inserts that are 99% identical to a region of a virulence plasmid found in avian pathogenic Escherichia coli. Characterization of the metagenomic DNA sequence identified a colicin V biosynthetic cluster as being responsible for the observed antibiotic effect of the metagenomic clone against E. coli. This study presents a scalable method to recover antibiotic gene clusters from humans using functional metagenomics and highlights a strategy to study bacteriocins in the human microbiome which can provide a resource for therapeutic discovery.
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Affiliation(s)
- Louis J. Cohen
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, Box 1069, New York, New York 10029, United States
| | - Sun Han
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
- Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, Box 1069, New York, New York 10029, United States
| | - Yun-Han Huang
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Sean F. Brady
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
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Descamps T, De Smet L, De Vos P, de Graaf D. Unbiased random mutagenesis contributes to a better understanding of the virulent behaviour ofPaenibacillus larvae. J Appl Microbiol 2017; 124:28-41. [DOI: 10.1111/jam.13611] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/09/2017] [Accepted: 09/28/2017] [Indexed: 01/12/2023]
Affiliation(s)
- T. Descamps
- Laboratory of Molecular Entomology and Bee Pathology; Faculty of Sciences; Ghent University; Ghent Belgium
| | - L. De Smet
- Laboratory of Molecular Entomology and Bee Pathology; Faculty of Sciences; Ghent University; Ghent Belgium
| | - P. De Vos
- Laboratory of Microbiology; Faculty of Sciences; Ghent University; Ghent Belgium
| | - D.C. de Graaf
- Laboratory of Molecular Entomology and Bee Pathology; Faculty of Sciences; Ghent University; Ghent Belgium
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Barraza DE, Ríos Colombo NS, Galván AE, Acuña L, Minahk CJ, Bellomio A, Chalón MC. New insights into enterocin CRL35: mechanism of action and immunity revealed by heterologous expression in Escherichia coli. Mol Microbiol 2017; 105:922-933. [PMID: 28692133 DOI: 10.1111/mmi.13746] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2017] [Indexed: 11/30/2022]
Abstract
The role of the class IIa bacteriocin membrane receptor protein remains unclear, and the following two different mechanisms have been proposed: the bacteriocin could interact with the receptor changing it to an open conformation or the receptor might act as an anchor allowing subsequent bacteriocin insertion and membrane disruption. Bacteriocin-producing cells synthesize an immunity protein that forms an inactive bacteriocin-receptor-immunity complex. To better understand the molecular mechanism of enterocin CRL35, the peptide was expressed as the suicidal probe EtpM-enterocin CRL35 in Escherichia coli, a naturally insensitive microorganism since it does not express the receptor. When the bacteriocin is anchored to the periplasmic face of the plasma membrane through the bitopic membrane protein, EtpM, E. coli cells depolarize and die. Moreover, co-expression of the immunity protein prevents the deleterious effect of EtpM-enterocin CRL35. The binding and anchoring of the bacteriocin to the membrane has demonstrated to be a sufficient condition for its membrane insertion. The final step of membrane disruption by EtpM-enterocin CRL35 is independent from the receptor, which means that the mannose PTS might not be involved in the pore structure. In addition, the immunity protein can protect even in the absence of the receptor.
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Affiliation(s)
- Daniela E Barraza
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Natalia S Ríos Colombo
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Adriana E Galván
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Leonardo Acuña
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Carlos J Minahk
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Augusto Bellomio
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
| | - Miriam C Chalón
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina
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Masschelein J, Jenner M, Challis GL. Antibiotics from Gram-negative bacteria: a comprehensive overview and selected biosynthetic highlights. Nat Prod Rep 2017. [PMID: 28650032 DOI: 10.1039/c7np00010c] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: up to 2017The overwhelming majority of antibiotics in clinical use originate from Gram-positive Actinobacteria. In recent years, however, Gram-negative bacteria have become increasingly recognised as a rich yet underexplored source of novel antimicrobials, with the potential to combat the looming health threat posed by antibiotic resistance. In this article, we have compiled a comprehensive list of natural products with antimicrobial activity from Gram-negative bacteria, including information on their biosynthetic origin(s) and molecular target(s), where known. We also provide a detailed discussion of several unusual pathways for antibiotic biosynthesis in Gram-negative bacteria, serving to highlight the exceptional biocatalytic repertoire of this group of microorganisms.
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Affiliation(s)
- J Masschelein
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - M Jenner
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - G L Challis
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
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Microcin PDI regulation and proteolytic cleavage are unique among known microcins. Sci Rep 2017; 7:42529. [PMID: 28205647 PMCID: PMC5311971 DOI: 10.1038/srep42529] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/09/2017] [Indexed: 11/16/2022] Open
Abstract
Microcin PDI inhibits a diversity of pathogenic Escherichia coli through the action of an effector protein, McpM. In this study we demonstrated that expression of the inhibitory phenotype is induced under low osmolarity conditions and expression is primarily controlled by the EnvZ/OmpR two-component regulatory system. Functional, mutagenesis and complementation experiments were used to empirically demonstrate that EnvZ is required for the inhibitory phenotype and that regulation of mcpM is dependent on binding of the phosphorylated OmpR to the mcpM promoter region. The phosphorylated OmpR may recognize three different binding sites within this promoter region. Site-directed mutagenesis revealed that the McpM precursor peptide includes two leader peptides that undergo sequential cleavage at positions G17/G18 and G35/A36 during export through the type I secretion system. Competition assays showed that both cleaved products are required for the PDI phenotype although we could not distinguish loss of function from loss of secretion in these assays. McpM has four cysteines within the mature peptide and site-directed mutagenesis experiments demonstrated that the first two cysteines are necessary for McpM to inhibit susceptible cells. Together these data combined with previous work indicate that MccPDI is unique amongst the microcins that have been described to date.
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35
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Purine Biosynthesis Metabolically Constrains Intracellular Survival of Uropathogenic Escherichia coli. Infect Immun 2016; 85:IAI.00471-16. [PMID: 27795353 DOI: 10.1128/iai.00471-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/10/2016] [Indexed: 02/05/2023] Open
Abstract
The ability to de novo synthesize purines has been associated with the intracellular survival of multiple bacterial pathogens. Uropathogenic Escherichia coli (UPEC), the predominant cause of urinary tract infections, undergoes a transient intracellular lifestyle during which bacteria clonally expand into multicellular bacterial communities within the cytoplasm of bladder epithelial cells. Here, we characterized the contribution of the conserved de novo purine biosynthesis-associated locus cvpA-purF to UPEC pathogenesis. Deletion of cvpA-purF, or of purF alone, abolished de novo purine biosynthesis but did not impact bacterial adherence properties in vitro or in the bladder lumen. However, upon internalization by bladder epithelial cells, UPEC deficient in de novo purine biosynthesis was unable to expand into intracytoplasmic bacterial communities over time, unless it was extrachromosomally complemented. These findings indicate that UPEC is deprived of purine nucleotides within the intracellular niche and relies on de novo purine synthesis to meet this metabolic requirement.
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Abstract
Selective pressures within the human host, including interactions with innate and adaptive immune responses, exposure to medical interventions such as antibiotics, and competition with commensal microbiota all facilitate the evolution of bacterial pathogens. In this chapter, we present examples of pathogen strategies that emerged as a result of selective pressures within the human host niche and discuss the resulting coevolutionary "arms race" between these organisms. In bacterial pathogens, many of the genes responsible for these strategies are encoded on mobile pathogenicity islands or plasmids, underscoring the importance of horizontal gene transfer in the emergence of virulent microbial species.
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Shehata HR, Ettinger CL, Eisen JA, Raizada MN. Genes Required for the Anti-fungal Activity of a Bacterial Endophyte Isolated from a Corn Landrace Grown Continuously by Subsistence Farmers Since 1000 BC. Front Microbiol 2016; 7:1548. [PMID: 27757101 PMCID: PMC5047915 DOI: 10.3389/fmicb.2016.01548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022] Open
Abstract
Endophytes are microbes that inhabit internal plant tissues without causing disease. Some endophytes are known to combat pathogens. The corn (maize) landrace Chapalote has been grown continuously by subsistence farmers in the Americas since 1000 BC, without the use of fungicides, and the crop remains highly valued by farmers, in part for its natural tolerance to pests. We hypothesized that the pathogen tolerance of Chapalote may, in part, be due to assistance from its endophytes. We previously identified a bacterial endophyte from Chapalote seeds, Burkholderia gladioli strain 3A12, for its ability to combat a diversity of crop pathogens, including Sclerotinia homoeocarpa, the most important fungal disease of creeping bentgrass, a relative of maize used here as a model system. Strain 3A12 represents a unique opportunity to understand the anti-fungal activities of an endophyte associated with a crop variety grown by subsistence farmers since ancient times. Here, microscopy combined with Tn5-mutagenesis demonstrates that the anti-fungal mode of action of 3A12 involves flagella-dependent swarming toward its pathogen target, attachment and biofilm-mediated microcolony formation. The mutant screen revealed that YajQ, a receptor for the secondary messenger c-di-GMP, is a critical signaling system that mediates this endophytic mobility-based defense for its host. Microbes from the traditional seeds of farmers may represent a new frontier in elucidating host-microbe mutualistic interactions.
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Affiliation(s)
- Hanan R. Shehata
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
- Department of Microbiology, School of Pharmacy, Mansoura UniversityMansoura, Egypt
| | - Cassandra L. Ettinger
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
| | - Jonathan A. Eisen
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
- Department of Medical Microbiology and Immunology, University of California Davis, DavisCA, USA
| | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
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Root-hair endophyte stacking in finger millet creates a physicochemical barrier to trap the fungal pathogen Fusarium graminearum. Nat Microbiol 2016; 1:16167. [PMID: 27669453 DOI: 10.1038/nmicrobiol.2016.167] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/10/2016] [Indexed: 12/31/2022]
Abstract
The ancient African crop, finger millet, has broad resistance to pathogens including the toxigenic fungus Fusarium graminearum. Here, we report the discovery of a novel plant defence mechanism resulting from an unusual symbiosis between finger millet and a root-inhabiting bacterial endophyte, M6 (Enterobacter sp.). Seed-coated M6 swarms towards root-invading Fusarium and is associated with the growth of root hairs, which then bend parallel to the root axis, subsequently forming biofilm-mediated microcolonies, resulting in a remarkable, multilayer root-hair endophyte stack (RHESt). The RHESt results in a physical barrier that prevents entry and/or traps F. graminearum, which is then killed. M6 thus creates its own specialized killing microhabitat. Tn5-mutagenesis shows that M6 killing requires c-di-GMP-dependent signalling, diverse fungicides and resistance to a Fusarium-derived antibiotic. Further molecular evidence suggests long-term host-endophyte-pathogen co-evolution. The end result of this remarkable symbiosis is reduced deoxynivalenol mycotoxin, potentially benefiting millions of subsistence farmers and livestock. Further results suggest that the anti-Fusarium activity of M6 may be transferable to maize and wheat. RHESt demonstrates the value of exploring ancient, orphan crop microbiomes.
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Draft Genome Sequence of the Oral Commensal Streptococcus oralis 89a with Interference Activity against Respiratory Pathogens. GENOME ANNOUNCEMENTS 2016; 4:4/1/e01546-15. [PMID: 26769934 PMCID: PMC4714116 DOI: 10.1128/genomea.01546-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the draft genome sequence of the oral commensal Streptococcus oralis 89a isolated from the throat of a healthy child during a streptococcal tonsillitis outbreak in Umeå, Sweden. S. oralis 89a was known to have interference activity against respiratory pathogens in which the colicin V was the potential bacteriocin-encoding gene.
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Silva-Valenzuela CA, Molina-Quiroz RC, Desai P, Valenzuela C, Porwollik S, Zhao M, Hoffman RM, Andrews-Polymenis H, Contreras I, Santiviago CA, McClelland M. Analysis of Two Complementary Single-Gene Deletion Mutant Libraries of Salmonella Typhimurium in Intraperitoneal Infection of BALB/c Mice. Front Microbiol 2016; 6:1455. [PMID: 26779130 PMCID: PMC4700939 DOI: 10.3389/fmicb.2015.01455] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/04/2015] [Indexed: 01/20/2023] Open
Abstract
Two pools of individual single gene deletion (SGD) mutants of S. Typhimurium 14028s encompassing deletions of 3,923 annotated non-essential ORFs and sRNAs were screened by intraperitoneal (IP) injection in BALB/c mice followed by recovery from spleen and liver 2 days post infection. The relative abundance of each mutant was measured by microarray hybridization. The two mutant libraries differed in the orientation of the antibiotic resistance cassettes (either sense-oriented Kan(R), SGD-K, or antisense-oriented Cam(R), SGD-C). Consistent systemic colonization defects were observed in both libraries and both organs for hundreds of mutants of genes previously reported to be important after IP injection in this animal model, and for about 100 new candidate genes required for systemic colonization. Four mutants with a range of apparent fitness defects were confirmed using competitive infections with the wild-type parental strain: ΔSTM0286, ΔSTM0551, ΔSTM2363, and ΔSTM3356. Two mutants, ΔSTM0286 and ΔSTM2363, were then complemented in trans with a plasmid encoding an intact copy of the corresponding wild-type gene, and regained the ability to fully colonize BALB/c mice systemically. These results suggest the presence of many more undiscovered Salmonella genes with phenotypes in IP infection of BALB/c mice, and validate the libraries for application to other systems.
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Affiliation(s)
- Cecilia A. Silva-Valenzuela
- Department of Microbiology and Molecular Genetics, University of California, IrvineIrvine, CA, USA
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Roberto C. Molina-Quiroz
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
- Center for Adaptation Genetics and Drug Resistance, Tufts UniversityBoston, MA, USA
| | - Prerak Desai
- Department of Microbiology and Molecular Genetics, University of California, IrvineIrvine, CA, USA
| | - Camila Valenzuela
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Steffen Porwollik
- Department of Microbiology and Molecular Genetics, University of California, IrvineIrvine, CA, USA
| | | | - Robert M. Hoffman
- Anticancer Inc.San Diego, CA, USA
- Department of Surgery, UC San Diego School of Medicine, University of California, San DiegoSan Diego, CA, USA
| | - Helene Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, Texas A&M UniversityCollege Station, TX, USA
| | - Inés Contreras
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Carlos A. Santiviago
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de ChileSantiago, Chile
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California, IrvineIrvine, CA, USA
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Microcin V Production in Lactobacillus plantarum LB-B1 Using Heterologous Leader Peptide from Pediocin PA-1. Curr Microbiol 2015; 72:357-62. [DOI: 10.1007/s00284-015-0927-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/09/2015] [Indexed: 01/01/2023]
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42
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Hwang IY, Tan MH, Koh E, Ho CL, Poh CL, Chang MW. Reprogramming microbes to be pathogen-seeking killers. ACS Synth Biol 2014; 3:228-37. [PMID: 24020906 DOI: 10.1021/sb400077j] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent examples of new genetic circuits that enable cells to acquire biosynthetic capabilities, such as specific pathogen killing, present an attractive therapeutic application of synthetic biology. Herein, we demonstrate a novel genetic circuit that reprograms Escherichia coli to specifically recognize, migrate toward, and eradicate both dispersed and biofilm-encased pathogenic Pseudomonas aeruginosa cells. The reprogrammed E. coli degraded the mature biofilm matrix and killed the latent cells encapsulated within by expressing and secreting the antimicrobial peptide microcin S and the nuclease DNaseI upon the detection of quorum sensing molecules naturally secreted by P. aeruginosa. Furthermore, the reprogrammed E. coli exhibited directed motility toward the pathogen through regulated expression of CheZ in response to the quorum sensing molecules. By integrating the pathogen-directed motility with the dual antimicrobial activity in E. coli, we achieved signifincantly improved killing activity against planktonic and mature biofilm cells due to target localization, thus creating an active pathogen seeking killer E. coli.
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Affiliation(s)
- In Young Hwang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Mui Hua Tan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Elvin Koh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Chun Loong Ho
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Chueh Loo Poh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Matthew Wook Chang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
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43
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Balciunas EM, Castillo Martinez FA, Todorov SD, Franco BDGDM, Converti A, Oliveira RPDS. Novel biotechnological applications of bacteriocins: A review. Food Control 2013. [DOI: 10.1016/j.foodcont.2012.11.025] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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44
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Erni B. The bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS): an interface between energy and signal transduction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2012. [DOI: 10.1007/s13738-012-0185-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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45
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Chalón MC, Acuña L, Morero RD, Minahk CJ, Bellomio A. Membrane-active bacteriocins to control Salmonella in foods. Food Res Int 2012. [DOI: 10.1016/j.foodres.2011.08.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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46
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Acuña L, Picariello G, Sesma F, Morero RD, Bellomio A. A new hybrid bacteriocin, Ent35-MccV, displays antimicrobial activity against pathogenic Gram-positive and Gram-negative bacteria. FEBS Open Bio 2012; 2:12-9. [PMID: 23650575 PMCID: PMC3642096 DOI: 10.1016/j.fob.2012.01.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/26/2012] [Accepted: 01/27/2012] [Indexed: 11/15/2022] Open
Abstract
Bacteriocins and microcins are ribosomally synthesized antimicrobial peptides that are usually active against phylogenetically related bacteria. Thus, bacteriocins are active against Gram-positive while microcins are active against Gram-negative bacteria. The narrow spectrum of action generally displayed by bacteriocins from lactic acid bacteria represents an important limitation for the application of these peptides as clinical drugs or as food biopreservatives. The present study describes the design and expression of a novel recombinant hybrid peptide combining enterocin CRL35 and microcin V named Ent35–MccV. The chimerical bacteriocin displayed antimicrobial activity against enterohemorrhagic Escherichia coli and Listeria monocytogenes clinical isolates, among other pathogenic bacteria. Therefore, Ent35–MccV may find important applications in food or pharmaceutical industries.
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Affiliation(s)
- Leonardo Acuña
- Instituto Superior de Investigaciones Biológicas (INSIBIO CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461 (T4000ILI), San Miguel de Tucumán, Argentina
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Morin N, Lanneluc I, Connil N, Cottenceau M, Pons AM, Sablé S. Mechanism of bactericidal activity of microcin L in Escherichia coli and Salmonella enterica. Antimicrob Agents Chemother 2011; 55:997-1007. [PMID: 21189348 PMCID: PMC3067116 DOI: 10.1128/aac.01217-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/19/2010] [Accepted: 12/14/2010] [Indexed: 11/20/2022] Open
Abstract
For the first time, the mechanism of action of microcin L (MccL) was investigated in live bacteria. MccL is a gene-encoded peptide produced by Escherichia coli LR05 that exhibits a strong antibacterial activity against related Enterobacteriaceae, including Salmonella enterica serovars Typhimurium and Enteritidis. We first subcloned the MccL genetic system to remove the sequences not involved in MccL production. We then optimized the MccL purification procedure to obtain large amounts of purified microcin to investigate its antimicrobial and membrane properties. We showed that MccL did not induce outer membrane permeabilization, which indicated that MccL did not use this way to kill the sensitive cell or to enter into it. Using a set of E. coli and Salmonella enterica mutants lacking iron-siderophore receptors, we demonstrated that the MccL uptake required the outer membrane receptor Cir. Moreover, the MccL bactericidal activity was shown to depend on the TonB protein that transduces the proton-motive force of the cytoplasmic membrane to transport iron-siderophore complexes across the outer membrane. Using carbonyl cyanide 3-chlorophenylhydrazone, which is known to fully dissipate the proton-motive force, we proved that the proton-motive force was required for the bactericidal activity of MccL on E. coli. In addition, we showed that a primary target of MccL could be the cytoplasmic membrane: a high level of MccL disrupted the inner membrane potential of E. coli cells. However, no permeabilization of the membrane was detected.
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Affiliation(s)
- Natacha Morin
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
| | - Isabelle Lanneluc
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
| | - Nathalie Connil
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
| | - Marie Cottenceau
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
| | - Anne Marie Pons
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
| | - Sophie Sablé
- Littoral Environnement Sociétés, UMR 6250 CNRS-ULR, Université de La Rochelle, UFR Sciences, Bât. Marie Curie, Avenue Michel Crépeau, 17042 La Rochelle cedex 01, France
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Papenfort K, Said N, Welsink T, Lucchini S, Hinton JCD, Vogel J. Specific and pleiotropic patterns of mRNA regulation by ArcZ, a conserved, Hfq-dependent small RNA. Mol Microbiol 2009; 74:139-158. [PMID: 19732340 DOI: 10.1111/j.1365-2958.2009.06857.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The small RNA, ArcZ (previously RyhA/SraH), was discovered in several genome-wide screens in Escherichia coli and Salmonella. Its high degree of genomic conservation, its frequent recovery by shotgun sequencing, and its association with the RNA chaperone, Hfq, identified ArcZ as an abundant enterobacterial 'core' small RNA, yet its function remained unknown. Here, we report that ArcZ acts as a post-transcriptional regulator in Salmonella, repressing the mRNAs of the widely distributed sdaCB (serine uptake) and tpx (oxidative stress) genes, and of STM3216, a horizontally acquired methyl-accepting chemotaxis protein (MCP). Both sdaCB and STM3216 are regulated by sequestration of the ribosome binding site. In contrast, the tpx mRNA is targeted in the coding sequence (CDS), arguing that CDS targeting is more common than appreciated. Transcriptomic analysis of an arcZ deletion strain further argued for the existence of a distinct set of Salmonella loci specifically regulated by ArcZ. In contrast, increased expression of the sRNA altered the steady-state levels of > 16% (> 750) of all Salmonella mRNAs, and rendered the bacteria non-motile. Deep sequencing detected a dramatically changed profile of Hfq-bound sRNAs and mRNAs, suggesting that the unprecedented pleiotropic effects by a single sRNA might in part be caused by altered post-transcriptional regulation.
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Affiliation(s)
- Kai Papenfort
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
| | - Nelly Said
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
| | - Tim Welsink
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
| | - Sacha Lucchini
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
| | - Jay C D Hinton
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
| | - Jörg Vogel
- Max Planck Institute for Infection Biology, RNA Biology Group, Charitéplatz 1, 10117 Berlin, Germany.Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College, Dublin 2, Ireland
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Involvement of the leucine response transcription factor LeuO in regulation of the genes for sulfa drug efflux. J Bacteriol 2009; 191:4562-71. [PMID: 19429622 DOI: 10.1128/jb.00108-09] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
LeuO, a LysR family transcription factor, exists in a wide variety of bacteria of the family Enterobacteriaceae and is involved in the regulation of as yet unidentified genes affecting the stress response and pathogenesis expression. Using genomic screening by systematic evolution of ligands by exponential enrichment (SELEX) in vitro, a total of 106 DNA sequences were isolated from 12 different regions of the Escherichia coli genome. All of the SELEX fragments formed complexes in vitro with purified LeuO. After Northern blot analysis of the putative target genes located downstream of the respective LeuO-binding sequence, a total of nine genes were found to be activated by LeuO, while three genes were repressed by LeuO. The LeuO target gene collection included several multidrug resistance genes. A phenotype microarray assay was conducted to identify the gene(s) responsible for drug resistance and the drug species that are under the control of the LeuO target gene(s). The results described herein indicate that the yjcRQP operon, one of the LeuO targets, is involved in sensitivity control against sulfa drugs. We propose to rename the yjcRQP genes the sdsRQP genes (sulfa drug sensitivity determinant).
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