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Torres M, Paszti S, Eberl L. Shedding light on bacteria-host interactions with the aid of TnSeq approaches. mBio 2024; 15:e0039024. [PMID: 38722161 PMCID: PMC11237515 DOI: 10.1128/mbio.00390-24] [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] [Indexed: 06/13/2024] Open
Abstract
Bacteria are highly adaptable and grow in diverse niches, where they often interact with eukaryotic organisms. These interactions with different hosts span the entire spectrum from symbiosis to pathogenicity and thus determine the lifestyle of the bacterium. Knowledge of the genetic determinants involved in animal and plant host colonization by pathogenic and mutualistic bacteria is not only crucial to discover new drug targets for disease management but also for developing novel biostimulant strategies. In the last decades, significant progress in genome-wide high-throughput technologies such as transposon insertion sequencing has led to the identification of pathways that enable efficient host colonization. However, the extent to which similar genes play a role in this process in different bacteria is yet unclear. This review highlights the commonalities and specificities of bacterial determinants important for bacteria-host interaction.
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Affiliation(s)
- Marta Torres
- Department of Plant and Microbial Biology, University of Zurich, Zürich, Switzerland
| | - Sarah Paszti
- Department of Plant and Microbial Biology, University of Zurich, Zürich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zürich, Switzerland
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2
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Wang BX, Leshchiner D, Luo L, Tuncel M, Hokamp K, Hinton JCD, Monack DM. High-throughput fitness experiments reveal specific vulnerabilities of human-adapted Salmonella during stress and infection. Nat Genet 2024; 56:1288-1299. [PMID: 38831009 PMCID: PMC11176087 DOI: 10.1038/s41588-024-01779-7] [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: 09/12/2023] [Accepted: 04/25/2024] [Indexed: 06/05/2024]
Abstract
Salmonella enterica is comprised of genetically distinct 'serovars' that together provide an intriguing model for exploring the genetic basis of pathogen evolution. Although the genomes of numerous Salmonella isolates with broad variations in host range and human disease manifestations have been sequenced, the functional links between genetic and phenotypic differences among these serovars remain poorly understood. Here, we conduct high-throughput functional genomics on both generalist (Typhimurium) and human-restricted (Typhi and Paratyphi A) Salmonella at unprecedented scale in the study of this enteric pathogen. Using a comprehensive systems biology approach, we identify gene networks with serovar-specific fitness effects across 25 host-associated stresses encountered at key stages of human infection. By experimentally perturbing these networks, we characterize previously undescribed pseudogenes in human-adapted Salmonella. Overall, this work highlights specific vulnerabilities encoded within human-restricted Salmonella that are linked to the degradation of their genomes, shedding light into the evolution of this enteric pathogen.
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Affiliation(s)
- Benjamin X Wang
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Lijuan Luo
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Miles Tuncel
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Jay C D Hinton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Denise M Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
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3
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Desai SK, Zhou Y, Dilawari R, Routh AL, Popov V, Kenney LJ. RpoS activates formation of Salmonella Typhi biofilms and drives persistence in the gall bladder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.26.564249. [PMID: 37961640 PMCID: PMC10634867 DOI: 10.1101/2023.10.26.564249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The development of strategies for targeting the asymptomatic carriage of Salmonella Typhi in chronic typhoid patients has suffered owing to our basic lack of understanding of the molecular mechanisms that enable the formation of S. Typhi biofilms. Traditionally, studies have relied on cholesterol-attached biofilms formed by a closely related serovar, Typhimurium, to mimic multicellular Typhi communities formed on human gallstones. In long-term infections, S. Typhi adopts the biofilm lifestyle to persist in vivo and survive in the carrier state, ultimately leading to the spread of infections via the fecal-oral route of transmission. In the present work, we studied S. Typhi biofilms directly, applied targeted as well as genome-wide genetic approaches to uncover unique biofilm components that do not conform to the CsgD-dependent pathway established in S. Typhimurium. We undertook a genome-wide Tn5 mutation screen in a highly successful parental lineage of S. Typhi, strain H58, in gallstone-mimicking conditions. We generated New Generation Sequencing libraries based on the ClickSeq technology to identify the key regulators, IraP and RpoS, and the matrix components as Sth fimbriae, Vi capsule and lipopolysaccharide. We discovered that the starvation sigma factor, RpoS, was required for the transcriptional activation of matrix-encoding genes in vitro, and for S. Typhi colonization in persistent infections in vivo, using a heterologous fish larval model. An rpoS null mutant failed to colonize the gall bladder in chronic zebrafish infections. Overall, our work uncovered a novel RpoS-driven paradigm for the formation of cholesterol-attached Typhi biofilms, and emphasized the role(s) of stress signaling pathways for adaptation in chronic infections. Our identification of the biofilm regulators in S. Typhi paves the way for the development of drugs against typhoid carriage, which will ultimately control the increased incidence of gall bladder cancer in typhoid carriers.
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4
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Kumwenda B, Canals R, Predeus AV, Zhu X, Kröger C, Pulford C, Wenner N, Lora LL, Li Y, Owen SV, Everett D, Hokamp K, Heyderman RS, Ashton PM, Gordon MA, Msefula CL, Hinton JCD. Salmonella enterica serovar Typhimurium ST313 sublineage 2.2 has emerged in Malawi with a characteristic gene expression signature and a fitness advantage. MICROLIFE 2024; 5:uqae005. [PMID: 38623411 PMCID: PMC11018118 DOI: 10.1093/femsml/uqae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 03/27/2024] [Indexed: 04/17/2024]
Abstract
Invasive non-typhoidal Salmonella (iNTS) disease is a serious bloodstream infection that targets immune-compromised individuals, and causes significant mortality in sub-Saharan Africa. Salmonella enterica serovar Typhimurium ST313 causes the majority of iNTS in Malawi. We performed an intensive comparative genomic analysis of 608 S. Typhimurium ST313 isolates dating between 1996 and 2018 from Blantyre, Malawi. We discovered that following the arrival of the well-characterized S. Typhimurium ST313 lineage 2 in 1999, two multidrug-resistant variants emerged in Malawi in 2006 and 2008, designated sublineages 2.2 and 2.3, respectively. The majority of S. Typhimurium isolates from human bloodstream infections in Malawi now belong to sublineages 2.2 or 2.3. To understand the emergence of the prevalent ST313 sublineage 2.2, we studied two representative strains, D23580 (lineage 2) and D37712 (sublineage 2.2). The chromosome of ST313 lineage 2 and sublineage 2.2 only differed by 29 SNPs/small indels and a 3 kb deletion of a Gifsy-2 prophage region including the sseI pseudogene. Lineage 2 and sublineage 2.2 had distinctive plasmid profiles. The transcriptome was investigated in 15 infection-relevant in vitro conditions and within macrophages. During growth in physiological conditions that do not usually trigger S. Typhimurium SPI2 gene expression, the SPI2 genes of D37712 were transcriptionally active. We identified down-regulation of flagellar genes in D37712 compared with D23580. Following phenotypic confirmation of transcriptomic differences, we discovered that sublineage 2.2 had increased fitness compared with lineage 2 during mixed growth in minimal media. We speculate that this competitive advantage is contributing to the emergence of sublineage 2.2 in Malawi.
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Affiliation(s)
- Benjamin Kumwenda
- School of Life Sciences and Allied Health Professions, Kamuzu University of Health Sciences Blantyre, Blantyre, 265, Malawi
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
- Malawi–Liverpool–Wellcome Programme, Blantyre, 3, Malawi
| | - Rocío Canals
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Alexander V Predeus
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Xiaojun Zhu
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Carsten Kröger
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Caisey Pulford
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Nicolas Wenner
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Lizeth Lacharme Lora
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Yan Li
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Siân V Owen
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Dean Everett
- Department of Public Health and Epidemiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, P.O. Box 127788, United Arab Emirates
| | - Karsten Hokamp
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Robert S Heyderman
- Malawi–Liverpool–Wellcome Programme, Blantyre, 3, Malawi
- Research Department of Infection, Division of Infection & Immunity, University College London, London, WC1E 6BT, United Kingdom
| | | | - Melita A Gordon
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
- Malawi–Liverpool–Wellcome Programme, Blantyre, 3, Malawi
| | - Chisomo L Msefula
- School of Life Sciences and Allied Health Professions, Kamuzu University of Health Sciences Blantyre, Blantyre, 265, Malawi
- Malawi–Liverpool–Wellcome Programme, Blantyre, 3, Malawi
| | - Jay C D Hinton
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
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Yang J, Barrila J, Nauman EA, Nydam SD, Yang S, Park J, Gutierrez-Jensen AD, Castro CL, Ott CM, Buss K, Steel J, Zakrajsek AD, Schuff MM, Nickerson CA. Incremental increases in physiological fluid shear progressively alter pathogenic phenotypes and gene expression in multidrug resistant Salmonella. Gut Microbes 2024; 16:2357767. [PMID: 38783686 PMCID: PMC11135960 DOI: 10.1080/19490976.2024.2357767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
The ability of bacteria to sense and respond to mechanical forces has important implications for pathogens during infection, as they experience wide fluid shear fluctuations in the host. However, little is known about how mechanical forces encountered in the infected host drive microbial pathogenesis. Herein, we combined mathematical modeling with hydrodynamic bacterial culture to profile transcriptomic and pathogenesis-related phenotypes of multidrug resistant S. Typhimurium (ST313 D23580) under different fluid shear conditions relevant to its transition from the intestinal tract to the bloodstream. We report that D23580 exhibited incremental changes in transcriptomic profiles that correlated with its pathogenic phenotypes in response to these progressive increases in fluid shear. This is the first demonstration that incremental changes in fluid shear forces alter stress responses and gene expression in any ST313 strain and offers mechanistic insight into how forces encountered by bacteria during infection might impact their disease-causing ability in unexpected ways.
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Affiliation(s)
- Jiseon Yang
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Jennifer Barrila
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
| | - Eric A. Nauman
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Seth D. Nydam
- Department of Animal Care & Technologies, Arizona State University, Tempe, AZ, USA
| | - Shanshan Yang
- Bioinformatics Core Facility, Bioscience, Knowledge Enterprise, Arizona State University, Tempe, AZ, USA
| | - Jin Park
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, AZ, USA
| | - Ami D. Gutierrez-Jensen
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Christian L. Castro
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- JES Tech, Houston, TX, USA
| | - C. Mark Ott
- Biomedical Research and Environmental Sciences Division, NASA Johnson Space Center, Houston, TX, USA
| | - Kristina Buss
- Bioinformatics Core Facility, Bioscience, Knowledge Enterprise, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, AZ, USA
| | - Jason Steel
- Bioinformatics Core Facility, Bioscience, Knowledge Enterprise, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, AZ, USA
| | - Anne D. Zakrajsek
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Mary M. Schuff
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Cheryl A. Nickerson
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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6
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Tsai CN, Massicotte MA, MacNair CR, Perry JN, Brown ED, Coombes BK. Screening under infection-relevant conditions reveals chemical sensitivity in multidrug resistant invasive non-typhoidal Salmonella (iNTS). RSC Chem Biol 2023; 4:600-612. [PMID: 37547457 PMCID: PMC10398353 DOI: 10.1039/d3cb00014a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/30/2023] [Indexed: 08/08/2023] Open
Abstract
Bloodstream infections caused by invasive, non-typhoidal Salmonella (iNTS) are a major global health concern, particularly in Africa where the pathogenic variant of Salmonella Typhimurium sequence type (ST) 313 is dominant. Unlike S. Typhimurium strains that cause gastroenteritis, iNTS strains cause bloodstream infections and are resistant to multiple first-line antibiotics, thus limiting current treatment options. Here, we developed and implemented multiple small molecule screens under physiological, infection-relevant conditions to reveal chemical sensitivities in ST313 and to identify host-directed therapeutics as entry points to drug discovery to combat the clinical burden of iNTS. Screening ST313 iNTS under host-mimicking growth conditions identified 92 compounds with antimicrobial activity despite inherent multidrug resistance. We characterized the antimicrobial activity of the nucleoside analog 3'-azido-3'-deoxythymidine as an exemplary compound from this screen, which depended on bacterial thymidine kinase activity for antimicrobial activity. In a companion macrophage-based screening platform designed to enrich for host-directed therapeutics, we identified three compounds (amodiaquine, berbamine, and indatraline) as actives that required the presence of host cells for antibacterial activity. These three compounds had antimicrobial activity only in the presence of host cells that significantly inhibited intracellular ST313 iNTS replication in macrophages. This work provides evidence that despite high invasiveness and multidrug resistance, ST313 iNTS remains susceptible to unconventional drug discovery approaches.
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Affiliation(s)
- Caressa N Tsai
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
- Michael G. DeGroote Institute for Infectious Disease Research Hamilton ON Canada
| | - Marie-Ange Massicotte
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
- Michael G. DeGroote Institute for Infectious Disease Research Hamilton ON Canada
| | - Craig R MacNair
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
- Michael G. DeGroote Institute for Infectious Disease Research Hamilton ON Canada
| | - Jordyn N Perry
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
| | - Eric D Brown
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
- Michael G. DeGroote Institute for Infectious Disease Research Hamilton ON Canada
| | - Brian K Coombes
- Department of Biochemistry & Biomedical Sciences, McMaster University Hamilton ON L8S 4L8 Canada
- Michael G. DeGroote Institute for Infectious Disease Research Hamilton ON Canada
- Farncombe Family Digestive Health Research Institute Hamilton ON Canada
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7
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Han M, Schierstaedt J, Duan Y, Trotereau J, Virlogeux-Payant I, Schikora A. Novel method to recover Salmonella enterica cells for Tn-Seq approaches from lettuce leaves and agricultural environments using combination of sonication, filtration, and dialysis membrane. J Microbiol Methods 2023; 208:106724. [PMID: 37054820 DOI: 10.1016/j.mimet.2023.106724] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 04/05/2023] [Accepted: 04/08/2023] [Indexed: 04/15/2023]
Abstract
Salmonella enterica in agricultural environments has become an important concern, due to its potential transmission to humans and the associated public health risks. To identify genes contributing to Salmonella adaptation to such environments, transposon sequencing has been used in recent years. However, isolating Salmonella from atypical hosts, such as plant leaves, can pose technical challenges due to low bacterial content and the difficulty to separate an adequate number of bacteria from host tissues. In this study, we describe a modified methodology using a combination of sonication and filtration to recover S. enterica cells from lettuce leaves. We successfully recovered over a total of 3.5 × 106Salmonella cells in each biological replicate from two six-week old lettuce leaves, 7 days after infiltration with a Salmonella suspension of 5 × 107 colony forming units (CFU)/mL. Moreover, we have developed a dialysis membrane system as an alternative method for recovering bacteria from culture medium, mimicking a natural environment. Inoculating 107 CFU/mL of Salmonella into the media based on plant (lettuce and tomato) leaf and diluvial sand soil, a final concentration of 109.5 and 108.5 CFU/mL was obtained, respectively. One millilitre of the bacterial suspension after 24 h incubation at 28 °C using 60 rpm agitation was pelleted, corresponding to 109.5 and 108.5 cells from leaf- or soil-based media. The recovered bacterial population, from both lettuce leaves and environment-mimicking media, can adequately cover a presumptive library density of 106 mutants. In conclusion, this protocol provides an effective method to recover a Salmonella transposon sequencing library from in planta and in vitro systems. We expect this novel technique to foster the study of Salmonella in atypical hosts and environments, as well as other comparable scenarios.
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Affiliation(s)
- Min Han
- Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, Braunschweig 38104, Germany
| | - Jasper Schierstaedt
- Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, Braunschweig 38104, Germany; Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Department Plant-Microbe Systems, Theodor-Echtermeyer Weg 1, Großbeeren 14979, Germany
| | - Yongming Duan
- Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, Braunschweig 38104, Germany
| | - Jérôme Trotereau
- INRAE Val de Loire, Université de Tours, UMR ISP, Nouzilly 37380, France
| | | | - Adam Schikora
- Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, Braunschweig 38104, Germany.
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Wang Z, Zhu S, Li C, Lyu L, Yu J, Wang D, Xu Z, Ni J, Gao B, Lu J, Yao YF. Gene essentiality profiling reveals a novel determinant of stresses preventing protein aggregation in Salmonella. Emerg Microbes Infect 2022; 11:1554-1571. [PMID: 35603550 PMCID: PMC9176671 DOI: 10.1080/22221751.2022.2081618] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Adaptation to various stresses during infection is important for Salmonella Typhimurium virulence, while the fitness determinants under infection-relevant stress conditions remain unknown. Here, we simulated conditions Salmonella encountered within the host or in the environment by 15 individual stresses as well as two model cell lines (epithelium and macrophage) to decipher the genes and pathways required for fitness. By high-resolution Tn-seq analysis, a total of 1242 genes were identified as essential for fitness under at least one stress condition. The comparative analysis of fitness determinants in 17 stress conditions indicated the essentiality of genes varied in different mimicking host niches. A total of 12 genes were identified as fitness determinants in all stress conditions, including recB, recC, and xseA (encode three exonuclease subunits necessary for DNA recombination repair) and a novel essential fitness gene yheM. YheM is a putative sulfurtransferase subunit that is responsible for tRNA modification, and our results showed that Salmonella lacking yheM accumulated more aggregates of endogenous protein than wild-type. Moreover, we established a scoring scheme for sRNA essentiality analysis and found STnc2080 of unknown function was essential for resistance to LL-37. In summary, we systematically dissected Salmonella gene essentiality profiling and demonstrated the general and specific adaptive requirements in infection-relevant niches. Our data not only provide valuable insights on how Salmonella responds to environmental stresses during infections but also highlight the potential clinical application of fitness determinants in vaccine development.
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Affiliation(s)
- Zuoqiang Wang
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Siqi Zhu
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, People's Republic of China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Congcong Li
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Lin Lyu
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jingchen Yu
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Danni Wang
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Zhihong Xu
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jinjing Ni
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Beile Gao
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, People's Republic of China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, People's Republic of China
| | - Jie Lu
- Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai, People's Republic of China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.,Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai, People's Republic of China.,Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, People's Republic of China
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9
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Bruna RE, Casal A, Bercovich B, Gramajo H, Rodríguez E, García Véscovi E. A natural product from Streptomyces targets PhoP and exerts antivirulence action against Salmonella enterica. J Antimicrob Chemother 2022; 77:3050-3063. [PMID: 35972206 DOI: 10.1093/jac/dkac278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/19/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The overprescription and misuse of classical antimicrobial compounds to treat gastrointestinal or systemic salmonellosis have been accelerating the surge of antibiotic-recalcitrant bacterial populations, posing a major public health challenge. Therefore, alternative therapeutic approaches to treat Salmonella infections are urgently required. OBJECTIVES To identify and characterize actinobacterial secreted compounds with inhibitory properties against the Salmonella enterica PhoP/PhoQ signal transduction system, crucial for virulence regulation. METHODS The methodology was based on a combination of the measurement of the activity of PhoP/PhoQ-dependent and -independent reporter genes and bioguided assays to screen for bioactive inhibitory metabolites present in culture supernatants obtained from a collection of actinobacterial isolates. Analogues of azomycin were used to analyse the functional groups required for the detected bioactivity and Salmonella mutants and complemented strains helped to dissect the azomycin mechanism of action. The tetrazolium dye colorimetric assay was used to investigate azomycin potential cytotoxicity on cultured macrophages. Salmonella intramacrophage replication capacity upon azomycin treatment was assessed using the gentamicin protection assay. RESULTS Sublethal concentrations of azomycin, a nitroheterocyclic compound naturally produced by Streptomyces eurocidicus, repressed the Salmonella PhoP/PhoQ system activity by targeting PhoP and inhibiting its transcriptional activity in a PhoQ- and aspartate phosphorylation-independent manner. Sublethal, non-cytotoxic concentrations of azomycin prevented Salmonella intramacrophage replication. CONCLUSIONS Azomycin selectively inhibits the activity of the Salmonella virulence regulator PhoP, a new activity described for this nitroheterocyclic compound that can be repurposed to develop novel anti-Salmonella therapeutic approaches.
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Affiliation(s)
- Roberto E Bruna
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Alejo Casal
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Bárbara Bercovich
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Hugo Gramajo
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Eduardo Rodríguez
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Eleonora García Véscovi
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
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10
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García V, Grønnemose RB, Torres-Puig S, Kudirkiene E, Piantelli M, Ahmed S, Andersen TE, Møller-Jensen J, Olsen JE, Herrero-Fresno A. Genome-wide analysis of fitness-factors in uropathogenic Escherichia coli during growth in laboratory media and during urinary tract infections. Microb Genom 2021; 7. [PMID: 34928200 PMCID: PMC8767336 DOI: 10.1099/mgen.0.000719] [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] [Indexed: 12/13/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) UTI89 is a well-characterized strain, which has mainly been used to study UPEC virulence during urinary tract infection (UTI). However, little is known on UTI89 key fitness-factors during growth in lab media and during UTI. Here, we used a transposon-insertion-sequencing approach (TraDIS) to reveal the UTI89 essential-genes for in vitro growth and fitness-gene-sets for growth in Luria broth (LB) and EZ-MOPS medium without glucose, as well as for human bacteriuria and mouse cystitis. A total of 293 essential genes for growth were identified and the set of fitness-genes was shown to differ depending on the growth media. A modified, previously validated UTI murine model, with administration of glucose prior to infection was applied. Selected fitness-genes for growth in urine and mouse-bladder colonization were validated using deletion-mutants. Novel fitness-genes, such as tusA, corA and rfaG; involved in sulphur-acquisition, magnesium-uptake, and LPS-biosynthesis, were proved to be important during UTI. Moreover, rfaG was confirmed as relevant in both niches, and therefore it may represent a target for novel UTI-treatment/prevention strategies.
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Affiliation(s)
- Vanesa García
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.,Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Rasmus B Grønnemose
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Sergi Torres-Puig
- Institute for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Egle Kudirkiene
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Mateo Piantelli
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Shahana Ahmed
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.,Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, MA, USA
| | - Thomas E Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Jakob Møller-Jensen
- Institute for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - John E Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ana Herrero-Fresno
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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11
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Hill PWS, Moldoveanu AL, Sargen M, Ronneau S, Glegola-Madejska I, Beetham C, Fisher RA, Helaine S. The vulnerable versatility of Salmonella antibiotic persisters during infection. Cell Host Microbe 2021; 29:1757-1773.e10. [PMID: 34731646 DOI: 10.1016/j.chom.2021.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/23/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022]
Abstract
Tolerance and persistence are superficially similar phenomena by which bacteria survive bactericidal antibiotics. It is assumed that the same physiology underlies survival of individual tolerant and persistent bacteria. However, by comparing tolerance and persistence during Salmonella Typhimurium infection, we reveal that these two phenomena are underpinned by different bacterial physiologies. Multidrug-tolerant mutant Salmonella enter a near-dormant state protected from immune-mediated genotoxic damages. However, the numerous tolerant cells, optimized for survival, lack the capabilities necessary to initiate infection relapse following antibiotic withdrawal. In contrast, persisters retain an active state. This leaves them vulnerable to accumulation of macrophage-induced dsDNA breaks but concurrently confers the versatility to initiate infection relapse if protected by RecA-mediated DNA repair. Accordingly, recurrent, invasive, non-typhoidal Salmonella clinical isolates display hallmarks of persistence rather than tolerance during antibiotic treatment. Our study highlights the complex trade-off that antibiotic-recalcitrant Salmonella balance to act as a reservoir for infection relapse.
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Affiliation(s)
- Peter W S Hill
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.
| | - Ana Laura Moldoveanu
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Molly Sargen
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Séverin Ronneau
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Izabela Glegola-Madejska
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Catrin Beetham
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Robert A Fisher
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Sophie Helaine
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
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12
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Usher B, Birkholz N, Beck IN, Fagerlund RD, Jackson SA, Fineran PC, Blower TR. Crystal structure of the anti-CRISPR repressor Aca2. J Struct Biol 2021; 213:107752. [PMID: 34116143 PMCID: PMC8434428 DOI: 10.1016/j.jsb.2021.107752] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/26/2021] [Accepted: 06/06/2021] [Indexed: 11/16/2022]
Abstract
The crystal structure of the anti-CRISPR repressor Aca2 has been solved to 1.34 Å. Aca2 contains a new dimerization domain for HTH transcriptional regulators. Aca2-like regulators are found encoded in diverse biological contexts.
Bacteria use adaptive CRISPR-Cas immune mechanisms to protect from invasion by bacteriophages and other mobile genetic elements. In response, bacteriophages and mobile genetic elements have co-evolved anti-CRISPR proteins to inhibit the bacterial defense. We and others have previously shown that anti-CRISPR associated (Aca) proteins can regulate this anti-CRISPR counter-attack. Here, we report the first structure of an Aca protein, the Aca2 DNA-binding transcriptional autorepressor from Pectobacterium carotovorum bacteriophage ZF40, determined to 1.34 Å. Aca2 presents a conserved N-terminal helix-turn-helix DNA-binding domain and a previously uncharacterized C-terminal dimerization domain. Dimerization positions the Aca2 recognition helices for insertion into the major grooves of target DNA, supporting its role in regulating anti-CRISPRs. Furthermore, database comparisons identified uncharacterized Aca2 structural homologs in pathogenic bacteria, suggesting that Aca2 represents the first characterized member of a more widespread family of transcriptional regulators.
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Affiliation(s)
- Ben Usher
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Izaak N Beck
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Robert D Fagerlund
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Bio-Protection Research Centre, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Tim R Blower
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK.
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13
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14
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Sánchez-Romero MA, Mérida-Floriano Á, Casadesús J. Copy Number Heterogeneity in the Virulence Plasmid of Salmonella enterica. Front Microbiol 2020; 11:599931. [PMID: 33343541 PMCID: PMC7746676 DOI: 10.3389/fmicb.2020.599931] [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: 08/28/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
Quantitative PCR analysis shows that the virulence plasmid of Salmonella enterica serovar Typhimurium (pSLT) is a low-copy-number plasmid, with 1–2 copies per chromosome. However, fluorescence microscopy observation of pSLT labeled with a lacO fluorescent tag reveals cell-to-cell differences in the number of foci, which ranges from 1 to 8. As each focus must correspond to ≥1 plasmid copy, the number of foci can be expected to indicate the minimal number of pSLT copies per cell. A correlation is found between the number of foci and the bacterial cell volume. In contrast, heterogeneity in the number of foci appears to be independent of the cell volume and may have stochastic origin. As a consequence of copy number heterogeneity, expression of a pSLT-bone reporter gene shows high levels of cell-to-cell variation, especially in actively dividing cultures. These observations support the notion that low-copy-number plasmids can be a source of gene expression noise in bacterial populations.
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Affiliation(s)
| | | | - Josep Casadesús
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
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15
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Honeycutt JD, Wenner N, Li Y, Brewer SM, Massis LM, Brubaker SW, Chairatana P, Owen SV, Canals R, Hinton JCD, Monack DM. Genetic variation in the MacAB-TolC efflux pump influences pathogenesis of invasive Salmonella isolates from Africa. PLoS Pathog 2020; 16:e1008763. [PMID: 32834002 PMCID: PMC7446830 DOI: 10.1371/journal.ppat.1008763] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023] Open
Abstract
The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.
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Affiliation(s)
- Jared D. Honeycutt
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Nicolas Wenner
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Yan Li
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Susan M. Brewer
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Liliana M. Massis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sky W. Brubaker
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Phoom Chairatana
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Siân V. Owen
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rocío Canals
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Jay C. D. Hinton
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Denise M. Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
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16
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Cain AK, Barquist L, Goodman AL, Paulsen IT, Parkhill J, van Opijnen T. A decade of advances in transposon-insertion sequencing. Nat Rev Genet 2020; 21:526-540. [PMID: 32533119 PMCID: PMC7291929 DOI: 10.1038/s41576-020-0244-x] [Citation(s) in RCA: 191] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2020] [Indexed: 01/12/2023]
Abstract
It has been 10 years since the introduction of modern transposon-insertion sequencing (TIS) methods, which combine genome-wide transposon mutagenesis with high-throughput sequencing to estimate the fitness contribution or essentiality of each genetic component in a bacterial genome. Four TIS variations were published in 2009: transposon sequencing (Tn-Seq), transposon-directed insertion site sequencing (TraDIS), insertion sequencing (INSeq) and high-throughput insertion tracking by deep sequencing (HITS). TIS has since become an important tool for molecular microbiologists, being one of the few genome-wide techniques that directly links phenotype to genotype and ultimately can assign gene function. In this Review, we discuss the recent applications of TIS to answer overarching biological questions. We explore emerging and multidisciplinary methods that build on TIS, with an eye towards future applications. In this Review, several experts discuss progress in the decade since the development of transposon-based approaches for bacterial genetic screens. They describe how advances in both experimental technologies and analytical strategies are resulting in insights into diverse biological processes.
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Affiliation(s)
- Amy K Cain
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg, Germany.,Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Andrew L Goodman
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.,Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Ian T Paulsen
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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