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Mårli MT, Oppegaard O, Porcellato D, Straume D, Kjos M. Genetic modification of Streptococcus dysgalactiae by natural transformation. mSphere 2024; 9:e0021424. [PMID: 38904369 PMCID: PMC11288034 DOI: 10.1128/msphere.00214-24] [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: 03/18/2024] [Accepted: 05/13/2024] [Indexed: 06/22/2024] Open
Abstract
Streptococcus dysgalactiae is an emerging human and animal pathogen. Functional studies of genes involved in virulence of S. dysgalactiae and other pyogenic group streptococci are often hampered by limited genetic tractability. It is known that pyogenic streptococci carry genes required for competence for natural transformation; however, in contrast to other streptococcal subgroups, there is limited evidence for gene transfer by natural transformation in these bacteria. In this study, we systematically assessed the genomes of 179 S. dysgalactiae strains of both human and animal origins (subsp. equisimilis and dysgalactiae, respectively) for the presence of genes required for natural transformation. While a considerable fraction of the strains contained inactive genes, the majority (64.2%) of the strains had an intact gene set. In selected strains, we examined the dynamics of competence activation after addition of competence-inducing pheromones using transcriptional reporter assays and exploratory RNA-seq. Based on these findings, we were able to establish a protocol allowing us to utilize natural transformation to construct deletion mutants by allelic exchange in several S. dysgalactiae strains of both subspecies. As part of the work, we deleted putative lactose utilization genes to study their role in growth on lactose. The data presented here provide new knowledge on the potential of horizonal gene transfer by natural transformation in S. dysgalactiae and, importantly, demonstrates the possibility to exploit natural transformation for genetic engineering in these bacteria. IMPORTANCE Numerous Streptococcus spp. exchange genes horizontally through natural transformation, which also facilitates efficient genetic engineering in these organisms. However, for the pyogenic group of streptococci, including the emerging pathogen Streptococcus dysgalactiae, there is limited experimental evidence for natural transformation. In this study, we demonstrate that natural transformation in vitro indeed is possible in S. dysgalactiae strains under optimal conditions. We utilized this method to perform gene deletion through allelic exchange in several strains, thereby paving the way for more efficient gene engineering methods in pyogenic streptococci.
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Affiliation(s)
- Marita Torrissen Mårli
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Oddvar Oppegaard
- Haukeland University Hospital, University of Bergen, Bergen, Norway
| | - Davide Porcellato
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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2
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Jana B, Liu X, Dénéréaz J, Park H, Leshchiner D, Liu B, Gallay C, Zhu J, Veening JW, van Opijnen T. CRISPRi-TnSeq maps genome-wide interactions between essential and non-essential genes in bacteria. Nat Microbiol 2024:10.1038/s41564-024-01759-x. [PMID: 39030344 DOI: 10.1038/s41564-024-01759-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 06/12/2024] [Indexed: 07/21/2024]
Abstract
Genetic interactions identify functional connections between genes and pathways, establishing gene functions or druggable targets. Here we use CRISPRi-TnSeq, CRISPRi-mediated knockdown of essential genes alongside TnSeq-mediated knockout of non-essential genes, to map genome-wide interactions between essential and non-essential genes in Streptococcus pneumoniae. Transposon-mutant libraries constructed in 13 CRISPRi strains enabled screening of ~24,000 gene pairs. This identified 1,334 genetic interactions, including 754 negative and 580 positive interactions. Network analyses show that 17 non-essential genes pleiotropically interact with more than half the essential genes tested. Validation experiments confirmed that a 7-gene subset protects against perturbations. Furthermore, we reveal hidden redundancies that compensate for essential gene loss, relationships between cell wall synthesis, integrity and cell division, and show that CRISPRi-TnSeq identifies synthetic and suppressor-type relationships between both functionally linked and disparate genes and pathways. Importantly, in species where CRISPRi and Tn-Seq are established, CRISPRi-TnSeq should be straightforward to implement.
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Affiliation(s)
- Bimal Jana
- Department of Biology, Boston College, Chestnut Hill, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Xue Liu
- Department of Pathogen Biology, Base for International Science and Technology Cooperation: Carson Cancer Stem Cell Vaccines R&D Center, International Cancer Center, Shenzhen University Health Science Center, Shenzhen, China
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Julien Dénéréaz
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Hongshik Park
- Department of Biology, Boston College, Chestnut Hill, MA, USA
| | | | - Bruce Liu
- Department of Biology, Boston College, Chestnut Hill, MA, USA
| | - Clément Gallay
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Junhao Zhu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
| | - Tim van Opijnen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Boston Children's Hospital, Division of Infectious Diseases, Harvard Medical School, Boston, MA, USA.
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3
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Prudhomme M, Johnston CHG, Soulet AL, Boyeldieu A, De Lemos D, Campo N, Polard P. Pneumococcal competence is a populational health sensor driving multilevel heterogeneity in response to antibiotics. Nat Commun 2024; 15:5625. [PMID: 38987237 PMCID: PMC11237056 DOI: 10.1038/s41467-024-49853-2] [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: 12/14/2023] [Accepted: 06/21/2024] [Indexed: 07/12/2024] Open
Abstract
Competence for natural transformation is a central driver of genetic diversity in bacteria. In the human pathogen Streptococcus pneumoniae, competence exhibits a populational character mediated by the stress-induced ComABCDE quorum-sensing (QS) system. Here, we explore how this cell-to-cell communication mechanism proceeds and the functional properties acquired by competent cells grown under lethal stress. We show that populational competence development depends on self-induced cells stochastically emerging in response to stresses, including antibiotics. Competence then propagates through the population from a low threshold density of self-induced cells, defining a biphasic Self-Induction and Propagation (SI&P) QS mechanism. We also reveal that a competent population displays either increased sensitivity or improved tolerance to lethal doses of antibiotics, dependent in the latter case on the competence-induced ComM division inhibitor. Remarkably, these surviving competent cells also display an altered transformation potential. Thus, the unveiled SI&P QS mechanism shapes pneumococcal competence as a health sensor of the clonal population, promoting a bet-hedging strategy that both responds to and drives cells towards heterogeneity.
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Affiliation(s)
- Marc Prudhomme
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Calum H G Johnston
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Anne-Lise Soulet
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Anne Boyeldieu
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - David De Lemos
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Nathalie Campo
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Patrice Polard
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.
- Université Paul Sabatier (Toulouse III), Toulouse, France.
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Liu Y, Zhou H, Wang J, Liu S, Xie GJ, Liu BF, Xing D. Regulatory Mechanisms of Quorum Sensing System of Bacteria in Response to Chlorine and Ozone Disinfection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38937254 DOI: 10.1021/acs.est.3c08305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Waterborne pathogens invariably present considerable threats to public health. The quorum sensing (QS) system is instrumental in coordinating bacterial growth and metabolisms. However, the responses and regulatory mechanisms of bacteria to various disinfection technologies through quorum sensing are still unclear. This study examines the inactivation effect of chlorination and ozonation on biofilms and planktonic cells of QS signaling-deficient mutants of Pseudomonas aeruginosa. Cell counting and viability assessment revealed that the combined disinfection of chlorine and ozone was the most effective for inactivating planktonic P. aeruginosa within 10 min of exposure. Additionally, microfluidic chip culture demonstrated that the secretion of quinolone signals escalated biofilms' disinfection resistance. Disinfection exposure significantly altered the gene expression of wild-type strains and QS signaling-deficient mutants. Moreover, the QS system triggered multilayered gene expression programs as a responsive protection to disinfectant exposure, including oxidative stress, ribosome synthesis, and the nutrient absorption of bacteria. These insights broaden our understanding of bacterial QS in response to disinfection, promising potential strategies toward efficient disinfection processes.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Huihui Zhou
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Jing Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Sitong Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
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5
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Sullivan GJ, Barquist L, Cain AK. A method to correct for local alterations in DNA copy number that bias functional genomics assays applied to antibiotic-treated bacteria. mSystems 2024; 9:e0066523. [PMID: 38470252 PMCID: PMC11019837 DOI: 10.1128/msystems.00665-23] [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: 07/07/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
Functional genomics techniques, such as transposon insertion sequencing and RNA-sequencing, are key to studying relative differences in bacterial mutant fitness or gene expression under selective conditions. However, certain stress conditions, mutations, or antibiotics can directly interfere with DNA synthesis, resulting in systematic changes in local DNA copy numbers along the chromosome. This can lead to artifacts in sequencing-based functional genomics data when comparing antibiotic treatment to an unstressed control. Further, relative differences in gene-wise read counts may result from alterations in chromosomal replication dynamics, rather than selection or direct gene regulation. We term this artifact "chromosomal location bias" and implement a principled statistical approach to correct it by calculating local normalization factors along the chromosome. These normalization factors are then directly incorporated into statistical analyses using standard RNA-sequencing analysis methods without modifying the read counts themselves, preserving important information about the mean-variance relationship in the data. We illustrate the utility of this approach by generating and analyzing a ciprofloxacin-treated transposon insertion sequencing data set in Escherichia coli as a case study. We show that ciprofloxacin treatment generates chromosomal location bias in the resulting data, and we further demonstrate that failing to correct for this bias leads to false predictions of mutant drug sensitivity as measured by minimum inhibitory concentrations. We have developed an R package and user-friendly graphical Shiny application, ChromoCorrect, that detects and corrects for chromosomal bias in read count data, enabling the application of functional genomics technologies to the study of antibiotic stress.IMPORTANCEAltered gene dosage due to changes in DNA replication has been observed under a variety of stresses with a variety of experimental techniques. However, the implications of changes in gene dosage for sequencing-based functional genomics assays are rarely considered. We present a statistically principled approach to correcting for the effect of changes in gene dosage, enabling testing for differences in the fitness effects or regulation of individual genes in the presence of confounding differences in DNA copy number. We show that failing to correct for these effects can lead to incorrect predictions of resistance phenotype when applying functional genomics assays to investigate antibiotic stress, and we provide a user-friendly application to detect and correct for changes in DNA copy number.
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Affiliation(s)
- Geraldine J. Sullivan
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Lars Barquist
- Faculty of Medicine, University of Würzburg, Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), Würzburg, Germany
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Amy K. Cain
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, Sydney, Australia
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Zhi Q, Tan G, Wu S, Ma Q, Fan J, Chen Y, Li J, Hu Z, Xiao Y, Li L, Liu Z, Yang Z, Yang Z, Meng D, Yin H, Tang Q, Liu T. What role do biocontrol agents with Mg 2+ play in the fate of antibiotic resistome and pathogenic bacteria in the phyllosphere? mSystems 2024; 9:e0112623. [PMID: 38506511 PMCID: PMC11019836 DOI: 10.1128/msystems.01126-23] [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: 11/20/2023] [Accepted: 01/10/2024] [Indexed: 03/21/2024] Open
Abstract
The contamination of the plant phyllosphere with antibiotics and antibiotic resistance genes (ARGs), caused by application of antibiotics, is a significant environmental issue in agricultural management. Alternatively, biocontrol agents are environmentally friendly and have attracted a lot of interest. However, the influence of biocontrol agents on the phyllosphere resistome remains unknown. In this study, we applied biocontrol agents to control the wildfire disease in the Solanaceae crops and investigated their effects on the resistome and the pathogen in the phyllosphere by using metagenomics. A total of 250 ARGs were detected from 15 samples, which showed a variation in distribution across treatments of biocontrol agents (BA), BA with Mg2+ (T1), BA with Mn2+ (T2), and kasugamycin (T3) and nontreated (CK). The results showed that the abundance of ARGs under the treatment of BA-Mg2+ was lower than that in the CK group. The abundance of cphA3 (carbapenem resistance), PME-1 (carbapenem resistance), tcr3 (tetracycline antibiotic resistance), and AAC (3)-VIIIa (aminoglycoside antibiotic resistance) in BA-Mg2+ was significantly higher than that in BA-Mn2+ (P < 0.05). The abundance of cphA3, PME_1, and tcr3 was significantly negatively related to the abundance of the phyllosphere pathogen Pseudomonas syringae (P < 0.05). We also found that the upstream and downstream regions of cphA3 were relatively conserved, in which rpl, rpm, and rps gene families were identified in most sequences (92%). The Ka/Ks of cphA3 was 0 in all observed sequences, indicating that under the action of purifying selection, nonsynonymous substitutions are often gradually eliminated in the population. Overall, this study clarifies the effect of biocontrol agents with Mg2+ on the distribution of the phyllosphere resistome and provides evolutionary insights into the biocontrol process. IMPORTANCE Our study applied metagenomics analysis to examine the impact of biocontrol agents (BAs) on the phyllosphere resistome and the pathogen. Irregular use of antibiotics has led to the escalating dissemination of antibiotic resistance genes (ARGs) in the environment. The majority of BA research has focused on the effect of monospecies on the plant disease control process, the role of the compound BA with nutrition elements in the phyllosphere disease, and the resistome is still unknown. We believe BAs are eco-friendly alternatives for antibiotics to combat the transfer of ARGs. Our results revealed that BA-Mg2+ had a lower relative abundance of ARGs compared to the CK group, and the phyllosphere pathogen Pseudomonas syringae was negatively related to three specific ARGs, cphA3, PME-1, and tcr3. These three genes also present different Ka/Ks. We believe that the identification of the distribution and evolution modes of ARGs further elucidates the ecological role and facilitates the development of BAs, which will attract general interest in this field.
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Affiliation(s)
- Qiqi Zhi
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Ge Tan
- China Tobacco Hunan Industrial Co., Ltd., Changsha, China
| | - Shaolong Wu
- Tobacco Research Institute of Hunan Province, Changsha, China
| | - Qianqian Ma
- College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Jianqiang Fan
- Technology Center, China Tobacco Fujian Industrial Co., Ltd, Xiamen, Fujian, China
| | - Yiqiang Chen
- Technology Center, China Tobacco Fujian Industrial Co., Ltd, Xiamen, Fujian, China
| | - Jingjing Li
- Technology Center, China Tobacco Fujian Industrial Co., Ltd, Xiamen, Fujian, China
| | - Zhengrong Hu
- Tobacco Research Institute of Hunan Province, Changsha, China
| | - Yansong Xiao
- Chenzhou Tobacco Company of Hunan Province, Chenzhou, China
| | - Liangzhi Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Zhenghua Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Zhaoyue Yang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Zhendong Yang
- School of Architecture and Civil Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Delong Meng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Huaqun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
| | - Qianjun Tang
- College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Tianbo Liu
- Tobacco Research Institute of Hunan Province, Changsha, China
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7
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Johnson CN, Wilde S, Tuomanen E, Rosch JW. Convergent impact of vaccination and antibiotic pressures on pneumococcal populations. Cell Chem Biol 2024; 31:195-206. [PMID: 38052216 PMCID: PMC10938186 DOI: 10.1016/j.chembiol.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/08/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023]
Abstract
Streptococcus pneumoniae is a remarkably adaptable and successful human pathogen, playing dual roles of both asymptomatic carriage in the nasopharynx and invasive disease including pneumonia, bacteremia, and meningitis. Efficacious vaccines and effective antibiotic therapies are critical to mitigating morbidity and mortality. However, clinical interventions can be rapidly circumvented by the pneumococcus by its inherent proclivity for genetic exchange. This leads to an underappreciated interplay between vaccine and antibiotic pressures on pneumococcal populations. Circulating populations have undergone dramatic shifts due to the introduction of capsule-based vaccines of increasing valency imparting strong selective pressures. These alterations in population structure have concurrent consequences on the frequency of antibiotic resistance profiles in the population. This review will discuss the interactions of these two selective forces. Understanding and forecasting the drivers of antibiotic resistance and capsule switching are of critical importance for public health, particularly for such a genetically promiscuous pathogen as S. pneumoniae.
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Affiliation(s)
- Cydney N Johnson
- Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shyra Wilde
- Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Elaine Tuomanen
- Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Jason W Rosch
- Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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Fishbein SRS, Mahmud B, Dantas G. Antibiotic perturbations to the gut microbiome. Nat Rev Microbiol 2023; 21:772-788. [PMID: 37491458 DOI: 10.1038/s41579-023-00933-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2023] [Indexed: 07/27/2023]
Abstract
Antibiotic-mediated perturbation of the gut microbiome is associated with numerous infectious and autoimmune diseases of the gastrointestinal tract. Yet, as the gut microbiome is a complex ecological network of microorganisms, the effects of antibiotics can be highly variable. With the advent of multi-omic approaches for systems-level profiling of microbial communities, we are beginning to identify microbiome-intrinsic and microbiome-extrinsic factors that affect microbiome dynamics during antibiotic exposure and subsequent recovery. In this Review, we discuss factors that influence restructuring of the gut microbiome on antibiotic exposure. We present an overview of the currently complex picture of treatment-induced changes to the microbial community and highlight essential considerations for future investigations of antibiotic-specific outcomes. Finally, we provide a synopsis of available strategies to minimize antibiotic-induced damage or to restore the pretreatment architectures of the gut microbial community.
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Affiliation(s)
- Skye R S Fishbein
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Bejan Mahmud
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
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9
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Maziero M, Lane D, Polard P, Bergé M. Fever-like temperature bursts promote competence development via an HtrA-dependent pathway in Streptococcus pneumoniae. PLoS Genet 2023; 19:e1010946. [PMID: 37699047 PMCID: PMC10516426 DOI: 10.1371/journal.pgen.1010946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 09/22/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023] Open
Abstract
Streptococcus pneumoniae (the pneumococcus) is well known for its ability to develop competence for natural DNA transformation. Competence development is regulated by an autocatalytic loop driven by variations in the basal level of transcription of the comCDE and comAB operons. These genes are part of the early gene regulon that controls expression of the late competence genes known to encode the apparatus of transformation. Several stressful conditions are known to promote competence development, although the induction pathways are remain poorly understood. Here we demonstrate that transient temperature elevation induces an immediate increase in the basal expression level of the comCDE operon and early genes that, in turn, stimulates its full induction, including that of the late competence regulon. This thermal regulation depends on the HtrA chaperone/protease and its proteolytic activity. We find that other competence induction stimulus, like norfloxacin, is not conveyed by the HtrA-dependent pathway. This finding strongly suggests that competence can be induced by at least two independent pathways and thus reinforces the view that competence is a general stress response system in the pneumococcus.
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Affiliation(s)
- Mickaël Maziero
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - David Lane
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Patrice Polard
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Mathieu Bergé
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), UMR5100, Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France
- Université Paul Sabatier (Toulouse III), Toulouse, France
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10
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Brück P, Wasser D, Soppa J. Ploidy in Vibrio natriegens: Very Dynamic and Rapidly Changing Copy Numbers of Both Chromosomes. Genes (Basel) 2023; 14:1437. [PMID: 37510340 PMCID: PMC10379091 DOI: 10.3390/genes14071437] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Vibrio natriegens is the fastest-growing bacterium, with a doubling time of approximately 12-14 min. It has a high potential for basic research and biotechnological applications, e.g., it can be used for the cell-free production of (labeled) heterologous proteins, for synthetic biological applications, and for the production of various compounds. However, the ploidy level in V. natriegens remains unknown. At nine time points throughout the growth curve, we analyzed the numbers of origins and termini of both chromosomes with qPCR and the relative abundances of all genomic sites with marker frequency analyses. During the lag phase until early exponential growth, the origin copy number and origin/terminus ratio of chromosome 1 increased severalfold, but the increase was lower for chromosome 2. This increase was paralleled by an increase in cell volume. During the exponential phase, the origin/terminus ratio and cell volume decreased again. This highly dynamic and fast regulation has not yet been described for any other species. In this study, the gene dosage increase in origin-adjacent genes during the lag phase is discussed together with the nonrandom distribution of genes on the chromosomes of V. natriegens. Taken together, the results of this study provide the first comprehensive overview of the chromosome dynamics in V. natriegens and will guide the optimization of molecular biological characterization and biotechnological applications.
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Affiliation(s)
- Patrik Brück
- Institute for Molecular Biosciences, Goethe University, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Daniel Wasser
- Institute for Molecular Biosciences, Goethe University, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Jörg Soppa
- Institute for Molecular Biosciences, Goethe University, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
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11
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Zhu S, Yang B, Wang Z, Liu Y. Augmented dissemination of antibiotic resistance elicited by non-antibiotic factors. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115124. [PMID: 37327521 DOI: 10.1016/j.ecoenv.2023.115124] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/24/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
The emergence and rapid spread of antibiotic resistance seriously compromise the clinical efficacy of current antibiotic therapies, representing a serious public health threat worldwide. Generally, drug-susceptible bacteria can acquire antibiotic resistance through genetic mutation or gene transfer, among which horizontal gene transfer (HGT) plays a dominant role. It is widely acknowledged that the sub-inhibitory concentrations of antibiotics are the key drivers in promoting the transmission of antibiotic resistance. However, accumulating evidence in recent years has shown that in addition to antibiotics, non-antibiotics can also accelerate the horizontal transfer of antibiotic resistance genes (ARGs). Nevertheless, the roles and potential mechanisms of non-antibiotic factors in the transmission of ARGs remain largely underestimated. In this review, we depict the four pathways of HGT and their differences, including conjugation, transformation, transduction and vesiduction. We summarize non-antibiotic factors accounting for the enhanced horizontal transfer of ARGs and their underlying molecular mechanisms. Finally, we discuss the limitations and implications of current studies.
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Affiliation(s)
- Shuyao Zhu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Bingqing Yang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhiqiang Wang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China.
| | - Yuan Liu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China; Institute of Comparative Medicine, Yangzhou University, Yangzhou, Jiangsu, China.
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12
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Moreno-Gámez S, Hochberg ME, van Doorn GS. Quorum sensing as a mechanism to harness the wisdom of the crowds. Nat Commun 2023; 14:3415. [PMID: 37296108 PMCID: PMC10256802 DOI: 10.1038/s41467-023-37950-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 04/05/2023] [Indexed: 06/12/2023] Open
Abstract
Bacteria release and sense small molecules called autoinducers in a process known as quorum sensing. The prevailing interpretation of quorum sensing is that by sensing autoinducer concentrations, bacteria estimate population density to regulate the expression of functions that are only beneficial when carried out by a sufficiently large number of cells. However, a major challenge to this interpretation is that the concentration of autoinducers strongly depends on the environment, often rendering autoinducer-based estimates of cell density unreliable. Here we propose an alternative interpretation of quorum sensing, where bacteria, by releasing and sensing autoinducers, harness social interactions to sense the environment as a collective. Using a computational model we show that this functionality can explain the evolution of quorum sensing and arises from individuals improving their estimation accuracy by pooling many imperfect estimates - analogous to the 'wisdom of the crowds' in decision theory. Importantly, our model reconciles the observed dependence of quorum sensing on both population density and the environment and explains why several quorum sensing systems regulate the production of private goods.
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Affiliation(s)
- Stefany Moreno-Gámez
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands.
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Michael E Hochberg
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, 34095, Montpellier, France
- Santa Fe Institute, Santa Fe, NM, 87501, USA
| | - G S van Doorn
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
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13
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Jana B, Liu X, Dénéréaz J, Park H, Leshchiner D, Liu B, Gallay C, Veening JW, van Opijnen T. CRISPRi-TnSeq: A genome-wide high-throughput tool for bacterial essential-nonessential genetic interaction mapping. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543074. [PMID: 37398100 PMCID: PMC10312587 DOI: 10.1101/2023.05.31.543074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Genetic interaction networks can help identify functional connections between genes and pathways, which can be leveraged to establish (new) gene function, drug targets, and fill pathway gaps. Since there is no optimal tool that can map genetic interactions across many different bacterial strains and species, we develop CRISPRi-TnSeq, a genome-wide tool that maps genetic interactions between essential genes and nonessential genes through the knockdown of a targeted essential gene (CRISPRi) and the simultaneous knockout of individual nonessential genes (Tn-Seq). CRISPRi-TnSeq thereby identifies, on a genome-wide scale, synthetic and suppressor-type relationships between essential and nonessential genes, enabling the construction of essential-nonessential genetic interaction networks. To develop and optimize CRISPRi-TnSeq, CRISPRi strains were obtained for 13 essential genes in Streptococcus pneumoniae, involved in different biological processes including metabolism, DNA replication, transcription, cell division and cell envelope synthesis. Transposon-mutant libraries were constructed in each strain enabling screening of ∼24,000 gene-gene pairs, which led to the identification of 1,334 genetic interactions, including 754 negative and 580 positive genetic interactions. Through extensive network analyses and validation experiments we identify a set of 17 pleiotropic genes, of which a subset tentatively functions as genetic capacitors, dampening phenotypic outcomes and protecting against perturbations. Furthermore, we focus on the relationships between cell wall synthesis, integrity and cell division and highlight: 1) how essential gene knockdown can be compensated by rerouting flux through nonessential genes in a pathway; 2) the existence of a delicate balance between Z-ring formation and localization, and septal and peripheral peptidoglycan (PG) synthesis to successfully accomplish cell division; 3) the control of c-di-AMP over intracellular K + and turgor, and thereby modulation of the cell wall synthesis machinery; 4) the dynamic nature of cell wall protein CozEb and its effect on PG synthesis, cell shape morphology and envelope integrity; 5) functional dependency between chromosome decatenation and segregation, and the critical link with cell division, and cell wall synthesis. Overall, we show that CRISPRi-TnSeq uncovers genetic interactions between closely functionally linked genes and pathways, as well as disparate genes and pathways, highlighting pathway dependencies and valuable leads for gene function. Importantly, since both CRISPRi and Tn-Seq are widely used tools, CRISPRi-TnSeq should be relatively easy to implement to construct genetic interaction networks across many different microbial strains and species.
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14
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Wright GM, Menzel J, Tatman PD, Black JC. Transition from Transient DNA Rereplication to Inherited Gene Amplification Following Prolonged Environmental Stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539886. [PMID: 37214911 PMCID: PMC10197558 DOI: 10.1101/2023.05.08.539886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cells require the ability to adapt to changing environmental conditions, however, it is unclear how these changes elicit stable permanent changes in genomes. We demonstrate that, in response to environmental metal exposure, the metallothionein (MT) locus undergoes DNA rereplication generating transient site-specific gene amplifications (TSSGs). Chronic metal exposure allows transition from MT TSSG to inherited MT gene amplification through homologous recombination within and outside of the MT locus. DNA rereplication of the MT locus is suppressed by H3K27me3 and EZH2. Long-term ablation of EZH2 activity eventually leads to integration and inheritance of MT gene amplifications without the selective pressure of metal exposure. The rereplication and inheritance of MT gene amplification is an evolutionarily conserved response to environmental metal from yeast to human. Our results describe a new paradigm for adaptation to environmental stress where targeted, transient DNA rereplication precedes stable inherited gene amplification.
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15
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Calderón-Franco D, van Loosdrecht MCM, Abeel T, Weissbrodt DG. Catch me if you can: capturing microbial community transformation by extracellular DNA using Hi-C sequencing. Antonie Van Leeuwenhoek 2023:10.1007/s10482-023-01834-z. [PMID: 37156983 DOI: 10.1007/s10482-023-01834-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
The transformation of environmental microorganisms by extracellular DNA is an overlooked mechanism of horizontal gene transfer and evolution. It initiates the acquisition of exogenous genes and propagates antimicrobial resistance alongside vertical and conjugative transfers. We combined mixed-culture biotechnology and Hi-C sequencing to elucidate the transformation of wastewater microorganisms with a synthetic plasmid encoding GFP and kanamycin resistance genes, in the mixed culture of chemostats exposed to kanamycin at concentrations representing wastewater, gut and polluted environments (0.01-2.5-50-100 mg L-1). We found that the phylogenetically distant Gram-negative Runella (102 Hi-C links), Bosea (35), Gemmobacter (33) and Zoogloea (24) spp., and Gram-positive Microbacterium sp. (90) were transformed by the foreign plasmid, under high antibiotic exposure (50 mg L-1). In addition, the antibiotic pressure shifted the origin of aminoglycoside resistance genes from genomic DNA to mobile genetic elements on plasmids accumulating in microorganisms. These results reveal the power of Hi-C sequencing to catch and surveil the transfer of xenogenetic elements inside microbiomes.
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Affiliation(s)
| | | | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, Delft, The Netherlands
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - David G Weissbrodt
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway.
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16
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Echlin H, Iverson A, Sardo U, Rosch JW. Airway proteolytic control of pneumococcal competence. PLoS Pathog 2023; 19:e1011421. [PMID: 37256908 PMCID: PMC10259803 DOI: 10.1371/journal.ppat.1011421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 06/12/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that colonizes the upper respiratory tract asymptomatically and, upon invasion, can lead to severe diseases including otitis media, sinusitis, meningitis, bacteremia, and pneumonia. One of the first lines of defense against pneumococcal invasive disease is inflammation, including the recruitment of neutrophils to the site of infection. The invasive pneumococcus can be cleared through the action of serine proteases generated by neutrophils. It is less clear how serine proteases impact non-invasive pneumococcal colonization, which is the key first step to invasion and transmission. One significant aspect of pneumococcal biology and adaptation in the respiratory tract is its natural competence, which is triggered by a small peptide CSP. In this study, we investigate if serine proteases are capable of degrading CSP and the impact this has on pneumococcal competence. We found that CSP has several potential sites for trypsin-like serine protease degradation and that there were preferential cleavage sites recognized by the proteases. Digestion of CSP with two different trypsin-like serine proteases dramatically reduced competence in a dose-dependent manner. Incubation of CSP with mouse lung homogenate also reduced recombination frequency of the pneumococcus. These ex vivo experiments suggested that serine proteases in the lower respiratory tract reduce pneumococcal competence. This was subsequently confirmed measuring in vivo recombination frequencies after induction of protease production via poly (I:C) stimulation and via co-infection with influenza A virus, which dramatically lowered recombination events. These data shed light on a new mechanism by which the host can modulate pneumococcal behavior and genetic exchange via direct degradation of the competence signaling peptide.
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Affiliation(s)
- Haley Echlin
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Amy Iverson
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Ugo Sardo
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
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17
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Ashour ME, Byrum AK, Meroni A, Xia J, Singh S, Galletto R, Rosenberg SM, Vindigni A, Mosammaparast N. Rapid profiling of DNA replication dynamics using mass spectrometry-based analysis of nascent DNA. J Cell Biol 2023; 222:e202207121. [PMID: 36795402 PMCID: PMC9960042 DOI: 10.1083/jcb.202207121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 12/09/2022] [Accepted: 01/19/2023] [Indexed: 02/17/2023] Open
Abstract
The primary method for probing DNA replication dynamics is DNA fiber analysis, which utilizes thymidine analog incorporation into nascent DNA, followed by immunofluorescent microscopy of DNA fibers. Besides being time-consuming and prone to experimenter bias, it is not suitable for studying DNA replication dynamics in mitochondria or bacteria, nor is it adaptable for higher-throughput analysis. Here, we present mass spectrometry-based analysis of nascent DNA (MS-BAND) as a rapid, unbiased, quantitative alternative to DNA fiber analysis. In this method, incorporation of thymidine analogs is quantified from DNA using triple quadrupole tandem mass spectrometry. MS-BAND accurately detects DNA replication alterations in both the nucleus and mitochondria of human cells, as well as bacteria. The high-throughput capability of MS-BAND captured replication alterations in an E. coli DNA damage-inducing gene library. Therefore, MS-BAND may serve as an alternative to the DNA fiber technique, with potential for high-throughput analysis of replication dynamics in diverse model systems.
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Affiliation(s)
- Mohamed E. Ashour
- Department of Pathology and Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Andrea K. Byrum
- Department of Pathology and Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
- Center for Childhood Cancer & Blood Diseases, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Alice Meroni
- Division of Oncology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Jun Xia
- Departments of Molecular and Human Genetics, Biochemistry and Molecular Biology, and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
- Department of Biomedical Sciences, Creighton University, Omaha, NE, USA
| | - Saurabh Singh
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Roberto Galletto
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Susan M. Rosenberg
- Departments of Molecular and Human Genetics, Biochemistry and Molecular Biology, and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Alessandro Vindigni
- Division of Oncology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Nima Mosammaparast
- Department of Pathology and Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
- Division of Oncology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
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18
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Morawska LP, Kuipers OP. Cell-to-cell non-conjugative plasmid transfer between Bacillus subtilis and lactic acid bacteria. Microb Biotechnol 2023; 16:784-798. [PMID: 36547214 PMCID: PMC10034627 DOI: 10.1111/1751-7915.14195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 11/15/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
Bacillus subtilis is a soil-dwelling bacterium that can interact with a plethora of other microorganisms in its natural habitat. Due to the versatile interactions and its ability to form nanotubes, i.e., recently described membrane structures that trade cytoplasmic content between neighbouring cells, we investigated the potential of HGT from B. subtilis to industrially-relevant members of lactic acid bacteria (LAB). To explore the interspecies HGT events, we developed a co-culturing protocol and provided proof of transfer of a small high copy non-conjugative plasmid from B. subtilis to LABs. Interestingly, the plasmid transfer did not involve conjugation nor activation of the competent state by B. subtilis. Moreover, our study shows for the first time non-conjugative cell-to-cell intraspecies plasmid transfer for non-competent Lactococcus lactis sp. cremoris strains. Our study indicates that cell-to-cell transformation is a ubiquitous form of HGT and can be potentially utilized as an alternative tool for natural (non-GMO) strain improvement.
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Affiliation(s)
- Luiza P Morawska
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Oscar P Kuipers
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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19
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Sharma V, Hünnefeld M, Luthe T, Frunzke J. Systematic analysis of prophage elements in actinobacterial genomes reveals a remarkable phylogenetic diversity. Sci Rep 2023; 13:4410. [PMID: 36932119 PMCID: PMC10023795 DOI: 10.1038/s41598-023-30829-z] [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: 06/25/2022] [Accepted: 03/02/2023] [Indexed: 03/19/2023] Open
Abstract
Actinobacteria represent one of the largest bacterial phyla harboring many species of high medical, biotechnological and ecological relevance. Prophage elements are major contributors to bacterial genome diversity and were shown to significantly shape bacterial fitness and host-microbe interactions. In this study, we performed a systematic analysis of prophage elements in 2406 complete actinobacterial genomes. Overall, 2106 prophage elements were predicted to be present in about 50% (1172/2406) of the analyzed datasets. Interestingly, these identified sequences compose a high prevalence of cryptic prophage elements, indicating genetic decay and domestication. Analysis of the sequence relationship of predicted prophages with known actinobacteriophage genomes revealed an exceptional high phylogenetic diversity of prophage elements. As a trend, we observed a higher prevalence of prophage elements in vicinity to the terminus. Analysis of the prophage-encoded gene functions revealed that prophage sequences significantly contribute to the bacterial antiviral immune system, but no biosynthetic gene clusters involved in the synthesis of known antiphage molecules were identified in prophage genomes. Overall, the current study highlights the remarkable diversity of prophages in actinobacterial genomes, with highly divergent prophages in actinobacterial genomes and thus provides an important basis for further investigation of phage-host interactions in this important bacterial phylum.
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Affiliation(s)
- Vikas Sharma
- Institute of Bio- and Geosciences (IBG-1) Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - Max Hünnefeld
- Institute of Bio- and Geosciences (IBG-1) Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Tom Luthe
- Institute of Bio- and Geosciences (IBG-1) Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences (IBG-1) Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany.
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20
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Chromosomal Position of Ribosomal Protein Genes Affects Long-Term Evolution of Vibrio cholerae. mBio 2023; 14:e0343222. [PMID: 36861972 PMCID: PMC10127744 DOI: 10.1128/mbio.03432-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
It is unclear how gene order within the chromosome influences genome evolution. Bacteria cluster transcription and translation genes close to the replication origin (oriC). In Vibrio cholerae, relocation of s10-spc-α locus (S10), the major locus of ribosomal protein genes, to ectopic genomic positions shows that its relative distance to the oriC correlates to a reduction in growth rate, fitness, and infectivity. To test the long-term impact of this trait, we evolved 12 populations of V. cholerae strains bearing S10 at an oriC-proximal or an oriC-distal location for 1,000 generations. During the first 250 generations, positive selection was the main force driving mutation. After 1,000 generations, we observed more nonadaptative mutations and hypermutator genotypes. Populations fixed inactivating mutations at many genes linked to virulence: flagellum, chemotaxis, biofilm, and quorum sensing. Throughout the experiment, all populations increased their growth rates. However, those bearing S10 close to oriC remained the fittest, indicating that suppressor mutations cannot compensate for the genomic position of the main ribosomal protein locus. Selection and sequencing of the fastest-growing clones allowed us to characterize mutations inactivating, among other sites, flagellum master regulators. Reintroduction of these mutations into the wild-type context led to a ≈10% growth improvement. In conclusion, the genomic location of ribosomal protein genes conditions the evolutionary trajectory of V. cholerae. While genomic content is highly plastic in prokaryotes, gene order is an underestimated factor that conditions cellular physiology and evolution. A lack of suppression enables artificial gene relocation as a tool for genetic circuit reprogramming. IMPORTANCE The bacterial chromosome harbors several entangled processes such as replication, transcription, DNA repair, and segregation. Replication begins bidirectionally at the replication origin (oriC) until the terminal region (ter) organizing the genome along the ori-ter axis gene order along this axis could link genome structure to cell physiology. Fast-growing bacteria cluster translation genes near oriC. In Vibrio cholerae, moving them away was feasible but at the cost of losing fitness and infectivity. Here, we evolved strains harboring ribosomal genes close or far from oriC. Growth rate differences persisted after 1,000 generations. No mutation was able to compensate for the growth defect, showing that ribosomal gene location conditions their evolutionary trajectory. Despite the high plasticity of bacterial genomes, evolution has sculpted gene order to optimize the ecological strategy of the microorganism. We observed growth rate improvement throughout the evolution experiment that occurred at expense of energetically costly processes such the flagellum biosynthesis and virulence-related functions. From the biotechnological point of view, manipulation of gene order enables altering bacterial growth with no escape events.
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21
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Liu C, Du P, Yang P, Zheng J, Yi J, Lu M, Shen N. Emergence and Inter- and Intrahost Evolution of Pandrug-Resistant Klebsiella pneumoniae Coharboring tmexCD1-toprJ1, blaNDM-1, and blaKPC-2. Microbiol Spectr 2023; 11:e0278622. [PMID: 36719204 PMCID: PMC10100677 DOI: 10.1128/spectrum.02786-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 01/09/2023] [Indexed: 02/01/2023] Open
Abstract
Klebsiella pneumoniae is capable of acquiring various exogenous genetic elements and subsequently conferring high antimicrobial resistance. Recently, a plasmid-mediated RND family multidrug efflux pump gene cluster, tmexCD1-toprJ1, was discovered in K. pneumoniae. In this study, we analyzed tigecycline-resistant K. pneumoniae isolates from patients from surveillance from 2017 to 2021. In addition to phenotype detection, including growth curves, plasmid transferability and stability, hypermucoviscosity, biofilm formation, and serum survival, by whole-genome sequencing, we analyzed the phylogenetic relationships of the isolates harboring tmexCD1-toprJ1 and discovered the composition of plasmids carrying tmexCD1-toprJ1. In total, we discovered that 12 tigecycline-resistant isolates from 5 patients possessed tmexCD1-toprJ1, designated sequence type 22 (ST22) and ST3691. An ST11 isolate harbored a partial tmexD1, and a complete toprJ1 (tmexC1 was lost) was tigecycline sensitive. All the ST22 tigecycline-resistant isolates coharbored tmexCD1-toprJ1, blaNDM-1, and blaKPC-2. tmexCD1-toprJ1 was encoded by a novel IncU plasmid in ST22 and an IncFIB/HI1B plasmid in ST3691, which presented differences in mobility and stability. Interestingly, isolates from the same patients presented heteroresistance to tigecycline, not only among isolates from different specimens but also those from the same sample, which might be attributed to the differential expression of tmexCD1-toprJ1 due to the dynamic genetic heterogeneity caused by relocating tmexCD1-toprJ1 close to the replication origin of plasmid. Here, we reported the emergence of K. pneumoniae isolates coharboring tmexCD1-toprJ1, blaNDM-1, and blaKPC-2. The results highlight the impact of in vivo genetic heterogeneity of tmexCD1-toprJ1-carrying elements on the in vivo variation of tigecycline resistance, which might have notable influences on antimicrobial treatment. IMPORTANCE Pandrug-resistant (PDR) Klebsiella pneumoniae poses a great challenge to public health, and tigecycline is an essential choice for antimicrobial treatment. In this study, we reported the emergence of PDR K. pneumoniae coharboring tmexCD1-toprJ1, blaNDM-1, and blaKPC-2, which belongs to ST22 and ST3691. By whole-genome analysis, we reconstructed the evolutionary map of the ST22 ancestor to become the PDR superbug by acquiring multiple genetic elements encoding tmexCD1-toprJ1 or blaNDM-1. Importantly, the genetic contexts of tmexCD1-toprJ1 among the ST22 isolates are different and present with various mobilities and stabilities. Furthermore, we also discovered the heterogeneity of tigecycline resistance during long-term infection of ST22, which might be attributed to the differential expression of tmexCD1-toprJ1 due to the dynamic genetic heterogeneity caused by relocating tmexCD1-toprJ1 close to the replication origin of plasmid. This study tracks the inter- and intrahost microevolution of the superbug PDR K. pneumoniae and highlights the importance of timely monitoring of the variation of pathogens during antimicrobial treatment.
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Affiliation(s)
- Chao Liu
- Department of Infectious Disease, Peking University Third Hospital, Beijing, China
- Center of Infectious Disease, Peking University Third Hospital, Beijing, China
| | | | - Ping Yang
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Jiajia Zheng
- Department of Laboratory Medicine, Peking University Third Hospital, Beijing, China
| | - Juan Yi
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Ming Lu
- Department of Infectious Disease, Peking University Third Hospital, Beijing, China
- Center of Infectious Disease, Peking University Third Hospital, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China
| | - Ning Shen
- Department of Infectious Disease, Peking University Third Hospital, Beijing, China
- Center of Infectious Disease, Peking University Third Hospital, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
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22
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Minhas V, Domenech A, Synefiaridou D, Straume D, Brendel M, Cebrero G, Liu X, Costa C, Baldry M, Sirard JC, Perez C, Gisch N, Hammerschmidt S, Håvarstein LS, Veening JW. Competence remodels the pneumococcal cell wall exposing key surface virulence factors that mediate increased host adherence. PLoS Biol 2023; 21:e3001990. [PMID: 36716340 PMCID: PMC9910801 DOI: 10.1371/journal.pbio.3001990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 02/09/2023] [Accepted: 01/04/2023] [Indexed: 02/01/2023] Open
Abstract
Competence development in the human pathogen Streptococcus pneumoniae controls several features such as genetic transformation, biofilm formation, and virulence. Competent bacteria produce so-called "fratricins" such as CbpD that kill noncompetent siblings by cleaving peptidoglycan (PGN). CbpD is a choline-binding protein (CBP) that binds to phosphorylcholine residues found on wall and lipoteichoic acids (WTA and LTA) that together with PGN are major constituents of the pneumococcal cell wall. Competent pneumococci are protected against fratricide by producing the immunity protein ComM. How competence and fratricide contribute to virulence is unknown. Here, using a genome-wide CRISPRi-seq screen, we show that genes involved in teichoic acid (TA) biosynthesis are essential during competence. We demonstrate that LytR is the major enzyme mediating the final step in WTA formation, and that, together with ComM, is essential for immunity against CbpD. Importantly, we show that key virulence factors PspA and PspC become more surface-exposed at midcell during competence, in a CbpD-dependent manner. Together, our work supports a model in which activation of competence is crucial for host adherence by increased surface exposure of its various CBPs.
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Affiliation(s)
- Vikrant Minhas
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne, Switzerland
| | - Arnau Domenech
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne, Switzerland
| | - Dimitra Synefiaridou
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne, Switzerland
| | - Daniel Straume
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Max Brendel
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, Universität Greifswald, Greifswald, Germany
| | | | - Xue Liu
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne, Switzerland,Guangdong Key Laboratory for Genome Stability and Human Disease Prevention, Department of Pharmacology, International Cancer Center, Shenzhen University Health Science Center, Shenzhen, China
| | - Charlotte Costa
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Mara Baldry
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Jean-Claude Sirard
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Camilo Perez
- Biozentrum, University of Basel, Basel, Switzerland
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, Universität Greifswald, Greifswald, Germany
| | - Leiv Sigve Håvarstein
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway,* E-mail: (LSH); (J-WV)
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne, Switzerland,* E-mail: (LSH); (J-WV)
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23
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Jim KK, Aprianto R, Koning R, Domenech A, Kurushima J, van de Beek D, Vandenbroucke-Grauls CMJE, Bitter W, Veening JW. Pneumolysin promotes host cell necroptosis and bacterial competence during pneumococcal meningitis as shown by whole-animal dual RNA-seq. Cell Rep 2022; 41:111851. [PMID: 36543127 PMCID: PMC9794515 DOI: 10.1016/j.celrep.2022.111851] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/16/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Pneumolysin is a major virulence factor of Streptococcus pneumoniae that plays a key role in interaction with the host during invasive disease. How pneumolysin influences these dynamics between host and pathogen interaction during early phase of central nervous system infection in pneumococcal meningitis remains unclear. Using a whole-animal in vivo dual RNA sequencing (RNA-seq) approach, we identify pneumolysin-specific transcriptional responses in both S. pneumoniae and zebrafish (Danio rerio) during early pneumococcal meningitis. By functional enrichment analysis, we identify host pathways known to be activated by pneumolysin and discover the importance of necroptosis for host survival. Inhibition of this pathway using the drug GSK'872 increases host mortality during pneumococcal meningitis. On the pathogen's side, we show that pneumolysin-dependent competence activation is crucial for intra-host replication and virulence. Altogether, this study provides new insights into pneumolysin-specific transcriptional responses and identifies key pathways involved in pneumococcal meningitis.
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Affiliation(s)
- Kin Ki Jim
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands; Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Rieza Aprianto
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Rutger Koning
- Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Arnau Domenech
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Jun Kurushima
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Diederik van de Beek
- Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Christina M J E Vandenbroucke-Grauls
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands
| | - Wilbert Bitter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands; Section of Molecular Microbiology, Amsterdam Institute for Molecules, Medicines and Systems, VU University Amsterdam, 1081 Amsterdam, the Netherlands
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland.
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A Genome-Wide CRISPR Interference Screen Reveals an StkP-Mediated Connection between Cell Wall Integrity and Competence in Streptococcus salivarius. mSystems 2022; 7:e0073522. [PMID: 36342134 PMCID: PMC9765292 DOI: 10.1128/msystems.00735-22] [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] [Indexed: 11/09/2022] Open
Abstract
Competence is one of the most efficient bacterial evolutionary and adaptative strategies by synchronizing production of antibacterial compounds and integration of DNA released by dead cells. In most streptococci, this tactic is orchestrated by the ComRS system, a pheromone communication device providing a short time window of activation in which only part of the population is responsive. Understanding how this developmental process integrates multiple inputs to fine-tune the adequate response is a long-standing question. However, essential genes involved in the regulation of ComRS have been challenging to study. In this work, we built a conditional mutant library using CRISPR interference and performed three complementary screens to investigate competence genetic regulation in the human commensal Streptococcus salivarius. We show that initiation of competence increases upon cell wall impairment, suggesting a connection between cell envelope stress and competence activation. Notably, we report a key role for StkP, a serine-threonine kinase known to regulate cell wall homeostasis. We show that StkP controls competence by a mechanism that reacts to peptidoglycan fragments. Together, our data suggest a key cell wall sensing mechanism coupling competence to cell envelope integrity. IMPORTANCE Survival of human commensal streptococci in the digestive tract requires efficient strategies which must be tightly and collectively controlled for responding to competitive pressure and drastic environmental changes. In this context, the autocrine signaling system ComRS controlling competence for natural transformation and predation in salivarius streptococci could be seen as a multi-input device integrating a variety of environmental stimuli. In this work, we revealed novel positive and negative competence modulators by using a genome-wide CRISPR interference strategy. Notably, we highlighted an unexpected connection between bacterial envelope integrity and competence activation that involves several cell wall sensors. Together, these results showcase how commensal streptococci can fine-tune the pheromone-based competence system by responding to multiple inputs affecting their physiological status in order to calibrate an appropriate collective behavior.
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25
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Barbuti MD, Myrbråten IS, Morales Angeles D, Kjos M. The cell cycle of Staphylococcus aureus: An updated review. Microbiologyopen 2022; 12:e1338. [PMID: 36825883 PMCID: PMC9733580 DOI: 10.1002/mbo3.1338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
As bacteria proliferate, DNA replication, chromosome segregation, cell wall synthesis, and cytokinesis occur concomitantly and need to be tightly regulated and coordinated. Although these cell cycle processes have been studied for decades, several mechanisms remain elusive, specifically in coccus-shaped cells such as Staphylococcus aureus. In recent years, major progress has been made in our understanding of how staphylococci divide, including new, fundamental insights into the mechanisms of cell wall synthesis and division site selection. Furthermore, several novel proteins and mechanisms involved in the regulation of replication initiation or progression of the cell cycle have been identified and partially characterized. In this review, we will summarize our current understanding of the cell cycle processes in the spheroid model bacterium S. aureus, with a focus on recent advances in the understanding of how these processes are regulated.
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Affiliation(s)
- Maria D. Barbuti
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Ine S. Myrbråten
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Danae Morales Angeles
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
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26
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Stebliankin V, Sazal M, Valdes C, Mathee K, Narasimhan G. A novel approach for combining the metagenome, metaresistome, metareplicome and causal inference to determine the microbes and their antibiotic resistance gene repertoire that contribute to dysbiosis. Microb Genom 2022; 8:mgen000899. [PMID: 36748547 PMCID: PMC9837561 DOI: 10.1099/mgen.0.000899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 09/11/2022] [Indexed: 12/24/2022] Open
Abstract
The use of whole metagenomic data to infer the relative abundance of all its microbes is well established. The same data can be used to determine the replication rate of all eubacterial taxa with circular chromosomes. Despite their availability, the replication rate profiles (metareplicome) have not been fully exploited in microbiome analyses. Another relatively new approach is the application of causal inferencing to analyse microbiome data that goes beyond correlational studies. A novel scalable pipeline called MeRRCI (Metagenome, metaResistome, and metaReplicome for Causal Inferencing) was developed. MeRRCI combines efficient computation of the metagenome (bacterial relative abundance), metaresistome (antimicrobial gene abundance) and metareplicome (replication rates), and integrates environmental variables (metadata) for causality analysis using Bayesian networks. MeRRCI was applied to an infant gut microbiome data set to investigate the microbial community's response to antibiotics. Our analysis suggests that the current treatment stratagem contributes to preterm infant gut dysbiosis, allowing a proliferation of pathobionts. The study highlights the specific antibacterial resistance genes that may contribute to exponential cell division in the presence of antibiotics for various pathogens, namely Klebsiella pneumoniae, Citrobacter freundii, Staphylococcus epidermidis, Veilonella parvula and Clostridium perfringens. These organisms often contribute to the harmful long-term sequelae seen in these young infants.
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Affiliation(s)
- Vitalii Stebliankin
- Bioinformatics Research Group (BioRG), Knight Foundation School of Computing and Information Sciences, Florida International University, Miami, FL, USA
| | - Musfiqur Sazal
- Bioinformatics Research Group (BioRG), Knight Foundation School of Computing and Information Sciences, Florida International University, Miami, FL, USA
- Present address: Microsoft Corporation, GA, Atlanta, USA
| | - Camilo Valdes
- Bioinformatics Research Group (BioRG), Knight Foundation School of Computing and Information Sciences, Florida International University, Miami, FL, USA
- Present address: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
| | - Kalai Mathee
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Giri Narasimhan
- Bioinformatics Research Group (BioRG), Knight Foundation School of Computing and Information Sciences, Florida International University, Miami, FL, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
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27
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Kulathunga DGRS, Fakher AA, Costa MDO. Actinobacillus suis
isolated from diseased pigs are phylogenetically related but harbour different number of toxin gene copies in their genomes. Vet Rec Open 2022; 9:e45. [PMID: 36213600 PMCID: PMC9528957 DOI: 10.1002/vro2.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 08/06/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Objective The Gram‐negative bacterium Actinobacillus suis is an agent of global importance to the swine industry and the cause of lethal respiratory or septicaemic disease in pigs of different ages. Between 2018 and 2019, seven commercial farms in western Canada experienced episodes of increased mortality due to A. suis infection in grower pigs. The goal of this work was to profile, with molecular methods, A. suis isolated from diseased pigs and to compare them to other isolates. Design This inferential observational study used nine western Canadian strains obtained from diseased lungs (n = 6), heart (n = 2) and brain (n = 1) and whole genome sequencing was performed. Comparative genomic analyses were performed to characterise the genetic variability, antimicrobial resistance and the virulence genes present. Results Compared to the reference strain (ATCC 33415), an increased number of RTX (repeats in the structural toxin) gene copies were identified in strains isolated from organs without a mucosal surface, thus theoretically harder to invade. Western Canadian strains did not harbour genes associated with resistance to antimicrobial agents used in swine production. Novel regions were also identified in the genomes of five of nine strains demonstrating recombination and emergence of novel strains. Conclusions The results obtained in this study were associated with the emergence of new lineages. An increased number of RTX toxin gene copies is suggested to be associated with increased virulence. This study will contribute to improve our understanding regarding A. suis and may help guide vaccine development and agent control measures.
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Affiliation(s)
| | - Alaa Abou Fakher
- Department of Population Health Sciences Faculty of Veterinary Medicine Utrecht University Yalelaan 7 Utrecht The Netherlands
| | - Matheus de Oliveira Costa
- Department of Large Animal Clinical Sciences Western College of Veterinary Medicine University of Saskatchewan Saskatoon Saskatchewan Canada
- Department of Population Health Sciences Faculty of Veterinary Medicine Utrecht University Yalelaan 7 Utrecht The Netherlands
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28
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Okoye CO, Nyaruaba R, Ita RE, Okon SU, Addey CI, Ebido CC, Opabunmi AO, Okeke ES, Chukwudozie KI. Antibiotic resistance in the aquatic environment: Analytical techniques and interactive impact of emerging contaminants. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2022; 96:103995. [PMID: 36210048 DOI: 10.1016/j.etap.2022.103995] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 09/19/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Antibiotic pollution is becoming an increasingly severe threat globally. Antibiotics have emerged as a new class of environmental pollutants due to their expanding usage and indiscriminate application in animal husbandry as growth boosters. Contamination of aquatic ecosystems by antibiotics can have a variety of negative impacts on the microbial flora of these water bodies, as well as lead to the development and spread of antibiotic-resistant genes. Various strategies for removing antibiotics from aqueous systems and environments have been developed. Many of these approaches, however, are constrained by their high operating costs and the generation of secondary pollutants. This review aims to summarize research on the distribution and effects of antibiotics in aquatic environments, their interaction with other emerging contaminants, and their remediation strategy. The ecological risks associated with antibiotics in aquatic ecosystems and the need for more effective monitoring and detection system are also highlighted.
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Affiliation(s)
- Charles Obinwanne Okoye
- Biofuels Institute, School of Environment & Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China; Department of Zoology & Environmental Biology, University of Nigeria, Nsukka 410001, Nigeria; Organization of African Academic Doctor, Nairobi, Kenya
| | - Raphael Nyaruaba
- Center for Biosafety Megascience, Wuhan Institute of Virology, CAS, Wuhan, PR China; Organization of African Academic Doctor, Nairobi, Kenya
| | - Richard Ekeng Ita
- Department of Biological Sciences Ritman University, Ikot Ekpene, Akwa Ibom State, Nigeria; Organization of African Academic Doctor, Nairobi, Kenya
| | - Samuel Ukpong Okon
- Department of Marine Science, Akwa Ibom State University, Mkpat Enin, P.M.B. 1167, Nigeria; Department of Ocean Engineering, Ocean College, Zhejiang University, Zhoushan 316021, PR China; Organization of African Academic Doctor, Nairobi, Kenya
| | - Charles Izuma Addey
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, PR China; Organization of African Academic Doctor, Nairobi, Kenya
| | - Chike C Ebido
- Department of Zoology & Environmental Biology, University of Nigeria, Nsukka 410001, Nigeria; Organization of African Academic Doctor, Nairobi, Kenya
| | | | - Emmanuel Sunday Okeke
- Department of Biochemistry, Faculty of Biological Sciences & Natural Science Unit, School of General Studies, University of Nigeria, Nsukka, Enugu State 410001, Nigeria; Institute of Environmental Health and Ecological Security, School of Environment and Safety Engineering, Jiangsu University, 212013, PR China; Organization of African Academic Doctor, Nairobi, Kenya.
| | - Kingsley Ikechukwu Chukwudozie
- Department of Microbiology, University of Nigeria, Nsukka, Enugu State 410001, Nigeria; Organization of African Academic Doctor, Nairobi, Kenya; Department of Clinical Medicine, School of Medicine, Jiangsu University 212013, PR China.
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29
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High pressure processing, acidic and osmotic stress increased resistance to aminoglycosides and tetracyclines and the frequency of gene transfer among strains from commercial starter and protective cultures. Food Microbiol 2022; 107:104090. [DOI: 10.1016/j.fm.2022.104090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 12/30/2022]
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30
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Gibson PS, Bexkens E, Zuber S, Cowley LA, Veening JW. The acquisition of clinically relevant amoxicillin resistance in Streptococcus pneumoniae requires ordered horizontal gene transfer of four loci. PLoS Pathog 2022; 18:e1010727. [PMID: 35877768 PMCID: PMC9352194 DOI: 10.1371/journal.ppat.1010727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/04/2022] [Accepted: 07/05/2022] [Indexed: 11/18/2022] Open
Abstract
Understanding how antimicrobial resistance spreads is critical for optimal application of new treatments. In the naturally competent human pathogen Streptococcus pneumoniae, resistance to β-lactam antibiotics is mediated by recombination events in genes encoding the target proteins, resulting in reduced drug binding affinity. However, for the front-line antibiotic amoxicillin, the exact mechanism of resistance still needs to be elucidated. Through successive rounds of transformation with genomic DNA from a clinically resistant isolate, we followed amoxicillin resistance development. Using whole genome sequencing, we showed that multiple recombination events occurred at different loci during one round of transformation. We found examples of non-contiguous recombination, and demonstrated that this could occur either through multiple D-loop formation from one donor DNA molecule, or by the integration of multiple DNA fragments. We also show that the final minimum inhibitory concentration (MIC) differs depending on recipient genome, explained by differences in the extent of recombination at key loci. Finally, through back transformations of mutant alleles and fluorescently labelled penicillin (bocillin-FL) binding assays, we confirm that pbp1a, pbp2b, pbp2x, and murM are the main resistance determinants for amoxicillin resistance, and that the order of allele uptake is important for successful resistance evolution. We conclude that recombination events are complex, and that this complexity contributes to the highly diverse genotypes of amoxicillin-resistant pneumococcal isolates.
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Affiliation(s)
- Paddy S. Gibson
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Evan Bexkens
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Sylvia Zuber
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Lauren A. Cowley
- Department of Biology & Biochemistry, Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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31
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Link Between Antibiotic Persistence and Antibiotic Resistance in Bacterial Pathogens. Front Cell Infect Microbiol 2022; 12:900848. [PMID: 35928205 PMCID: PMC9343593 DOI: 10.3389/fcimb.2022.900848] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/21/2022] [Indexed: 12/15/2022] Open
Abstract
Both, antibiotic persistence and antibiotic resistance characterize phenotypes of survival in which a bacterial cell becomes insensitive to one (or even) more antibiotic(s). However, the molecular basis for these two antibiotic-tolerant phenotypes is fundamentally different. Whereas antibiotic resistance is genetically determined and hence represents a rather stable phenotype, antibiotic persistence marks a transient physiological state triggered by various stress-inducing conditions that switches back to the original antibiotic sensitive state once the environmental situation improves. The molecular basics of antibiotic resistance are in principle well understood. This is not the case for antibiotic persistence. Under all culture conditions, there is a stochastically formed, subpopulation of persister cells in bacterial populations, the size of which depends on the culture conditions. The proportion of persisters in a bacterial population increases under different stress conditions, including treatment with bactericidal antibiotics (BCAs). Various models have been proposed to explain the formation of persistence in bacteria. We recently hypothesized that all physiological culture conditions leading to persistence converge in the inability of the bacteria to re-initiate a new round of DNA replication caused by an insufficient level of the initiator complex ATP-DnaA and hence by the lack of formation of a functional orisome. Here, we extend this hypothesis by proposing that in this persistence state the bacteria become more susceptible to mutation-based antibiotic resistance provided they are equipped with error-prone DNA repair functions. This is - in our opinion - in particular the case when such bacterial populations are exposed to BCAs.
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Affiliation(s)
- Wolfgang Eisenreich
- Bavarian NMR Center – Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
- *Correspondence: Wolfgang Eisenreich,
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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32
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Liu Y, Yang F, Wang S, Chi W, Ding L, Liu T, Zhu F, Ji D, Zhou J, Fang Y, Zhang J, Xiang P, Zhang Y, Zhao H. HopE and HopD Porin-Mediated Drug Influx Contributes to Intrinsic Antimicrobial Susceptibility and Inhibits Streptomycin Resistance Acquisition by Natural Transformation in Helicobacter pylori. Microbiol Spectr 2022; 10:e0198721. [PMID: 35234510 PMCID: PMC9045298 DOI: 10.1128/spectrum.01987-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/21/2022] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori is a human pathogen competent for natural transformation. Intrinsic and acquired antibiotic resistance contribute to the survival and multiplication of H. pylori under antibiotics. While drug-resistance dissemination by natural transformation (NT)-mediated horizontal gene transfer remains poorly understood in H. pylori. The purpose of the study was to investigate the role of H. pylori porins (HopA, HopB, HopC, HopD, and HopE) in the intrinsic antibiotic resistance and to preliminarily reveal the potential effect of HopE and HopD porins in streptomycin resistance acquisition after NT in the presence of antibiotics. Using traditional antibiotic susceptibility tests and growth curve analysis, we found the MIC values of metronidazole, clarithromycin, levofloxacin, tetracycline, rifampin, and streptomycin in mutants lacking HopE and/or HopD were significantly elevated compare to those in wild-type strain. The quantitative analysis of the tetramethyl rhodamine isothiocyanate (TRITC)-labeled streptomycin accumulation at the single-cell level showed reduced streptomycin intracellular fluorescence in ΔhopE and ΔhopD mutant cells. Furthermore, in the presence of translation-inhibiting antibiotic streptomycin, the resistance acquisition frequency was decreased in the wild-type strain, which could be reversed by mutants lacking HopE and HopD that restored relatively high resistance acquisition frequencies. By transforming a pUC19-rpsLmut-sfgfp linear plasmid carrying a streptomycin conferring mutation, we observed that the impaired ability of rpsLmut synthesis in the wild-type strain was restored in the ΔhopE and ΔhopD mutant transformants. Our study revealed that in the presence of streptomycin, resistance acquisition at least partially relied on the deletion of the hopE and hopD genes, because their loss reduced streptomycin concentration in the cell and thus restored the expression of the resistance-conferring gene, which was inhibited by streptomycin in wild-type strain. The loss of HopE and HopD influx activity may also preserve resistance acquisition by transformation in the presence of antibiotics with other modes of action. IMPORTANCE Helicobacter pylori is constitutively competent for natural transformation (NT) and possesses an efficient system for homologous recombination, which could be utilized to study the NT-mediated horizontal gene transfer induced antibiotic resistance acquisition. Bacterial porins have drawn renewed attention because of their crucial role in antibiotic susceptibility. From the perspective of porin-mediated influx in H. pylori, our study preliminarily revealed the important role of HopE and HopD porins not only in preserving the intrinsic susceptibility to specific antibiotic but also in evading acquired antibiotic resistance by NT in the presence of translation-inhibiting antimicrobial. Therefore, the loss of HopE or HopD porin in H. pylori genomes, combined with the large number of secreted or cell-free genetic elements carrying mutations conferring antibiotic resistance, may raise the possibility that this mechanism plays a potential role in the propagation of antibiotic resistance within H. pylori communities.
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Affiliation(s)
- Yixin Liu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Feng Yang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Su Wang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Wenjing Chi
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Li Ding
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Tao Liu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Feng Zhu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Danian Ji
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Jun Zhou
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Yi Fang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Jinghao Zhang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Ping Xiang
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Yanmei Zhang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Hu Zhao
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
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Zhou GW, Zheng F, Fan XT, Li MJ, Sun QY, Zhu YG, Yang XR. Host age increased conjugal plasmid transfer in gut microbiota of the soil invertebrate Caenorhabditis elegans. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127525. [PMID: 34879519 DOI: 10.1016/j.jhazmat.2021.127525] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/03/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Plasmid conjugation contributes greatly to the spread of antibiotic resistance genes (ARGs) in soils. However, the spread potential in the gut of soil fauna remains poorly studied, and little was known about the impact of host age on ARGs dissemination in the gut microbiota of soil animals. Here, the typical nematode-Caenorhabditis elegans was employed as the model soil animal, aiming to investigate transfer of broad-host-range IncP-1ɛ from Escherichia coli MG1655 to gut microbiota within 6 days under varied temperature gradients (15, 20 and 25 °C) using qPCR combined with plate screening. Results showed that conjugation rates increased with incubation time and rising temperature in the gut of C. elegans, sharing a similar trend with abundances of plasmid conjugation relevant genes such as trbBp (mating pair formation) and trfAp (plasmid replication). Incubation time and temperature significantly shaped the gut microbial community of C. elegans. Core microbiota in the gut of C. elegans, including Enterobacteriaceae, Lactobacillaceae and Leuconostocaceae, constituted a large part of transconjugal pool for plasmid IncP-1ɛ. Our results highlight an important sink of gut microbiota for ARGs dissemination and upregulation of ARGs transfer in the gut microbiota with host age, further potentially stimulating evolution of ARGs in terrestrial environments.
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Affiliation(s)
- Guo-Wei Zhou
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Fei Zheng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; School of Life Sciences, Hebei University, Baoding 071002, China
| | - Xiao-Ting Fan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming-Jun Li
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Qing-Ye Sun
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Ru Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Janoušková M, Straw ML, Su YC, Riesbeck K. Gene Expression Regulation in Airway Pathogens: Importance for Otitis Media. Front Cell Infect Microbiol 2022; 12:826018. [PMID: 35252035 PMCID: PMC8895709 DOI: 10.3389/fcimb.2022.826018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Otitis media (OM) is an inflammatory disorder in the middle ear. It is mainly caused by viruses or bacteria associated with the airways. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are the three main pathogens in infection-related OM, especially in younger children. In this review, we will focus upon the multifaceted gene regulation mechanisms that are well-orchestrated in S. pneumoniae, H. influenzae, and M. catarrhalis during the course of infection in the middle ear either in experimental OM or in clinical settings. The sophisticated findings from the past 10 years on how the othopathogens govern their virulence phenotypes for survival and host adaptation via phase variation- and quorum sensing-dependent gene regulation, will be systematically discussed. Comprehensive understanding of gene expression regulation mechanisms employed by pathogens during the onset of OM may provide new insights for the design of a new generation of antimicrobial agents in the fight against bacterial pathogens while combating the serious emergence of antimicrobial resistance.
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Dugar G, Hofmann A, Heermann DW, Hamoen LW. A chromosomal loop anchor mediates bacterial genome organization. Nat Genet 2022; 54:194-201. [PMID: 35075232 DOI: 10.1038/s41588-021-00988-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 11/19/2021] [Indexed: 12/22/2022]
Abstract
Nucleoprotein complexes play an integral role in genome organization of both eukaryotes and prokaryotes. Apart from their role in locally structuring and compacting DNA, several complexes are known to influence global organization by mediating long-range anchored chromosomal loop formation leading to spatial segregation of large sections of DNA. Such megabase-range interactions are ubiquitous in eukaryotes, but have not been demonstrated in prokaryotes. Here, using a genome-wide sedimentation-based approach, we found that a transcription factor, Rok, forms large nucleoprotein complexes in the bacterium Bacillus subtilis. Using chromosome conformation capture and live-imaging of DNA loci, we show that these complexes robustly interact with each other over large distances. Importantly, these Rok-dependent long-range interactions lead to anchored chromosomal loop formation, thereby spatially isolating large sections of DNA, as previously observed for insulator proteins in eukaryotes.
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Affiliation(s)
- Gaurav Dugar
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands.
| | - Andreas Hofmann
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Dieter W Heermann
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Leendert W Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands.
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Jo JH, Harkins CP, Schwardt NH, Portillo JA, Zimmerman MD, Carter CL, Hossen MA, Peer CJ, Polley EC, Dartois V, Figg WD, Moutsopoulos NM, Segre JA, Kong HH. Alterations of human skin microbiome and expansion of antimicrobial resistance after systemic antibiotics. Sci Transl Med 2021; 13:eabd8077. [PMID: 34936382 DOI: 10.1126/scitranslmed.abd8077] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Jay-Hyun Jo
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Catriona P Harkins
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Microbial Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole H Schwardt
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jessica A Portillo
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | -
- NIH Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthew D Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Claire L Carter
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Md Amir Hossen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Cody J Peer
- Clinical Pharmacology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eric C Polley
- Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20850, USA
| | - Véronique Dartois
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - William D Figg
- Clinical Pharmacology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Niki M Moutsopoulos
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julia A Segre
- Microbial Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Heidi H Kong
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Liu G, Thomsen LE, Olsen JE. Antimicrobial-induced horizontal transfer of antimicrobial resistance genes in bacteria: a mini-review. J Antimicrob Chemother 2021; 77:556-567. [PMID: 34894259 DOI: 10.1093/jac/dkab450] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The emergence and spread of antimicrobial resistance (AMR) among pathogenic bacteria constitute an accelerating crisis for public health. The selective pressures caused by increased use and misuse of antimicrobials in medicine and livestock production have accelerated the overall selection of resistant bacteria. In addition, horizontal gene transfer (HGT) plays an important role in the spread of resistance genes, for example mobilizing reservoirs of AMR from commensal bacteria into pathogenic ones. Antimicrobials, besides antibacterial function, also result in undesirable effects in the microbial populations, including the stimulation of HGT. The main aim of this narrative review was to present an overview of the current knowledge of the impact of antimicrobials on HGT in bacteria, including the effects of transformation, transduction and conjugation, as well as other less well-studied mechanisms of HGT. It is widely accepted that conjugation plays a major role in the spread of AMR in bacteria, and the focus of this review is therefore mainly on the evidence provided that antimicrobial treatment affects this process. Other mechanisms of HGT have so far been deemed less important in this respect; however, recent discoveries suggest their role may be larger than previously thought, and the review provides an update on the rather limited knowledge currently available regarding the impact of antimicrobial treatment on these processes as well. A conclusion from the review is that there is an urgent need to investigate the mechanisms of antimicrobial-induced HGT, since this will be critical for developing new strategies to combat the spread of AMR.
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Affiliation(s)
- Gang Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, China.,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - Line Elnif Thomsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
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Simulated Microgravity Promotes Horizontal Gene Transfer of Antimicrobial Resistance Genes between Bacterial Genera in the Absence of Antibiotic Selective Pressure. Life (Basel) 2021; 11:life11090960. [PMID: 34575109 PMCID: PMC8468678 DOI: 10.3390/life11090960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/05/2021] [Accepted: 09/09/2021] [Indexed: 11/18/2022] Open
Abstract
Bacteria are able to adapt and survive in harsh and changing environments through many mechanisms, with one of them being horizontal gene transfer (HGT). This process is one of the leading culprits in the spread of antimicrobial resistance (AMR) within bacterial communities and could pose a significant health threat to astronauts if they fell ill, especially on long-duration space missions. In order to better understand the degree of HGT activity that could occur in space, biosafety level-2, donor and recipient bacteria were co-cultured under simulated microgravity (SMG) on Earth with concomitant 1G controls. Two AMR genes, blaOXA-500 and ISAba1, from the donor Acinetobacter pittii, were tracked in four recipient strains of Staphylococcus aureus (which did not harbor those genes) using polymerase chain reaction. All four S. aureus strains that were co-cultured with A. pittii under SMG had a significantly higher number of isolates that were now blaOXA-500- and ISAba1-positive compared to growth at 1G. The acquisition of these genes by the recipient induced a phenotypic change, as these isolates were now resistant to oxacillin, which they were previously susceptible to. This is a novel study, presenting, for the first time, increased HGT activity under SMG and the potential impact of the space environment in promoting increased gene dissemination within bacterial communities.
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Huang M, Liu M, Huang L, Wang M, Jia R, Zhu D, Chen S, Zhao X, Zhang S, Gao Q, Zhang L, Cheng A. The activation and limitation of the bacterial natural transformation system: The function in genome evolution and stability. Microbiol Res 2021; 252:126856. [PMID: 34454311 DOI: 10.1016/j.micres.2021.126856] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/19/2021] [Accepted: 08/22/2021] [Indexed: 12/26/2022]
Abstract
Bacteria can take up exogenous naked DNA and integrate it into their genomes, which has been regarded as a main contributor to bacterial evolution. The competent status of bacteria is influenced by environmental cues and by the immune systems of bacteria. Here, we review recent advances in understanding the working mechanisms underlying activation of the natural transformation system and limitations thereof. Environmental stresses including the presence of antimicrobials can activate the natural transformation system. However, bacterial enzymes (nucleases), non-coding RNAs, specific DNA sequences, the restriction-modification (R-M) systems, CRISPR-Cas systems and prokaryotic Argonaute proteins (Agos) are have been found to be involved in the limitation of the natural transformation system. Together, this review represents an opportunity to gain insight into bacterial genome stability and evolution.
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Affiliation(s)
- Mi Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Li Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Dekang Zhu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan, 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, 611130, PR China.
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Khemici V, Prudhomme M, Polard P. Tight Interplay between Replication Stress and Competence Induction in Streptococcus pneumoniae. Cells 2021; 10:cells10081938. [PMID: 34440707 PMCID: PMC8394987 DOI: 10.3390/cells10081938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/15/2021] [Accepted: 07/20/2021] [Indexed: 11/18/2022] Open
Abstract
Cells respond to genome damage by inducing restorative programs, typified by the SOS response of Escherichia coli. Streptococcus pneumoniae (the pneumococcus), with no equivalent to the SOS system, induces the genetic program of competence in response to many types of stress, including genotoxic drugs. The pneumococcal competence regulon is controlled by the origin-proximal, auto-inducible comCDE operon. It was previously proposed that replication stress induces competence through continued initiation of replication in cells with arrested forks, thereby increasing the relative comCDE gene dosage and expression and accelerating the onset of competence. We have further investigated competence induction by genome stress. We find that absence of RecA recombinase stimulates competence induction, in contrast to SOS response, and that double-strand break repair (RexB) and gap repair (RecO, RecR) initiation effectors confer a similar effect, implying that recombinational repair removes competence induction signals. Failure of replication forks provoked by titrating PolC polymerase with the base analogue HPUra, over-supplying DnaA initiator, or under-supplying DnaE polymerase or DnaC helicase stimulated competence induction. This induction was not correlated with concurrent changes in origin-proximal gene dosage. Our results point to arrested and unrepaired replication forks, rather than increased comCDE dosage, as a basic trigger of pneumococcal competence.
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Affiliation(s)
- Vanessa Khemici
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Integrative (CBI), Centre National de la Recherche Scientifique (CNRS), 31062 Toulouse, France; (V.K.); (M.P.)
- Université de Toulouse, Université Paul Sabatier, 31062 Toulouse, France
| | - Marc Prudhomme
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Integrative (CBI), Centre National de la Recherche Scientifique (CNRS), 31062 Toulouse, France; (V.K.); (M.P.)
- Université de Toulouse, Université Paul Sabatier, 31062 Toulouse, France
| | - Patrice Polard
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Integrative (CBI), Centre National de la Recherche Scientifique (CNRS), 31062 Toulouse, France; (V.K.); (M.P.)
- Université de Toulouse, Université Paul Sabatier, 31062 Toulouse, France
- Correspondence:
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Lella M, Tal-Gan Y. Strategies to Attenuate the Competence Regulon in Streptococcus pneumoniae. Pept Sci (Hoboken) 2021; 113:e24222. [PMID: 34337308 PMCID: PMC8323945 DOI: 10.1002/pep2.24222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/19/2021] [Indexed: 12/18/2022]
Abstract
Streptococcus pneumoniae is an opportunistic respiratory human pathogen that poses a continuing threat to human health. Natural competence for genetic transformation in S. pneumoniae plays an important role in aiding pathogenicity and it is the best-characterized feature to acquire antimicrobial resistance genes by a frequent process of recombination. In S. pneumoniae, competence, along with virulence factor production, is controlled by a cell-density communication mechanism termed the competence regulon. In this review, we present the recent advances in the development of alternative methods to attenuate the pathogenicity of S. pneumoniae by targeting the various stages of the non-essential competence regulon communication system. We mainly focus on new developments related to competitively intercepting the competence regulon signaling through the introduction of promising dominant-negative Competence Stimulating Peptide (dnCSP) scaffolds. We also discuss recent reports on antibiotics that can block CSP export by disturbing the proton motive force (PMF) across the membrane and various ways to control the pneumococcal pathogenicity by activating the counter signaling circuit and targeting the pneumococcal proteome.
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Affiliation(s)
- Muralikrishna Lella
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557 (USA)
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557 (USA)
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Abstract
Studying the interactions of bacterial viruses (phages) with their bacterial hosts may lead to better understanding of bacterial mechanisms and consequently enable better manipulation of bacterial pathogens. In this study, we characterized the activity of a protein from phage T5, called T5.015. This protein binds to another protein, Ung, and uses its activity to selectively cleave dUMP-containing DNA. Such cleavage of the bacterial DNA stops bacterial DNA replication and also prevents bacterial division. Presumably, the phage DNA is protected from this activity as Ung does not act on the phage DNA, probably due to lower incorporation of the Ung substrate, dUMP. We believe that the findings are general to many phages and reveal a mechanism of self-versus-foreign DNA discrimination. Bacteriophages (phages) have evolved efficient means to take over the machinery of the bacterial host. The molecular tools at their disposal may be applied to manipulate bacteria and to divert molecular pathways at will. Here, we describe a bacterial growth inhibitor, gene product T5.015, encoded by the T5 phage. High-throughput sequencing of genomic DNA of bacterial mutants, resistant to this inhibitor, revealed disruptive mutations in the Escherichia coli ung gene, suggesting that growth inhibition mediated by T5.015 depends on the uracil-excision activity of Ung. We validated that growth inhibition is abrogated in the absence of ung and confirmed physical binding of Ung by T5.015. In addition, biochemical assays with T5.015 and Ung indicated that T5.015 mediates endonucleolytic activity at abasic sites generated by the base-excision activity of Ung. Importantly, the growth inhibition resulting from the endonucleolytic activity is manifested by DNA replication and cell division arrest. We speculate that the phage uses this protein to selectively cause cleavage of the host DNA, which possesses more misincorporated uracils than that of the phage. This protein may also enhance phage utilization of the available resources in the infected cell, since halting replication saves nucleotides, and stopping cell division maintains both daughters of a dividing cell.
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Li JW, Wyllie RM, Jensen PA. A Novel Competence Pathway in the Oral Pathogen Streptococcus sobrinus. J Dent Res 2021; 100:542-548. [PMID: 33876976 DOI: 10.1177/0022034520979150] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Streptococcus sobrinus is an etiologic cause of dental caries (tooth decay) in humans. Our knowledge of S. sobrinus is scant despite the organism's important role in oral health. It is widely believed that S. sobrinus lacks the natural competence pathways that are used by other streptococci to regulate growth, virulence, and quorum sensing. The lack of natural competence has also prevented genetic manipulation of S. sobrinus, limiting our knowledge of its pathogenicity. We discovered that most strains of S. sobrinus contain a new class of the ComRS competence system. Although S. sobrinus is typically placed among the mutans group streptococci, the S. sobrinus ComRS system is most similar to the competence pathways in the salivarius group. Unlike all other ComRS systems, the S. sobrinus pathway contains 2 copies of the transcriptional regulator ComR and has a peptide pheromone (XIP) that lacks any aromatic amino acids. Synthetic XIP enables transformation of S. sobrinus with plasmid or linear DNA, and we leverage this newfound genetic tractability to confirm that only 1 of the ComR homologs is required for induced competence while the other appears to suppress competence. Exogenous XIP increases the expression of bacteriocin gene clusters and produces an antimicrobial response that inhibits growth of S. mutans. We also identified 2 strains of S. sobrinus that appear to be "cheaters" by either not responding to or not producing XIP. We show how a recombination event in the nonresponsive strain could restore function of the ComRS pathway but delete the gene encoding XIP. Thus, the S. sobrinus ComRS pathway provides new tools for studying this pathogen and offers a lens into the evolution of ecological cheaters.
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Affiliation(s)
- J W Li
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - R M Wyllie
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - P A Jensen
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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High-Resolution Differentiation of Enteric Bacteria in Premature Infant Fecal Microbiomes Using a Novel rRNA Amplicon. mBio 2021; 12:mBio.03656-20. [PMID: 33593974 PMCID: PMC8545133 DOI: 10.1128/mbio.03656-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Identifying and tracking microbial strains as microbiomes evolve are major challenges in the field of microbiome research. We utilized a new sequencing kit that combines DNA extraction with PCR amplification of a large region of the rRNA operon and downstream bioinformatic data analysis. Longitudinal microbiome samples of coadmitted twins from two different neonatal intensive care units (NICUs) were analyzed using an ∼2,500-base amplicon that spans the 16S and 23S rRNA genes and mapped to a new, custom 16S-23S rRNA database. Amplicon sequence variants (ASVs) inferred using DADA2 provided sufficient resolution for the differentiation of rRNA variants from closely related but not previously sequenced Klebsiella, Escherichia coli, and Enterobacter strains, among the first bacteria colonizing the gut of these infants after admission to the NICU. Distinct ASV groups (fingerprints) were monitored between coadmitted twins over time, demonstrating the potential to track the source and spread of both commensals and pathogens. The high-resolution taxonomy obtained from long amplicon sequencing enables the tracking of strains temporally and spatially as microbiomes are established in infants in the hospital environment.
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CcrZ is a pneumococcal spatiotemporal cell cycle regulator that interacts with FtsZ and controls DNA replication by modulating the activity of DnaA. Nat Microbiol 2021; 6:1175-1187. [PMID: 34373624 PMCID: PMC8387234 DOI: 10.1038/s41564-021-00949-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/07/2021] [Indexed: 02/07/2023]
Abstract
Most bacteria replicate and segregate their DNA concomitantly while growing, before cell division takes place. How bacteria synchronize these different cell cycle events to ensure faithful chromosome inheritance by daughter cells is poorly understood. Here, we identify Cell Cycle Regulator protein interacting with FtsZ (CcrZ) as a conserved and essential protein in pneumococci and related Firmicutes such as Bacillus subtilis and Staphylococcus aureus. CcrZ couples cell division with DNA replication by controlling the activity of the master initiator of DNA replication, DnaA. The absence of CcrZ causes mis-timed and reduced initiation of DNA replication, which subsequently results in aberrant cell division. We show that CcrZ from Streptococcus pneumoniae interacts directly with the cytoskeleton protein FtsZ, which places CcrZ in the middle of the newborn cell where the DnaA-bound origin is positioned. This work uncovers a mechanism for control of the bacterial cell cycle in which CcrZ controls DnaA activity to ensure that the chromosome is replicated at the right time during the cell cycle.
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Johnston CH, Soulet AL, Bergé M, Prudhomme M, De Lemos D, Polard P. The alternative sigma factor σ X mediates competence shut-off at the cell pole in Streptococcus pneumoniae. eLife 2020; 9:62907. [PMID: 33135635 PMCID: PMC7665891 DOI: 10.7554/elife.62907] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/31/2020] [Indexed: 12/22/2022] Open
Abstract
Competence is a widespread bacterial differentiation program driving antibiotic resistance and virulence in many pathogens. Here, we studied the spatiotemporal localization dynamics of the key regulators that master the two intertwined and transient transcription waves defining competence in Streptococcus pneumoniae. The first wave relies on the stress-inducible phosphorelay between ComD and ComE proteins, and the second on the alternative sigma factor σX, which directs the expression of the DprA protein that turns off competence through interaction with phosphorylated ComE. We found that ComD, σX and DprA stably co-localize at one pole in competent cells, with σX physically conveying DprA next to ComD. Through this polar DprA targeting function, σX mediates the timely shut-off of the pneumococcal competence cycle, preserving cell fitness. Altogether, this study unveils an unprecedented role for a transcription σ factor in spatially coordinating the negative feedback loop of its own genetic circuit.
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Affiliation(s)
- Calum Hg Johnston
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Anne-Lise Soulet
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Matthieu Bergé
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France.,Dept. Microbiology and Molecular Medicine, Institute of Genetics & Genomics in Geneva (iGE3), Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Marc Prudhomme
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France
| | - David De Lemos
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France
| | - Patrice Polard
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM ; UMR5100), Centre de Biologie Intégrative (CBI), Centre Nationale de la Recherche Scientifique (CNRS), Toulouse, France.,Université Paul Sabatier (Toulouse III), Toulouse, France
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The evolution of bacterial pathogens in the Anthropocene. INFECTION GENETICS AND EVOLUTION 2020; 86:104611. [PMID: 33130070 DOI: 10.1016/j.meegid.2020.104611] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/23/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022]
Abstract
Humankind has become a primary driver of global environmental and climate change. The extent of planetary change is such that it has been proposed to classify the current geological age as the 'Anthropocene'. Anthropogenic environmental degradation presents numerous threats to human health and wellbeing, including an increased risk of infectious disease. This review focuses on how processes such as pollution, climate change and human-mediated dispersal could affect the evolution of bacterial pathogens. Effects of environmental change on the 'big five' of evolution: mutation rate, recombination (horizontal gene transfer), migration, selection and drift are discussed. Microplastic pollution is used as a case study to highlight the combined effects of some of these processes on the evolutionary diversification of human pathogens. Although the evidence is still incomplete, a picture is emerging that environmental pathogens could evolve at increased rates in the Anthropocene, with potential consequences for human infection.
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Abstract
Gram-positive bacteria employ an array of secreted peptides to control population-level behaviors in response to environmental cues. We review mechanistic and functional features of secreted peptides produced by the human pathogen Streptococcus pneumoniae. We discuss sequence features, mechanisms of transport, and receptors for 3 major categories of small peptides: the double-glycine peptides, the Rap, Rgg, NprR, PlcR, and PrgX (RRNPP)-binding peptides, and the lanthionine-containing peptides. We highlight the impact of factors that contribute to carriage and pathogenesis, specifically genetic diversity, microbial competition, biofilm development, and environmental adaptation. A recent expansion in pneumococcal peptide studies reveals a complex network of interacting signaling systems where multiple peptides are integrated into the same signaling pathway, allowing multiple points of entry into the pathway and extending information content in new directions. In addition, since peptides are present in the extracellular milieu, there are opportunities for crosstalk, quorum sensing (QS), as well as intra- and interstrain and species interactions. Knowledge on the manner that population-level behaviors contribute to disease provides an avenue for the design and development of anti-infective strategies.
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Synthetic gene-regulatory networks in the opportunistic human pathogen Streptococcus pneumoniae. Proc Natl Acad Sci U S A 2020; 117:27608-27619. [PMID: 33087560 PMCID: PMC7959565 DOI: 10.1073/pnas.1920015117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is a major human pathogen responsible for enormous global morbidity and mortality. Despite this, the pneumococcus makes up part of the commensal nasopharyngeal flora. How the pneumococcus switches from this commensal to pathogenic state and causes disease is unclear and very likely involves variability in expression of its virulence factors. Here, we used synthetic biology approaches to generate complex gene-regulatory networks such as logic gates and toggle switches. We show that these networks are functional in vivo to control capsule production in an influenza-superinfection model. This opens the field of systematically testing the role of phenotypic variation in pneumococcal virulence. The approaches used here may serve as an example for synthetic biology projects in unrelated organisms. Streptococcus pneumoniae can cause disease in various human tissues and organs, including the ear, the brain, the blood, and the lung, and thus in highly diverse and dynamic environments. It is challenging to study how pneumococci control virulence factor expression, because cues of natural environments and the presence of an immune system are difficult to simulate in vitro. Here, we apply synthetic biology methods to reverse-engineer gene expression control in S. pneumoniae. A selection platform is described that allows for straightforward identification of transcriptional regulatory elements out of combinatorial libraries. We present TetR- and LacI-regulated promoters that show expression ranges of four orders of magnitude. Based on these promoters, regulatory networks of higher complexity are assembled, such as logic AND gates and IMPLY gates. We demonstrate single-copy genome-integrated toggle switches that give rise to bimodal population distributions. The tools described here can be used to mimic complex expression patterns, such as the ones found for pneumococcal virulence factors. Indeed, we were able to rewire gene expression of the capsule operon, the main pneumococcal virulence factor, to be externally inducible (YES gate) or to act as an IMPLY gate (only expressed in absence of inducer). Importantly, we demonstrate that these synthetic gene-regulatory networks are functional in an influenza A virus superinfection murine model of pneumonia, paving the way for in vivo investigations of the importance of gene expression control on the pathogenicity of S. pneumoniae.
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Kurushima J, Campo N, van Raaphorst R, Cerckel G, Polard P, Veening JW. Unbiased homeologous recombination during pneumococcal transformation allows for multiple chromosomal integration events. eLife 2020; 9:e58771. [PMID: 32965219 PMCID: PMC7567608 DOI: 10.7554/elife.58771] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/22/2020] [Indexed: 01/25/2023] Open
Abstract
The spread of antimicrobial resistance and vaccine escape in the human pathogen Streptococcus pneumoniae can be largely attributed to competence-induced transformation. Here, we studied this process at the single-cell level. We show that within isogenic populations, all cells become naturally competent and bind exogenous DNA. We find that transformation is highly efficient and that the chromosomal location of the integration site or whether the transformed gene is encoded on the leading or lagging strand has limited influence on recombination efficiency. Indeed, we have observed multiple recombination events in single recipients in real-time. However, because of saturation and because a single-stranded donor DNA replaces the original allele, transformation efficiency has an upper threshold of approximately 50% of the population. The fixed mechanism of transformation results in a fail-safe strategy for the population as half of the population generally keeps an intact copy of the original genome.
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Affiliation(s)
- Jun Kurushima
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of LausanneLausanneSwitzerland
| | - Nathalie Campo
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI)ToulouseFrance
| | - Renske van Raaphorst
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of LausanneLausanneSwitzerland
| | - Guillaume Cerckel
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of LausanneLausanneSwitzerland
| | - Patrice Polard
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI)ToulouseFrance
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of LausanneLausanneSwitzerland
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