1
|
Mikucki A, Kahler CM. Microevolution and Its Impact on Hypervirulence, Antimicrobial Resistance, and Vaccine Escape in Neisseria meningitidis. Microorganisms 2023; 11:3005. [PMID: 38138149 PMCID: PMC10745880 DOI: 10.3390/microorganisms11123005] [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: 11/06/2023] [Revised: 12/07/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023] Open
Abstract
Neisseria meningitidis is commensal of the human pharynx and occasionally invades the host, causing the life-threatening illness invasive meningococcal disease. The meningococcus is a highly diverse and adaptable organism thanks to natural competence, a propensity for recombination, and a highly repetitive genome. These mechanisms together result in a high level of antigenic variation to invade diverse human hosts and evade their innate and adaptive immune responses. This review explores the ways in which this diversity contributes to the evolutionary history and population structure of the meningococcus, with a particular focus on microevolution. It examines studies on meningococcal microevolution in the context of within-host evolution and persistent carriage; microevolution in the context of meningococcal outbreaks and epidemics; and the potential of microevolution to contribute to antimicrobial resistance and vaccine escape. A persistent theme is the idea that the process of microevolution contributes to the development of new hyperinvasive meningococcal variants. As such, microevolution in this species has significant potential to drive future public health threats in the form of hypervirulent, antibiotic-resistant, vaccine-escape variants. The implications of this on current vaccination strategies are explored.
Collapse
Affiliation(s)
- August Mikucki
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA 6009, Australia;
- Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Perth, WA 6009, Australia
| | - Charlene M. Kahler
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA 6009, Australia;
- Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Perth, WA 6009, Australia
| |
Collapse
|
2
|
Central Role of Sibling Small RNAs NgncR_162 and NgncR_163 in Main Metabolic Pathways of Neisseria gonorrhoeae. mBio 2023; 14:e0309322. [PMID: 36598194 PMCID: PMC9973317 DOI: 10.1128/mbio.03093-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Small bacterial regulatory RNAs (sRNAs) have been implicated in the regulation of numerous metabolic pathways. In most of these studies, sRNA-dependent regulation of mRNAs or proteins of enzymes in metabolic pathways has been predicted to affect the metabolism of these bacteria. However, only in a very few cases has the role in metabolism been demonstrated. Here, we performed a combined transcriptome and metabolome analysis to define the regulon of the sibling sRNAs NgncR_162 and NgncR_163 (NgncR_162/163) and their impact on the metabolism of Neisseria gonorrhoeae. These sRNAs have been reported to control genes of the citric acid and methylcitric acid cycles by posttranscriptional negative regulation. By transcriptome analysis, we now expand the NgncR_162/163 regulon by several new members and provide evidence that the sibling sRNAs act as both negative and positive regulators of target gene expression. Newly identified NgncR_162/163 targets are mostly involved in transport processes, especially in the uptake of glycine, phenylalanine, and branched-chain amino acids. NgncR_162/163 also play key roles in the control of serine-glycine metabolism and, hence, probably affect biosyntheses of nucleotides, vitamins, and other amino acids via the supply of one-carbon (C1) units. Indeed, these roles were confirmed by metabolomics and metabolic flux analysis, which revealed a bipartite metabolic network with glucose degradation for the supply of anabolic pathways and the usage of amino acids via the citric acid cycle for energy metabolism. Thus, by combined deep RNA sequencing (RNA-seq) and metabolomics, we significantly extended the regulon of NgncR_162/163 and demonstrated the role of NgncR_162/163 in the regulation of central metabolic pathways of the gonococcus. IMPORTANCE Neisseria gonorrhoeae is a major human pathogen which infects more than 100 million people every year. An alarming development is the emergence of gonococcal strains that are resistant against virtually all antibiotics used for their treatment. Despite the medical importance and the vanishing treatment options of gonococcal infections, the bacterial metabolism and its regulation have been only weakly defined until today. Using RNA-seq, metabolomics, and 13C-guided metabolic flux analysis, we here investigated the gonococcal metabolism and its regulation by the previously studied sibling sRNAs NgncR_162/163. The results demonstrate the regulation of transport processes and metabolic pathways involved in the biosynthesis of nucleotides, vitamins, and amino acids by NgncR_162/163. In particular, the combination of transcriptome and metabolic flux analyses provides a heretofore unreached depth of understanding the core metabolic pathways and their regulation by the neisserial sibling sRNAs. This integrative approach may therefore also be suitable for the functional analysis of a growing number of other bacterial metabolic sRNA regulators.
Collapse
|
3
|
Park SH, Jeong SJ, Ha SC. Structural basis for the toxic activity of MafB2 from maf genomic island 2 (MGI-2) in N. meningitidis B16B6. Sci Rep 2023; 13:3365. [PMID: 36849501 PMCID: PMC9970974 DOI: 10.1038/s41598-023-30528-9] [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: 11/29/2022] [Accepted: 02/24/2023] [Indexed: 03/01/2023] Open
Abstract
The Maf polymorphic toxin system is involved in conflict between strains found in pathogenic Neisseria species such as Neisseria meningitidis and Neisseria gonorrhoeae. The genes encoding the Maf polymorphic toxin system are found in specific genomic islands called maf genomic islands (MGIs). In the MGIs, the MafB and MafI encode toxin and immunity proteins, respectively. Although the C-terminal region of MafB (MafB-CT) is specific for toxic activity, the underlying enzymatic activity that renders MafB-CT toxic is unknown in many MafB proteins due to lack of homology with domain of known function. Here we present the crystal structure of the MafB2-CTMGI-2B16B6/MafI2MGI-2B16B6 complex from N. meningitidis B16B6. MafB2-CTMGI-2B16B6 displays an RNase A fold similar to mouse RNase 1, although the sequence identity is only ~ 14.0%. MafB2-CTMGI-2B16B6 forms a 1:1 complex with MafI2MGI-2B16B6 with a Kd value of ~ 40 nM. The complementary charge interaction of MafI2MGI-2B16B6 with the substrate binding surface of MafB2-CTMGI-2B16B6 suggests that MafI2MGI-2B16B6 inhibits MafB2-CTMGI-2B16B6 by blocking access of RNA to the catalytic site. An in vitro enzymatic assay showed that MafB2-CTMGI-2B16B6 has ribonuclease activity. Mutagenesis and cell toxicity assays demonstrated that His335, His402 and His409 are important for the toxic activity of MafB2-CTMGI-2B16B6, suggesting that these residues are critical for its ribonuclease activity. These data provide structural and biochemical evidence that the origin of the toxic activity of MafB2MGI-2B16B6 is the enzymatic activity degrading ribonucleotides.
Collapse
Affiliation(s)
- So Hyeon Park
- grid.49100.3c0000 0001 0742 4007Beamline Department, Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673 Republic of Korea
| | - Sun Ju Jeong
- grid.49100.3c0000 0001 0742 4007Beamline Department, Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673 Republic of Korea
| | - Sung Chul Ha
- Beamline Department, Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673, Republic of Korea.
| |
Collapse
|
4
|
Aggarwal SD, Lees JA, Jacobs NT, Bee GCW, Abruzzo AR, Weiser JN. BlpC-mediated selfish program leads to rapid loss of Streptococcus pneumoniae clonal diversity during infection. Cell Host Microbe 2023; 31:124-134.e5. [PMID: 36395758 PMCID: PMC9839470 DOI: 10.1016/j.chom.2022.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/27/2022] [Accepted: 10/20/2022] [Indexed: 11/17/2022]
Abstract
Successful colonization of a host requires bacterial adaptation through genetic and population changes that are incompletely defined. Using chromosomal barcoding and high-throughput sequencing, we investigate the population dynamics of Streptococcus pneumoniae during infant mouse colonization. Within 1 day post inoculation, diversity was reduced >35-fold with expansion of a single clonal lineage. This loss of diversity was not due to immune factors, microbiota, or exclusive genetic drift. Rather, bacteriocins induced by the BlpC-quorum sensing pheromone resulted in predation of kin cells. In this intra-strain competition, the subpopulation reaching a quorum likely eliminates others that have yet to activate the blp locus. Additionally, this reduced diversity restricts the number of unique clones that establish colonization during transmission between hosts. Genetic variation in the blp locus was also associated with altered transmissibility in a human population, further underscoring the importance of BlpC in clonal selection and its role as a selfish element.
Collapse
Affiliation(s)
- Surya D Aggarwal
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA.
| | - John A Lees
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA; European Bioinformatics Institute, European Molecular Biology Laboratory, Hinxton CB10 1SD, UK; MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W12 7TA, UK
| | - Nathan T Jacobs
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Gavyn Chern Wei Bee
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Annie R Abruzzo
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Jeffrey N Weiser
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
5
|
Arenas J. Editorial: Pathogenic Neisseria: Pathogenicity, vaccines, and antibiotic resistance. Front Cell Infect Microbiol 2023; 12:1119244. [PMID: 36683679 PMCID: PMC9850228 DOI: 10.3389/fcimb.2022.1119244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 12/21/2022] [Indexed: 01/06/2023] Open
Affiliation(s)
- Jesús Arenas
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| |
Collapse
|
6
|
Talà A, Calcagnile M, Resta SC, Pennetta A, De Benedetto GE, Alifano P. Thiostrepton, a resurging drug inhibiting the stringent response to counteract antibiotic-resistance and expression of virulence determinants in Neisseria gonorrhoeae. Front Microbiol 2023; 14:1104454. [PMID: 36910221 PMCID: PMC9998046 DOI: 10.3389/fmicb.2023.1104454] [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: 11/21/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
Due to the increased resistance to all available antibiotics and the lack of vaccines, Neisseria gonorrhoeae (the gonococcus) poses an urgent threat. Although the mechanisms of virulence and antibiotic resistance have been largely investigated in this bacterium, very few studies have addressed the stringent response (SR) that in pathogenic bacteria controls the expression of genes involved in host-pathogen interaction and tolerance and persistence toward antibiotics. In this study, the results of the transcriptome analysis of a clinical isolate of N. gonorrhoeae, after induction of the SR by serine hydroxamate, provided us with an accurate list of genes that are transcriptionally modulated during the SR. The list includes genes associated with metabolism, cellular machine functions, host-pathogen interaction, genome plasticity, and antibiotic tolerance and persistence. Moreover, we found that the artificial induction of the SR in N. gonorrhoeae by serine hydroxamate is prevented by thiostrepton, a thiopeptide antibiotic that is known to interact with ribosomal protein L11, thereby inhibiting functions of EF-Tu and EF-G, and binding of pppGpp synthase I (RelA) to ribosome upon entry of uncharged tRNA. We found that N. gonorrhoeae is highly sensitive to thiostrepton under in vitro conditions, and that thiostrepton, in contrast to other antibiotics, does not induce tolerance or persistence. Finally, we observed that thiostrepton attenuated the expression of key genes involved in the host-pathogen interaction. These properties make thiostrepton a good drug candidate for dampening bacterial virulence and preventing antibiotic tolerance and persistence. The ongoing challenge is to increase the bioavailability of thiostrepton through the use of chemistry and nanotechnology.
Collapse
Affiliation(s)
- Adelfia Talà
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Matteo Calcagnile
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Silvia Caterina Resta
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Antonio Pennetta
- Laboratory of Analytical and Isotopic Mass Spectrometry, Department of Cultural Heritage, University of Salento, Lecce, Italy
| | - Giuseppe Egidio De Benedetto
- Laboratory of Analytical and Isotopic Mass Spectrometry, Department of Cultural Heritage, University of Salento, Lecce, Italy
| | - Pietro Alifano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| |
Collapse
|
7
|
Hespanhol JT, Karman L, Sanchez-Limache DE, Bayer-Santos E. Intercepting biological messages: Antibacterial molecules targeting nucleic acids during interbacterial conflicts. Genet Mol Biol 2023; 46:e20220266. [PMID: 36880694 PMCID: PMC9990079 DOI: 10.1590/1678-4685-gmb-2022-0266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/25/2022] [Indexed: 03/08/2023] Open
Abstract
Bacteria live in polymicrobial communities and constantly compete for resources. These organisms have evolved an array of antibacterial weapons to inhibit the growth or kill competitors. The arsenal comprises antibiotics, bacteriocins, and contact-dependent effectors that are either secreted in the medium or directly translocated into target cells. During bacterial antagonistic encounters, several cellular components important for life become a weak spot prone to an attack. Nucleic acids and the machinery responsible for their synthesis are well conserved across the tree of life. These molecules are part of the information flow in the central dogma of molecular biology and mediate long- and short-term storage for genetic information. The aim of this review is to summarize the diversity of antibacterial molecules that target nucleic acids during antagonistic interbacterial encounters and discuss their potential to promote the emergence antibiotic resistance.
Collapse
Affiliation(s)
- Julia Takuno Hespanhol
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Lior Karman
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | | | - Ethel Bayer-Santos
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| |
Collapse
|
8
|
Maynard-Smith L, Derrick JP, Borrow R, Lucidarme J, Maiden MCJ, Heyderman RS, Harrison OB. Genome-Wide Association Studies Identify an Association of Transferrin Binding Protein B Variation and Invasive Serogroup Y Meningococcal Disease in Older Adults. J Infect Dis 2022; 226:2204-2214. [PMID: 36322504 PMCID: PMC9748998 DOI: 10.1093/infdis/jiac430] [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: 05/20/2022] [Revised: 10/24/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Neisseria meningitidis serogroup Y, especially ST-23 clonal complex (Y:cc23), represents a larger proportion of invasive meningococcal disease (IMD) in older adults compared to younger individuals. This study explored the meningococcal genetic variation underlying this association. METHODS Maximum-likelihood phylogenies and the pangenome were analyzed using whole-genome sequence (WGS) data from 200 Y:cc23 isolates in the Neisseria PubMLST database. Genome-wide association studies (GWAS) were performed on WGS data from 250 Y:cc23 isolates from individuals with IMD aged ≥65 years versus < 65 years. RESULTS Y:cc23 meningococcal variants did not cluster by age group or disease phenotype in phylogenetic analyses. Pangenome comparisons found no differences in presence or absence of genes in IMD isolates from the different age groups. GWAS identified differences in nucleotide polymorphisms within the transferrin-binding protein B (tbpB) gene in isolates from individuals ≥65 years of age. TbpB structure modelling suggests these may impact binding of human transferrin. CONCLUSIONS These data suggest differential iron scavenging capacity amongst Y:cc23 meningococci isolated from older compared to younger patients. Iron acquisition is essential for many bacterial pathogens including the meningococcus. These polymorphisms may facilitate colonization, thereby increasing the risk of disease in vulnerable older people with altered nasopharyngeal microbiomes and nutritional status.
Collapse
Affiliation(s)
- Laura Maynard-Smith
- Correspondence: Laura Maynard-Smith, MBBS, Division of Infection and Immunity, University College London, Gower Street, London WC1E 6BT, UK ()
| | - Jeremy P Derrick
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom
| | - Ray Borrow
- Meningococcal Reference Unit, UK Health Security Agency, Manchester, United Kingdom
| | - Jay Lucidarme
- Meningococcal Reference Unit, UK Health Security Agency, Manchester, United Kingdom
| | | | - Robert S Heyderman
- Division of Infection and Immunity, University College London, London, United Kingdom
| | | |
Collapse
|
9
|
Liu Y, Liu S, Pan Z, Ren Y, Jiang Y, Wang F, Li DD, Li YZ, Zhang Z. PAT: a comprehensive database of prokaryotic antimicrobial toxins. Nucleic Acids Res 2022; 51:D452-D459. [PMID: 36243963 PMCID: PMC9825508 DOI: 10.1093/nar/gkac879] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/22/2022] [Accepted: 09/30/2022] [Indexed: 01/29/2023] Open
Abstract
Antimicrobial toxins help prokaryotes win competitive advantages in intraspecific or interspecific conflicts and are also a critical factor affecting the pathogenicity of many pathogens that threaten human health. Although many studies have revealed that antagonism based on antimicrobial toxins plays a central role in prokaryotic life, a database on antimicrobial toxins remains lacking. Here, we present the prokaryotic antimicrobial toxin database (PAT, http://bioinfo.qd.sdu.edu.cn/PAT/), a comprehensive data resource collection on experimentally validated antimicrobial toxins. PAT has organized information, derived from the reported literature, on antimicrobial toxins, as well as the corresponding immunity proteins, delivery mechanisms, toxin activities, structural characteristics, sequences, etc. Moreover, we also predict potential antimicrobial toxins in prokaryotic reference genomes and show the taxonomic information and environmental distribution of typical antimicrobial toxins. These details have been fully incorporated into the PAT database, where users can browse, search, download, analyse and view informative statistics and detailed information. PAT resources have already been used in our prediction and identification of prokaryotic antimicrobial toxins and may contribute to promoting the efficient investigation of antimicrobial toxin functions, the discovery of novel antimicrobial toxins, and an improved understanding of the biological roles and significance of these toxins.
Collapse
Affiliation(s)
- Ya Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Sheng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Zhuo Pan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yu Ren
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yiru Jiang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Feng Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Dan-dan Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yue-zhong Li
- Correspondence may also be addressed to Yue-zhong Li. Tel: +86 532 58631539;
| | - Zheng Zhang
- To whom correspondence should be addressed. Tel: +86 532 58631557;
| |
Collapse
|
10
|
Frazier MN, Riccio AA, Wilson IM, Copeland WC, Stanley RE. Recent insights into the structure and function of coronavirus ribonucleases. FEBS Open Bio 2022; 12:1567-1583. [PMID: 35445579 PMCID: PMC9110870 DOI: 10.1002/2211-5463.13414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/07/2022] [Accepted: 04/19/2022] [Indexed: 11/10/2022] Open
Abstract
Coronaviruses use approximately two-thirds of their 30-kb genomes to encode nonstructural proteins (nsps) with diverse functions that assist in viral replication and transcription, and evasion of the host immune response. The SARS-CoV-2 pandemic has led to renewed interest in the molecular mechanisms used by coronaviruses to infect cells and replicate. Among the 16 Nsps involved in replication and transcription, coronaviruses encode two ribonucleases that process the viral RNA-an exonuclease (Nsp14) and an endonuclease (Nsp15). In this review, we discuss recent structural and biochemical studies of these nucleases and the implications for drug discovery.
Collapse
Affiliation(s)
- Meredith N. Frazier
- Signal Transduction LaboratoryDepartment of Health and Human ServicesNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| | - Amanda A. Riccio
- Genome Integrity and Structural Biology LaboratoryDepartment of Health and Human ServicesNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| | - Isha M. Wilson
- Signal Transduction LaboratoryDepartment of Health and Human ServicesNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| | - William C. Copeland
- Genome Integrity and Structural Biology LaboratoryDepartment of Health and Human ServicesNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| | - Robin E. Stanley
- Signal Transduction LaboratoryDepartment of Health and Human ServicesNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| |
Collapse
|
11
|
Baerentsen R, Tang CM, Exley RM. Et tu, Neisseria? Conflicts of Interest Between Neisseria Species. Front Cell Infect Microbiol 2022; 12:913292. [PMID: 35811666 PMCID: PMC9263626 DOI: 10.3389/fcimb.2022.913292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/27/2022] [Indexed: 11/24/2022] Open
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are two obligate human pathogens that have evolved to be uniquely adapted to their host. The meningococcus is frequently carried asymptomatically in the nasopharynx, while gonococcal infection of the urogenital tract usually elicits a marked local inflammatory response. Other members of the Neisseria genus are abundant in the upper airway where they could engage in co-operative or competitive interactions with both these pathogens. Here, we briefly outline the potential sites of contact between Neisseria spp. in the body, with emphasis on the upper airway, and describe the growing yet circumstantial evidence for antagonism from carriage studies and human volunteer challenge models with Neisseria lactamica. Recent laboratory studies have characterized antagonistic mechanisms that enable competition between Neisseria species. Several of these mechanisms, including Multiple Adhesin family (Mafs), Two Partner Secretion Systems, and Type VI secretion system, involve direct contact between bacteria; the genetic organisation of these systems, and the domain structure of their effector molecules have striking similarities. Additionally, DNA from one species of Neisseria can be toxic to another species, following uptake. More research is needed to define the full repertoire of antagonistic mechanisms in Neisseria spp., their distribution in strains, their range of activity, and contribution to survival in vivo. Understanding the targets of effectors could reveal how antagonistic relationships between close relatives shape subsequent interactions between pathogens and their hosts.
Collapse
|
12
|
Mikucki A, McCluskey NR, Kahler CM. The Host-Pathogen Interactions and Epicellular Lifestyle of Neisseria meningitidis. Front Cell Infect Microbiol 2022; 12:862935. [PMID: 35531336 PMCID: PMC9072670 DOI: 10.3389/fcimb.2022.862935] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/28/2022] [Indexed: 01/17/2023] Open
Abstract
Neisseria meningitidis is a gram-negative diplococcus and a transient commensal of the human nasopharynx. It shares and competes for this niche with a number of other Neisseria species including N. lactamica, N. cinerea and N. mucosa. Unlike these other members of the genus, N. meningitidis may become invasive, crossing the epithelium of the nasopharynx and entering the bloodstream, where it rapidly proliferates causing a syndrome known as Invasive Meningococcal Disease (IMD). IMD progresses rapidly to cause septic shock and meningitis and is often fatal despite aggressive antibiotic therapy. While many of the ways in which meningococci survive in the host environment have been well studied, recent insights into the interactions between N. meningitidis and the epithelial, serum, and endothelial environments have expanded our understanding of how IMD develops. This review seeks to incorporate recent work into the established model of pathogenesis. In particular, we focus on the competition that N. meningitidis faces in the nasopharynx from other Neisseria species, and how the genetic diversity of the meningococcus contributes to the wide range of inflammatory and pathogenic potentials observed among different lineages.
Collapse
Affiliation(s)
- August Mikucki
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Nicolie R. McCluskey
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- College of Science, Health, Engineering and Education, Telethon Kids Institute, Murdoch University, Perth, WA, Australia
| | - Charlene M. Kahler
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- *Correspondence: Charlene M. Kahler,
| |
Collapse
|
13
|
Li H, Tan Y, Zhang D. Genomic discovery and structural dissection of a novel type of polymorphic toxin system in gram-positive bacteria. Comput Struct Biotechnol J 2022; 20:4517-4531. [PMID: 36051883 PMCID: PMC9424270 DOI: 10.1016/j.csbj.2022.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 11/26/2022] Open
Abstract
Bacteria have developed several molecular conflict systems to facilitate kin recognition and non-kin competition to gain advantages in the acquisition of growth niches and of limited resources. One such example is a large class of so-called polymorphic toxin systems (PTSs), which comprise a variety of the toxin proteins secreted via T2SS, T5SS, T6SS, T7SS and many others. These systems are highly divergent in terms of sequence/structure, domain architecture, toxin-immunity association, and organization of the toxin loci, which makes it difficult to identify and characterize novel systems using traditional experimental and bioinformatic strategies. In recent years, we have been developing and utilizing unique genome-mining strategies and pipelines, based on the organizational principles of both domain architectures and genomic loci of PTSs, for an effective and comprehensive discovery of novel PTSs, dissection of their components, and prediction of their structures and functions. In this study, we present our systematic discovery of a new type of PTS (S8-PTS) in several gram-positive bacteria. We show that the S8-PTS contains three components: a peptidase of the S8 family (subtilases), a polymorphic toxin, and an immunity protein. We delineated the typical organization of these polymorphic toxins, in which a N-terminal signal peptide is followed by a potential receptor binding domain, BetaH, and one of 16 toxin domains. We classified each toxin domain by the distinct superfamily to which it belongs, identifying nine BECR ribonucleases, one Restriction Endonuclease, one HNH nuclease, two novel toxin domains homologous to the VOC enzymes, one toxin domain with the Frataxin-like fold, and several other unique toxin families such as Ntox33 and HicA. Accordingly, we identified 20 immunity families and classified them into different classes of folds. Further, we show that the S8-PTS-associated peptidases are analogous to many other processing peptidases found in T5SS, T7SS, T9SS, and many proprotein-processing peptidases, indicating that they function to release the toxin domains during secretion. The S8-PTSs are mostly found in animal and plant-associated bacteria, including many pathogens. We propose S8-PTSs will facilitate the competition of these bacteria with other microbes or contribute to the pathogen-host interactions.
Collapse
Affiliation(s)
- Huan Li
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
| | - Yongjun Tan
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
| | - Dapeng Zhang
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
- Program of Bioinformatics and Computational Biology, College of Arts & Sciences, Saint Louis University, MO 63103, USA
- Corresponding author at: Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA.
| |
Collapse
|
14
|
Tan Y, Wang C, Schneider T, Li H, de Souza RF, Tang X, Swisher Grimm KD, Hsieh TF, Wang X, Li X, Zhang D. Comparative Phylogenomic Analysis Reveals Evolutionary Genomic Changes and Novel Toxin Families in Endophytic Liberibacter Pathogens. Microbiol Spectr 2021; 9:e0050921. [PMID: 34523996 PMCID: PMC8557891 DOI: 10.1128/spectrum.00509-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/10/2021] [Indexed: 01/02/2023] Open
Abstract
Liberibacter pathogens are the causative agents of several severe crop diseases worldwide, including citrus Huanglongbing and potato zebra chip. These bacteria are endophytic and nonculturable, which makes experimental approaches challenging and highlights the need for bioinformatic analysis in advancing our understanding about Liberibacter pathogenesis. Here, we performed an in-depth comparative phylogenomic analysis of the Liberibacter pathogens and their free-living, nonpathogenic, ancestral species, aiming to identify major genomic changes and determinants associated with their evolutionary transitions in living habitats and pathogenicity. Using gene neighborhood analysis and phylogenetic classification, we systematically uncovered, annotated, and classified all prophage loci into four types, including one previously unrecognized group. We showed that these prophages originated through independent gene transfers at different evolutionary stages of Liberibacter and only the SC-type prophage was associated with the emergence of the pathogens. Using ortholog clustering, we vigorously identified two additional sets of genomic genes, which were either lost or gained in the ancestor of the pathogens. Consistent with the habitat change, the lost genes were enriched for biosynthesis of cellular building blocks. Importantly, among the gained genes, we uncovered several previously unrecognized toxins, including new toxins homologous to the EspG/VirA effectors, a YdjM phospholipase toxin, and a secreted endonuclease/exonuclease/phosphatase (EEP) protein. Our results substantially extend the knowledge of the evolutionary events and potential determinants leading to the emergence of endophytic, pathogenic Liberibacter species, which will facilitate the design of functional experiments and the development of new methods for detection and blockage of these pathogens. IMPORTANCELiberibacter pathogens are associated with several severe crop diseases, including citrus Huanglongbing, the most destructive disease to the citrus industry. Currently, no effective cure or treatments are available, and no resistant citrus variety has been found. The fact that these obligate endophytic pathogens are not culturable has made it extremely challenging to experimentally uncover the genes/proteins important to Liberibacter pathogenesis. Further, earlier bioinformatics studies failed to identify key genomic determinants, such as toxins and effector proteins, that underlie the pathogenicity of the bacteria. In this study, an in-depth comparative genomic analysis of Liberibacter pathogens along with their ancestral nonpathogenic species identified the prophage loci and several novel toxins that are evolutionarily associated with the emergence of the pathogens. These results shed new light on the disease mechanism of Liberibacter pathogens and will facilitate the development of new detection and blockage methods targeting the toxins.
Collapse
Affiliation(s)
- Yongjun Tan
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
| | - Cindy Wang
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
| | - Theresa Schneider
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
| | - Huan Li
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
| | - Robson Francisco de Souza
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Xueming Tang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Kylie D. Swisher Grimm
- United States Department of Agriculture—Agricultural Research Service, Temperate Tree Fruit and Vegetable Research Unit, Prosser, Washington, USA
| | - Tzung-Fu Hsieh
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
- Plants for Human Health Institute, North Carolina State University, Kannapolis, North Carolina, USA
| | - Xu Wang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
- Alabama Agricultural Experiment Station, Auburn University, Auburn, Alabama, USA
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Xu Li
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
- Plants for Human Health Institute, North Carolina State University, Kannapolis, North Carolina, USA
| | - Dapeng Zhang
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
- Bioinformatics and Computational Biology Program, College of Arts & Sciences, Saint Louis University, St. Louis, Missouri, USA
| |
Collapse
|
15
|
Mullally CA, Mikucki A, Wise MJ, Kahler CM. Modelling evolutionary pathways for commensalism and hypervirulence in Neisseria meningitidis. Microb Genom 2021; 7. [PMID: 34704920 PMCID: PMC8627216 DOI: 10.1099/mgen.0.000662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis, the meningococcus, resides exclusively in humans and causes invasive meningococcal disease (IMD). The population of N. meningitidis is structured into stable clonal complexes by limited horizontal recombination in this naturally transformable species. N. meningitidis is an opportunistic pathogen, with some clonal complexes, such as cc53, effectively acting as commensal colonizers, while other genetic lineages, such as cc11, are rarely colonizers but are over-represented in IMD and are termed hypervirulent. This study examined theoretical evolutionary pathways for pathogenic and commensal lineages by examining the prevalence of horizontally acquired genomic islands (GIs) and loss-of-function (LOF) mutations. Using a collection of 4850 genomes from the BIGSdb database, we identified 82 GIs in the pan-genome of 11 lineages (10 hypervirulent and one commensal lineage). A new computational tool, Phaser, was used to identify frameshift mutations, which were examined for statistically significant association with genetic lineage. Phaser identified a total of 144 frameshift loci of which 105 were shown to have a statistically significant non-random distribution in phase status. The 82 GIs, but not the LOF loci, were associated with genetic lineage and invasiveness using the disease carriage ratio metric. These observations have been integrated into a new model that infers the early events of the evolution of the human adapted meningococcus. These pathways are enriched for GIs that are involved in modulating attachment to the host, growth rate, iron uptake and toxin expression which are proposed to increase competition within the meningococcal population for the limited environmental niche of the human nasopharynx. We surmise that competition for the host mucosal surface with the nasopharyngeal microbiome has led to the selection of isolates with traits that enable access to cell types (non-phagocytic and phagocytic) in the submucosal tissues leading to an increased risk for IMD.
Collapse
Affiliation(s)
- Christopher A. Mullally
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
| | - August Mikucki
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
| | - Michael J. Wise
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
- School of Physics, Mathematics and Computing, University of Western Australia, Perth, Australia
| | - Charlene M. Kahler
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
- Telethon Kids Institute, Perth Children’s Hospital, Perth, Australia
- *Correspondence: Charlene M. Kahler,
| |
Collapse
|
16
|
Earle SG, Lobanovska M, Lavender H, Tang C, Exley RM, Ramos-Sevillano E, Browning DF, Kostiou V, Harrison OB, Bratcher HB, Varani G, Tang CM, Wilson DJ, Maiden MCJ. Genome-wide association studies reveal the role of polymorphisms affecting factor H binding protein expression in host invasion by Neisseria meningitidis. PLoS Pathog 2021; 17:e1009992. [PMID: 34662348 PMCID: PMC8553145 DOI: 10.1371/journal.ppat.1009992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/28/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
Many invasive bacterial diseases are caused by organisms that are ordinarily harmless components of the human microbiome. Effective interventions against these microbes require an understanding of the processes whereby symbiotic or commensal relationships transition into pathology. Here, we describe bacterial genome-wide association studies (GWAS) of Neisseria meningitidis, a common commensal of the human respiratory tract that is nevertheless a leading cause of meningitis and sepsis. An initial GWAS discovered bacterial genetic variants, including single nucleotide polymorphisms (SNPs), associated with invasive meningococcal disease (IMD) versus carriage in several loci across the meningococcal genome, encoding antigens and other extracellular components, confirming the polygenic nature of the invasive phenotype. In particular, there was a significant peak of association around the fHbp locus, encoding factor H binding protein (fHbp), which promotes bacterial immune evasion of human complement by recruiting complement factor H (CFH) to the meningococcal surface. The association around fHbp with IMD was confirmed by a validation GWAS, and we found that the SNPs identified in the validation affected the 5' region of fHbp mRNA, altering secondary RNA structures, thereby increasing fHbp expression and enhancing bacterial escape from complement-mediated killing. This finding is consistent with the known link between complement deficiencies and CFH variation with human susceptibility to IMD. These observations demonstrate the importance of human and bacterial genetic variation across the fHbp:CFH interface in determining IMD susceptibility, the transition from carriage to disease.
Collapse
Affiliation(s)
- Sarah G. Earle
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
| | - Mariya Lobanovska
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Hayley Lavender
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Changyan Tang
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
| | - Rachel M. Exley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | | | - Douglas F. Browning
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Vasiliki Kostiou
- Nuffield Department of Clinical Medicine, Experimental Medicine Division, John Radcliffe Hospital, Oxford, United Kingdom
| | | | | | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Christoph M. Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Daniel J. Wilson
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
- Department for Continuing Education, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Martin C. J. Maiden
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| |
Collapse
|
17
|
Arenas J, Catón L, van den Hoeven T, de Maat V, Cruz Herrero J, Tommassen J. The outer-membrane protein MafA of Neisseria meningitidis constitutes a novel protein secretion pathway specific for the fratricide protein MafB. Virulence 2021; 11:1701-1715. [PMID: 33315509 PMCID: PMC7738311 DOI: 10.1080/21505594.2020.1851940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
MafB proteins are toxins secreted by Neisseria spp. which are involved in interbacterial competition. Their secretion mechanism has so far not been elucidated. Each strain can produce several MafB variants. On the chromosome, the mafB genes are localized on genomic islands also containing mafA genes. MafA proteins have a role in virulence with reported activities in adhesion and transcytosis of pathogenic Neisseria, a priori unrelated to MafB activities. In this study, we investigated the possible involvement of MafA in the transport of MafB across the outer membrane of Neisseria meningitidis. In wild-type strains, proteolytic fragments of MafB proteins were detected in the extracellular medium. In the absence of MafA, secretion was abrogated, and, in the case of MafBI, full-length and truncated polypeptides were detected inside the cells and inside outer-membrane vesicles. MafBI secretion required its cognate MafA, whereas MafBIII could use any MafA. Heterologous expression in Escherichia coli showed that MafBIII is transported to a cell-surface-exposed, i.e. protease-accessible, location in a MafA-dependent way. MafA itself was found to be localized to the outer membrane, forming large oligomeric complexes. As homologs were found in diverse bacteria, the Maf system represents a new protein secretion system in Gram-negative bacteria.
Collapse
Affiliation(s)
- Jesús Arenas
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands.,Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza , Zaragoza, Spain
| | - Laura Catón
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands
| | - Tom van den Hoeven
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands
| | - Vincent de Maat
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands
| | - Juan Cruz Herrero
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Utrecht University , Utrecht, Netherlands
| |
Collapse
|
18
|
Zachary M, Bauer S, Klepsch M, Wagler K, Hüttel B, Rudel T, Beier D. Identification and initial characterization of a new pair of sibling sRNAs of Neisseria gonorrhoeae involved in type IV pilus biogenesis. MICROBIOLOGY-SGM 2021; 167. [PMID: 34515630 DOI: 10.1099/mic.0.001080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Non-coding regulatory RNAs mediate post-transcriptional gene expression control by a variety of mechanisms relying mostly on base-pairing interactions with a target mRNA. Though a plethora of putative non-coding regulatory RNAs have been identified by global transcriptome analysis, knowledge about riboregulation in the pathogenic Neisseriae is still limited. Here we report the initial characterization of a pair of sRNAs of N. gonorrhoeae, TfpR1 and TfpR2, which exhibit a similar secondary structure and identical single-stranded seed regions, and therefore might be considered as sibling sRNAs. By combination of in silico target prediction and sRNA pulse expression followed by differential RNA sequencing we identified target genes of TfpR1 which are involved in type IV pilus biogenesis and DNA damage repair. We provide evidence that members of the TfpR1 regulon can also be targeted by the sibling TfpR2.
Collapse
Affiliation(s)
- Marie Zachary
- Chair of Microbiology, Biocenter, University of Würzburg, Germany
| | - Susanne Bauer
- Chair of Microbiology, Biocenter, University of Würzburg, Germany
| | | | - Katharina Wagler
- Chair of Microbiology, Biocenter, University of Würzburg, Germany
| | | | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Germany
| | - Dagmar Beier
- Chair of Microbiology, Biocenter, University of Würzburg, Germany
| |
Collapse
|
19
|
Peterson SB, Bertolli SK, Mougous JD. The Central Role of Interbacterial Antagonism in Bacterial Life. Curr Biol 2021; 30:R1203-R1214. [PMID: 33022265 DOI: 10.1016/j.cub.2020.06.103] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The study of bacteria interacting with their environment has historically centered on strategies for obtaining nutrients and resisting abiotic stresses. We argue this focus has deemphasized a third facet of bacterial life that is equally central to their existence: namely, the threat to survival posed by antagonizing bacteria. The diversity and ubiquity of interbacterial antagonism pathways is becoming increasingly apparent, and the insidious manner by which interbacterial toxins disarm their targets emphasizes the highly evolved nature of these processes. Studies examining the role of antagonism in natural communities reveal it can serve many functions, from facilitating colonization of naïve habitats to maintaining bacterial community stability. The pervasiveness of antagonistic pathways is necessarily matched by an equally extensive array of defense strategies. These overlap with well characterized, central stress response pathways, highlighting the contribution of bacterial interactions to shaping cell physiology. In this review, we build the case for the ubiquity and importance of interbacterial antagonism.
Collapse
Affiliation(s)
- S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Savannah K Bertolli
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA.
| |
Collapse
|
20
|
Song N, Chen L, Zhou Z, Ren X, Liu B, Zhou S, Wang C, Wu Y, Waterfield NR, Yang J, Yang G. Genome-wide dissection reveals diverse pathogenic roles of bacterial Tc toxins. PLoS Pathog 2021; 17:e1009102. [PMID: 33540421 PMCID: PMC7861908 DOI: 10.1371/journal.ppat.1009102] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/26/2020] [Indexed: 12/21/2022] Open
Abstract
Tc toxins were originally identified in entomopathogenic bacteria, which are important as biological pest control agents. Tc toxins are heteromeric exotoxins composed of three subunit types, TcA, TcB, and TcC. The C-terminal portion of the TcC protein encodes the actual toxic domain, which is translocated into host cells by an injectosome nanomachine comprising the other subunits. Currently the pathogenic roles and distribution of Tc toxins among different bacterial genera remain unclear. Here we have performed a comprehensive genome-wide analysis, and established a database that includes 1,608 identified Tc loci containing 2,528 TcC proteins in 1,421 Gram-negative and positive bacterial genomes. Our findings indicate that TcCs conform to the architecture of typical polymorphic toxins, with C-terminal hypervariable regions (HVR) encoding more than 100 different classes of putative toxic domains, most of which have not been previously recognized. Based on further analysis of Tc loci in the genomes of all Salmonella and Yersinia strains in EnteroBase, a “two-level” evolutionary dynamics scenario is proposed for TcC homologues. This scenario implies that the conserved TcC RHS core domain plays a critical role in the taxonomical specific distribution of TcC HVRs. This study provides an extensive resource for the future development of Tc toxins as valuable agrochemical tools. It furthermore implies that Tc proteins, which are encoded by a wide range of pathogens, represent an important versatile toxin superfamily with diverse pathogenic mechanisms. Entomopathogenic bacteria deploy a range of toxins to combat their insect hosts. The Tc toxins were first identified in Photorhabdus as having potent oral toxicity to insects, with a mode of action distinct from the well-studied Bacillus thuringiensis Cry toxins. As such the Tc toxins have been considered as potential candidates for novel crop protection strategies. This could mitigate against the potential risks of pest insects developing resistance to the traditionally used Cry toxin-based systems. To date, the generality of diverse Tc toxins and their related pathogenic roles has remained mainly obscure. Our analysis has showed Tc toxins are widely distributed among Gram-negative and positive bacterial genomes. A database was constructed including thousands of Tc loci with hundreds of different putative TcC toxic domains, any one of which might represent candidates for the development of future pest control systems. Moreover, the findings of this study are of wider significance because Tc toxin homologues have been shown to be encoded by a range of human pathogens. These include Salmonella and Yersinia, suggesting their potential roles in human infectious diseases. Together, this study describes the characteristics and distribution of Tc toxins among diverse bacterial genera, and provides a new insight into their roles in different pathogenesis mechanisms. This study also describes findings of potential importance to their development as tools for biotechnological applications.
Collapse
Affiliation(s)
- Nan Song
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lihong Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhemin Zhou
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Xingmei Ren
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Bo Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Siyu Zhou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Caihong Wang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yun Wu
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | | | - Jian Yang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (JY); (GY)
| | - Guowei Yang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- * E-mail: (JY); (GY)
| |
Collapse
|
21
|
Comprehensive Bioinformatic Assessments of the Variability of Neisseria gonorrhoeae Vaccine Candidates. mSphere 2021; 6:6/1/e00977-20. [PMID: 33536323 PMCID: PMC7860988 DOI: 10.1128/msphere.00977-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A protective vaccine is the only viable way to stop the spread of gonorrhea in the face of rising antibiotic resistance. However, the notorious phase and antigenic variation of Neisseria gonorrhoeae surface proteins remains one of the challenges in vaccine development. To facilitate vaccine advancement efforts, we carried out comprehensive bioinformatic analyses of sequence variation by comparing 34 gonorrhea antigen candidates among >5,000 clinical N. gonorrhoeae isolates deposited in the Neisseria PubMLST database. Eight protein antigens showed exceptional conservation by having a single allele variant distributed in >80% of isolates. An additional 18 vaccine candidates were represented by ≤3 alleles in >50% of N. gonorrhoeae isolates globally. Phylogenetic analyses highlighted closely related antigen variants and additionally showed that AniA and FetB were the closest between N. gonorrhoeae and N. meningitidis Up to 44% of N. meningitidis alleles for both antigens have premature stop codons, suggesting differential expression. Mapping polymorphisms to the available three-dimensional structures of 12 antigens revealed low-frequency surface polymorphisms. PorB and TbpB possessed numerous high-prevalence polymorphic sites. While TbpA was also highly variable, conserved loops were nonetheless identified. A high degree of sequence conservation, the distribution of a single antigen variant among N. gonorrhoeae strains globally, or low-frequency sequence polymorphisms in surface loops make ACP, AniA, BamA, BamE, MtrE, NspA, NGO0778, NGO1251, NGO1985, OpcA, PldA, Slam2, and ZnuD promising candidates for a gonorrhea vaccine. Finally, the commonly used N. gonorrhoeae FA1090 strain emerges as a vaccine prototype, as it carries antigen sequence types identical to the most broadly distributed antigen variants.IMPORTANCE Neisseria gonorrhoeae, the Gram-negative bacterium responsible for the sexually transmitted infection gonorrhea, is categorized as a high-priority pathogen for research and development efforts. N. gonorrhoeae's "superbug" status, its high morbidity, and the serious health impact associated with gonorrhea highlight the importance of vaccine development. One of the longstanding barriers to developing an effective vaccine against N. gonorrhoeae is the remarkable variability of surface-exposed antigens. In this report, we addressed this roadblock by applying extensive bioinformatic analyses to 34 gonorrhea antigen candidates among >5,000 clinical N. gonorrhoeae isolates. Our studies are important, as they reveal promising, conserved gonorrhea vaccine candidates and aid structural vaccinology. Moreover, these approaches are broadly applicable to other infectious diseases where surface antigen variability impedes successful vaccine design.
Collapse
|
22
|
Genetic Evidence for SecY Translocon-Mediated Import of Two Contact-Dependent Growth Inhibition (CDI) Toxins. mBio 2021; 12:mBio.03367-20. [PMID: 33531386 PMCID: PMC7858069 DOI: 10.1128/mbio.03367-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Many bacterial species interact via direct cell-to-cell contact using CDI systems, which provide a mechanism to inject toxins that inhibit bacterial growth into one another. Here, we find that two CDI toxins, one that depolarizes membranes and another that degrades RNA, exploit the universally conserved SecY translocon machinery used to export proteins for target cell entry. The C-terminal (CT) toxin domains of contact-dependent growth inhibition (CDI) CdiA proteins target Gram-negative bacteria and must breach both the outer and inner membranes of target cells to exert growth inhibitory activity. Here, we examine two CdiA-CT toxins that exploit the bacterial general protein secretion machinery after delivery into the periplasm. A Ser281Phe amino acid substitution in transmembrane segment 7 of SecY, the universally conserved channel-forming subunit of the Sec translocon, decreases the cytotoxicity of the membrane depolarizing orphan10 toxin from enterohemorrhagic Escherichia coli EC869. Target cells expressing secYS281F and lacking either PpiD or YfgM, two SecY auxiliary factors, are fully protected from CDI-mediated inhibition either by CdiA-CTo10EC869 or by CdiA-CTGN05224, the latter being an EndoU RNase CdiA toxin from Klebsiella aerogenes GN05224 that has a related cytoplasm entry domain. RNase activity of CdiA-CTGN05224 was reduced in secYS281F target cells and absent in secYS281F ΔppiD or secYS281F ΔyfgM target cells during competition co-cultures. Importantly, an allele-specific mutation in secY (secYG313W) renders ΔppiD or ΔyfgM target cells specifically resistant to CdiA-CTGN05224 but not to CdiA-CTo10EC869, further suggesting a direct interaction between SecY and the CDI toxins. Our results provide genetic evidence of a unique confluence between the primary cellular export route for unfolded polypeptides and the import pathways of two CDI toxins.
Collapse
|
23
|
de Moraes MH, Hsu F, Huang D, Bosch DE, Zeng J, Radey MC, Simon N, Ledvina HE, Frick JP, Wiggins PA, Peterson SB, Mougous JD. An interbacterial DNA deaminase toxin directly mutagenizes surviving target populations. eLife 2021; 10:62967. [PMID: 33448264 PMCID: PMC7901873 DOI: 10.7554/elife.62967] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/14/2021] [Indexed: 12/12/2022] Open
Abstract
When bacterial cells come in contact, antagonism mediated by the delivery of toxins frequently ensues. The potential for such encounters to have long-term beneficial consequences in recipient cells has not been investigated. Here, we examined the effects of intoxication by DddA, a cytosine deaminase delivered via the type VI secretion system (T6SS) of Burkholderia cenocepacia. Despite its killing potential, we observed that several bacterial species resist DddA and instead accumulate mutations. These mutations can lead to the acquisition of antibiotic resistance, indicating that even in the absence of killing, interbacterial antagonism can have profound consequences on target populations. Investigation of additional toxins from the deaminase superfamily revealed that mutagenic activity is a common feature of these proteins, including a representative we show targets single-stranded DNA and displays a markedly divergent structure. Our findings suggest that a surprising consequence of antagonistic interactions between bacteria could be the promotion of adaptation via the action of directly mutagenic toxins.
Collapse
Affiliation(s)
- Marcos H de Moraes
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - FoSheng Hsu
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Dean Huang
- Department of Physics, University of Washington, Seattle, United States
| | - Dustin E Bosch
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, United States
| | - Jun Zeng
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Noah Simon
- Department of Biostatistics, University of Washington School of Public Health, Seattle, United States
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Jacob P Frick
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Paul A Wiggins
- Department of Physics, University of Washington, Seattle, United States
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States.,Department of Biochemistry, University of Washington School of Medicine, Seattle, United States.,Howard Hughes Medical Institute, University of Washington, Seattle, United States
| |
Collapse
|
24
|
The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion. Proc Natl Acad Sci U S A 2020; 117:33540-33548. [PMID: 33323487 DOI: 10.1073/pnas.1919350117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteria deploy rearrangement hotspot (Rhs) proteins as toxic effectors against both prokaryotic and eukaryotic target cells. Rhs proteins are characterized by YD-peptide repeats, which fold into a large β-cage structure that encapsulates the C-terminal toxin domain. Here, we show that Rhs effectors are essential for type VI secretion system (T6SS) activity in Enterobacter cloacae (ECL). ECL rhs - mutants do not kill Escherichia coli target bacteria and are defective for T6SS-dependent export of hemolysin-coregulated protein (Hcp). The RhsA and RhsB effectors of ECL both contain Pro-Ala-Ala-Arg (PAAR) repeat domains, which bind the β-spike of trimeric valine-glycine repeat protein G (VgrG) and are important for T6SS activity in other bacteria. Truncated RhsA that retains the PAAR domain is capable of forming higher-order, thermostable complexes with VgrG, yet these assemblies fail to restore secretion activity to ∆rhsA ∆rhsB mutants. Full T6SS-1 activity requires Rhs that contains N-terminal transmembrane helices, the PAAR domain, and an intact β-cage. Although ∆rhsA ∆rhsB mutants do not kill target bacteria, time-lapse microscopy reveals that they assemble and fire T6SS contractile sheaths at ∼6% of the frequency of rhs + cells. Therefore, Rhs proteins are not strictly required for T6SS assembly, although they greatly increase secretion efficiency. We propose that PAAR and the β-cage provide distinct structures that promote secretion. PAAR is clearly sufficient to stabilize trimeric VgrG, but efficient assembly of T6SS-1 also depends on an intact β-cage. Together, these domains enforce a quality control checkpoint to ensure that VgrG is loaded with toxic cargo before assembling the secretion apparatus.
Collapse
|
25
|
Muir A, Gurung I, Cehovin A, Bazin A, Vallenet D, Pelicic V. Construction of a complete set of Neisseria meningitidis mutants and its use for the phenotypic profiling of this human pathogen. Nat Commun 2020; 11:5541. [PMID: 33139723 PMCID: PMC7606547 DOI: 10.1038/s41467-020-19347-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/05/2020] [Indexed: 01/29/2023] Open
Abstract
The bacterium Neisseria meningitidis causes life-threatening meningitis and sepsis. Here, we construct a complete collection of defined mutants in protein-coding genes of this organism, identifying all genes that are essential under laboratory conditions. The collection, named NeMeSys 2.0, consists of individual mutants in 1584 non-essential genes. We identify 391 essential genes, which are associated with basic functions such as expression and preservation of genome information, cell membrane structure and function, and metabolism. We use this collection to shed light on the functions of diverse genes, including a gene encoding a member of a previously unrecognised class of histidinol-phosphatases; a set of 20 genes required for type IV pili function; and several conditionally essential genes encoding antitoxins and/or immunity proteins. We expect that NeMeSys 2.0 will facilitate the phenotypic profiling of a major human bacterial pathogen.
Collapse
Affiliation(s)
- Alastair Muir
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ishwori Gurung
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ana Cehovin
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Adelme Bazin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
| |
Collapse
|
26
|
Ruhe ZC, Low DA, Hayes CS. Polymorphic Toxins and Their Immunity Proteins: Diversity, Evolution, and Mechanisms of Delivery. Annu Rev Microbiol 2020; 74:497-520. [PMID: 32680451 DOI: 10.1146/annurev-micro-020518-115638] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
All bacteria must compete for growth niches and other limited environmental resources. These existential battles are waged at several levels, but one common strategy entails the transfer of growth-inhibitory protein toxins between competing cells. These antibacterial effectors are invariably encoded with immunity proteins that protect cells from intoxication by neighboring siblings. Several effector classes have been described, each designed to breach the cell envelope of target bacteria. Although effector architectures and export pathways tend to be clade specific, phylogenetically distant species often deploy closely related toxin domains. Thus, diverse competition systems are linked through a common reservoir of toxin-immunity pairs that is shared via horizontal gene transfer. These toxin-immunity protein pairs are extraordinarily diverse in sequence, and this polymorphism underpins an important mechanism of self/nonself discrimination in bacteria. This review focuses on the structures, functions, and delivery mechanisms of polymorphic toxin effectors that mediate bacterial competition.
Collapse
Affiliation(s)
- Zachary C Ruhe
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA;
| | - David A Low
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA; .,Biomolecular Science and Engineering Program, University of California, Santa Barbara, California 93106, USA
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA; .,Biomolecular Science and Engineering Program, University of California, Santa Barbara, California 93106, USA
| |
Collapse
|
27
|
Hughes-Games A, Roberts AP, Davis SA, Hill DJ. Identification of integrative and conjugative elements in pathogenic and commensal Neisseriaceae species via genomic distributions of DNA uptake sequence dialects. Microb Genom 2020; 6:e000372. [PMID: 32375974 PMCID: PMC7371117 DOI: 10.1099/mgen.0.000372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 04/13/2020] [Indexed: 02/02/2023] Open
Abstract
Mobile genetic elements (MGEs) are key factors responsible for dissemination of virulence determinants and antimicrobial-resistance genes amongst pathogenic bacteria. Conjugative MGEs are notable for their high gene loads donated per transfer event, broad host ranges and phylogenetic ubiquity amongst prokaryotes, with the subclass of chromosomally inserted integrative and conjugative elements (ICEs) being particularly abundant. The focus on a small number of model systems has biased the study of ICEs towards those conferring readily selectable phenotypes to host cells, whereas the identification and characterization of integrated cryptic elements remains challenging. Even though antimicrobial resistance and horizontally acquired virulence genes are major factors aggravating neisserial infection, conjugative MGEs of Neisseria gonorrhoeae and Neisseria meningitidis remain poorly characterized. Using a phenotype-independent approach based on atypical distributions of DNA uptake sequences (DUSs) in MGEs relative to the chromosomal background, we have identified two groups of chromosomally integrated conjugative elements in Neisseria: one found almost exclusively in pathogenic species possibly deriving from the genus Kingella, the other belonging to a group of Neisseria mucosa-like commensals. The former element appears to enable transfer of traditionally gonococcal-specific loci such as the virulence-associated toxin-antitoxin system fitAB to N. meningitidis chromosomes, whilst the circular form of the latter possesses a unique attachment site (attP) sequence seemingly adapted to exploit DUS motifs as chromosomal integration sites. In addition to validating the use of DUS distributions in Neisseriaceae MGE identification, the >170 identified ICE sequences provide a valuable resource for future studies of ICE evolution and host adaptation.
Collapse
Affiliation(s)
- Alex Hughes-Games
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
- Bristol Centre for Functional Nanomaterials, HH Wills Physics Laboratory, University of Bristol, Bristol, UK
| | - Adam P. Roberts
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Sean A. Davis
- School of Chemistry, University of Bristol, Bristol, UK
| | - Darryl J. Hill
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| |
Collapse
|
28
|
Kaundal S, Deep A, Kaur G, Thakur KG. Molecular and Biochemical Characterization of YeeF/YezG, a Polymorphic Toxin-Immunity Protein Pair From Bacillus subtilis. Front Microbiol 2020; 11:95. [PMID: 32117125 PMCID: PMC7033585 DOI: 10.3389/fmicb.2020.00095] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/16/2020] [Indexed: 12/25/2022] Open
Abstract
Polymorphic toxins are important and widespread elements of bacterial warfare that help in restricting the growth of competitors, aiding kin selection, and shaping the bacterial communities. Although widespread, polymorphic toxin systems (PTS) have been extensively studied in Gram-negative bacteria, there are limited studies describing PTS in Gram-positive bacteria. The present study characterizes YeeF/YezG, a predicted member of a PF04740 family of the polymorphic toxin-immunity system from a Gram-positive bacteria Bacillus subtilis. The expression of the C-terminal toxic domain of YeeF (YeeF-CT) causes growth inhibition and gross morphological changes in Escherichia coli. The observed toxic effects are neutralized by the co-expression of yezG, a gene present downstream of yeeF, confirming YeeF-CT/YezG as a toxin/immunity protein pair. Biochemical and in vivo studies reveal that YeeF-CT causes toxicity due to its non-specific metal-dependent DNase activity. This is different from the previously reported RNase activity from the three B. subtilis toxins belonging to PF04740 family. Isothermal titration calorimetry (ITC) data analysis suggests that YeeF-CT binds YezG with a dissociation constant in the nanomolar range. Analytical ultracentrifugation studies revealed that YeeF-CT forms a homodimer and binds with two molecules of monomeric YezG immunity protein to form a 2:2 stochiometric heterotetrameric complex. Biolayer interferometry and electrophoretic mobility shift assays show that YeeF-CT/YezG/DNA forms a stable ternary complex implicating that YezG is an exosite inhibitor of YeeF-CT. This study extends the molecular targets of the toxins in the PF04740 family and thus, this family of toxins can be broadly classified as nucleases harboring either DNases or RNases activities.
Collapse
Affiliation(s)
- Soni Kaundal
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific & Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Amar Deep
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific & Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Gundeep Kaur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific & Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific & Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| |
Collapse
|
29
|
Káňová E, Tkáčová Z, Bhide K, Kulkarni A, Jiménez-Munguía I, Mertinková P, Drážovská M, Tyagi P, Bhide M. Transcriptome analysis of human brain microvascular endothelial cells response to Neisseria meningitidis and its antigen MafA using RNA-seq. Sci Rep 2019; 9:18763. [PMID: 31822804 PMCID: PMC6904618 DOI: 10.1038/s41598-019-55409-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 11/28/2019] [Indexed: 01/25/2023] Open
Abstract
Interaction of Neisseria meningitidis (NM) with human brain microvascular endothelial cells (hBMECs) initiates of multiple cellular processes, which allow bacterial translocation across the blood-brain barrier (BBB). NM is equipped with several antigens, which interacts with the host cell receptors. Recently we have shown that adhesin MafA (UniProtKB-X5EG71), relatively less studied protein, is one of those surface exposed antigens that adhere to hBMECs. The present study was designed to comprehensively map the undergoing biological processes in hBMECs challenged with NM or MafA using RNA sequencing. 708 and 726 differentially expressed genes (DEGs) were identified in hBMECs exposed to NM and MafA, respectively. Gene ontology analysis of the DEGs revealed that several biological processes, which may alter the permeability of BBB, were activated. Comparative analysis of DEGs revealed that MafA, alike NM, might provoke TLR-dependent pathway and augment cytokine response. Moreover, both MafA and NM were able to induce genes involved in cell surface modifications, endocytosis, extracellular matrix remodulation and anoikis/apoptosis. In conclusion, this study for the first time describes effect of NM on the global gene expression in hBMECs using high-throughput RNA-seq. It also presents ability of MafA to induce gene expression, which might aid NM in breaching the BBB.
Collapse
Affiliation(s)
- Evelína Káňová
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Zuzana Tkáčová
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Katarína Bhide
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Amod Kulkarni
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Irene Jiménez-Munguía
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Patrícia Mertinková
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Monika Drážovská
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Punit Tyagi
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia
| | - Mangesh Bhide
- Laboratory of Biomedical Microbiology and Immunology, The University of Veterinary Medicine and Pharmacy, Komenskeho 73, 04001, Kosice, Slovakia. .,Institute of Neuroimmunology of Slovak Academy of Sciences, 84510, Bratislava, Slovakia.
| |
Collapse
|
30
|
Płaczkiewicz J, Adamczyk-Popławska M, Lasek R, Bącal P, Kwiatek A. Inactivation of Genes Encoding MutL and MutS Proteins Influences Adhesion and Biofilm Formation by Neisseria gonorrhoeae. Microorganisms 2019; 7:microorganisms7120647. [PMID: 31817122 PMCID: PMC6955733 DOI: 10.3390/microorganisms7120647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 11/16/2022] Open
Abstract
Neisseria gonorrhoeae is an etiological agent of gonorrhea, which remains a global health problem. This bacterium possesses MutL and MutS DNA repair proteins encoded by mutL and mutS genes, whose inactivation causes a mutator phenotype. We have demonstrated the differential gene expression in N. gonorrhoeae mutL and mutS mutants using DNA microarrays. A subset of differentially expressed genes encodes proteins that can influence adhesion and biofilm formation. Compared to the wild-type strain, N. gonorrhoeae mutL and mutS mutants formed denser biofilms with increased biofilm-associated biomass on the abiotic surface. The N. gonorrhoeae mutS::km, but not the mutL mutant, was also more adherent and invasive to human epithelial cells. Further, during infection of epithelial cells with N. gonorrhoeae mutS::km, the expression of some bacterial genes encoding proteins that can influence gonococcal adhesion was changed compared with their expression in cells infected with the wild-type gonococcus, as well as of human genes' encoding receptors utilized by N. gonorrhoeae (CD46, CEACAM 1, HSPG 2). Thus, deficiency in the mutS gene resulting in increased mutation frequency in singular organisms can be beneficial in populations because these mutants can be a source of features linked to microbial fitness.
Collapse
Affiliation(s)
- Jagoda Płaczkiewicz
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Monika Adamczyk-Popławska
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Robert Lasek
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Pawel Bącal
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Poland
| | - Agnieszka Kwiatek
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
- Correspondence: ; Tel.: +48-22-554-14-21
| |
Collapse
|
31
|
Convergent Evolution of the Barnase/EndoU/Colicin/RelE (BECR) Fold in Antibacterial tRNase Toxins. Structure 2019; 27:1660-1674.e5. [PMID: 31515004 DOI: 10.1016/j.str.2019.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/03/2019] [Accepted: 08/20/2019] [Indexed: 11/20/2022]
Abstract
Contact-dependent growth inhibition (CDI) is a form of interbacterial competition mediated by CdiB-CdiA two-partner secretion systems. CdiA effector proteins carry polymorphic C-terminal toxin domains (CdiA-CT), which are neutralized by specific CdiI immunity proteins to prevent self-inhibition. Here, we present the crystal structures of CdiA-CT⋅CdiI complexes from Klebsiella pneumoniae 342 and Escherichia coli 3006. The toxins adopt related folds that resemble the ribonuclease domain of colicin D, and both are isoacceptor-specific tRNases that cleave the acceptor stem of deacylated tRNAGAUIle. Although the toxins are similar in structure and substrate specificity, CdiA-CTKp342 activity requires translation factors EF-Tu and EF-Ts, whereas CdiA-CTEC3006 is intrinsically active. Furthermore, the corresponding immunity proteins are unrelated in sequence and structure. CdiIKp342 forms a dimeric β sandwich, whereas CdiIEC3006 is an α-solenoid monomer. Given that toxin-immunity genes co-evolve as linked pairs, these observations suggest that the similarities in toxin structure and activity reflect functional convergence.
Collapse
|
32
|
Ruhe ZC, Subramanian P, Song K, Nguyen JY, Stevens TA, Low DA, Jensen GJ, Hayes CS. Programmed Secretion Arrest and Receptor-Triggered Toxin Export during Antibacterial Contact-Dependent Growth Inhibition. Cell 2019; 175:921-933.e14. [PMID: 30388452 DOI: 10.1016/j.cell.2018.10.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/31/2018] [Accepted: 09/05/2018] [Indexed: 12/21/2022]
Abstract
Contact-dependent growth inhibition (CDI) entails receptor-mediated delivery of CdiA-derived toxins into Gram-negative target bacteria. Using electron cryotomography, we show that each CdiA effector protein forms a filament extending ∼33 nm from the cell surface. Remarkably, the extracellular filament represents only the N-terminal half of the effector. A programmed secretion arrest sequesters the C-terminal half of CdiA, including the toxin domain, in the periplasm prior to target-cell recognition. Upon binding receptor, CdiA secretion resumes, and the periplasmic FHA-2 domain is transferred to the target-cell outer membrane. The C-terminal toxin region of CdiA then penetrates into the target-cell periplasm, where it is cleaved for subsequent translocation into the cytoplasm. Our findings suggest that the FHA-2 domain assembles into a transmembrane conduit for toxin transport into the periplasm of target bacteria. We propose that receptor-triggered secretion ensures that FHA-2 export is closely coordinated with integration into the target-cell outer membrane. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Zachary C Ruhe
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Poorna Subramanian
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kiho Song
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Josephine Y Nguyen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Taylor A Stevens
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - David A Low
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, Pasadena, CA 91125, USA.
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
| |
Collapse
|
33
|
Sannigrahi A, Nandi I, Chall S, Jawed JJ, Halder A, Majumdar S, Karmakar S, Chattopadhyay K. Conformational Switch Driven Membrane Pore Formation by Mycobacterium Secretory Protein MPT63 Induces Macrophage Cell Death. ACS Chem Biol 2019; 14:1601-1610. [PMID: 31241303 DOI: 10.1021/acschembio.9b00327] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Virulent Mycobacterium tuberculosis (MTB) strains cause cell death of macrophages (Mϕ) inside TB granuloma using a mechanism which is not well understood. Many bacterial systems utilize toxins to induce host cell damage, which occurs along with immune evasion. These toxins often use chameleon sequences to generate an environment-sensitive conformational switch, facilitating the process of infection. The presence of toxins is not yet known for MTB. Here, we show that MTB-secreted immunogenic MPT63 protein undergoes a switch from β-sheet to helix in response to mutational and environmental stresses. MPT63 in its helical form creates pores in both synthetic and Mϕ membranes, while the native β-sheet protein remains inert toward membrane interactions. Using fluorescence correlation spectroscopy and atomic force microscopy, we show further that the helical form undergoes self-association to produce toxic oligomers of different morphology. Trypan blue and flow cytometry analyses reveal that the helical state can be utilized by MTB for killing Mϕ cells. Collectively, our study emphasizes for the first time a toxin-like behavior of MPT63 induced by an environment-dependent conformational switch, resulting in membrane pore formation by toxic oligomers and Mϕ cell death.
Collapse
Affiliation(s)
- Achinta Sannigrahi
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Indrani Nandi
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sayantani Chall
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
| | | | - Animesh Halder
- Department of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Subrata Majumdar
- Department of Molecular Medicine, Bose Institute, Kolkata 700054, India
| | - Sanat Karmakar
- Department of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Krishnananda Chattopadhyay
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
34
|
Tipping MJ, Gibbs KA. Peer pressure from a Proteus mirabilis self-recognition system controls participation in cooperative swarm motility. PLoS Pathog 2019; 15:e1007885. [PMID: 31323074 PMCID: PMC6682164 DOI: 10.1371/journal.ppat.1007885] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 08/05/2019] [Accepted: 06/03/2019] [Indexed: 11/25/2022] Open
Abstract
Colonies of the opportunistic pathogen Proteus mirabilis can distinguish self from non-self: in swarming colonies of two different strains, one strain excludes the other from the expanding colony edge. Predominant models characterize bacterial kin discrimination as immediate antagonism towards non-kin cells, typically through delivery of toxin effector molecules from one cell into its neighbor. Upon effector delivery, receiving cells must either neutralize it by presenting a cognate anti-toxin as would a clonal sibling, or suffer cell death or irreversible growth inhibition as would a non-kin cell. Here we expand this paradigm to explain the non-lethal Ids self-recognition system, which stops access to a social behavior in P. mirabilis by selectively and transiently inducing non-self cells into a growth-arrested lifestyle incompatible with cooperative swarming. This state is characterized by reduced expression of genes associated with protein synthesis, virulence, and motility, and also causes non-self cells to tolerate previously lethal concentrations of antibiotics. We show that temporary activation of the stringent response is necessary for entry into this state, ultimately resulting in the iterative exclusion of non-self cells as a swarm colony migrates outwards. These data clarify the intricate connection between non-lethal recognition and the lifecycle of P. mirabilis swarm colonies. A resident of animal intestines, Proteus mirabilis is a major cause of catheter-associated urinary tract infections and can cause recurrent, persistent infections. Swarming, which is a collective behavior that promotes centimeter-scale population migration, is implicated in colonization of bladders and kidneys. A regulatory factor of swarming is kin recognition, which involves the transfer of a self-identity protein from one cell into a physically adjacent neighboring cell. However, how kin recognition regulates swarming was previously unclear. We have now shown a mechanism linking kin recognition, swarm migration, and antibiotics tolerance: cells induce a transient antibiotics-tolerant, persister-like state in adjacent non-identical cells which in turn prevents non-identical cells from continuing to participate in collective swarming. These affected non-identical cells continue to exhibit large-scale gene expression suggesting an active shift into a different expression state. These data provide two key insights for the field. First, kin recognition can be a regulatory mechanism that acts with spatial and temporal precision. Second, induction into an antibiotics-tolerant state, instead of occurring stochastically, can be physically and spatially regulated by neighboring cells. These insights highlight the importance of further developing four-dimensional (time and X-, Y-, Z-axes) model systems for interrogating cell-cell signaling and control in microbial populations.
Collapse
Affiliation(s)
- Murray J. Tipping
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Karine A. Gibbs
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
35
|
Coureuil M, Jamet A, Bille E, Lécuyer H, Bourdoulous S, Nassif X. Molecular interactions between Neisseria meningitidis and its human host. Cell Microbiol 2019; 21:e13063. [PMID: 31167044 PMCID: PMC6899865 DOI: 10.1111/cmi.13063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/21/2019] [Accepted: 05/30/2019] [Indexed: 02/06/2023]
Abstract
Neisseria meningitidis is a Gram‐negative bacterium that asymptomatically colonises the nasopharynx of humans. For an unknown reason, N. meningitidis can cross the nasopharyngeal barrier and invade the bloodstream where it becomes one of the most harmful extracellular bacterial pathogen. This infectious cycle involves the colonisation of two different environments. (a) In the nasopharynx, N. meningitidis grow on the top of mucus‐producing epithelial cells surrounded by a complex microbiota. To survive and grow in this challenging environment, the meningococcus expresses specific virulence factors such as polymorphic toxins and MDAΦ. (b) Meningococci have the ability to survive in the extra cellular fluids including blood and cerebrospinal fluid. The interaction of N. meningitidis with human endothelial cells leads to the formation of typical microcolonies that extend overtime and promote vascular injury, disseminated intravascular coagulation, and acute inflammation. In this review, we will focus on the interplay between N. meningitidis and these two different niches at the cellular and molecular level and discuss the use of inhibitors of piliation as a potent therapeutic approach.
Collapse
Affiliation(s)
- Mathieu Coureuil
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France
| | - Anne Jamet
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Emmanuelle Bille
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Hervé Lécuyer
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Sandrine Bourdoulous
- Université de Paris, UMR_S 1151, Paris, France.,Inserm, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France
| | - Xavier Nassif
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| |
Collapse
|
36
|
Baarda BI, Zielke RA, Le Van A, Jerse AE, Sikora AE. Neisseria gonorrhoeae MlaA influences gonococcal virulence and membrane vesicle production. PLoS Pathog 2019; 15:e1007385. [PMID: 30845186 PMCID: PMC6424457 DOI: 10.1371/journal.ppat.1007385] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/19/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023] Open
Abstract
The six-component maintenance of lipid asymmetry (Mla) system is responsible for retrograde transport of phospholipids, ensuring the barrier function of the Gram-negative cell envelope. Located within the outer membrane, MlaA (VacJ) acts as a channel to shuttle phospholipids from the outer leaflet. We identified Neisseria gonorrhoeae MlaA (ngo2121) during high-throughput proteomic mining for potential therapeutic targets against this medically important human pathogen. Our follow-up phenotypic microarrays revealed that lack of MlaA results in a complex sensitivity phenome. Herein we focused on MlaA function in cell envelope biogenesis and pathogenesis. We demonstrate the existence of two MlaA classes among 21 bacterial species, characterized by the presence or lack of a lipoprotein signal peptide. Purified truncated N. gonorrhoeae MlaA elicited antibodies that cross-reacted with a panel of different Neisseria. Little is known about MlaA expression; we provide the first evidence that MlaA levels increase in stationary phase and under anaerobiosis but decrease during iron starvation. Lack of MlaA resulted in higher cell counts during conditions mimicking different host niches; however, it also significantly decreased colony size. Antimicrobial peptides such as polymyxin B exacerbated the size difference while human defensin was detrimental to mutant viability. Consistent with the proposed role of MlaA in vesicle biogenesis, the ΔmlaA mutant released 1.7-fold more membrane vesicles. Comparative proteomics of cell envelopes and native membrane vesicles derived from ΔmlaA and wild type bacteria revealed enrichment of TadA–which recodes proteins through mRNA editing–as well as increased levels of adhesins and virulence factors. MlaA-deficient gonococci significantly outcompeted (up to 16-fold) wild-type bacteria in the murine lower genital tract, suggesting the growth advantage or increased expression of virulence factors afforded by inactivation of mlaA is advantageous in vivo. Based on these results, we propose N. gonorrhoeae restricts MlaA levels to modulate cell envelope homeostasis and fine-tune virulence. The Gram-negative outer membrane is a formidable barrier, primarily because of its asymmetric composition. A layer of lipopolysaccharide is exposed to the external environment and phospholipids are on the internal face of the outer membrane. MlaA is part of a bacterial system that prevents phospholipid accumulation within the lipopolysaccharide layer. If MlaA is removed, membrane asymmetry is disrupted and bacteria become more vulnerable to certain antimicrobials. Neisseria gonorrhoeae causes millions of infections worldwide annually. A growing number are resistant to available antibiotics. Improving our understanding of gonococcal pathogenicity and basic biological processes is required to facilitate the discovery of new weapons against gonorrhea. We investigated the role of MlaA in N. gonorrhoeae and found that when MlaA was absent, bacteria were more sensitive to antibiotics and human defensins. However, the mutant bacteria produced more membrane vesicles–packages of proteins wrapped in membrane material. Mutant vesicles and cell envelopes were enriched in proteins that contribute to disease. These alterations significantly increased mutant fitness during experimental infection of the female mouse genital tract. Our results provide new insights into the processes N. gonorrhoeae uses to fine-tune its ability to stay fit in the hostile environment of the genital tract.
Collapse
Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Adriana Le Van
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Ann E. Jerse
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America
- * E-mail:
| |
Collapse
|
37
|
De Gregorio E, Zarrilli R, Di Nocera PP. Contact-dependent growth inhibition systems in Acinetobacter. Sci Rep 2019; 9:154. [PMID: 30655547 PMCID: PMC6336857 DOI: 10.1038/s41598-018-36427-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/21/2018] [Indexed: 11/09/2022] Open
Abstract
In bacterial contact-dependent growth inhibition (CDI) systems, CdiA proteins are exported to the outer membrane by cognate CdiB proteins. CdiA binds to receptors on susceptible bacteria and subsequently delivers its C-terminal toxin domain (CdiA-CT) into neighbouring target cells. Whereas self bacteria produce CdiI antitoxins, non-self bacteria lack antitoxins and are therefore inhibited in their growth by CdiA. In silico surveys of pathogenic Acinetobacter genomes have enabled us to identify >40 different CDI systems, which we sorted into two distinct groups. Type-II CdiAs are giant proteins (3711 to 5733 residues) with long arrays of 20-mer repeats. Type-I CdiAs are smaller (1900-2400 residues), lack repeats and feature central heterogeneity (HET) regions, that vary in size and sequence and can be exchanged between CdiA proteins. HET regions in most type-I proteins confer the ability to adopt a coiled-coil conformation. CdiA-CT and pretoxin modules differ significantly between type-I and type-II CdiAs. Moreover, type-II genes only have remnants of genes in their 3' end regions that have been displaced by the insertion of novel cdi sequences. Type-I and type-II CDI systems are equally abundant in A. baumannii, whereas A. pittii and A. nosocomialis predominantly feature type-I and type-II systems, respectively.
Collapse
Affiliation(s)
- Eliana De Gregorio
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.,Dipartimento di Sanità Pubblica, Università Federico II, Via Sergio Pansini 5, 80131, Naples, Italy
| | - Raffaele Zarrilli
- Dipartimento di Sanità Pubblica, Università Federico II, Via Sergio Pansini 5, 80131, Naples, Italy.
| | - Pier Paolo Di Nocera
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.
| |
Collapse
|
38
|
Michalska K, Quan Nhan D, Willett JLE, Stols LM, Eschenfeldt WH, Jones AM, Nguyen JY, Koskiniemi S, Low DA, Goulding CW, Joachimiak A, Hayes CS. Functional plasticity of antibacterial EndoU toxins. Mol Microbiol 2018; 109:509-527. [PMID: 29923643 PMCID: PMC6173971 DOI: 10.1111/mmi.14007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2018] [Indexed: 01/05/2023]
Abstract
Bacteria use several different secretion systems to deliver toxic EndoU ribonucleases into neighboring cells. Here, we present the first structure of a prokaryotic EndoU toxin in complex with its cognate immunity protein. The contact-dependent growth inhibition toxin CdiA-CTSTECO31 from Escherichia coli STEC_O31 adopts the eukaryotic EndoU fold and shares greatest structural homology with the nuclease domain of coronavirus Nsp15. The toxin contains a canonical His-His-Lys catalytic triad in the same arrangement as eukaryotic EndoU domains, but lacks the uridylate-specific ribonuclease activity that characterizes the superfamily. Comparative sequence analysis indicates that bacterial EndoU domains segregate into at least three major clades based on structural variations in the N-terminal subdomain. Representative EndoU nucleases from clades I and II degrade tRNA molecules with little specificity. In contrast, CdiA-CTSTECO31 and other clade III toxins are specific anticodon nucleases that cleave tRNAGlu between nucleotides C37 and m2 A38. These findings suggest that the EndoU fold is a versatile scaffold for the evolution of novel substrate specificities. Such functional plasticity may account for the widespread use of EndoU effectors by diverse inter-bacterial toxin delivery systems.
Collapse
Affiliation(s)
- Karolina Michalska
- Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, IL, USA.,Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL, USA
| | - Dinh Quan Nhan
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Julia L E Willett
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Lucy M Stols
- Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, IL, USA
| | - William H Eschenfeldt
- Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, IL, USA
| | - Allison M Jones
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Josephine Y Nguyen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Sanna Koskiniemi
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - David A Low
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA.,Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, USA
| | - Celia W Goulding
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, USA.,Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne, IL, USA.,Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL, USA.,Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA.,Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, USA
| |
Collapse
|
39
|
Harrison OB, Schoen C, Retchless AC, Wang X, Jolley KA, Bray JE, Maiden MCJ. Neisseria genomics: current status and future perspectives. Pathog Dis 2018; 75:3861976. [PMID: 28591853 PMCID: PMC5827584 DOI: 10.1093/femspd/ftx060] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/05/2017] [Indexed: 12/17/2022] Open
Abstract
High-throughput whole genome sequencing has unlocked a multitude of possibilities enabling members of the Neisseria genus to be examined with unprecedented detail, including the human pathogens Neisseria meningitidis and Neisseria gonorrhoeae. To maximise the potential benefit of this for public health, it is becoming increasingly important to ensure that this plethora of data are adequately stored, disseminated and made readily accessible. Investigations facilitating cross-species comparisons as well as the analysis of global datasets will allow differences among and within species and across geographic locations and different times to be identified, improving our understanding of the distinct phenotypes observed. Recent advances in high-throughput platforms that measure the transcriptome, proteome and/or epigenome are also becoming increasingly employed to explore the complexities of Neisseria biology. An integrated approach to the analysis of these is essential to fully understand the impact these may have in the Neisseria genus. This article reviews the current status of some of the tools available for next generation sequence analysis at the dawn of the ‘post-genomic’ era.
Collapse
Affiliation(s)
| | - Christoph Schoen
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg 97080, Germany
| | - Adam C Retchless
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Xin Wang
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Keith A Jolley
- Department of Zoology, University of Oxford, Oxford OX1 3SY, UK
| | - James E Bray
- Department of Zoology, University of Oxford, Oxford OX1 3SY, UK
| | | |
Collapse
|
40
|
Abstract
Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhoeae, possesses several mobile genetic elements (MGEs). The MGEs such as transposable elements mediate intrachromosomal rearrangements, while plasmids and the gonococcal genetic island are involved in interchromosomal gene transfer. Additionally, gonococcal MGEs serve as hotspots for recombination and integration of other genetic elements such as bacteriophages, contribute to gene regulation or spread genes through gonococcal populations by horizontal gene transfer. In this review, we summarise the literature on the structure and biology of MGEs and discuss how these genetic elements may play a role in the pathogenesis and spread of antimicrobial resistance in N. gonorrhoeae. Although an abundance of information about gonococcal MGEs exists (mainly from whole genome sequencing and bioinformatic analysis), there are still many open questions on how MGEs influence the biology of N. gonorrhoeae.
Collapse
Affiliation(s)
- Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Steven B Lewis
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| |
Collapse
|
41
|
Ghosh A, Baltekin Ö, Wäneskog M, Elkhalifa D, Hammarlöf DL, Elf J, Koskiniemi S. Contact-dependent growth inhibition induces high levels of antibiotic-tolerant persister cells in clonal bacterial populations. EMBO J 2018; 37:embj.201798026. [PMID: 29572241 DOI: 10.15252/embj.201798026] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 02/08/2018] [Accepted: 02/21/2018] [Indexed: 12/31/2022] Open
Abstract
Bacterial populations can use bet-hedging strategies to cope with rapidly changing environments. One example is non-growing cells in clonal bacterial populations that are able to persist antibiotic treatment. Previous studies suggest that persisters arise in bacterial populations either stochastically through variation in levels of global signalling molecules between individual cells, or in response to various stresses. Here, we show that toxins used in contact-dependent growth inhibition (CDI) create persisters upon direct contact with cells lacking sufficient levels of CdiI immunity protein, which would otherwise bind to and neutralize toxin activity. CDI-mediated persisters form through a feedforward cycle where the toxic activity of the CdiA toxin increases cellular (p)ppGpp levels, which results in Lon-mediated degradation of the immunity protein and more free toxin. Thus, CDI systems mediate a population density-dependent bet-hedging strategy, where the fraction of non-growing cells is increased only when there are many cells of the same genotype. This may be one of the mechanisms of how CDI systems increase the fitness of their hosts.
Collapse
Affiliation(s)
- Anirban Ghosh
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Özden Baltekin
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Marcus Wäneskog
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Dina Elkhalifa
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Disa L Hammarlöf
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Johan Elf
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Sanna Koskiniemi
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
42
|
Kryshtafovych A, Albrecht R, Baslé A, Bule P, Caputo AT, Carvalho AL, Chao KL, Diskin R, Fidelis K, Fontes CMGA, Fredslund F, Gilbert HJ, Goulding CW, Hartmann MD, Hayes CS, Herzberg O, Hill JC, Joachimiak A, Kohring GW, Koning RI, Lo Leggio L, Mangiagalli M, Michalska K, Moult J, Najmudin S, Nardini M, Nardone V, Ndeh D, Nguyen TH, Pintacuda G, Postel S, van Raaij MJ, Roversi P, Shimon A, Singh AK, Sundberg EJ, Tars K, Zitzmann N, Schwede T. Target highlights from the first post-PSI CASP experiment (CASP12, May-August 2016). Proteins 2018; 86 Suppl 1:27-50. [PMID: 28960539 PMCID: PMC5820184 DOI: 10.1002/prot.25392] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/19/2017] [Accepted: 09/25/2017] [Indexed: 12/27/2022]
Abstract
The functional and biological significance of the selected CASP12 targets are described by the authors of the structures. The crystallographers discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP12 experiment.
Collapse
Affiliation(s)
- Andriy Kryshtafovych
- Genome Center, University of California, Davis, 451 Health Sciences Drive, Davis, California, 95616
| | - Reinhard Albrecht
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, 72076, Germany
| | - Arnaud Baslé
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Pedro Bule
- CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Portugal, Lisboa
| | - Alessandro T Caputo
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England, United Kingdom
| | - Ana Luisa Carvalho
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Cien⁁cias e Tecnologia, Universidade Nova de Lisboa, Caparica, 2829-516, Portugal
| | - Kinlin L Chao
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, 20850
| | - Ron Diskin
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Krzysztof Fidelis
- Genome Center, University of California, Davis, 451 Health Sciences Drive, Davis, California, 95616
| | - Carlos M G A Fontes
- CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Portugal, Lisboa
| | - Folmer Fredslund
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Harry J Gilbert
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Celia W Goulding
- Department of Molecular Biology and Biochemistry/Pharmaceutical Sciences, University of California Irvine, Irvine, California, 92697
| | - Marcus D Hartmann
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, 72076, Germany
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology/Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California, 93106
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, 20850
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, 20742
| | - Johan C Hill
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England, United Kingdom
| | - Andrzej Joachimiak
- Argonne National Laboratory, Midwest Center for Structural Genomics/Structural Biology Center, Biosciences Division, Argonne, Illinois, 60439
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, 60637
| | - Gert-Wieland Kohring
- Microbiology, Saarland University, Campus Building A1.5, Saarbrücken, Saarland, D-66123, Germany
| | - Roman I Koning
- Netherlands Centre for Electron Nanoscopy, Institute of Biology Leiden, Leiden University, 2333, CC Leiden, The Netherlands
- Department of Molecular Cell Biology, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Marco Mangiagalli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, 20126, Italy
| | - Karolina Michalska
- Argonne National Laboratory, Midwest Center for Structural Genomics/Structural Biology Center, Biosciences Division, Argonne, Illinois, 60439
| | - John Moult
- Department of Cell Biology and Molecular genetics, University of Maryland, 9600 Gudelsky Drive, Institute for Bioscience and Biotechnology Research, Rockville, Maryland, 20850
| | - Shabir Najmudin
- CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Portugal, Lisboa
| | - Marco Nardini
- Department of Biosciences, University of Milano, Milano, 20133, Italy
| | - Valentina Nardone
- Department of Biosciences, University of Milano, Milano, 20133, Italy
| | - Didier Ndeh
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Thanh-Hong Nguyen
- Department of Macromolecular Structures, Centro Nacional de Biotecnologia (CSIC), calle Darwin 3, Madrid, 28049, Spain
| | - Guido Pintacuda
- Université de Lyon, Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Villeurbanne, 69100, France
| | - Sandra Postel
- University of Maryland School of Medicine, Institute of Human Virology, Baltimore, Maryland, 21201
| | - Mark J van Raaij
- Department of Macromolecular Structures, Centro Nacional de Biotecnologia (CSIC), calle Darwin 3, Madrid, 28049, Spain
| | - Pietro Roversi
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England, United Kingdom
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, University Road, Leicester, LE1 7RN, UK
| | - Amir Shimon
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Abhimanyu K Singh
- School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, United Kingdom
| | - Eric J Sundberg
- Department of Medicine and Department of Microbiology and Immunology, University of Maryland School of Medicine, Institute of Human Virology, Baltimore, Maryland, 21201
| | - Kaspars Tars
- Latvian Biomedical Research and Study Center, Rātsupītes 1, Riga, LV1067, Latvia
- Faculty of Biology, Department of Molecular Biology, University of Latvia, Jelgavas 1, Riga, LV-1004, Latvia
| | - Nicole Zitzmann
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England, United Kingdom
| | - Torsten Schwede
- Biozentrum/SIB Swiss Institute of Bioinformatics, Klingelbergstrasse 50, Basel, 4056, Switzerland
| |
Collapse
|
43
|
Abstract
Bacteria host an arsenal of antagonism-mediating molecules to combat for ecologic space. Bacteriocins represent a pivotal group of secreted antibacterial peptides and proteins assisting in this fight, mainly eliminating relatives. Colicin M, a model for peptidoglycan-interfering bacteriocins in Gram-negative bacteria, appears to be part of a set of polymorphic toxins equipped with such a catalytic domain (ColM) targeting lipid II. Diversifying recombination has enabled parasitism of different receptors and has also given rise to hybrid bacteriocins in which ColM is associated with another toxin module. Remarkably, ColM toxins have recruited a diverse array of immunity partners, comprising cytoplasmic membrane-associated proteins with different topologies. Together, these findings suggest that different immunity mechanisms have evolved for ColM, in contrast to bacteriocins with nuclease activities.
Collapse
|
44
|
Spencer-Smith R, Gould SW, Pulijala M, Snyder LAS. Investigating Potential Chromosomal Rearrangements during Laboratory Culture of Neisseria gonorrhoeae. Microorganisms 2018; 6:microorganisms6010010. [PMID: 29361673 PMCID: PMC5874624 DOI: 10.3390/microorganisms6010010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 12/19/2017] [Accepted: 01/19/2018] [Indexed: 01/02/2023] Open
Abstract
Comparisons of genome sequence data between different strains and isolates of Neisseria spp., such as Neisseria gonorrhoeae, reveal that over the evolutionary history of these organisms, large scale chromosomal rearrangements have occurred. Factors within the genomes, such as repetitive sequences and prophage, are believed to have contributed to these observations. However, the timescale in which rearrangements occur is not clear, nor whether it might be expected for them to happen in the laboratory. In this study, N. gonorrhoeae was repeatedly passaged in the laboratory and assessed for large scale chromosomal rearrangements. Using gonococcal strain NCCP11945, for which there is a complete genome sequence, cultures were passaged for eight weeks in the laboratory. The resulting genomic DNA was assessed using Pulsed Field Gel Electrophoresis, comparing the results to the predicted results from the genome sequence data. Three cultures generated Pulsed Field Gel Electrophoresis patterns that varied from the genomic data and were further investigated for potential chromosomal rearrangements.
Collapse
Affiliation(s)
- Russell Spencer-Smith
- School of Life Sciences, Pharmacy, and Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK.
- National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Simon W Gould
- School of Life Sciences, Pharmacy, and Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK.
| | - Madhuri Pulijala
- School of Life Sciences, Pharmacy, and Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK.
| | - Lori A S Snyder
- School of Life Sciences, Pharmacy, and Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK.
| |
Collapse
|
45
|
Pseudomonas aeruginosa Contact-Dependent Growth Inhibition Plays Dual Role in Host-Pathogen Interactions. mSphere 2017; 2:mSphere00336-17. [PMID: 29152577 PMCID: PMC5687917 DOI: 10.1128/msphere.00336-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/20/2017] [Indexed: 12/29/2022] Open
Abstract
How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance. Microorganisms exist in a diverse ecosystem and have evolved many different mechanisms for sensing and influencing the polymicrobial environment around them, utilizing both diffusible and contact-dependent signals. Contact-dependent growth inhibition (CDI) is one such communication system employed by Gram-negative bacteria. In addition to CDI mediation of growth inhibition, recent studies have demonstrated CDI-mediated control of communal behaviors such as biofilm formation. We postulated that CDI may therefore play an active role in host-pathogen interactions, allowing invading strains to establish themselves at polymicrobial mucosal interfaces through competitive interactions while simultaneously facilitating pathogenic capabilities via CDI-mediated signaling. Here, we show that Pseudomonas aeruginosa produces two CDI systems capable of mediating competition under conditions of growth on a surface or in liquid. Furthermore, we demonstrated a novel role for these systems in contributing to virulence in acute infection models, likely via posttranscriptional regulation of beneficial behaviors. While we did not observe any role for the P. aeruginosa CDI systems in biofilm biogenesis, we did identify for the first time robust CDI-mediated competition during interaction with a mammalian host using a model of chronic respiratory tract infection, as well as evidence that CDI expression is maintained in chronic lung infections. These findings reveal a previously unappreciated role for CDI in host-pathogen interactions and emphasize their importance during infection. IMPORTANCE How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance.
Collapse
|
46
|
A widespread family of polymorphic toxins encoded by temperate phages. BMC Biol 2017; 15:75. [PMID: 28851366 PMCID: PMC5576092 DOI: 10.1186/s12915-017-0415-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/07/2017] [Indexed: 12/21/2022] Open
Abstract
Background Polymorphic toxins (PTs) are multi-domain bacterial exotoxins belonging to distinct families that share common features in terms of domain organization. PTs are found in all major bacterial clades, including many toxic effectors of type V and type VI secretion systems. PTs modulate the dynamics of microbial communities by killing or inhibiting the growth of bacterial competitors lacking protective immunity proteins. Results In this work, we identified a novel widespread family of PTs, named MuF toxins, which were exclusively encoded within temperate phages and their prophages. By analyzing the predicted proteomes of 1845 bacteriophages and 2464 bacterial genomes, we found that MuF-containing proteins were frequently part of the DNA packaging module of tailed phages. Interestingly, MuF toxins were abundant in the human gut microbiome. Conclusions Our results uncovered the presence of the MuF toxin family in the temperate phages of Firmicutes. The MuF toxin family is likely to play an important role in the ecology of the human microbiota where pathogens and commensal species belonging to the Firmicutes are abundant. We propose that MuF toxins could be delivered by phages into host bacteria and either influence the lysogeny decision or serve as bacterial weapons by inhibiting the growth of competing bacteria. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0415-1) contains supplementary material, which is available to authorized users.
Collapse
|
47
|
Diversity and distribution of nuclease bacteriocins in bacterial genomes revealed using Hidden Markov Models. PLoS Comput Biol 2017; 13:e1005652. [PMID: 28715501 PMCID: PMC5536347 DOI: 10.1371/journal.pcbi.1005652] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/31/2017] [Accepted: 06/21/2017] [Indexed: 11/28/2022] Open
Abstract
Bacteria exploit an arsenal of antimicrobial peptides and proteins to compete with each other. Three main competition systems have been described: type six secretion systems (T6SS); contact dependent inhibition (CDI); and bacteriocins. Unlike T6SS and CDI systems, bacteriocins do not require contact between bacteria but are diffusible toxins released into the environment. Identified almost a century ago, our understanding of bacteriocin distribution and prevalence in bacterial populations remains poor. In the case of protein bacteriocins, this is because of high levels of sequence diversity and difficulties in distinguishing their killing domains from those of other competition systems. Here, we develop a robust bioinformatics pipeline exploiting Hidden Markov Models for the identification of nuclease bacteriocins (NBs) in bacteria of which, to-date, only a handful are known. NBs are large (>60 kDa) toxins that target nucleic acids (DNA, tRNA or rRNA) in the cytoplasm of susceptible bacteria, usually closely related to the producing organism. We identified >3000 NB genes located on plasmids or on the chromosome from 53 bacterial species distributed across different ecological niches, including human, animals, plants, and the environment. A newly identified NB predicted to be specific for Pseudomonas aeruginosa (pyocin Sn) was produced and shown to kill P. aeruginosa thereby validating our pipeline. Intriguingly, while the genes encoding the machinery needed for NB translocation across the cell envelope are widespread in Gram-negative bacteria, NBs are found exclusively in γ-proteobacteria. Similarity network analysis demonstrated that NBs fall into eight groups each with a distinct arrangement of protein domains involved in import. The only structural feature conserved across all groups was a sequence motif critical for cell-killing that is generally not found in bacteriocins targeting the periplasm, implying a specific role in translocating the nuclease to the cytoplasm. Finally, we demonstrate a significant association between nuclease colicins, NBs specific for Escherichia coli, and virulence factors, suggesting NBs play a role in infection processes, most likely by enabling pathogens to outcompete commensal bacteria. Bacteria deploy a variety of antimicrobials to kill competing bacteria. Nuclease bacteriocins are a miscellaneous group of protein toxins that target closely related species, cleaving nucleic acids in the cytoplasm. It has proved difficult to establish how widespread bacteriocins are in bacterial populations due to the high diversity of bacteriocin-encoding genes. Here, we describe an in silico approach to identify nuclease bacteriocin genes in bacterial genomes and to distinguish them from other competition toxins. Bacteria that contain nuclease bacteriocin genes are found in many different types of environment but are prevalent in niches where interbacterial competition is likely to be high. Nuclease bacteriocins are found exclusively in γ-proteobacteria and are particularly abundant in the Enterobacteriaceae and Pseudomonadaceae families. Although the sequences we identify are indeed diverse (<20% sequence identity between protein families) we show that all nuclease bacteriocins contain an invariant motif, usually within a common structural scaffold, that is implicated in translocating the cytotoxic nuclease to the cytoplasm. Finally, we show that nuclease bacteriocins in pathogenic E. coli are strongly associated with virulence factors suggesting they play a role in pathogenicity mechanisms.
Collapse
|
48
|
Tommassen J, Arenas J. Biological Functions of the Secretome of Neisseria meningitidis. Front Cell Infect Microbiol 2017; 7:256. [PMID: 28670572 PMCID: PMC5472700 DOI: 10.3389/fcimb.2017.00256] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/29/2017] [Indexed: 11/13/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterial pathogen that normally resides as a commensal in the human nasopharynx but occasionally causes disease with high mortality and morbidity. To interact with its environment, it transports many proteins across the outer membrane to the bacterial cell surface and into the extracellular medium for which it deploys the common and well-characterized autotransporter, two-partner and type I secretion mechanisms, as well as a recently discovered pathway for the surface exposure of lipoproteins. The surface-exposed and secreted proteins serve roles in host-pathogen interactions, including adhesion to host cells and extracellular matrix proteins, evasion of nutritional immunity imposed by iron-binding proteins of the host, prevention of complement activation, neutralization of antimicrobial peptides, degradation of immunoglobulins, and permeabilization of epithelial layers. Furthermore, they have roles in interbacterial interactions, including the formation and dispersal of biofilms and the suppression of the growth of bacteria competing for the same niche. Here, we will review the protein secretion systems of N. meningitidis and focus on the functions of the secreted proteins.
Collapse
Affiliation(s)
- Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht UniversityUtrecht, Netherlands
| | - Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht UniversityUtrecht, Netherlands
| |
Collapse
|
49
|
Marin MA, Fonseca E, Encinas F, Freitas F, Camargo DA, Coimbra RS, de Filippis I, Vicente AC. The invasive Neisseria meningitidis MenC CC103 from Brazil is characterized by an accessory gene repertoire. Sci Rep 2017; 7:1617. [PMID: 28487566 PMCID: PMC5431661 DOI: 10.1038/s41598-017-01671-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 03/30/2017] [Indexed: 12/21/2022] Open
Abstract
Neisseria meningitidis infections are a major issue for global health. The invasive MenC ST-103 clonal complex (CC103) has been the most prevalent in meningococcal outbreaks in Brazil, occurring also in several countries worldwide. Here we have analysed the population structure and accessory genome of MenC CC103 strains from a global perspective. An in-depth phylogenomic analysis revealed a lineage of N. meningitidis causing meningitis in Brazil and the United Kingdom. This lineage was also characterized as harbouring a particular accessory genome composed of CRISPR/Cas and restriction modification systems. This lineage was also characterized by a genomic island resembling an integrative and conjugative element. This island carried genes potentially associated with virulence and fitness. We propose this accessory gene repertoire could be contributing to the spatial-temporal persistence of the invasive MenC CC103 lineage.
Collapse
Affiliation(s)
- Michel Abanto Marin
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz (IOC) - Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil, 4365, Rio de Janeiro, Brazil.
| | - Erica Fonseca
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz (IOC) - Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil, 4365, Rio de Janeiro, Brazil
| | - Fernando Encinas
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz (IOC) - Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil, 4365, Rio de Janeiro, Brazil
| | - Fernanda Freitas
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz (IOC) - Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil, 4365, Rio de Janeiro, Brazil
| | | | - Roney Santos Coimbra
- Neurogenômica, Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG, Brazil
| | - Ivano de Filippis
- Instituto Nacional de Controle de Qualidade em Saúde (INCQS), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Ana Carolina Vicente
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz (IOC) - Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil, 4365, Rio de Janeiro, Brazil
| |
Collapse
|
50
|
Pérez-Ortega J, Rodríguez A, Ribes E, Tommassen J, Arenas J. Interstrain Cooperation in Meningococcal Biofilms: Role of Autotransporters NalP and AutA. Front Microbiol 2017; 8:434. [PMID: 28382026 PMCID: PMC5360712 DOI: 10.3389/fmicb.2017.00434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/02/2017] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis (Nm) and Neisseria lactamica (Nl) are commensal bacteria that live in the human nasopharynx, where they form microcolonies. In contrast to Nl, Nm occasionally causes blood and/or meningitis infection with often fatal consequences. Here, we studied interactions between neisserial strains during biofilm formation. Fluorescent strains were engineered and analyzed for growth in single- and dual-strain biofilms with confocal laser-scanning microscopy. Different strains of diverse Neisseria species formed microcolonies of different sizes and morphologies. Pair-wise combinations of two invasive Nm strains and one Nm carrier isolate showed that these strains can coexist in spite of the fact that they produce toxins to combat congeners. This lack of competition was even observed when the biofilms were formed under nutrient limitation and can be explained by the observation that the separate microcolonies within mixed biofilms are mostly lineage specific. However, these microcolonies showed different levels of interaction. The coexistence of two strains was also observed in mixed biofilms of Nm and Nl strains. Inactivation of the autotransporter NalP, which prevents the release of the heparin-binding antigen NHBA and the α-peptide of IgA protease from the cell surface, and/or the production of autotransporter AutA increased interactions between microcolonies, as evidenced by close contacts between microcolonies on the substratum. Qualitative and quantitative analysis revealed an altered spatial distribution of each strain in mixed biofilms with consequences for the biomass, biofilm architecture and bacterial viability depending on the synthesis of NalP and AutA, the expression of which is prone to phase variation. Being in a consortium resulted in some cases in commensalism and cooperative behavior, which promoted attachment to the substratum or increased survival, possibly as result of the shared use of the biofilm matrix. We hypothesize that Nm strains can cooperate during host colonization, but, possibly, the different capacities of the microcolonies of each strain to resist the host's defenses limits the long-term coexistence of strains in the host.
Collapse
Affiliation(s)
- Jesús Pérez-Ortega
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Antonio Rodríguez
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Eduardo Ribes
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jesús Arenas
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| |
Collapse
|