1
|
Dramé I, Rossez Y, Krzewinski F, Charbonnel N, Ollivier-Nakusi L, Briandet R, Dague E, Forestier C, Balestrino D. FabR, a regulator of membrane lipid homeostasis, is involved in Klebsiella pneumoniae biofilm robustness. mBio 2024:e0131724. [PMID: 39240091 DOI: 10.1128/mbio.01317-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 08/06/2024] [Indexed: 09/07/2024] Open
Abstract
Biofilm is a dynamic structure from which individual bacteria and micro-aggregates are released to subsequently colonize new niches by either detachment or dispersal. Screening of a transposon mutant library identified genes associated with the alteration of Klebsiella pneumoniae biofilm including fabR, which encodes a transcriptional regulator involved in membrane lipid homeostasis. An isogenic ∆fabR mutant formed more biofilm than the wild-type (WT) strain and its trans-complemented strain. The thick and round aggregates observed with ∆fabR were resistant to extensive washes, unlike those of the WT strain. Confocal microscopy and BioFlux microfluidic observations showed that fabR deletion was associated with biofilm robustness and impaired erosion over time. The genes fabB and yqfA associated with fatty acid metabolism were significantly overexpressed in the ∆fabR strain, in both planktonic and biofilm conditions. Two monounsaturated fatty acids, palmitoleic acid (C16:1) and oleic acid (C18:1), were found in higher proportion in biofilm cells than in planktonic forms, whereas heptadecenoic acid (C17:1) and octadecanoic acid, 11-methoxy (C18:0-OCH3) were found in higher proportion in the planktonic lifestyle. The fabR mutation induced variations in the fatty acid composition, with no clear differences in the amounts of saturated fatty acids (SFA) and unsaturated fatty acids for the planktonic lifestyle but lower SFA in the biofilm form. Atomic force microscopy showed that deletion of fabR is associated with decreased K. pneumoniae cell rigidity in the biofilm lifestyle, as well as a softer, more elastic biofilm with increased cell cohesion compared to the wild-type strain.IMPORTANCEKlebsiella pneumoniae is an opportunistic pathogen responsible for a wide range of nosocomial infections. The success of this pathogen is due to its high resistance to antibiotics and its ability to form biofilms. The molecular mechanisms involved in biofilm formation have been largely described but the dispersal process that releases individual and aggregate cells from mature biofilm is less well documented while it is associated with the colonization of new environments and thus new threats. Using a multidisciplinary approach, we show that modifications of bacterial membrane fatty acid composition lead to variations in the biofilm robustness, and subsequent bacterial detachment and biofilm erosion over time. These results enhance our understanding of the genetic requirements for biofilm formation in K. pneumoniae that affect the time course of biofilm development and the embrittlement step preceding its dispersal that will make it possible to control K. pneumoniae infections.
Collapse
Affiliation(s)
- Ibrahima Dramé
- Université Clermont Auvergne, CNRS, LMGE, Clermont-Ferrand, France
| | - Yannick Rossez
- Université Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Frederic Krzewinski
- Université Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | | | | | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Etienne Dague
- LAAS-CNRS, CNRS, Univeristé de Toulouse, Toulouse, France
| | | | | |
Collapse
|
2
|
Anderson MT, Himpsl SD, Kingsley LG, Smith SN, Bachman MA, Mobley HLT. Infection characteristics among Serratia marcescens capsule lineages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.23.609398. [PMID: 39229111 PMCID: PMC11370568 DOI: 10.1101/2024.08.23.609398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Serratia marcescens is a healthcare-associated pathogen that causes bloodstream infections, pneumonia, and urinary tract infections. The capsule polysaccharide of S. marcescens is a critical fitness determinant during infection and recent work established the relationship between capsule locus (KL) genetic sequences within the species. Strains belonging to KL1 and KL2 capsule clades produce sialylated polysaccharides and represent the largest subpopulation of isolates from clinical origin while the S. marcescens type strain and other environmental isolates were classified as KL5. In this work, the contribution of these and other capsules to pathogenesis in multiple infection models was determined. Using a murine tail vein injection model of bacteremia, clinical strains demonstrated capsule-dependent colonization of spleen, liver, and kidney following inoculation. The KL5 strain, in contrast, exhibited no loss of survival in this model when capsule genes were deleted. Furthermore, the wild-type KL5 strain was cleared more rapidly from both the spleen and liver compared to a KL1 strain. Similar results were observed in a bacteremic pneumonia model in that all tested strains of clinical origin demonstrated a requirement for capsule in both the primary lung infection site and for bloodstream dissemination to other organs. Finally, strains from each KL clade were tested for the role of capsule in internalization by bone marrow-derived macrophages. Only the sialylated KL1 and KL2 clade strains, representing the majority of clinical isolates, exhibited capsule-dependent inhibition of internalization, suggesting that capsule-mediated resistance to macrophage phagocytosis may enhance survival and antibacterial defenses during infection. IMPORTANCE Bacterial bloodstream infections result from evasion of the host innate immune system and stable colonization following an initial inoculation event from either an internal or external source. Capsule polysaccharides play a protective role for Serratia marcescens during bacteremia but there is abundant genetic diversity at the capsule-encoding locus within the species. This study compares the infection characteristics of S. marcescens isolates belonging to five different capsule types and defines the contributions to infection fitness for each type. By characterizing the differences in capsule dependence and infection potential between S. marcescens strains, efforts to combat these life-threatening infections can be focused toward identifying strategies that target the most critical genetic lineages of this important opportunistic pathogen.
Collapse
|
3
|
Selinidis MA, Corliss AC, Chappell J, Silberg JJ. Ribozyme-Mediated Gene-Fragment Complementation for Nondestructive Reporting of DNA Transfer within Soil. ACS Synth Biol 2024. [PMID: 39145471 DOI: 10.1021/acssynbio.4c00264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Enzymes that produce volatile metabolites can be coded into genetic circuits to report nondisruptively on microbial behaviors in hard-to-image soils. However, these enzyme reporters remain challenging to apply in gene transfer studies due to leaky off states that can lead to false positives. To overcome this problem, we designed a reporter that uses ribozyme-mediated gene-fragment complementation of a methyl halide transferase (MHT) to regulate the synthesis of methyl halide gases. We split the mht gene into two nonfunctional fragments and attached these to a pair of splicing ribozyme fragments. While the individual mht-ribozyme fragments did not produce methyl halides when transcribed alone in Escherichia coli, coexpression resulted in a spliced transcript that translated the MHT reporter. When cells containing one mht-ribozyme fragment transcribed from a mobile plasmid were mixed with cells that transcribed the second mht-ribozyme fragment, methyl halides were only detected following rare conjugation events. When conjugation was performed in soil, it led to a 16-fold increase in methyl halides in the soil headspace. These findings show how ribozyme-mediated gene-fragment complementation can achieve tight control of protein reporter production, a level of control that will be critical for monitoring the effects of soil conditions on gene transfer and the fidelity of biocontainment measures developed for environmental applications.
Collapse
Affiliation(s)
- Malyn A Selinidis
- Department of BioSciences, Rice University, MS-140, 6100 Main Street, Houston, Texas 77005, United States
| | - Andrew C Corliss
- Department of Bioengineering, Rice University, MS-142, 6100 Main Street, Houston, Texas 77005, United States
| | - James Chappell
- Department of BioSciences, Rice University, MS-140, 6100 Main Street, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, MS-142, 6100 Main Street, Houston, Texas 77005, United States
| | - Jonathan J Silberg
- Department of BioSciences, Rice University, MS-140, 6100 Main Street, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, MS-142, 6100 Main Street, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, MS-362, 6100 Main Street, Houston, Texas 77005, United States
| |
Collapse
|
4
|
Maestri A, Pons BJ, Pursey E, Chong CE, Gandon S, Custodio R, Olina A, Agapov A, Chisnall MAW, Grasso A, Paterson S, Szczelkun MD, Baker KS, van Houte S, Chevallereau A, Westra ER. The bacterial defense system MADS interacts with CRISPR-Cas to limit phage infection and escape. Cell Host Microbe 2024; 32:1412-1426.e11. [PMID: 39094583 DOI: 10.1016/j.chom.2024.07.005] [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: 08/09/2023] [Revised: 04/23/2024] [Accepted: 07/08/2024] [Indexed: 08/04/2024]
Abstract
The constant arms race between bacteria and their parasites has resulted in a large diversity of bacterial defenses, with many bacteria carrying multiple systems. Here, we report the discovery of a phylogenetically widespread defense system, coined methylation-associated defense system (MADS), which is distributed across gram-positive and gram-negative bacteria. MADS interacts with a CRISPR-Cas system in its native host to provide robust and durable resistance against phages. While phages can acquire epigenetic-mediated resistance against MADS, co-existence of MADS and a CRISPR-Cas system limits escape emergence. MADS comprises eight genes with predicted nuclease, ATPase, kinase, and methyltransferase domains, most of which are essential for either self/non-self discrimination, DNA restriction, or both. The complex genetic architecture of MADS and MADS-like systems, relative to other prokaryotic defenses, points toward highly elaborate mechanisms of sensing infections, defense activation, and/or interference.
Collapse
Affiliation(s)
- Alice Maestri
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Benoit J Pons
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Elizabeth Pursey
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Charlotte E Chong
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 7ZB, UK; Department of Genetics, University of Cambridge, Downing Place, Cambridge CB2 3EH, UK
| | - Sylvain Gandon
- CEFE, CNRS, Université de Montpellier, EPHE, IRD, Montpellier 34293, France
| | - Rafael Custodio
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Anna Olina
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Aleksei Agapov
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Matthew A W Chisnall
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Anita Grasso
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Steve Paterson
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 7ZB, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - Kate S Baker
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 7ZB, UK; Department of Genetics, University of Cambridge, Downing Place, Cambridge CB2 3EH, UK
| | - Stineke van Houte
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK
| | - Anne Chevallereau
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris 75014, France.
| | - Edze R Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK.
| |
Collapse
|
5
|
Vizzarro G, Lemopoulos A, Adams DW, Blokesch M. Vibrio cholerae pathogenicity island 2 encodes two distinct types of restriction systems. J Bacteriol 2024:e0014524. [PMID: 39133004 DOI: 10.1128/jb.00145-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 07/15/2024] [Indexed: 08/13/2024] Open
Abstract
In response to predation by bacteriophages and invasion by other mobile genetic elements such as plasmids, bacteria have evolved specialized defense systems that are often clustered together on genomic islands. The O1 El Tor strains of Vibrio cholerae responsible for the ongoing seventh cholera pandemic (7PET) contain a characteristic set of genomic islands involved in host colonization and disease, many of which contain defense systems. Notably, Vibrio pathogenicity island 2 contains several characterized defense systems as well as a putative type I restriction-modification (T1RM) system, which, interestingly, is interrupted by two genes of unknown function. Here, we demonstrate that the T1RM system is active, methylates the host genomes of a representative set of 7PET strains, and identify a specific recognition sequence that targets non-methylated plasmids for restriction. We go on to show that the two genes embedded within the T1RM system encode a novel two-protein modification-dependent restriction system related to the GmrSD family of type IV restriction enzymes. Indeed, we show that this system has potent anti-phage activity against diverse members of the Tevenvirinae, a subfamily of bacteriophages with hypermodified genomes. Taken together, these results expand our understanding of how this highly conserved genomic island contributes to the defense of pandemic V. cholerae against foreign DNA. IMPORTANCE Defense systems are immunity systems that allow bacteria to counter the threat posed by bacteriophages and other mobile genetic elements. Although these systems are numerous and highly diverse, the most common types are restriction enzymes that can specifically recognize and degrade non-self DNA. Here, we show that the Vibrio pathogenicity island 2, present in the pathogen Vibrio cholerae, encodes two types of restriction systems that use distinct mechanisms to sense non-self DNA. The first system is a classical Type I restriction-modification system, and the second is a novel modification-dependent type IV restriction system that recognizes hypermodified cytosines. Interestingly, these systems are embedded within each other, suggesting that they are complementary to each other by targeting both modified and non-modified phages.
Collapse
Affiliation(s)
- Grazia Vizzarro
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alexandre Lemopoulos
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - David William Adams
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Melanie Blokesch
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| |
Collapse
|
6
|
Bier SB, Toska J, Zhao W, Suthianthong P, Proespraiwong P, Robins WP, Mekalanos J. A coordinated attack by a bacterial secretion system and a small molecule drives prey specificity. Commun Biol 2024; 7:958. [PMID: 39117895 PMCID: PMC11310501 DOI: 10.1038/s42003-024-06637-0] [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: 02/15/2024] [Accepted: 07/26/2024] [Indexed: 08/10/2024] Open
Abstract
Vibrio species are recognized for their role in food- and water-borne diseases in humans, fish, and aquatic invertebrates. We screened bacterial strains isolated from raw food shrimp for those that are bactericidal to Vibrio strains. Here we identify and characterize Aeromonas dhakensis strain A603 which shows robust bactericidal activity specifically towards Vibrio and related taxa but less potency toward other Gram-negative species. Using the A603 genome and genetic analysis, we show that two antibacterial mechanisms account for its vibriocidal activity -- a highly potent Type Six Secretion System (T6SS) and biosynthesis of a vibriocidal phenazine-like small molecule, named here as Ad-Phen. Further analysis indicates coregulation between Ad-Phen and a pore-forming T6SS effector TseC, which potentiates V. cholerae to killing by Ad-Phen.
Collapse
Affiliation(s)
- S B Bier
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - J Toska
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - W Zhao
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Disease. The Sixth Affiliated Hospital, School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - P Suthianthong
- Charoen Pokphand Foods PCL. Aquatic Animal Health Research Center, Samutsakorn, Thailand
| | - P Proespraiwong
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - W P Robins
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | - J Mekalanos
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
7
|
Hu K, Chou CW, Wilke CO, Finkelstein IJ. Distinct horizontal transfer mechanisms for type I and type V CRISPR-associated transposons. Nat Commun 2024; 15:6653. [PMID: 39103341 DOI: 10.1038/s41467-024-50816-w] [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: 07/11/2023] [Accepted: 07/22/2024] [Indexed: 08/07/2024] Open
Abstract
CASTs use both CRISPR-associated proteins and Tn7-family transposons for RNA-guided vertical and horizontal transmission. CASTs encode minimal CRISPR arrays but can't acquire new spacers. Here, we report that CASTs can co-opt defense-associated CRISPR arrays for horizontal transmission. A bioinformatic analysis shows that CASTs co-occur with defense-associated CRISPR systems, with the highest prevalence for type I-B and type V CAST sub-types. Using an E. coli quantitative transposition assay and in vitro reconstitution, we show that CASTs can use CRISPR RNAs from these defense systems. A high-resolution structure of the type I-F CAST-Cascade in complex with a type III-B CRISPR RNA reveals that Cas6 recognizes direct repeats via sequence-independent π - π interactions. In addition to using heterologous CRISPR arrays, type V CASTs can also transpose via an unguided mechanism, even when the S15 co-factor is over-expressed. Over-expressing S15 and the trans-activating CRISPR RNA or a single guide RNA reduces, but does not abrogate, off-target integration for type V CASTs. Our findings suggest that some CASTs may exploit defense-associated CRISPR arrays and that this fact must be considered when porting CASTs to heterologous bacterial hosts. More broadly, this work will guide further efforts to engineer the activity and specificity of CASTs for gene editing applications.
Collapse
Affiliation(s)
- Kuang Hu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Chia-Wei Chou
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Claus O Wilke
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
8
|
Chen PY, Chen YC, Chen PP, Lin KT, Sargsyan K, Hsu CP, Wang WL, Hsia KC, Ting SY. A whole-cell platform for discovering synthetic cell adhesion molecules in bacteria. Nat Commun 2024; 15:6568. [PMID: 39095377 PMCID: PMC11297345 DOI: 10.1038/s41467-024-51017-1] [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: 07/26/2024] [Indexed: 08/04/2024] Open
Abstract
Developing programmable bacterial cell-cell adhesion is of significant interest due to its versatile applications. Current methods that rely on presenting cell adhesion molecules (CAMs) on bacterial surfaces are limited by the lack of a generalizable strategy to identify such molecules targeting bacterial membrane proteins in their natural states. Here, we introduce a whole-cell screening platform designed to discover CAMs targeting bacterial membrane proteins within a synthetic bacteria-displayed nanobody library. Leveraging the potency of the bacterial type IV secretion system-a contact-dependent DNA delivery nanomachine-we have established a positive feedback mechanism to selectively enrich for bacteria displaying nanobodies that target antigen-expressing cells. Our platform successfully identified functional CAMs capable of recognizing three distinct outer membrane proteins (TraN, OmpA, OmpC), demonstrating its efficacy in CAM discovery. This approach holds promise for engineering bacterial cell-cell adhesion, such as directing the antibacterial activity of programmed inhibitor cells toward target bacteria in mixed populations.
Collapse
Affiliation(s)
- Po-Yin Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan
| | - Yung-Chih Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Po-Pang Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Biochemistry and Molecular Biology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Kuan-Ting Lin
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Program in Molecular Medicine, National Yang-Ming Chao-Tung University and Academia Sinica, Taipei, Taiwan
| | | | - Chao-Ping Hsu
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan
| | - Wei-Le Wang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan
- Program in Molecular Medicine, National Yang-Ming Chao-Tung University and Academia Sinica, Taipei, Taiwan
| | - Kuo-Chiang Hsia
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan
- Institute of Biochemistry and Molecular Biology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - See-Yeun Ting
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan.
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
9
|
Bobonis J, Yang ALJ, Voogdt CGP, Typas A. TAC-TIC, a high-throughput genetics method to identify triggers or blockers of bacterial toxin-antitoxin systems. Nat Protoc 2024; 19:2231-2249. [PMID: 38724726 DOI: 10.1038/s41596-024-00988-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/14/2024] [Indexed: 08/09/2024]
Abstract
Toxin-antitoxin systems (TAs) are abundant in bacterial chromosomes and can arrest growth under stress, but usually remain inactive. TAs have been increasingly implicated in halting the growth of infected bacteria from bacteriophages or foreign genetic elements1,2 to protect the population (abortive infection, Abi). The vast diversity and abundance of TAs and other Abi systems3 suggest they play an important immunity role, yet what allows them to sense attack remains largely enigmatic. Here, we describe a method called toxin activation-inhibition conjugation (TAC-TIC), which we used to identify gene products that trigger or block the toxicity of phage-defending tripartite retron-TAs4. TAC-TIC employs high-density arrayed mobilizable gene-overexpression libraries, which are transferred into cells carrying the full TA system or only its toxic component, on inducible vectors. The double-plasmid transconjugants are then pinned on inducer-containing agar plates and their colony fitness is quantified to identify gene products that trigger a TA to inhibit growth (TAC), or that block it from acting (TIC). TAC-TIC is optimized for the Singer ROTOR pinning robot, but can also be used with other robots or manual pinners, and allows screening tens of thousands of genes against any TA or Abi (with toxicity) within a week. Finally, we present a dual conjugation donor/cloning strain (Escherichia coli DATC), which accelerates the construction of TAC-TIC gene-donor libraries from phages, enabling the use of TAC-TIC for identifying TA triggers and antidefense mechanisms in phage genomes.
Collapse
Affiliation(s)
- Jacob Bobonis
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Alessio Ling Jie Yang
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Carlos Geert Pieter Voogdt
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany.
| |
Collapse
|
10
|
Woodward SE, Neufeld LMP, Peña-Díaz J, Feng W, Serapio-Palacios A, Tarrant I, Deng W, Finlay BB. Both pathogen and host dynamically adapt pH responses along the intestinal tract during enteric bacterial infection. PLoS Biol 2024; 22:e3002761. [PMID: 39146372 PMCID: PMC11349234 DOI: 10.1371/journal.pbio.3002761] [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: 01/06/2024] [Revised: 08/27/2024] [Accepted: 07/19/2024] [Indexed: 08/17/2024] Open
Abstract
Enteric pathogens navigate distinct regional microenvironments within the intestine that cue important adaptive behaviors. We investigated the response of Citrobacter rodentium, a model of human pathogenic Escherichia coli infection in mice, to regional gastrointestinal pH. We found that small intestinal pH (4.4-4.8) triggered virulence gene expression and altered cell morphology, supporting initial intestinal attachment, while higher pH, representative of C. rodentium's replicative niches further along the murine intestine, supported pathogen growth. Gastric pH, a key barrier to intestinal colonization, caused significant accumulation of intra-bacterial reactive oxygen species (ROS), inhibiting growth of C. rodentium and related human pathogens. Within-host adaptation increased gastric acid survival, which may be due to a robust acid tolerance response (ATR) induced at colonic pH. However, the intestinal environment changes throughout the course of infection. We found that murine gastric pH decreases postinfection, corresponding to increased serum gastrin levels and altered host expression of acid secretion-related genes. Similar responses following Salmonella infection may indicate a protective host response to limit further pathogen ingestion. Together, we highlight interlinked bacterial and host adaptive pH responses as an important component of host-pathogen coevolution.
Collapse
Affiliation(s)
- Sarah E. Woodward
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Laurel M. P. Neufeld
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Jorge Peña-Díaz
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Wenny Feng
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Antonio Serapio-Palacios
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Isabel Tarrant
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Wanyin Deng
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - B. Brett Finlay
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| |
Collapse
|
11
|
Robins WP, Meader BT, Toska J, Mekalanos JJ. DdmABC-dependent death triggered by viral palindromic DNA sequences. Cell Rep 2024; 43:114450. [PMID: 39002129 DOI: 10.1016/j.celrep.2024.114450] [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: 05/08/2023] [Revised: 04/24/2024] [Accepted: 06/20/2024] [Indexed: 07/15/2024] Open
Abstract
Defense systems that recognize viruses provide important insights into both prokaryotic and eukaryotic innate immunity mechanisms. Such systems that restrict foreign DNA or trigger cell death have recently been recognized, but the molecular signals that activate many of these remain largely unknown. Here, we characterize one such system in pandemic Vibrio cholerae responsible for triggering cell density-dependent death (CDD) of cells in response to the presence of certain genetic elements. We show that the key component is the Lamassu DdmABC anti-phage/plasmid defense system. We demonstrate that signals that trigger CDD were palindromic DNA sequences in phages and plasmids that are predicted to form stem-loop hairpins from single-stranded DNA. Our results suggest that agents that damage DNA also trigger DdmABC activation and inhibit cell growth. Thus, any infectious process that results in damaged DNA, particularly during DNA replication, can in theory trigger DNA restriction and death through the DdmABC abortive infection system.
Collapse
Affiliation(s)
- William P Robins
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
| | - Bradley T Meader
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Jonida Toska
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - John J Mekalanos
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
| |
Collapse
|
12
|
Woldetsadik YA, Lazinski DW, Camilli A. A Vibrio cholerae Anti-Phage System Depletes Nicotinamide Adenine Dinucleotide to Restrict Virulent Bacteriophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599363. [PMID: 38948830 PMCID: PMC11212891 DOI: 10.1101/2024.06.17.599363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Bacteria and their predatory viruses (bacteriophages or phages) are in a perpetual molecular arms race. This has led to the evolution of numerous phage defensive systems in bacteria that are still being discovered, as well as numerous ways of interference or circumvention on the part of phages. Here, we identify a unique molecular battle between the classical biotype of Vibrio cholerae and virulent phages ICP1, ICP2, and ICP3. We show that classical biotype strains resist almost all isolates of these phages due to a 25-kb genomic island harboring several putative anti-phage systems. We observed that one of these systems, Nezha, encoding SIR2-like and helicase proteins, inhibited the replication of all three phages. Bacterial SIR2-like enzymes degrade the essential metabolic coenzyme nicotinamide adenine dinucleotide (NAD+), thereby preventing replication of the invading phage. In support of this mechanism, we identified one phage isolate, ICP1_2001, which circumvents Nezha by encoding two putative NAD+ regeneration enzymes. By restoring the NAD+ pool, we hypothesize that this system antagonizes Nezha without directly interacting with either protein and should be able to antagonize other anti-phage systems that deplete NAD+.
Collapse
Affiliation(s)
- Yishak A. Woldetsadik
- Department of Molecular Biology and Microbiology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - David W. Lazinski
- Department of Molecular Biology and Microbiology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| |
Collapse
|
13
|
Vialetto E, Miele S, Goren MG, Yu J, Yu Y, Collias D, Beamud B, Osbelt L, Lourenço M, Strowig T, Brisse S, Barquist L, Qimron U, Bikard D, Beisel C. Systematic interrogation of CRISPR antimicrobials in Klebsiella pneumoniae reveals nuclease-, guide- and strain-dependent features influencing antimicrobial activity. Nucleic Acids Res 2024; 52:6079-6091. [PMID: 38661215 PMCID: PMC11162776 DOI: 10.1093/nar/gkae281] [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: 07/14/2023] [Revised: 03/24/2024] [Accepted: 04/03/2024] [Indexed: 04/26/2024] Open
Abstract
CRISPR-Cas systems can be utilized as programmable-spectrum antimicrobials to combat bacterial infections. However, how CRISPR nucleases perform as antimicrobials across target sites and strains remains poorly explored. Here, we address this knowledge gap by systematically interrogating the use of CRISPR antimicrobials using multidrug-resistant and hypervirulent strains of Klebsiella pneumoniae as models. Comparing different Cas nucleases, DNA-targeting nucleases outperformed RNA-targeting nucleases based on the tested targets. Focusing on AsCas12a that exhibited robust targeting across different strains, we found that the elucidated modes of escape varied widely, restraining opportunities to enhance killing. We also encountered individual guide RNAs yielding different extents of clearance across strains, which were linked to an interplay between improper gRNA folding and strain-specific DNA repair and survival. To explore features that could improve targeting across strains, we performed a genome-wide screen in different K. pneumoniae strains that yielded guide design rules and trained an algorithm for predicting guide efficiency. Finally, we showed that Cas12a antimicrobials can be exploited to eliminate K. pneumoniae when encoded in phagemids delivered by T7-like phages. Altogether, our results highlight the importance of evaluating antimicrobial activity of CRISPR antimicrobials across relevant strains and define critical parameters for efficient CRISPR-based targeting.
Collapse
Affiliation(s)
- Elena Vialetto
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Solange Miele
- Institut Pasteur, Université Paris Cité, Synthetic Biology, Paris, France
| | - Moran G Goren
- Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Jiaqi Yu
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Yanying Yu
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Daphne Collias
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Beatriz Beamud
- Institut Pasteur, Université Paris Cité, Synthetic Biology, Paris, France
| | - Lisa Osbelt
- Helmholtz Centre for Infection Research (HZI), 38124 Braunschweig, Germany
- German Center for Infection Research (DZIF), partner site Hannover-Braunschweig, 38124 Braunschweig, Germany
| | - Marta Lourenço
- Institut Pasteur, Université Paris Cité, Biodiversity and Epidemiology of Bacterial Pathogens, Paris, France
| | - Till Strowig
- Helmholtz Centre for Infection Research (HZI), 38124 Braunschweig, Germany
- German Center for Infection Research (DZIF), partner site Hannover-Braunschweig, 38124 Braunschweig, Germany
| | - Sylvain Brisse
- Institut Pasteur, Université Paris Cité, Biodiversity and Epidemiology of Bacterial Pathogens, Paris, France
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
- University of Würzburg, Medical Faculty, 97080 Würzburg, Germany
| | - Udi Qimron
- Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - David Bikard
- Institut Pasteur, Université Paris Cité, Synthetic Biology, Paris, France
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
- University of Würzburg, Medical Faculty, 97080 Würzburg, Germany
| |
Collapse
|
14
|
Basta DW, Campbell IW, Sullivan EJ, Hotinger JA, Hullahalli K, Waldor MK. Inducible transposon mutagenesis for genome-scale forward genetics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.21.595064. [PMID: 38826325 PMCID: PMC11142078 DOI: 10.1101/2024.05.21.595064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Transposon insertion sequencing (Tn-seq) is a powerful method for genome-scale functional genetics in bacteria. However, its effectiveness is often limited by a lack of mutant diversity, caused by either inefficient transposon delivery or stochastic loss of mutants due to population bottlenecks. Here, we introduce "InducTn-seq", which leverages inducible mutagenesis for temporal control of transposition. InducTn-seq generates millions of transposon mutants from a single colony, enabling the sensitive detection of subtle fitness defects and transforming binary classifications of gene essentiality into a quantitative fitness measurement across both essential and non-essential genes. Using a mouse model of infectious colitis, we show that InducTn-seq bypasses a highly restrictive host bottleneck to generate a diverse transposon mutant population from the few cells that initiate infection, revealing the role of oxygen-related metabolic plasticity in pathogenesis. Overall, InducTn-seq overcomes the limitations of traditional Tn-seq, unlocking new possibilities for genome-scale forward genetic screens in bacteria.
Collapse
Affiliation(s)
- David W. Basta
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ian W. Campbell
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Emily J. Sullivan
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Julia A Hotinger
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Karthik Hullahalli
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Boston, MA, USA
| |
Collapse
|
15
|
Kalvapalle PB, Sridhar S, Silberg JJ, Stadler LB. Long-duration environmental biosensing by recording analyte detection in DNA using recombinase memory. Appl Environ Microbiol 2024; 90:e0236323. [PMID: 38551351 PMCID: PMC11022584 DOI: 10.1128/aem.02363-23] [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: 01/13/2024] [Accepted: 02/20/2024] [Indexed: 04/18/2024] Open
Abstract
Microbial biosensors that convert environmental information into real-time visual outputs are limited in their sensing abilities in complex environments, such as soil and wastewater, due to optical inaccessibility. Biosensors that could record transient exposure to analytes within a large time window for later retrieval represent a promising approach to solve the accessibility problem. Here, we test the performance of recombinase-memory biosensors that sense a sugar (arabinose) and a microbial communication molecule (3-oxo-C12-L-homoserine lactone) over 8 days (~70 generations) following analyte exposure. These biosensors sense the analyte and trigger the expression of a recombinase enzyme which flips a segment of DNA, creating a genetic memory, and initiates fluorescent protein expression. The initial designs failed over time due to unintended DNA flipping in the absence of the analyte and loss of the flipped state after exposure to the analyte. Biosensor performance was improved by decreasing recombinase expression, removing the fluorescent protein output, and using quantitative PCR to read out stored information. Application of memory biosensors in wastewater isolates achieved memory of analyte exposure in an uncharacterized Pseudomonas isolate. By returning these engineered isolates to their native environments, recombinase-memory systems are expected to enable longer duration and in situ investigation of microbial signaling, cross-feeding, community shifts, and gene transfer beyond the reach of traditional environmental biosensors.IMPORTANCEMicrobes mediate ecological processes over timescales that can far exceed the half-lives of transient metabolites and signals that drive their collective behaviors. We investigated strategies for engineering microbes to stably record their transient exposure to a chemical over many generations through DNA rearrangements. We identify genetic architectures that improve memory biosensor performance and characterize these in wastewater isolates. Memory biosensors are expected to be useful for monitoring cell-cell signals in biofilms, detecting transient exposure to chemical pollutants, and observing microbial cross-feeding through short-lived metabolites within cryptic methane, nitrogen, and sulfur cycling processes. They will also enable in situ studies of microbial responses to ephemeral environmental changes, or other ecological processes that are currently challenging to monitor non-destructively using real-time biosensors and analytical instruments.
Collapse
Affiliation(s)
| | - Swetha Sridhar
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, Texas, USA
| | - Jonathan J. Silberg
- Department of BioSciences, Rice University, Houston, Texas, USA
- Department of Bioengineering, Rice University, Houston, Texas, USA
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA
| | - Lauren B. Stadler
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas, USA
| |
Collapse
|
16
|
Alvarado Obando M, Rey-Varela D, Cava F, Dörr T. Genetic interaction mapping reveals functional relationships between peptidoglycan endopeptidases and carboxypeptidases. PLoS Genet 2024; 20:e1011234. [PMID: 38598601 PMCID: PMC11034669 DOI: 10.1371/journal.pgen.1011234] [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: 10/16/2023] [Revised: 04/22/2024] [Accepted: 03/25/2024] [Indexed: 04/12/2024] Open
Abstract
Peptidoglycan (PG) is the main component of the bacterial cell wall; it maintains cell shape while protecting the cell from internal osmotic pressure and external environmental challenges. PG synthesis is essential for bacterial growth and survival, and a series of PG modifications are required to allow expansion of the sacculus. Endopeptidases (EPs), for example, cleave the crosslinks between adjacent PG strands to allow the incorporation of newly synthesized PG. EPs are collectively essential for bacterial growth and must likely be carefully regulated to prevent sacculus degradation and cell death. However, EP regulation mechanisms are poorly understood. Here, we used TnSeq to uncover novel EP regulators in Vibrio cholerae. This screen revealed that the carboxypeptidase DacA1 (PBP5) alleviates EP toxicity. dacA1 is essential for viability on LB medium, and this essentiality was suppressed by EP overexpression, revealing that EP toxicity both mitigates, and is mitigated by, a defect in dacA1. A subsequent suppressor screen to restore viability of ΔdacA1 in LB medium identified hypomorphic mutants in the PG synthesis pathway, as well as mutations that promote EP activation. Our data thus reveal a more complex role of DacA1 in maintaining PG homeostasis than previously assumed.
Collapse
Affiliation(s)
- Manuela Alvarado Obando
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| | - Diego Rey-Varela
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Science for Life Laboratory (SciLifeLab), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Felipe Cava
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Science for Life Laboratory (SciLifeLab), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Tobias Dörr
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute for Host-Microbe Interactions and Disease (CIHMID), Ithaca, New York, United States of America
| |
Collapse
|
17
|
Wood WN, Rubio MA, Leiva LE, Phillips GJ, Ibba M. Methionyl-tRNA synthetase synthetic and proofreading activities are determinants of antibiotic persistence. Front Microbiol 2024; 15:1384552. [PMID: 38601944 PMCID: PMC11004401 DOI: 10.3389/fmicb.2024.1384552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/12/2024] [Indexed: 04/12/2024] Open
Abstract
Bacterial antibiotic persistence is a phenomenon where bacteria are exposed to an antibiotic and the majority of the population dies while a small subset enters a low metabolic, persistent, state and are able to survive. Once the antibiotic is removed the persistent population can resuscitate and continue growing. Several different molecular mechanisms and pathways have been implicated in this phenomenon. A common mechanism that may underly bacterial antibiotic persistence is perturbations in protein synthesis. To investigate this mechanism, we characterized four distinct metG mutants for their ability to increase antibiotic persistence. Two metG mutants encode changes near the catalytic site of MetRS and the other two mutants changes near the anticodon binding domain. Mutations in metG are of particular interest because MetRS is responsible for aminoacylation both initiator tRNAMet and elongator tRNAMet indicating that these mutants could impact translation initiation and/or translation elongation. We observed that all the metG mutants increased the level of antibiotic persistence as did reduced transcription levels of wild type metG. Although, the MetRS variants did not have an impact on MetRS activity itself, they did reduce translation rates. It was also observed that the MetRS variants affected the proofreading mechanism for homocysteine and that these mutants' growth is hypersensitive to homocysteine. Taken together with previous findings, our data indicate that both reductions in cellular Met-tRNAMet synthetic capacity and reduced proofreading of homocysteine by MetRS variants are positive determinants for bacterial antibiotic persistence.
Collapse
Affiliation(s)
- Whitney N. Wood
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
- Schmid College of Science and Technology, Chapman University, Orange, CA, United States
| | - Miguel Angel Rubio
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
| | - Lorenzo Eugenio Leiva
- Schmid College of Science and Technology, Chapman University, Orange, CA, United States
| | - Gregory J. Phillips
- Department of Veterinary Microbiology, Iowa State University, Ames, IA, United States
| | - Michael Ibba
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
- Schmid College of Science and Technology, Chapman University, Orange, CA, United States
| |
Collapse
|
18
|
Nicholson TL, Waack U, Fleming DS, Chen Q, Miller LC, Merkel TJ, Stibitz S. The contribution of BvgR, RisA, and RisS to global gene regulation, intracellular cyclic-di-GMP levels, motility, and biofilm formation in Bordetella bronchiseptica. Front Microbiol 2024; 15:1305097. [PMID: 38516008 PMCID: PMC10955343 DOI: 10.3389/fmicb.2024.1305097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 02/20/2024] [Indexed: 03/23/2024] Open
Abstract
Bordetella bronchiseptica is a highly contagious respiratory bacterial veterinary pathogen. In this study the contribution of the transcriptional regulators BvgR, RisA, RisS, and the phosphorylation of RisA to global gene regulation, intracellular cyclic-di-GMP levels, motility, and biofilm formation were evaluated. Next Generation Sequencing (RNASeq) was used to differentiate the global gene regulation of both virulence-activated and virulence-repressed genes by each of these factors. The BvgAS system, along with BvgR, RisA, and the phosphorylation of RisA served in cyclic-di-GMP degradation. BvgR and unphosphorylated RisA were found to temporally regulate motility. Additionally, BvgR, RisA, and RisS were found to be required for biofilm formation.
Collapse
Affiliation(s)
- Tracy L. Nicholson
- Agricultural Research Service, USDA, National Animal Disease Center, Ames, IA, United States
| | - Ursula Waack
- Agricultural Research Service, USDA, National Animal Disease Center, Ames, IA, United States
- United States Department of Energy, Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Damarius S. Fleming
- USDA, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States
| | - Qing Chen
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, United States
| | - Laura C. Miller
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Tod J. Merkel
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, United States
| | - Scott Stibitz
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, United States
| |
Collapse
|
19
|
Couce A, Limdi A, Magnan M, Owen SV, Herren CM, Lenski RE, Tenaillon O, Baym M. Changing fitness effects of mutations through long-term bacterial evolution. Science 2024; 383:eadd1417. [PMID: 38271521 DOI: 10.1126/science.add1417] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 12/12/2023] [Indexed: 01/27/2024]
Abstract
The distribution of fitness effects of new mutations shapes evolution, but it is challenging to observe how it changes as organisms adapt. Using Escherichia coli lineages spanning 50,000 generations of evolution, we quantify the fitness effects of insertion mutations in every gene. Macroscopically, the fraction of deleterious mutations changed little over time whereas the beneficial tail declined sharply, approaching an exponential distribution. Microscopically, changes in individual gene essentiality and deleterious effects often occurred in parallel; altered essentiality is only partly explained by structural variation. The identity and effect sizes of beneficial mutations changed rapidly over time, but many targets of selection remained predictable because of the importance of loss-of-function mutations. Taken together, these results reveal the dynamic-but statistically predictable-nature of mutational fitness effects.
Collapse
Affiliation(s)
- Alejandro Couce
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, IAME, F-75018 Paris, France
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), 28223 Madrid, Spain
| | - Anurag Limdi
- Department of Biomedical Informatics, and Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Melanie Magnan
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, IAME, F-75018 Paris, France
| | - Siân V Owen
- Department of Biomedical Informatics, and Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Cristina M Herren
- Department of Biomedical Informatics, and Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA 02115, USA
- Department of Marine and Environmental Sciences, Northeastern University, Boston, MA 02115, USA
| | - Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
- Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, MI 48824, USA
| | - Olivier Tenaillon
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, IAME, F-75018 Paris, France
- Université Paris Cité, Inserm, Institut Cochin, F-75014 Paris, France
| | - Michael Baym
- Department of Biomedical Informatics, and Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
20
|
Tripathi S, Voogdt CGP, Bassler SO, Anderson M, Huang PH, Sakenova N, Capraz T, Jain S, Koumoutsi A, Bravo AM, Trotter V, Zimmerman M, Sonnenburg JL, Buie C, Typas A, Deutschbauer AM, Shiver AL, Huang KC. Randomly barcoded transposon mutant libraries for gut commensals I: Strategies for efficient library construction. Cell Rep 2024; 43:113517. [PMID: 38142397 DOI: 10.1016/j.celrep.2023.113517] [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: 07/27/2023] [Revised: 10/22/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Randomly barcoded transposon mutant libraries are powerful tools for studying gene function and organization, assessing gene essentiality and pathways, discovering potential therapeutic targets, and understanding the physiology of gut bacteria and their interactions with the host. However, construction of high-quality libraries with uniform representation can be challenging. In this review, we survey various strategies for barcoded library construction, including transposition systems, methods of transposon delivery, optimal library size, and transconjugant selection schemes. We discuss the advantages and limitations of each approach, as well as factors to consider when selecting a strategy. In addition, we highlight experimental and computational advances in arraying condensed libraries from mutant pools. We focus on examples of successful library construction in gut bacteria and their application to gene function studies and drug discovery. Given the need for understanding gene function and organization in gut bacteria, we provide a comprehensive guide for researchers to construct randomly barcoded transposon mutant libraries.
Collapse
Affiliation(s)
- Surya Tripathi
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carlos Geert Pieter Voogdt
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Stefan Oliver Bassler
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Grabengasse 1, 69117 Heidelberg, Germany
| | - Mary Anderson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Po-Hsun Huang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nazgul Sakenova
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Tümay Capraz
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sunit Jain
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Alexandra Koumoutsi
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Afonso Martins Bravo
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Valentine Trotter
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michael Zimmerman
- Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Justin L Sonnenburg
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cullen Buie
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Athanasios Typas
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany.
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Kerwyn Casey Huang
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
21
|
Rachwalski K, Tu MM, Madden SJ, French S, Hansen DM, Brown ED. A mobile CRISPRi collection enables genetic interaction studies for the essential genes of Escherichia coli. CELL REPORTS METHODS 2024; 4:100693. [PMID: 38262349 PMCID: PMC10832289 DOI: 10.1016/j.crmeth.2023.100693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/27/2023] [Accepted: 12/22/2023] [Indexed: 01/25/2024]
Abstract
Advances in gene editing, in particular CRISPR interference (CRISPRi), have enabled depletion of essential cellular machinery to study the downstream effects on bacterial physiology. Here, we describe the construction of an ordered E. coli CRISPRi collection, designed to knock down the expression of 356 essential genes with the induction of a catalytically inactive Cas9, harbored on the conjugative plasmid pFD152. This mobile CRISPRi library can be conjugated into other ordered genetic libraries to assess combined effects of essential gene knockdowns with non-essential gene deletions. As proof of concept, we probed cell envelope synthesis with two complementary crosses: (1) an Lpp deletion into every CRISPRi knockdown strain and (2) the lolA knockdown plasmid into the Keio collection. These experiments revealed a number of notable genetic interactions for the essential phenotype probed and, in particular, showed suppressing interactions for the loci in question.
Collapse
Affiliation(s)
- Kenneth Rachwalski
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Megan M Tu
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Sean J Madden
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Shawn French
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Drew M Hansen
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Eric D Brown
- Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada.
| |
Collapse
|
22
|
Garin T, Brin C, Préveaux A, Brault A, Briand M, Simonin M, Barret M, Journet L, Sarniguet A. The type VI secretion system of Stenotrophomonas rhizophila CFBP13503 limits the transmission of Xanthomonas campestris pv. campestris 8004 from radish seeds to seedlings. MOLECULAR PLANT PATHOLOGY 2024; 25:e13412. [PMID: 38279854 PMCID: PMC10777753 DOI: 10.1111/mpp.13412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/20/2023] [Accepted: 11/27/2023] [Indexed: 01/29/2024]
Abstract
Stenotrophomonas rhizophila CFBP13503 is a seedborne commensal bacterial strain, which is efficiently transmitted to seedlings and can outcompete the phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc8004). The type VI secretion system (T6SS), an interference contact-dependent mechanism, is a critical component of interbacterial competition. The involvement of the T6SS of S. rhizophila CFBP13503 in the inhibition of Xcc8004 growth and seed-to-seedling transmission was assessed. The T6SS cluster of S. rhizophila CFBP13503 and nine putative effectors were identified. Deletion of two T6SS structural genes, hcp and tssB, abolished the competitive advantage of S. rhizophila against Xcc8004 in vitro. The population sizes of these two bacterial species were monitored in seedlings after inoculation of radish seeds with mixtures of Xcc8004 and either S. rhizophila wild-type (wt) strain or isogenic hcp mutant. A significant decrease in the population size of Xcc8004 was observed during confrontation with the S. rhizophila wt in comparison with T6SS-deletion mutants in germinated seeds and seedlings. We found that the T6SS distribution among 835 genomes of the Stenotrophomonas genus is scarce. In contrast, in all available S. rhizophila genomes, T6SS clusters are widespread and mainly belong to the T6SS group i4. In conclusion, the T6SS of S. rhizophila CFBP13503 is involved in the antibiosis against Xcc8004 and reduces seedling transmission of Xcc8004 in radish. The distribution of this T6SS cluster in the S. rhizophila complex could make it possible to exploit these strains as biocontrol agents against X. campestris pv. campestris.
Collapse
Affiliation(s)
- Tiffany Garin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Chrystelle Brin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Anne Préveaux
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Agathe Brault
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Martial Briand
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Marie Simonin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Matthieu Barret
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Laure Journet
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Institut de Microbiologie de la MéditerranéeAix‐Marseille Université‐CNRS, UMR 7255MarseilleFrance
| | - Alain Sarniguet
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| |
Collapse
|
23
|
Zumkeller C, Schindler D, Felder J, Waldminghaus T. Modular Assembly of Synthetic Secondary Chromosomes. Methods Mol Biol 2024; 2819:157-187. [PMID: 39028507 DOI: 10.1007/978-1-0716-3930-6_9] [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] [Indexed: 07/20/2024]
Abstract
The development of novel DNA assembly methods in recent years has paved the way for the construction of synthetic replicons to be used for basic research and biotechnological applications. A learning-by-building approach can now answer questions about how chromosomes must be constructed to maintain genetic information. Here we describe an efficient pipeline for the design and assembly of synthetic, secondary chromosomes in Escherichia coli based on the popular modular cloning (MoClo) system.
Collapse
Affiliation(s)
- Celine Zumkeller
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Branch for Bioresources, Giessen, Germany
| | - Daniel Schindler
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Jennifer Felder
- Technische Universität Darmstadt, Faculty of Biology, Darmstadt, Germany
| | | |
Collapse
|
24
|
Kačar D, Cañedo LM, Rodríguez P, Schleissner C, de la Calle F, García JL, Galán B. Tailoring modifications in labrenzin synthesis: a-la-carte production of pathway intermediates. Microb Biotechnol 2024; 17:e14355. [PMID: 37909860 PMCID: PMC10832518 DOI: 10.1111/1751-7915.14355] [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: 06/22/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 11/03/2023] Open
Abstract
Pederin-family polyketides today constitute a group of more than 30 molecules being produced as natural products by different microorganisms across multitude of ecological niches. They are mostly known for their extreme cytotoxic activity and the decades of long exploration as potential antitumor drugs. The difference in their potency and biological activity lies in the tailoring modifications of the core molecule. Despite the isolation of many pederin-like molecules until the date, only marine bacterium Labrenzia sp. PHM005 was reported as a cultivable producer and able to be genetically modified. Here, we study the role of tailoring enzymes from the lab gene cluster responsible for methylation and hydroxylation of labrenzin core molecule. We managed to produce a spectrum of differently tailored labrenzin analogs for the development of future drugs. This work constitutes one-step forward in understanding the biosynthesis of pederin-family polyketides and provides the tools to modify and overproduce these anticancer drugs in a-la-carte manner in Labrenzia sp. PHM005, but also in other producers in the future.
Collapse
Affiliation(s)
- Dina Kačar
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita SalasAgencia Estatal Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| | | | - Pilar Rodríguez
- Research and Development DepartmentPharmaMar S.A.MadridSpain
| | | | | | - José Luis García
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita SalasAgencia Estatal Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| | - Beatriz Galán
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita SalasAgencia Estatal Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| |
Collapse
|
25
|
Kim J, Lu LC, Gao X, Hofmockel KS, Masiello CA, Silberg JJ. Using Methyl Bromide for Interspecies Cell-Cell Signaling and As a Reporter in a Model Soil Consortium. ACS Synth Biol 2023; 12:3743-3753. [PMID: 37991716 DOI: 10.1021/acssynbio.3c00559] [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] [Indexed: 11/23/2023]
Abstract
Soil microbial communities with reduced complexity are emerging as model systems for studying consortia-scale phenotypes. To establish synthetic biology tools for studying these communities in hard-to-image environmental materials, we evaluated whether a single member of a model soil consortium (MSC) can be programmed to report on gene expression without requiring matrix disruption. For these studies, we targeted a five-membered MSC that includes Dyadobacter fermentans, Ensifer adhaerens, Rhodococcus sp003130705, Streptomyces sp001905665, and Variovorax beijingensis. By coupling the expression of a methyl halide transferase to a constitutive promoter, we show that V. beijingensis can be programmed to synthesize methyl halides that accumulate in the soil headspace at levels that are ≥24-fold higher than all other MSC members across a range of environmentally relevant hydration conditions. We find that methyl halide production can report on an MSC promoter that is activated by changes in water potential, and we demonstrate that a synthetic gas signal can be read out directly using gas chromatography and indirectly using a soil-derived Methylorubrum that is programmed to produce a visual output in response to methyl halides. These tools will be useful for future studies that investigate how MSC responds to dynamic hydration conditions, such as drought and flood events induced by climate change, which can alter soil water potential and induce the release of stored carbon.
Collapse
Affiliation(s)
- Jiwoo Kim
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Li Chieh Lu
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Xiaodong Gao
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States
| | - Kirsten S Hofmockel
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Caroline A Masiello
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Jonathan J Silberg
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, Texas 77005, United States
| |
Collapse
|
26
|
Peña-Díaz J, Woodward SE, Creus-Cuadros A, Serapio-Palacios A, Ortiz-Jiménez S, Deng W, Finlay BB. Quorum sensing modulates bacterial virulence and colonization dynamics of the gastrointestinal pathogen Citrobacter rodentium. Gut Microbes 2023; 15:2267189. [PMID: 37842938 PMCID: PMC10580866 DOI: 10.1080/19490976.2023.2267189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/02/2023] [Indexed: 10/17/2023] Open
Abstract
Quorum Sensing (QS) is a form of cell-to-cell communication that enables bacteria to modify behavior according to their population density. While QS has been proposed as a potential intervention against pathogen infection, QS-mediated communication within the mammalian digestive tract remains understudied. Using an LC-MS/MS approach, we discovered that Citrobacter rodentium, a natural murine pathogen used to model human infection by pathogenic Escherichia coli, utilizes the CroIR system to produce three QS-molecules. We then profiled their accumulation both in vitro and across different gastrointestinal sites over the course of infection. Importantly, we found that in the absence of QS capabilities the virulence of C. rodentium is enhanced. This highlights the role of QS as an effective mechanism to regulate virulence according to the pathogen's spatio-temporal context to optimize colonization and transmission success. These results also demonstrate that inhibiting QS may not always be an effective strategy for the control of virulence.
Collapse
Affiliation(s)
- Jorge Peña-Díaz
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Sarah E. Woodward
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Anna Creus-Cuadros
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Antonio Serapio-Palacios
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Stephanie Ortiz-Jiménez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Wanyin Deng
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - B. Brett Finlay
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
27
|
Ciolli Mattioli C, Eisner K, Rosenbaum A, Wang M, Rivalta A, Amir A, Golding I, Avraham R. Physiological stress drives the emergence of a Salmonella subpopulation through ribosomal RNA regulation. Curr Biol 2023; 33:4880-4892.e14. [PMID: 37879333 PMCID: PMC10843543 DOI: 10.1016/j.cub.2023.09.064] [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: 06/08/2023] [Revised: 08/24/2023] [Accepted: 09/26/2023] [Indexed: 10/27/2023]
Abstract
Bacteria undergo cycles of growth and starvation to which they must adapt swiftly. One important strategy for adjusting growth rates relies on ribosomal levels. Although high ribosomal levels are required for fast growth, their dynamics during starvation remain unclear. Here, we analyzed ribosomal RNA (rRNA) content of individual Salmonella cells by using fluorescence in situ hybridization (rRNA-FISH) and measured a dramatic decrease in rRNA numbers only in a subpopulation during nutrient limitation, resulting in a bimodal distribution of cells with high and low rRNA content. During nutritional upshifts, the two subpopulations were associated with distinct phenotypes. Using a transposon screen coupled with rRNA-FISH, we identified two mutants, DksA and RNase I, acting on rRNA transcription shutdown and degradation, which abolished the formation of the subpopulation with low rRNA content. Our work identifies a bacterial mechanism for regulation of ribosomal bimodality that may be beneficial for population survival during starvation.
Collapse
Affiliation(s)
- Camilla Ciolli Mattioli
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kfir Eisner
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Aviel Rosenbaum
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Mengyu Wang
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andre' Rivalta
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ariel Amir
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ido Golding
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Roi Avraham
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
28
|
Trotereau J, Jouan R, Naquin D, Branger M, Schouler C, Velge P, Mergaert P, Virlogeux-Payant I. Construction and characterization of a saturated Tn-seq library of Salmonella Typhimurium ATCC 14028. Microbiol Resour Announc 2023; 12:e0036523. [PMID: 37795997 PMCID: PMC10653002 DOI: 10.1128/mra.00365-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/25/2023] [Indexed: 10/06/2023] Open
Abstract
Salmonella enterica is an important foodborne pathogen. Here, we present the construction and characterization of a high-density transposon sequencing library of the Salmonella Typhimurium ATCC 14028 strain. Essential, advantageous, and disadvantageous genes for growth in rich culture medium were identified on the chromosome and the pSLT plasmid.
Collapse
Affiliation(s)
| | - Romain Jouan
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | - Delphine Naquin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | | | | | | | - Peter Mergaert
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | | |
Collapse
|
29
|
Ferguson S, Abel NB, Reid D, Madsen LH, Luu TB, Andersen KR, Stougaard J, Radutoiu S. A simple and efficient protocol for generating transgenic hairy roots using Agrobacterium rhizogenes. PLoS One 2023; 18:e0291680. [PMID: 37910566 PMCID: PMC10619795 DOI: 10.1371/journal.pone.0291680] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 09/01/2023] [Indexed: 11/03/2023] Open
Abstract
For decades, Agrobacterium rhizogenes (now Rhizobium rhizogenes), the causative agent of hairy root disease, has been harnessed as an interkingdom DNA delivery tool for generating transgenic hairy roots on a wide variety of plants. One of the strategies involves the construction of transconjugant R. rhizogenes by transferring gene(s) of interest into previously constructed R. rhizogenes pBR322 acceptor strains; little has been done, however, to improve upon this system since its implementation. We developed a simplified method utilising bi-parental mating in conjunction with effective counterselection for generating R. rhizogenes transconjugants. Central to this was the construction of a new Modular Cloning (MoClo) compatible pBR322-derived integration vector (pIV101). Although this protocol remains limited to pBR322 acceptor strains, pIV101 facilitated an efficient construction of recombinant vectors, effective screening of transconjugants, and RP4-based mobilisation compatibility that enabled simplified conjugal transfer. Transconjugants from this system were tested on Lotus japonicus and found to be efficient for the transformation of transgenic hairy roots and supported infection of nodules by a rhizobia symbiont. The expedited protocol detailed herein substantially decreased both the time and labour for creating transconjugant R. rhizogenes for the subsequent transgenic hairy root transformation of Lotus, and it could readily be applied for the transformation of other plants.
Collapse
Affiliation(s)
- Shaun Ferguson
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Nikolaj B. Abel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Dugald Reid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Department of Animal, Plant and Soil Sciences, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Lene H. Madsen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Thi-Bich Luu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Kasper R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Simona Radutoiu
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| |
Collapse
|
30
|
Zhu Q, Lin Q, Jiang Y, Chen S, Tian J, Yang S, Li Y, Li M, Wang Y, Shen C, Meng S, Yang L, Feng Y, Qu J. Construction and application of the conditionally essential gene knockdown library in Klebsiella pneumoniae to screen potential antimicrobial targets and virulence genes via Mobile-CRISPRi-seq. Appl Environ Microbiol 2023; 89:e0095623. [PMID: 37815340 PMCID: PMC10617577 DOI: 10.1128/aem.00956-23] [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: 06/05/2023] [Accepted: 08/09/2023] [Indexed: 10/11/2023] Open
Abstract
Klebsiella pneumoniae is a ubiquitous human pathogen, and its clinical treatment faces two major challenges: multidrug resistance and the pathogenesis of hypervirulent K. pneumoniae. The discovery and study of conditionally essential (CE) genes that can function as potential antimicrobial targets has always been a research concern due to their restriction in the development of novel antibiotics. However, the lack of essential functional genomic data has hampered the study of the mechanisms of essential genes related to antimicrobial susceptibility. In this study, we developed a pooled CE genes mobile clustered regularly interspaced short palindromic repeat (CRISPR) interference screening method (Mobile-CRISPRi-seq) for K. pneumoniae to identify genes that play critical roles in antimicrobial fitness in vitro and host immunity in vivo. Targeting 870 predicted CE genes in K. pneumoniae, Mobile-CRISPRi-seq uncovered the depletion of tetrahydrofolate synthesis pathway genes folB and folP under trimethoprim pressure. Our screening also identified genes waaE and fldA related to polymyxin and β-lactam susceptibility by applying a screening strategy based on Mobile-CRISPRi-seq and comparative genomics. Furthermore, using a mouse infection model and Mobile-CRISPRi-seq, multiple virulence genes were identified, and among these genes, pal, yciS, and ribB were demonstrated to contribute to the pathogenesis of K. pneumoniae. This study provides a simple, rapid, and effective platform for screening potential antimicrobial targets and virulence genes in K. pneumoniae, and this broadly applicable system can be expanded for high-throughput functional gene study in multiple pathogenic bacteria, especially in gram-negative bacteria. IMPORTANCE The discovery and investigation of conditionally essential (CE) genes that can function as potential antimicrobial targets has always been a research concern because of the restriction of antimicrobial targets in the development of novel antibiotics. In this study, we developed a pooled CE gene-wide mobile clustered regularly interspaced short palindromic repeat (CRISPR) interference sequencing (Mobile-CRISPRi-seq) strategy in Klebsiella pneumoniae to identify genes that play critical roles in the fitness of antimicrobials in vitro and host immunity in vivo. The data suggest a robust tool to screen for loss-of-function phenotypes in a pooled gene knockdown library in K. pneumoniae, and Mobile-CRISPRi-seq may be expanded to multiple bacteria for screening and identification of genes with crucial roles in the fitness of antimicrobials and hosts.
Collapse
Affiliation(s)
- Qing Zhu
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Qiang Lin
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, Guangdong Province, China
| | - Yushan Jiang
- BSL-3 Laboratory (Guangdong), Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Shuyan Chen
- Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Junxuan Tian
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Shijin Yang
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Yuanchun Li
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Mengjun Li
- BSL-3 Laboratory (Guangdong), Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yuelin Wang
- BSL-3 Laboratory (Guangdong), Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Chenguang Shen
- BSL-3 Laboratory (Guangdong), Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Songdong Meng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Center for Biosafety Mega-Science, Chinese Academy of Sciences (CAS), Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liang Yang
- Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
- Key University Laboratory of Metabolism and Health of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Youjun Feng
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Jiuxin Qu
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| |
Collapse
|
31
|
Sünderhauf D, Klümper U, Gaze WH, Westra ER, van Houte S. Interspecific competition can drive plasmid loss from a focal species in a microbial community. THE ISME JOURNAL 2023; 17:1765-1773. [PMID: 37558861 PMCID: PMC10504238 DOI: 10.1038/s41396-023-01487-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
Plasmids are key disseminators of antimicrobial resistance genes and virulence factors, and it is therefore critical to predict and reduce plasmid spread within microbial communities. The cost of plasmid carriage is a key metric that can be used to predict plasmids' ecological fate, and it is unclear whether plasmid costs are affected by growth partners in a microbial community. We carried out competition experiments and tracked plasmid maintenance using a model system consisting of a synthetic and stable five-species community and a broad host-range plasmid, engineered to carry different payloads. We report that both the cost of plasmid carriage and its long-term maintenance in a focal strain depended on the presence of competitors, and that these interactions were species specific. Addition of growth partners increased the cost of a high-payload plasmid to a focal strain, and accordingly, plasmid loss from the focal species occurred over a shorter time frame. We propose that the destabilising effect of interspecific competition on plasmid maintenance may be leveraged in clinical and natural environments to cure plasmids from focal strains.
Collapse
Affiliation(s)
- David Sünderhauf
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK.
| | - Uli Klümper
- Department Hydrosciences, Technische Universität Dresden, Institute of Hydrobiology, Dresden, Germany
| | - William H Gaze
- European Centre for Environment and Human Health, University of Exeter Medical School, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - Edze R Westra
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - Stineke van Houte
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK.
| |
Collapse
|
32
|
Alker AT, Farrell MV, Aspiras AE, Dunbar TL, Fedoriouk A, Jones JE, Mikhail SR, Salcedo GY, Moore BS, Shikuma NJ. A modular plasmid toolkit applied in marine bacteria reveals functional insights during bacteria-stimulated metamorphosis. mBio 2023; 14:e0150223. [PMID: 37530556 PMCID: PMC10470607 DOI: 10.1128/mbio.01502-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 08/03/2023] Open
Abstract
A conspicuous roadblock to studying marine bacteria for fundamental research and biotechnology is a lack of modular synthetic biology tools for their genetic manipulation. Here, we applied, and generated new parts for, a modular plasmid toolkit to study marine bacteria in the context of symbioses and host-microbe interactions. To demonstrate the utility of this plasmid system, we genetically manipulated the marine bacterium Pseudoalteromonas luteoviolacea, which stimulates the metamorphosis of the model tubeworm, Hydroides elegans. Using these tools, we quantified constitutive and native promoter expression, developed reporter strains that enable the imaging of host-bacteria interactions, and used CRISPR interference (CRISPRi) to knock down a secondary metabolite and a host-associated gene. We demonstrate the broader utility of this modular system for testing the genetic tractability of marine bacteria that are known to be associated with diverse host-microbe symbioses. These efforts resulted in the successful conjugation of 12 marine strains from the Alphaproteobacteria and Gammaproteobacteria classes. Altogether, the present study demonstrates how synthetic biology strategies enable the investigation of marine microbes and marine host-microbe symbioses with potential implications for environmental restoration and biotechnology. IMPORTANCE Marine Proteobacteria are attractive targets for genetic engineering due to their ability to produce a diversity of bioactive metabolites and their involvement in host-microbe symbioses. Modular cloning toolkits have become a standard for engineering model microbes, such as Escherichia coli, because they enable innumerable mix-and-match DNA assembly and engineering options. However, such modular tools have not yet been applied to most marine bacterial species. In this work, we adapt a modular plasmid toolkit for use in a set of 12 marine bacteria from the Gammaproteobacteria and Alphaproteobacteria classes. We demonstrate the utility of this genetic toolkit by engineering a marine Pseudoalteromonas bacterium to study their association with its host animal Hydroides elegans. This work provides a proof of concept that modular genetic tools can be applied to diverse marine bacteria to address basic science questions and for biotechnology innovations.
Collapse
Affiliation(s)
- Amanda T. Alker
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Morgan V. Farrell
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Alpher E. Aspiras
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Tiffany L. Dunbar
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Andriy Fedoriouk
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Jeffrey E. Jones
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Sama R. Mikhail
- Department of Biology, San Diego State University, San Diego, California, USA
| | | | - Bradley S. Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California, USA
| | - Nicholas J. Shikuma
- Department of Biology, San Diego State University, San Diego, California, USA
| |
Collapse
|
33
|
Rudenko O, Baseggio L, McGuigan F, Barnes AC. Transforming the untransformable with knockout minicircles: High-efficiency transformation and vector-free allelic exchange knockout in the fish pathogen Photobacterium damselae. Microbiologyopen 2023; 12:e1374. [PMID: 37642481 PMCID: PMC10441182 DOI: 10.1002/mbo3.1374] [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: 06/22/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023] Open
Abstract
Gene inactivation studies are critical in pathogenic bacteria, where insights into species biology can guide the development of vaccines and treatments. Allelic exchange via homologous recombination is a generic method of targeted gene editing in bacteria. However, generally applicable protocols are lacking, and suboptimal approaches are often used for nonstandard but epidemiologically important species. Photobacterium damselae subsp. piscicida (Pdp) is a primary pathogen of fish in aquaculture and has been considered hard to transform since the mid-1990s. Consequently, conjugative transfer of RK2/RP4 suicide vectors from Escherichia coli S17-1/SM10 donor strains, a system prone to off-target mutagenesis, was used to deliver the allelic exchange DNA in previous studies. Here we have achieved efficient electrotransformation in Pdp using a salt-free highly concentrated sucrose solution, which performs as a hypertonic wash buffer, cryoprotectant, and electroporation buffer. High-efficiency transformation has enabled vector-free mutagenesis for which we have employed circular minimalistic constructs (knockout minicircles) containing only allelic exchange essentials that were generated by Gibson assembly. Preparation of competent cells using sucrose and electroporation/integration of minicircles had virtually no detectable off-target promutagenic effect. In contrast, a downstream sacB selection apparently induced several large deletions via mobilization of transposable elements. Electroporation of minicircles into sucrose-treated cells is a versatile broadly applicable approach that may facilitate allelic exchange in a wide range of microbial species. The method permitted inactivation of a primary virulence factor unique to Pdp, apoptogenic toxin AIP56, demonstrating the efficacy of minicircles for difficult KO targets located on the high copy number of small plasmids.
Collapse
Affiliation(s)
- Oleksandra Rudenko
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| | - Laura Baseggio
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| | - Fynn McGuigan
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Andrew C. Barnes
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| |
Collapse
|
34
|
Obando MA, Dörr T. Novel role for peptidoglycan carboxypeptidases in maintaining the balance between bacterial cell wall synthesis and degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548665. [PMID: 37503280 PMCID: PMC10369974 DOI: 10.1101/2023.07.12.548665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Peptidoglycan (PG) is the main component of the bacterial cell wall; it maintains cell shape while protecting the cell from internal osmotic pressure and external environmental challenges. PG synthesis is essential for bacterial growth and survival, and a series of PG modifications are required to allow expansion of the sacculus. Endopeptidases (EPs), for example, cleave the crosslinks between adjacent PG strands to allow the incorporation of newly synthesized PG. EPs are collectively essential for bacterial growth and must likely be carefully regulated to prevent sacculus degradation and cell death. However, EP regulation mechanisms are poorly understood. Here, we used TnSeq to uncover novel EP regulation factors in Vibrio cholerae. This screen revealed that the carboxypeptidase DacA1 (PBP5) alleviates EP toxicity. dacA1 is essential for viability on LB medium, and this essentiality was suppressed by EP overexpression, revealing that EP toxicity both mitigates, and is mitigated by, a defect in dacA1. A subsequent suppressor screen to restore viability of ΔdacA1 in LB medium was answered by hypomorphic mutants in the PG synthesis pathway, as well as mutations that promote PG degradation. Our data thus reveal a key role of DacA1 in maintaining the balance between PG synthesis and degradation.
Collapse
Affiliation(s)
- Manuela Alvarado Obando
- Department of Microbiology, Cornell University, Ithaca, NY
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Tobias Dörr
- Department of Microbiology, Cornell University, Ithaca, NY
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| |
Collapse
|
35
|
Hu K, Chia-Wei C, Wilke CO, Finkelstein IJ. Distinct horizontal transfer mechanisms for type I and type V CRISPR-associated transposons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.03.531003. [PMID: 37502928 PMCID: PMC10369902 DOI: 10.1101/2023.03.03.531003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
CRISPR-associated transposons (CASTs) co-opt CRISPR-Cas proteins and Tn7-family transposons for RNA-guided vertical and horizontal transmission. CASTs encode minimal CRISPR arrays but can't acquire new spacers. Here, we show that CASTs instead co-opt defense-associated CRISPR arrays for horizontal transmission. A bioinformatic analysis shows that all CAST sub-types co-occur with defense-associated CRISPR-Cas systems. Using an E. coli quantitative transposition assay, we show that CASTs use CRISPR RNAs (crRNAs) from these defense systems for horizontal gene transfer. A high-resolution structure of the type I-F CAST-Cascade in complex with a type III-B crRNA reveals that Cas6 recognizes direct repeats via sequence-independent π - π interactions. In addition to using heterologous CRISPR arrays, type V CASTs can also transpose via a crRNA-independent unguided mechanism, even when the S15 co-factor is over-expressed. Over-expressing S15 and the trans-activating CRISPR RNA (tracrRNA) or a single guide RNA (sgRNA) reduces, but does not abrogate, off-target integration for type V CASTs. Exploiting new spacers in defense-associated CRISPR arrays explains how CASTs horizontally transfer to new hosts. More broadly, this work will guide further efforts to engineer the activity and specificity of CASTs for gene editing applications.
Collapse
Affiliation(s)
- Kuang Hu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Chou Chia-Wei
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Claus O. Wilke
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Ilya J. Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, 78712, USA
| |
Collapse
|
36
|
Jensen SJ, Ruhe ZC, Williams AF, Nhan DQ, Garza-Sánchez F, Low DA, Hayes CS. Paradoxical Activation of a Type VI Secretion System Phospholipase Effector by Its Cognate Immunity Protein. J Bacteriol 2023; 205:e0011323. [PMID: 37212679 PMCID: PMC10294671 DOI: 10.1128/jb.00113-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/03/2023] [Indexed: 05/23/2023] Open
Abstract
Type VI secretion systems (T6SSs) deliver cytotoxic effector proteins into target bacteria and eukaryotic host cells. Antibacterial effectors are invariably encoded with cognate immunity proteins that protect the producing cell from self-intoxication. Here, we identify transposon insertions that disrupt the tli immunity gene of Enterobacter cloacae and induce autopermeabilization through unopposed activity of the Tle phospholipase effector. This hyperpermeability phenotype is T6SS dependent, indicating that the mutants are intoxicated by Tle delivered from neighboring sibling cells rather than by internally produced phospholipase. Unexpectedly, an in-frame deletion of tli does not induce hyperpermeability because Δtli null mutants fail to deploy active Tle. Instead, the most striking phenotypes are associated with disruption of the tli lipoprotein signal sequence, which prevents immunity protein localization to the periplasm. Immunoblotting reveals that most hyperpermeable mutants still produce Tli, presumably from alternative translation initiation codons downstream of the signal sequence. These observations suggest that cytosolic Tli is required for the activation and/or export of Tle. We show that Tle growth inhibition activity remains Tli dependent when phospholipase delivery into target bacteria is ensured through fusion to the VgrG β-spike protein. Together, these findings indicate that Tli has distinct functions, depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to neutralize incoming effector proteins, while a cytosolic pool of Tli is required to activate the phospholipase domain of Tle prior to T6SS-dependent export. IMPORTANCE Gram-negative bacteria use type VI secretion systems deliver toxic effector proteins directly into neighboring competitors. Secreting cells also produce specific immunity proteins that neutralize effector activities to prevent autointoxication. Here, we show the Tli immunity protein of Enterobacter cloacae has two distinct functions, depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to block Tle lipase effector activity, while cytoplasmic Tli is required to activate the lipase prior to export. These results indicate Tle interacts transiently with its cognate immunity protein to promote effector protein folding and/or packaging into the secretion apparatus.
Collapse
Affiliation(s)
- Steven J. Jensen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Zachary C. Ruhe
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - August F. Williams
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Dinh Q. Nhan
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Fernando Garza-Sánchez
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - David A. Low
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
- Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Christopher S. Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
- Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California, USA
| |
Collapse
|
37
|
Elston KM, Phillips LE, Leonard SP, Young E, Holley JAC, Ahsanullah T, McReynolds B, Moran NA, Barrick JE. The Pathfinder plasmid toolkit for genetically engineering newly isolated bacteria enables the study of Drosophila-colonizing Orbaceae. ISME COMMUNICATIONS 2023; 3:49. [PMID: 37225918 PMCID: PMC10209150 DOI: 10.1038/s43705-023-00255-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 04/18/2023] [Accepted: 05/11/2023] [Indexed: 05/26/2023]
Abstract
Toolkits of plasmids and genetic parts streamline the process of assembling DNA constructs and engineering microbes. Many of these kits were designed with specific industrial or laboratory microbes in mind. For researchers interested in non-model microbial systems, it is often unclear which tools and techniques will function in newly isolated strains. To address this challenge, we designed the Pathfinder toolkit for quickly determining the compatibility of a bacterium with different plasmid components. Pathfinder plasmids combine three different broad-host-range origins of replication with multiple antibiotic resistance cassettes and reporters, so that sets of parts can be rapidly screened through multiplex conjugation. We first tested these plasmids in Escherichia coli, a strain of Sodalis praecaptivus that colonizes insects, and a Rosenbergiella isolate from leafhoppers. Then, we used the Pathfinder plasmids to engineer previously unstudied bacteria from the family Orbaceae that were isolated from several fly species. Engineered Orbaceae strains were able to colonize Drosophila melanogaster and could be visualized in fly guts. Orbaceae are common and abundant in the guts of wild-caught flies but have not been included in laboratory studies of how the Drosophila microbiome affects fly health. Thus, this work provides foundational genetic tools for studying microbial ecology and host-associated microbes, including bacteria that are a key constituent of the gut microbiome of a model insect species.
Collapse
Affiliation(s)
- Katherine M Elston
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Laila E Phillips
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Sean P Leonard
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Eleanor Young
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jo-Anne C Holley
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, 78712, USA
- Freshman Research Initiative, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Tasneem Ahsanullah
- Freshman Research Initiative, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Braydin McReynolds
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Nancy A Moran
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jeffrey E Barrick
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
38
|
Lang H, Wang H, Wang H, Zhong Z, Xie X, Zhang W, Guo J, Meng L, Hu X, Zhang X, Zheng H. Engineered symbiotic bacteria interfering Nosema redox system inhibit microsporidia parasitism in honeybees. Nat Commun 2023; 14:2778. [PMID: 37210527 DOI: 10.1038/s41467-023-38498-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/05/2023] [Indexed: 05/22/2023] Open
Abstract
Nosema ceranae is an intracellular parasite invading the midgut of honeybees, which causes serious nosemosis implicated in honeybee colony losses worldwide. The core gut microbiota is involved in protecting against parasitism, and the genetically engineering of the native gut symbionts provides a novel and efficient way to fight pathogens. Here, using laboratory-generated bees mono-associated with gut members, we find that Snodgrassella alvi inhibit microsporidia proliferation, potentially via the stimulation of host oxidant-mediated immune response. Accordingly, N. ceranae employs the thioredoxin and glutathione systems to defend against oxidative stress and maintain a balanced redox equilibrium, which is essential for the infection process. We knock down the gene expression using nanoparticle-mediated RNA interference, which targets the γ-glutamyl-cysteine synthetase and thioredoxin reductase genes of microsporidia. It significantly reduces the spore load, confirming the importance of the antioxidant mechanism for the intracellular invasion of the N. ceranae parasite. Finally, we genetically modify the symbiotic S. alvi to deliver dsRNA corresponding to the genes involved in the redox system of the microsporidia. The engineered S. alvi induces RNA interference and represses parasite gene expression, thereby inhibits the parasitism significantly. Specifically, N. ceranae is most suppressed by the recombinant strain corresponding to the glutathione synthetase or by a mixture of bacteria expressing variable dsRNA. Our findings extend our previous understanding of the protection of gut symbionts against N. ceranae and provide a symbiont-mediated RNAi system for inhibiting microsporidia infection in honeybees.
Collapse
Affiliation(s)
- Haoyu Lang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Hao Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Haoqing Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Zhaopeng Zhong
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Xianbing Xie
- Department of Laboratory Animal Science, Nanchang University, 330006, Nanchang, China
| | - Wenhao Zhang
- Faculty of Agriculture and Food, Kunming University of Science and Technology, 650031, Kunming, China
| | - Jun Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650031, Kunming, China
| | - Liang Meng
- BGI-Qingdao, BGI-Shenzhen, 266555, Qingdao, China
| | - Xiaosong Hu
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Xue Zhang
- College of Plant Protection, China Agricultural University, 100083, Beijing, China
| | - Hao Zheng
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China.
| |
Collapse
|
39
|
Jo D, Kim H, Lee Y, Kim J, Ryu S. Characterization and genomic study of EJP2, a novel jumbo phage targeting antimicrobial resistant Escherichia coli. Front Microbiol 2023; 14:1194435. [PMID: 37250060 PMCID: PMC10213699 DOI: 10.3389/fmicb.2023.1194435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 04/25/2023] [Indexed: 05/31/2023] Open
Abstract
The emergence of antimicrobial resistance (AMR) Escherichia coli has noticeably increased in recent years worldwide and causes serious public health concerns. As alternatives to antibiotics, bacteriophages are regarded as promising antimicrobial agents. In this study, we isolated and characterized a novel jumbo phage EJP2 that specifically targets AMR E. coli strains. EJP2 belonged to the Myoviridae family with an icosahedral head (120.9 ± 2.9 nm) and a non-contractile tail (111.1 ± 0.6 nm), and contained 349,185 bp double-stranded DNA genome with 540 putative ORFs, suggesting that EJP2 could be classified as jumbo phage. The functions of genes identified in EJP2 genome were mainly related to nucleotide metabolism, DNA replication, and recombination. Comparative genomic analysis revealed that EJP2 was categorized in the group of Rak2-related virus and presented low sequence similarity at the nucleotide and amino acid level compared to other E. coli jumbo phages. EJP2 had a broad host spectrum against AMR E. coli as well as pathogenic E. coli and recognized LPS as a receptor for infection. Moreover, EJP2 treatment could remove over 80% of AMR E. coli biofilms on 96-well polystyrene, and exhibit synergistic antimicrobial activity with cefotaxime against AMR E. coli. These results suggest that jumbo phage EJP2 could be used as a potential biocontrol agent to combat the AMR issue in food processing and clinical environments.
Collapse
|
40
|
Walker-Sünderhauf D, Klümper U, Pursey E, Westra ER, Gaze WH, van Houte S. Removal of AMR plasmids using a mobile, broad host-range CRISPR-Cas9 delivery tool. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001334. [PMID: 37226834 PMCID: PMC10268836 DOI: 10.1099/mic.0.001334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 04/24/2023] [Indexed: 05/26/2023]
Abstract
Antimicrobial resistance (AMR) genes are widely disseminated on plasmids. Therefore, interventions aimed at blocking plasmid uptake and transfer may curb the spread of AMR. Previous studies have used CRISPR-Cas-based technology to remove plasmids encoding AMR genes from target bacteria, using either phage- or plasmid-based delivery vehicles that typically have narrow host ranges. To make this technology feasible for removal of AMR plasmids from multiple members of complex microbial communities, an efficient, broad host-range delivery vehicle is needed. We engineered the broad host-range IncP1-plasmid pKJK5 to encode cas9 programmed to target an AMR gene. We demonstrate that the resulting plasmid pKJK5::csg has the ability to block the uptake of AMR plasmids and to remove resident plasmids from Escherichia coli. Furthermore, due to its broad host range, pKJK5::csg successfully blocked AMR plasmid uptake in a range of environmental, pig- and human-associated coliform isolates, as well as in isolates of two species of Pseudomonas. This study firmly establishes pKJK5::csg as a promising broad host-range CRISPR-Cas9 delivery tool for AMR plasmid removal, which has the potential to be applied in complex microbial communities to remove AMR genes from a broad range of bacterial species.
Collapse
Affiliation(s)
- David Walker-Sünderhauf
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - Uli Klümper
- Institute of Hydrobiology, Technische Universität Dresden, 01217 Dresden, Germany
| | - Elizabeth Pursey
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - Edze R. Westra
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - William H. Gaze
- European Centre for Environment and Human Health, University of Exeter Medical School, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| | - Stineke van Houte
- Centre for Ecology and Conservation, University of Exeter, Environment and Sustainability Institute, Penryn, TR10 9FE, UK
| |
Collapse
|
41
|
Jensen SJ, Ruhe ZC, Williams AF, Nhan DQ, Garza-Sánchez F, Low DA, Hayes CS. Paradoxical activation of a type VI secretion system (T6SS) phospholipase effector by its cognate immunity protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534661. [PMID: 37034769 PMCID: PMC10081291 DOI: 10.1101/2023.03.28.534661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Type VI secretion systems (T6SS) deliver cytotoxic effector proteins into target bacteria and eukaryotic host cells. Antibacterial effectors are invariably encoded with cognate immunity proteins that protect the producing cell from self-intoxication. Here, we identify transposon insertions that disrupt the tli immunity gene of Enterobacter cloacae and induce auto-permeabilization through unopposed activity of the Tle phospholipase effector. This hyper-permeability phenotype is T6SS-dependent, indicating that the mutants are intoxicated by Tle delivered from neighboring sibling cells rather than by internally produced phospholipase. Unexpectedly, an in-frame deletion of tli does not induce hyper-permeability because Δ tli null mutants fail to deploy active Tle. Instead, the most striking phenotypes are associated with disruption of the tli lipoprotein signal sequence, which prevents immunity protein localization to the periplasm. Immunoblotting reveals that most hyper-permeable mutants still produce Tli, presumably from alternative translation initiation codons downstream of the signal sequence. These observations suggest that cytosolic Tli is required for the activation and/or export of Tle. We show that Tle growth inhibition activity remains Tli-dependent when phospholipase delivery into target bacteria is ensured through fusion to the VgrG β-spike protein. Together, these findings indicate that Tli has distinct functions depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to neutralize incoming effector proteins, while a cytosolic pool of Tli is required to activate the phospholipase domain of Tle prior to T6SS-dependent export.
Collapse
|
42
|
Keller M, Han X, Dörr T. Disrupting Central Carbon Metabolism Increases β-Lactam Antibiotic Susceptibility in Vibrio cholerae. J Bacteriol 2023; 205:e0047622. [PMID: 36840595 PMCID: PMC10029711 DOI: 10.1128/jb.00476-22] [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: 12/21/2022] [Accepted: 01/31/2023] [Indexed: 02/24/2023] Open
Abstract
Antibiotic tolerance, the ability of bacteria to sustain viability in the presence of typically bactericidal antibiotics for extended time periods, is an understudied contributor to treatment failure. The Gram-negative pathogen Vibrio cholerae, the causative agent of cholera, becomes highly tolerant to β-lactam antibiotics (penicillin and related compounds) in a process requiring the two-component system VxrAB. VxrAB is induced by exposure to cell wall damaging conditions, which results in the differential regulation of >100 genes. While the effectors of VxrAB are relatively well known, VxrAB environment-sensing and activation mechanisms remain a mystery. Here, we used transposon mutagenesis to screen for mutants that spontaneously upregulate VxrAB signaling. This screen was answered by genes known to be required for proper cell envelope homeostasis, validating the approach. Unexpectedly, we also uncovered a new connection between central carbon metabolism and antibiotic tolerance in Vibrio cholerae. Inactivation of pgi (vc0374, coding for glucose-6-phosphate isomerase) resulted in an intracellular accumulation of glucose-6-phosphate and fructose-6-phosphate, concomitant with a marked cell envelope defect, resulting in VxrAB induction. Deletion of pgi also increased sensitivity to β-lactams and conferred a growth defect on salt-free LB, phenotypes that could be suppressed by deleting sugar uptake systems and by supplementing cell wall precursors in the growth medium. Our data suggest an important connection between central metabolism and cell envelope integrity and highlight a potential new target for developing novel antimicrobial agents. IMPORTANCE Antibiotic tolerance (the ability to survive exposure to antibiotics) is a stepping stone toward antibiotic resistance (the ability to grow in the presence of antibiotics), an increasingly common cause of antibiotic treatment failure. The mechanisms promoting tolerance are poorly understood. Here, we identified central carbon metabolism as a key contributor to antibiotic tolerance and resistance. A strain with a mutation in a sugar utilization pathway accumulates metabolites that likely shut down the synthesis of cell wall precursors, which weakens the cell wall and thus increases susceptibility to cell wall-active drugs. Our results illuminate the connection between central carbon metabolism and cell wall homeostasis in V. cholerae and suggest that interfering with metabolism may be a fruitful future strategy for the development of antibiotic adjuvants.
Collapse
Affiliation(s)
- Megan Keller
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Xiang Han
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Tobias Dörr
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
- Department of Microbiology, Cornell University, Ithaca, New York, USA
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, USA
| |
Collapse
|
43
|
Dual-Uptake Mode of the Antibiotic Phazolicin Prevents Resistance Acquisition by Gram-Negative Bacteria. mBio 2023; 14:e0021723. [PMID: 36802165 PMCID: PMC10128002 DOI: 10.1128/mbio.00217-23] [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: 02/23/2023] Open
Abstract
Phazolicin (PHZ) is a peptide antibiotic exhibiting narrow-spectrum activity against rhizobia closely related to its producer, Rhizobium sp. strain Pop5. Here, we show that the frequency of spontaneous PHZ-resistant mutants in Sinorhizobium meliloti is below the detection limit. We find that PHZ can enter S. meliloti cells through two distinct promiscuous peptide transporters, BacA and YejABEF, which belong to the SLiPT (SbmA-like peptide transporter) and ABC (ATP-binding cassette) transporter families, respectively. The dual-uptake mode explains the lack of observed resistance acquisition because the simultaneous inactivation of both transporters is necessary for resistance to PHZ. Since both BacA and YejABEF are essential for the development of functional symbiosis of S. meliloti with leguminous plants, the unlikely acquisition of PHZ resistance via the inactivation of these transporters is further disfavored. A whole-genome transposon sequencing screen did not reveal additional genes that can provide strong PHZ resistance when inactivated. However, it was found that the capsular polysaccharide KPS, the novel putative envelope polysaccharide PPP (PHZ-protecting polysaccharide), as well as the peptidoglycan layer jointly contribute to the sensitivity of S. meliloti to PHZ, most likely serving as barriers that reduce the amount of PHZ transported inside the cell. IMPORTANCE Many bacteria produce antimicrobial peptides to eliminate competitors and create an exclusive niche. These peptides act either by membrane disruption or by inhibiting essential intracellular processes. The Achilles' heel of the latter type of antimicrobials is their dependence on transporters to enter susceptible cells. Transporter inactivation results in resistance. Here, we show that a rhizobial ribosome-targeting peptide, phazolicin (PHZ), uses two different transporters, BacA and YejABEF, to enter the cells of a symbiotic bacterium, Sinorhizobium meliloti. This dual-entry mode dramatically reduces the probability of the appearance of PHZ-resistant mutants. Since these transporters are also crucial for S. meliloti symbiotic associations with host plants, their inactivation in natural settings is strongly disfavored, making PHZ an attractive lead for the development of biocontrol agents for agriculture.
Collapse
|
44
|
Elston KM, Phillips LE, Leonard SP, Young E, Holley JAC, Ahsanullah T, McReynolds B, Moran NA, Barrick JE. The Pathfinder plasmid toolkit for genetically engineering newly isolated bacteria enables the study of Drosophila -colonizing Orbaceae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528778. [PMID: 36824770 PMCID: PMC9949093 DOI: 10.1101/2023.02.15.528778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Toolkits of plasmids and genetic parts streamline the process of assembling DNA constructs and engineering microbes. Many of these kits were designed with specific industrial or laboratory microbes in mind. For researchers interested in non-model microbial systems, it is often unclear which tools and techniques will function in newly isolated strains. To address this challenge, we designed the Pathfinder toolkit for quickly determining the compatibility of a bacterium with different plasmid components. Pathfinder plasmids combine three different broad-host-range origins of replication with multiple antibiotic resistance cassettes and reporters, so that sets of parts can be rapidly screened through multiplex conjugation. We first tested these plasmids in Escherichia coli , a strain of Sodalis praecaptivus that colonizes insects, and a Rosenbergiella isolate from leafhoppers. Then, we used the Pathfinder plasmids to engineer previously unstudied bacteria from the family Orbaceae that were isolated from several fly species. Engineered Orbaceae strains were able to colonize Drosophila melanogaster and could be visualized in fly guts. Orbaceae are common and abundant in the guts of wild-caught flies but have not been included in laboratory studies of how the Drosophila microbiome affects fly health. Thus, this work provides foundational genetic tools for studying new host-associated microbes, including bacteria that are a key constituent of the gut microbiome of a model insect species. IMPORTANCE To fully understand how microbes have evolved to interact with their environments, one must be able to modify their genomes. However, it can be difficult and laborious to discover which genetic tools and approaches work for a new isolate. Bacteria from the recently described Orbaceae family are common in the microbiomes of insects. We developed the Pathfinder plasmid toolkit for testing the compatibility of different genetic parts with newly cultured bacteria. We demonstrate its utility by engineering Orbaceae strains isolated from flies to express fluorescent proteins and characterizing how they colonize the Drosophila melanogaster gut. Orbaceae are widespread in Drosophila in the wild but have not been included in laboratory studies examining how the gut microbiome affects fly nutrition, health, and longevity. Our work establishes a path for genetic studies aimed at understanding and altering interactions between these and other newly isolated bacteria and their hosts.
Collapse
Affiliation(s)
- Katherine M. Elston
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Laila E. Phillips
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sean P. Leonard
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Eleanor Young
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jo-anne C. Holley
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
- Freshman Research Initiative, The University of Texas at Austin, Austin, TX 78712, USA
| | - Tasneem Ahsanullah
- Freshman Research Initiative, The University of Texas at Austin, Austin, TX 78712, USA
| | - Braydin McReynolds
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Nancy A. Moran
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey E. Barrick
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| |
Collapse
|
45
|
Mijnendonckx K, Rogiers T, Giménez Del Rey FJ, Merroun ML, Williamson A, Ali MM, Charlier D, Leys N, Boon N, Van Houdt R. PrsQ 2, a small periplasmic protein involved in increased uranium resistance in the bacterium Cupriavidus metallidurans. JOURNAL OF HAZARDOUS MATERIALS 2023; 444:130410. [PMID: 36413896 DOI: 10.1016/j.jhazmat.2022.130410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Uranium contamination is a widespread problem caused by natural and anthropogenic activities. Although microorganisms thrive in uranium-contaminated environments, little is known about the actual molecular mechanisms mediating uranium resistance. Here, we investigated the resistance mechanisms driving the adaptation of Cupriavidus metallidurans NA4 to toxic uranium concentrations. We selected a spontaneous mutant able to grow in the presence of 1 mM uranyl nitrate compared to 250 µM for the parental strain. The increased uranium resistance was acquired via the formation of periplasmic uranium-phosphate precipitates facilitated by the increased expression of a genus-specific small periplasmic protein, PrsQ2, regulated as non-cognate target of the CzcS2-CzcR2 two-component system. This study shows that bacteria can adapt to toxic uranium concentrations and explicates the complete genetic circuit behind the adaptation.
Collapse
Affiliation(s)
- Kristel Mijnendonckx
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Tom Rogiers
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Francisco J Giménez Del Rey
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium; Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Mohamed L Merroun
- Campus Fuentenueva, Department of Microbiology, University of Granada, Granada, Spain.
| | - Adam Williamson
- Center for Microbial Ecology and Technology, UGent, Ghent, Belgium.
| | - Md Muntasir Ali
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Daniel Charlier
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Nico Boon
- Center for Microbial Ecology and Technology, UGent, Ghent, Belgium.
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| |
Collapse
|
46
|
Jaén-Luchoro D, Karlsson R, Busquets A, Piñeiro-Iglesias B, Karami N, Marathe NP, Moore ERB. Knockout of Targeted Plasmid-Borne β-Lactamase Genes in an Extended-Spectrum-β-Lactamase-Producing Escherichia coli Strain: Impact on Resistance and Proteomic Profile. Microbiol Spectr 2023; 11:e0386722. [PMID: 36622237 PMCID: PMC9927464 DOI: 10.1128/spectrum.03867-22] [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: 10/01/2022] [Accepted: 12/09/2022] [Indexed: 01/10/2023] Open
Abstract
Resistance to β-lactams is known to be multifactorial, although the underlying mechanisms are not well established. The aim of our study was to develop a system for assessing the phenotypic and proteomic responses of bacteria to antibiotic stress as a result of the loss of selected antimicrobial resistance genes. We applied homologous recombination to knock out plasmid-borne β-lactamase genes (blaOXA-1, blaTEM-1, and blaCTX-M15) in Escherichia coli CCUG 73778, generating knockout clone variants lacking the respective deleted β-lactamases. Quantitative proteomic analyses were performed on the knockout variants and the wild-type strain, using bottom-up liquid chromatography tandem mass spectrometry (LC-MS/MS), after exposure to different concentrations of cefadroxil. Loss of the blaCTX-M-15 gene had the greatest impact on the resulting protein expression dynamics, while losses of blaOXA-1 and blaTEM-1 affected fewer proteins' expression levels. Proteins involved in antibiotic resistance, cell membrane integrity, stress, and gene expression and unknown function proteins exhibited differential expression. The present study provides a framework for studying protein expression in response to antibiotic exposure and identifying the genomic, proteomic, and phenotypic impacts of resistance gene loss. IMPORTANCE The critical situation regarding antibiotic resistance requires a more in-depth effort for understanding underlying mechanisms involved in antibiotic resistance, beyond just detecting resistance genes. The methodology presented in this work provides a framework for knocking out selected resistance factors, to study the adjustments of the bacterium in response to a particular antibiotic stress, elucidating the genetic response and proteins that are mobilized. The protocol uses MS-based determination of the proteins that are expressed in response to an antibiotic, enabling the selection of strong candidates representing putative resistance factors or mechanisms and providing a basis for future studies to understand their implications in antibiotic resistance. This allows us to better understand how the cell responds to the presence of the antibiotic when a specific gene is lost and, consequently, identify alternative targets for possible future treatment development.
Collapse
Affiliation(s)
- Daniel Jaén-Luchoro
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research, University of Gothenburg, Gothenburg, Sweden
- Culture Collection University of Gothenburg, Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Roger Karlsson
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
- Nanoxis Consulting AB, Gothenburg, Sweden
| | - Antonio Busquets
- Microbiology, Department of Biology, University of the Balearic Islands, Palma de Mallorca, Spain
| | - Beatriz Piñeiro-Iglesias
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Gothenburg, Sweden
- Culture Collection University of Gothenburg, Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Nahid Karami
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
| | | | - Edward R. B. Moore
- Department of Infectious Diseases, Institute for Biomedicine, Sahlgrenska Academy of the University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research, University of Gothenburg, Gothenburg, Sweden
- Culture Collection University of Gothenburg, Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
| |
Collapse
|
47
|
Arroyo-Mendoza M, Proctor A, Correa-Medina A, Brand MW, Rosas V, Wannemuehler MJ, Phillips GJ, Hinton DM. The E. coli pathobiont LF82 encodes a unique variant of σ 70 that results in specific gene expression changes and altered phenotypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.523653. [PMID: 36798310 PMCID: PMC9934711 DOI: 10.1101/2023.02.08.523653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
LF82, an adherent invasive Escherichia coli pathobiont, is associated with ileal Crohn's disease, an inflammatory bowel disease of unknown etiology. Although LF82 contains no virulence genes, it carries several genetic differences, including single nucleotide polymorphisms (SNPs), that distinguish it from nonpathogenic E. coli. We have identified and investigated an extremely rare SNP that is within the highly conserved rpoD gene, encoding σ70, the primary sigma factor for RNA polymerase. We demonstrate that this single residue change (D445V) results in specific transcriptome and phenotypic changes that are consistent with multiple phenotypes observed in LF82, including increased antibiotic resistance and biofilm formation, modulation of motility, and increased capacity for methionine biosynthesis. Our work demonstrates that a single residue change within the bacterial primary sigma factor can lead to multiple alterations in gene expression and phenotypic changes, suggesting an underrecognized mechanism by which pathobionts and other strain variants with new phenotypes can emerge.
Collapse
Affiliation(s)
- Melissa Arroyo-Mendoza
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Dr., Bethesda, MD, United States, 20892
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States, 50011
| | - Alexandra Proctor
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States, 50011
| | - Abraham Correa-Medina
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Dr., Bethesda, MD, United States, 20892
| | - Meghan Wymore Brand
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States, 50011
| | - Virginia Rosas
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Dr., Bethesda, MD, United States, 20892
| | - Michael J Wannemuehler
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States, 50011
| | - Gregory J Phillips
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States, 50011
| | - Deborah M Hinton
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Dr., Bethesda, MD, United States, 20892
| |
Collapse
|
48
|
Alker AT, Aspiras AE, Dunbar TL, Farrell MV, Fedoriouk A, Jones JE, Mikhail SR, Salcedo GY, Moore BS, Shikuma NJ. A modular plasmid toolkit applied in marine Proteobacteria reveals functional insights during bacteria-stimulated metamorphosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.526474. [PMID: 36778221 PMCID: PMC9915575 DOI: 10.1101/2023.01.31.526474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A conspicuous roadblock to studying marine bacteria for fundamental research and biotechnology is a lack of modular synthetic biology tools for their genetic manipulation. Here, we applied, and generated new parts for, a modular plasmid toolkit to study marine bacteria in the context of symbioses and host-microbe interactions. To demonstrate the utility of this plasmid system, we genetically manipulated the marine bacterium Pseudoalteromonas luteoviolacea , which stimulates the metamorphosis of the model tubeworm, Hydroides elegans . Using these tools, we quantified constitutive and native promoter expression, developed reporter strains that enable the imaging of host-bacteria interactions, and used CRISPR interference (CRISPRi) to knock down a secondary metabolite and a host-associated gene. We demonstrate the broader utility of this modular system for rapidly creating and iteratively testing genetic tractability by modifying marine bacteria that are known to be associated with diverse host-microbe symbioses. These efforts enabled the successful transformation of twelve marine strains across two Proteobacteria classes, four orders and ten genera. Altogether, the present study demonstrates how synthetic biology strategies enable the investigation of marine microbes and marine host-microbe symbioses with broader implications for environmental restoration and biotechnology.
Collapse
|
49
|
Montoya AP, Wendlandt CE, Benedict AB, Roberts M, Piovia-Scott J, Griffitts JS, Porter SS. Hosts winnow symbionts with multiple layers of absolute and conditional discrimination mechanisms. Proc Biol Sci 2023; 290:20222153. [PMID: 36598018 PMCID: PMC9811631 DOI: 10.1098/rspb.2022.2153] [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: 01/05/2023] Open
Abstract
In mutualism, hosts select symbionts via partner choice and preferentially direct more resources to symbionts that provide greater benefits via sanctions. At the initiation of symbiosis, prior to resource exchange, it is not known how the presence of multiple symbiont options (i.e. the symbiont social environment) impacts partner choice outcomes. Furthermore, little research addresses whether hosts primarily discriminate among symbionts via sanctions, partner choice or a combination. We inoculated the legume, Acmispon wrangelianus, with 28 pairs of fluorescently labelled Mesorhizobium strains that vary continuously in quality as nitrogen-fixing symbionts. We find that hosts exert robust partner choice, which enhances their fitness. This partner choice is conditional such that a strain's success in initiating nodules is impacted by other strains in the social environment. This social genetic effect is as important as a strain's own genotype in determining nodulation and has both transitive (consistent) and intransitive (idiosyncratic) effects on the probability that a symbiont will form a nodule. Furthermore, both absolute and conditional partner choice act in concert with sanctions, among and within nodules. Thus, multiple forms of host discrimination act as a series of sieves that optimize host benefits and select for costly symbiont cooperation in mixed symbiont populations.
Collapse
Affiliation(s)
- Angeliqua P. Montoya
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| | - Camille E. Wendlandt
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| | - Alex B. Benedict
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Miles Roberts
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| | - Jonah Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| | - Joel S. Griffitts
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Stephanie S. Porter
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| |
Collapse
|
50
|
Vogt SL, Serapio-Palacios A, Woodward SE, Santos AS, de Vries SP, Daigneault MC, Brandmeier LV, Grant AJ, Maskell DJ, Allen-Vercoe E, Finlay BB. Enterohemorrhagic Escherichia coli responds to gut microbiota metabolites by altering metabolism and activating stress responses. Gut Microbes 2023; 15:2190303. [PMID: 36951510 PMCID: PMC10038027 DOI: 10.1080/19490976.2023.2190303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/08/2023] [Indexed: 03/24/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a major cause of severe bloody diarrhea, with potentially lethal complications, such as hemolytic uremic syndrome. In humans, EHEC colonizes the colon, which is also home to a diverse community of trillions of microbes known as the gut microbiota. Although these microbes and the metabolites that they produce represent an important component of EHEC's ecological niche, little is known about how EHEC senses and responds to the presence of gut microbiota metabolites. In this study, we used a combined RNA-Seq and Tn-Seq approach to characterize EHEC's response to metabolites from an in vitro culture of 33 human gut microbiota isolates (MET-1), previously demonstrated to effectively resolve recurrent Clostridioides difficile infection in human patients. Collectively, the results revealed that EHEC adjusts to growth in the presence of microbiota metabolites in two major ways: by altering its metabolism and by activating stress responses. Metabolic adaptations to the presence of microbiota metabolites included increased expression of systems for maintaining redox balance and decreased expression of biotin biosynthesis genes, reflecting the high levels of biotin released by the microbiota into the culture medium. In addition, numerous genes related to envelope and oxidative stress responses (including cpxP, spy, soxS, yhcN, and bhsA) were upregulated during EHEC growth in a medium containing microbiota metabolites. Together, these results provide insight into the molecular mechanisms by which pathogens adapt to the presence of competing microbes in the host environment, which ultimately may enable the development of therapies to enhance colonization resistance and prevent infection.
Collapse
Affiliation(s)
- Stefanie L. Vogt
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Sarah E. Woodward
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew S. Santos
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stefan P.W. de Vries
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Michelle C. Daigneault
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Lisa V. Brandmeier
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew J. Grant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Duncan J. Maskell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - B. Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|