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Cianciotto NP. The type II secretion system as an underappreciated and understudied mediator of interbacterial antagonism. Infect Immun 2024; 92:e0020724. [PMID: 38980047 PMCID: PMC11320942 DOI: 10.1128/iai.00207-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024] Open
Abstract
Interbacterial antagonism involves all major phyla, occurs across the full range of ecological niches, and has great significance for the environment, clinical arena, and agricultural and industrial sectors. Though the earliest insight into interbacterial antagonism traces back to the discovery of antibiotics, a paradigm shift happened when it was learned that protein secretion systems (e.g., types VI and IV secretion systems) deliver toxic "effectors" against competitors. However, a link between interbacterial antagonism and the Gram-negative type II secretion system (T2SS), which exists in many pathogens and environmental species, is not evident in prior reviews on bacterial competition or T2SS function. A current examination of the literature revealed four examples of a T2SS or one of its known substrates having a bactericidal activity against a Gram-positive target or another Gram-negative. When further studied, the T2SS effectors proved to be peptidases that target the peptidoglycan of the competitor. There are also reports of various bacteriolytic enzymes occurring in the culture supernatants of some other Gram-negative species, and a link between these bactericidal activities and T2SS is suggested. Thus, a T2SS can be a mediator of interbacterial antagonism, and it is possible that many T2SSs have antibacterial outputs. Yet, at present, the T2SS remains relatively understudied for its role in interbacterial competition. Arguably, there is a need to analyze the T2SSs of a broader range of species for their role in interbacterial antagonism. Such investigation offers, among other things, a possible pathway toward developing new antimicrobials for treating disease.
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Affiliation(s)
- Nicholas P. Cianciotto
- Department of Microbiology-Immunology, Northwestern University School of Medicine, Chicago, Illinois, USA
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Cheng M, Chen R, Liao L. T2SS-peptidase XcpA associated with LasR evolutional phenotypic variations provides a fitness advantage to Pseudomonas aeruginosa PAO1. Front Microbiol 2023; 14:1256785. [PMID: 37954251 PMCID: PMC10637944 DOI: 10.3389/fmicb.2023.1256785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/06/2023] [Indexed: 11/14/2023] Open
Abstract
The Gram-negative opportunistic pathogen Pseudomonas aeruginosa possesses hierarchical quorum sensing (QS) systems. The intricate QS network of P. aeruginosa synchronizes a suite of virulence factors, contributing to the mortality and morbidity linked to the pathogenicity of this bacterium. Previous studies have revealed that variations in the lasR gene are frequently observed in chronic isolates of cystic fibrosis (CF). Specifically, LasRQ45stop was identified as a common variant among CF, lasR mutants during statistical analysis of the clinical lasR mutants in the database. In this study, we introduced LasRQ45stop into the chromosome of P. aeruginosa PAO1 through allelic replacement. The social traits of PAO1 LasRQ45stop were found to be equivalent to those of PAO1 LasR-null isolates. By co-evolving with the wild-type in caseinate broth, elastase-phenotypic-variability variants were derived from the LasRQ45stop subpopulation. Upon further examination of four LasRQ45stop sublines, we determined that the variation of T2SS-peptidase xcpA and mexT genes plays a pivotal role in the divergence of various phenotypes, including public goods elastase secretion and other pathogenicity traits. Furthermore, XcpA mutants demonstrated a fitness advantage compared to parent strains during co-evolution. Numerous phenotypic variations were associated with subline-specific genetic alterations. Collectively, these findings suggest that even within the same parental subline, there is ongoing microevolution of individual mutational trajectory diversity during adaptation.
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Affiliation(s)
- Mengmeng Cheng
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Ruiyi Chen
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - Lisheng Liao
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
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Zhang G, Li C, Li Y, Chen D, Li Z, Ouyang G, Wang Z. Discovery and Mechanism of Azatryptanthrin Derivatives as Novel Anti-Phytopathogenic Bacterial Agents for Potent Bactericide Candidates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:6288-6300. [PMID: 37040536 DOI: 10.1021/acs.jafc.3c01120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The natural alkaloids of tryptanthrin and their derivatives have a wide range of biological activities. In this research, four series of azatryptanthrin derivatives containing 4-aza/3-aza/2-aza/1-aza tryptanthrin were prepared by condensation cyclization reaction against plant pathogens to develop a new natural product-based bacterial pesticide. Compound 4Aza-8 displayed a remarkable growth inhibitory effect on pathogenic bacteria of Xanthomonas axonopodis pv. citri (Xac), Xanthomonas oryzae pv. Oryzae (Xoo), and Pseudomonas syringae pv. actinidiae (Psa) with the final corrected EC50 values of 0.312, 1.91, and 18.0 μg/mL, respectively, which were greatly superior than that of tryptanthrin (Tryp). Moreover, 4Aza-8 also showed effective therapeutic and protective activities in vivo on citrus canker. Further mechanism studies on Xac elucidated that compound 4Aza-8 was able to affect the growth curve of Xac and the formation of biofilm, cause severe shrinkage in bacterial morphology, increase reactive oxygen species levels, and induce apoptosis in bacterial cells. Quantitative analysis of differential protein profiles found that the major differences were mainly concentrated on the endometrial protein in the bacterial secretion system pathway, which blocked the membrane transport and affected the transfer of DNA to the host cell. In summary, these research results suggest that 4Aza-8 represents a promising anti-phytopathogenic-bacteria agent, which is worth being further investigated as a bactericide candidate.
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Affiliation(s)
- Guanglong Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Chengpeng Li
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
| | - Yan Li
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
| | - Danping Chen
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
| | - Zhuirui Li
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
| | - Guiping Ouyang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
| | - Zhenchao Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, Guizhou 550025, China
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Kim H, Kim ES, Cho JH, Song M, Cho JH, Kim S, Keum GB, Kwak J, Doo H, Pandey S, Park SH, Lee JH, Jung H, Hur TY, Kim JK, Oh KK, Kim HB, Lee JH. Exploring the Microbial Community and Functional Characteristics of the Livestock Feces Using the Whole Metagenome Shotgun Sequencing. J Microbiol Biotechnol 2023; 33:51-60. [PMID: 36517072 PMCID: PMC9896000 DOI: 10.4014/jmb.2209.09013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/17/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
The foodborne illness is the important public health concerns, and the livestock feces are known to be one of the major reservoirs of foodborne pathogens. Also, it was reported that 45.5% of foodborne illness outbreaks have been associated with the animal products contaminated with the livestock feces. In addition, it has been known that the persistence of a pathogens depends on many potential virulent factors including the various virulent genes. Therefore, the first step to understanding the public health risk of livestock feces is to identify and describe microbial communities and potential virulent genes that contribute to bacterial pathogenicity. We used the whole metagenome shotgun sequencing to evaluate the prevalence of foodborne pathogens and to characterize the virulence associated genes in pig and chicken feces. Our data showed that the relative abundance of potential foodborne pathogens, such as Bacillus cereus was higher in chickens than pigs at the species level while the relative abundance of foodborne pathogens including Campylobacter coli was only detected in pigs. Also, the microbial functional characteristics of livestock feces revealed that the gene families related to "Biofilm formation and quorum sensing" were highly enriched in pigs than chicken. Moreover, the variety of gene families associated with "Resistance to antibiotics and toxic compounds" were detected in both animals. These results will help us to prepare the scientific action plans to improve awareness and understanding of the public health risks of livestock feces.
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Affiliation(s)
- Hyeri Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Eun Sol Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jin Ho Cho
- Department of Animal Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Minho Song
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, Republic of Korea
| | - Jae Hyoung Cho
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Sheena Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Gi Beom Keum
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jinok Kwak
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Hyunok Doo
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Sriniwas Pandey
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Seung-Hwan Park
- Korean Collection for Type Cultures, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Republic of Korea
| | - Ju Huck Lee
- Korean Collection for Type Cultures, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Republic of Korea
| | - Hyunjung Jung
- Animal Nutrition & Physiology Division, National Institute of Animal Science, RDA, Wanju, Republic of Korea
| | - Tai Young Hur
- Animal Diseases & Health Division, National Institute of Animal Science, RDA, Wanju, Republic of Korea
| | - Jae-Kyung Kim
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Kwang Kyo Oh
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Hyeun Bum Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea,Corresponding authors H.B. Kim Phone: +82-41-550-3653 E-mail:
| | - Ju-Hoon Lee
- Department of Food Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea,J.H. Lee Phone: +82-2-880-4854 E-mail:
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In through the Out Door: A Functional Virulence Factor Secretion System Is Necessary for Phage Infection in Ralstonia solanacearum. mBio 2022; 13:e0147522. [PMID: 36314808 PMCID: PMC9765573 DOI: 10.1128/mbio.01475-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023] Open
Abstract
Bacteriophages put intense selective pressure on microbes, which must evolve diverse resistance mechanisms to survive continuous phage attacks. We used a library of spontaneous Bacteriophage Insensitive Mutants (BIMs) to learn how the plant pathogen Ralstonia solanacearum resists the virulent lytic podophage phiAP1. Phenotypic and genetic characterization of many BIMs suggested that the R. solanacearum Type II Secretion System (T2SS) plays a key role in phiAP1 infection. Using precision engineered mutations that permit T2SS assembly but either inactivate the T2SS GspE ATPase or sterically block the secretion portal, we demonstrated that phiAP1 needs a functional T2SS to infect R. solanacearum. This distinction between the static presence of T2SS components, which is necessary but not sufficient for phage sensitivity, and the energized and functional T2SS, which is sufficient, implies that binding interactions alone cannot explain the role of the T2SS in phiAP1 infection. Rather, our results imply that some aspect of the resetting of the T2SS, such as disassembly of the pseudopilus, is required. Because R. solanacearum secretes multiple virulence factors via the T2SS, acquiring resistance to phiAP1 also dramatically reduced R. solanacearum virulence on tomato plants. This acute fitness trade-off suggests this group of phages may be a sustainable control strategy for an important crop disease. IMPORTANCE Ralstonia solanacearum is a destructive plant pathogen that causes lethal bacterial wilt disease in hundreds of diverse plant hosts, including many economically important crops. Phages that kill R. solanacearum could offer effective and environmentally friendly wilt disease control, but only if the bacterium cannot easily evolve resistance. Encouragingly, most R. solanacearum mutants resistant to the virulent lytic phage phiAP1 no longer secreted multiple virulence factors and had much reduced fitness and virulence on tomato plants. Further analysis revealed that phage phiAP1 needs a functional type II secretion system to infect R. solanacearum, suggesting this podophage uses a novel infection mechanism.
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Type IV Pili Are a Critical Virulence Factor in Clinical Isolates of Paenibacillus thiaminolyticus. mBio 2022; 13:e0268822. [PMID: 36374038 PMCID: PMC9765702 DOI: 10.1128/mbio.02688-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Hydrocephalus, the leading indication for childhood neurosurgery worldwide, is particularly prevalent in low- and middle-income countries. Hydrocephalus preceded by an infection, or postinfectious hydrocephalus, accounts for up to 60% of hydrocephalus in these areas. Since many children with hydrocephalus suffer poor long-term outcomes despite surgical intervention, prevention of hydrocephalus remains paramount. Our previous studies implicated a novel bacterial pathogen, Paenibacillus thiaminolyticus, as a causal agent of neonatal sepsis and postinfectious hydrocephalus in Uganda. Here, we report the isolation of three P. thiaminolyticus strains, Mbale, Mbale2, and Mbale3, from patients with postinfectious hydrocephalus. We constructed complete genome assemblies of the clinical isolates as well as the nonpathogenic P. thiaminolyticus reference strain and performed comparative genomic and proteomic analyses to identify potential virulence factors. All three isolates carry a unique beta-lactamase gene, and two of the three isolates exhibit resistance in culture to the beta-lactam antibiotics penicillin and ampicillin. In addition, a cluster of genes carried on a mobile genetic element that encodes a putative type IV pilus operon is present in all three clinical isolates but absent in the reference strain. CRISPR-mediated deletion of the gene cluster substantially reduced the virulence of the Mbale strain in mice. Comparative proteogenomic analysis identified various additional potential virulence factors likely acquired on mobile genetic elements in the virulent strains. These results provide insight into the emergence of virulence in P. thiaminolyticus and suggest avenues for the diagnosis and treatment of this novel bacterial pathogen. IMPORTANCE Postinfectious hydrocephalus, a devastating sequela of neonatal infection, is associated with increased childhood mortality and morbidity. A novel bacterial pathogen, Paenibacillus thiaminolyticus, is highly associated with postinfectious hydrocephalus in an African cohort. Whole-genome sequencing, RNA sequencing, and proteomics of clinical isolates and a reference strain in combination with CRISPR editing identified type IV pili as a critical virulence factor for P. thiaminolyticus infection. Acquisition of a type IV pilus-encoding mobile genetic element critically contributed to converting a nonpathogenic strain of P. thiaminolyticus into a pathogen capable of causing devastating diseases. Given the widespread presence of type IV pilus in pathogens, the presence of the type IV pilus operon could serve as a diagnostic and therapeutic target in P. thiaminolyticus and related bacteria.
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Zhang D, Wang Z, Yamamoto N, Wang M, Yi X, Li P, Lin R, Nasimi Z, Okada K, Mochida K, Noutoshi Y, Zheng A. Secreted Glycosyltransferase RsIA_GT of Rhizoctonia solani AG-1 IA Inhibits Defense Responses in Nicotiana benthamiana. Pathogens 2022; 11:pathogens11091026. [PMID: 36145458 PMCID: PMC9501517 DOI: 10.3390/pathogens11091026] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 11/16/2022] Open
Abstract
Anastomosis group AG-1 IA of Rhizoctonia solani Khün has a wide host range and threatens crop production. Various glycosyltransferases secreted by phytopathogenic fungi play an essential role in pathogenicity. Previously, we identified a glycosyltransferase RsIA_GT (AG11A_09161) as a secreted protein-encoding gene of R. solani AG-1 IA, whose expression levels increased during infection in rice. In this study, we further characterized the virulence function of RsIA_GT. It is conserved not only in Basidiomycota, including multiple anastomosis groups of R. solani, but also in other primary fungal taxonomic categories. RsIA_GT possesses a signal peptide (SP) for protein secretion, and its functionality was proven using yeast and Nicotiana benthamiana. The SP-truncated form of RsIA_GT (RsIA_GT(ΔS)) expressed in Escherichia coli-induced lesion-like phenotype in rice leaves when applied to punched leaves. However, Agrobacterium-mediated transient expressions of both the full-length RsIA_GT and RsIA_GT(ΔS) did not induce cell death in N. benthamiana leaves. Instead, only RsIA_GT(ΔS) suppressed the cell death induced by two reference cell death factors BAX and INF1 in N.benthamiana. RsIA_GT(ΔS)R154A D168A D170A, a mutant RsIA_GT(ΔS) for the glycosyltransferase catalytic domain, still suppressed the BAX- or INF1-induced cell death, suggesting that the cell death suppression activity of RsIA_GT(ΔS) would be independent from its enzymatic activity. RsIA_GT(ΔS) also suppressed the H2O2 production and callose deposition and showed an effect on the induction of defense genes associated with the expression of BAX and INF1. The transient expression of RsIA_GT(ΔS) in N. benthamiana enhanced the lesion area caused by R. solani AG-1 IA. The secreted glycosyltransferase, RsIA_GT, of R. solani AG-1 IA is likely to have a dual role in virulence inside and outside of host cells.
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Affiliation(s)
- Danhua Zhang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhaoyilin Wang
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Naoki Yamamoto
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingyue Wang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaoqun Yi
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Ping Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Runmao Lin
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zohreh Nasimi
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Kazunori Okada
- Agro-Biotechnology Research Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keiichi Mochida
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, Yokohama 2300045, Japan
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama 2300045, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama 2440813, Japan
- School of Information and Data Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
| | - Aiping Zheng
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Chengdu 611130, China
- Correspondence:
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Xu S, Zhang Z, Xie X, Shi Y, Chai A, Fan T, Li B, Li L. Comparative genomics provides insights into the potential biocontrol mechanism of two Lysobacter enzymogenes strains with distinct antagonistic activities. Front Microbiol 2022; 13:966986. [PMID: 36033849 PMCID: PMC9410377 DOI: 10.3389/fmicb.2022.966986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Lysobacter enzymogenes has been applied as an abundant beneficial microorganism to control plant disease; however, most L. enzymogenes strains have been mainly reported to control fungal diseases, not bacterial diseases. In this study, two L. enzymogenes strains were characterized, of which CX03 displayed a broad spectrum of antagonistic activities toward multiple bacteria, while CX06 exhibited a broad spectrum of antagonistic activities toward diverse fungi and oomycete, and the whole genomes of the two strains were sequenced and compared. The genome annotation showed that the CX03 genome comprised a 5,947,018 bp circular chromosome, while strain CX06 comprised a circular 6,206,196 bp chromosome. Phylogenetic analysis revealed that CX03 had a closer genetic relationship with L. enzymogenes ATCC29487T and M497-1, while CX06 was highly similar to L. enzymogenes C3. Functional gene annotation analyses of the two L. enzymogenes strains showed that many genes or gene clusters associated with the biosynthesis of different secondary metabolites were found in strains CX03 and CX06, which may be responsible for the different antagonistic activities against diverse plant pathogens. Moreover, comparative genomic analysis revealed the difference in bacterial secretory systems between L. enzymogenes strains CX03 and CX06. In addition, numerous conserved genes related to siderophore biosynthesis, quorum sensing, two-component systems, flagellar biosynthesis and chemotaxis were also identified in the genomes of strains CX03 and CX06. Most reported L. enzymogenes strains were proven mainly to suppress fungi, while CX03 exhibited direct inhibitory activities toward plant bacterial pathogens and showed an obvious role in managing bacterial disease. This study provides a novel understanding of the biocontrol mechanisms of L. enzymogenes, and reveals great potential for its application in plant disease control.
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Affiliation(s)
| | | | | | | | | | | | - Baoju Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lei Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
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Filloux A. Bacterial protein secretion systems: Game of types. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35536734 DOI: 10.1099/mic.0.001193] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein trafficking across the bacterial envelope is a process that contributes to the organisation and integrity of the cell. It is the foundation for establishing contact and exchange between the environment and the cytosol. It helps cells to communicate with one another, whether they establish symbiotic or competitive behaviours. It is instrumental for pathogenesis and for bacteria to subvert the host immune response. Understanding the formation of envelope conduits and the manifold strategies employed for moving macromolecules across these channels is a fascinating playground. The diversity of the nanomachines involved in this process logically resulted in an attempt to classify them, which is where the protein secretion system types emerged. As our knowledge grew, so did the number of types, and their rightful nomenclature started to be questioned. While this may seem a semantic or philosophical issue, it also reflects scientific rigour when it comes to assimilating findings into textbooks and science history. Here I give an overview on bacterial protein secretion systems, their history, their nomenclature and why it can be misleading for newcomers in the field. Note that I do not try to suggest a new nomenclature. Instead, I explore the reasons why naming could have escaped our control and I try to reiterate basic concepts that underlie protein trafficking cross membranes.
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Affiliation(s)
- Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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Xu S, Zhao Y, Peng Y, Shi Y, Xie X, Chai A, Li B, Li L. Comparative Genomics Assisted Functional Characterization of Rahnella aceris ZF458 as a Novel Plant Growth Promoting Rhizobacterium. Front Microbiol 2022; 13:850084. [PMID: 35444623 PMCID: PMC9015054 DOI: 10.3389/fmicb.2022.850084] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/24/2022] [Indexed: 11/25/2022] Open
Abstract
Many Rahnella strains have been widely described as plant growth-promoting rhizobacteria with the potential to benefit plant growth and protect plants from pathogens. R. aceris ZF458 is a beneficial plant bacterium isolated from swamp soil with the potential for biocontrol. Strain ZF458 has shown broad-spectrum antagonistic activities against a variety of plant pathogens and exhibited a dramatic effect on controlling Agrobacterium tumefaciens in sunflowers. The R. aceris ZF458 genome sequence contained a 4,861,340-bp circular chromosome and two plasmids, with an average G + C content of 52.20%. Phylogenetic analysis demonstrated that R. aceris ZF458 was closely related to R. aceris SAP-19. Genome annotation and comparative genomics identified the conservation and specificity of large numbers of genes associated with nitrogen fixation, plant growth hormone production, organic acid biosynthesis and pyrroloquinoline quinone production that specific to benefiting plants in strain ZF458. In addition, numerous conserved genes associated with environmental adaption, including the bacterial secretion system, selenium metabolism, two-component system, flagella biosynthesis, chemotaxis, and acid resistance, were also identified in the ZF458 genome. Overall, this was the first study to systematically analyze the genes linked with plant growth promotion and environmental adaption in R. aceris. The aim of this study was to derive genomic information that would provide an in-depth insight of the mechanisms of plant growth-promoting rhizobacteria, and could be further exploited to improve the application of R. aceris ZF458 in the agriculture field.
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Affiliation(s)
- Shuai Xu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yurong Zhao
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yue Peng
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yanxia Shi
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xuewen Xie
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ali Chai
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baoju Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lei Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
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Proteomic analysis of the periodontal pathogen Prevotella intermedia secretomes in biofilm and planktonic lifestyles. Sci Rep 2022; 12:5636. [PMID: 35379855 PMCID: PMC8980031 DOI: 10.1038/s41598-022-09085-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/04/2022] [Indexed: 11/10/2022] Open
Abstract
Prevotella intermedia is an important species associated with periodontitis. Despite the remarkable clinical significance, little is known about the molecular basis for its virulence. The aim of this study was to characterize the secretome of P. intermedia in biofilm and planktonic life mode. The biofilm secretome showed 109 proteins while the planktonic secretome showed 136 proteins. The biofilm and the planktonic secretomes contained 17 and 33 signal-peptide bearing proteins, 13 and 18 lipoproteins, respectively. Superoxide reductase, sensor histidine kinase, C40 family peptidase, elongation factor Tu, threonine synthase etc. were unique to biofilm. Of the ~ 30 proteins with predicted virulence potential from biofilm and planktonic secretomes, only 6 were common between the two groups, implying large differences between biofilm and planktonic modes of P. intermedia. From Gene Ontology biofilm secretome displayed a markedly higher percent proteins compared to planktonic secretome in terms of cellular amino acid metabolic process, nitrogen compound metabolic process etc. Inflammatory cytokine profile analysis revealed that only the biofilm secretome, not the planktonic one, induced important cytokines such as MIP-1α/MIP-1β, IL-1β, and IL-8. In conclusion, the revealed differences in the protein profiles of P. intermedia biofilm and planktonic secretomes may trigger further questions about molecular mechanisms how this species exerts its virulence potential in the oral cavity.
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Molecular Investigation of Outer Membrane Channel Genes Among Multidrug Resistance Clinical Pseudomonas Aeruginosa Isolates. Rep Biochem Mol Biol 2022; 11:102-110. [PMID: 35765529 PMCID: PMC9208561 DOI: 10.52547/rbmb.11.1.102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/19/2021] [Indexed: 01/11/2023]
Abstract
Background Multidrug resistance Pseudomonas aeruginosa (MDRPA) is most important issue in healthcare setting. It can secrete many virulence effector proteins via its secretion system type (T1SS-T6SS). They are using them as conductor for delivering the effector proteins outside to begins harmful effect on host cell increasing pathogenicity, competition against other microorganism and nutrient acquisition. Methods The study include investigation of 50 isolates of MDRPA for transport secretion system and resistance for antibiotics. Molecular diagnosis using P. aeruginosa specific primer pairs, investigation of AprF, HasF, XcpQ, HxcQ, PscC, CdrB, CupB3, and Hcp using specific primer pairs by PCR were also performed. Results The results revealed high resistance to beta lactam antibiotics (78% for ceftazidime, 78% for cefepime and 46% for piperacillin) can indicate possessing of isolates for beta lactamases and this confirmed by dropping resistance to piperacillin to 16% when combined with tazobactam. Also, the results shown the ability of MDRPA for pyocyanin biosynthesis using the system of genes. Conclusion The current study conclude that all isolates of P. aeruginosa were highly virulent due to their possessing of all transport secretion system to deliver different effector proteins with possible harmful effects of these proteins.
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Mallick T, Mishra R, Mohanty S, Joshi RK. Genome Wide Analysis of the Potato Soft Rot Pathogen Pectobacterium carotovorum Strain ICMP 5702 to Predict Novel Insights into Its Genetic Features. THE PLANT PATHOLOGY JOURNAL 2022; 38:102-114. [PMID: 35385916 PMCID: PMC9343900 DOI: 10.5423/ppj.oa.12.2021.0190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Pectobacterium carotovorum subsp. carotovorum (Pcc) is a gram-negative, broad host range bacterial pathogen which causes soft rot disease in potatoes as well as other vegetables worldwide. While Pectobacterium infection relies on the production of major cell wall degrading enzymes, other virulence factors and the mechanism of genetic adaptation of this pathogen is not yet clear. In the present study, we have performed an in-depth genome-wide characterization of Pcc strain ICMP5702 isolated from potato and compared it with other pathogenic bacteria from the Pectobacterium genus to identify key virulent determinants. The draft genome of Pcc ICMP5702 contains 4,774,457 bp with a G + C content of 51.90% and 4,520 open reading frames. Genome annotation revealed prominent genes encoding key virulence factors such as plant cell wall degrading enzymes, flagella-based motility, phage proteins, cell membrane structures, and secretion systems. Whereas, a majority of determinants were conserved among the Pectobacterium strains, few notable genes encoding AvrE-family type III secretion system effectors, pectate lyase and metalloprotease in addition to the CRISPR-Cas based adaptive immune system were uniquely represented. Overall, the information generated through this study will contribute to decipher the mechanism of infection and adaptive immunity in Pcc.
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Affiliation(s)
- Tista Mallick
- Department of Biotechnology, Rama Devi Women’s University, Bhubaneswar 751022, Odisha, India
| | - Rukmini Mishra
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar 751022, Odisha, India
| | - Sasmita Mohanty
- Department of Biotechnology, Rama Devi Women’s University, Bhubaneswar 751022, Odisha, India
| | - Raj Kumar Joshi
- Department of Biotechnology, Rama Devi Women’s University, Bhubaneswar 751022, Odisha, India
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Dadashi M, Chen L, Nasimian A, Ghavami S, Duan K. Putative RNA Ligase RtcB Affects the Switch between T6SS and T3SS in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:12561. [PMID: 34830443 PMCID: PMC8619066 DOI: 10.3390/ijms222212561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 01/22/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is a significant cause of infection in immunocompromised individuals, cystic fibrosis patients, and burn victims. To benefit its survival, the bacterium adapt to either a motile or sessile lifestyle when infecting the host. The motile bacterium has an often activated type III secretion system (T3SS), which is virulent to the host, whereas the sessile bacterium harbors an active T6SS and lives in biofilms. Regulatory pathways involving Gac-Rsm or secondary messengers such as c-di-GMP determine which lifestyle is favorable for P. aeruginosa. Here, we introduce the RNA binding protein RtcB as a modulator of the switch between motile and sessile bacterial lifestyles. Using the wild-type P. aeruginosa PAO1, and a retS mutant PAO1(∆retS) in which T3SS is repressed and T6SS active, we show that deleting rtcB led to simultaneous expression of T3SS and T6SS in both PAO1(∆rtcB) and PAO1(∆rtcB∆retS). The deletion of rtcB also increased biofilm formation in PAO1(∆rtcB) and restored the motility of PAO1(∆rtcB∆retS). RNA-sequencing data suggested RtcB as a global modulator affecting multiple virulence factors, including bacterial secretion systems. Competitive killing and infection assays showed that the three T6SS systems (H1, H2, and H3) in PAO1(∆rtcB) were activated into a functional syringe, and could compete with Escherichia coli and effectively infect lettuce. Western blotting and RT-PCR results showed that RtcB probably exerted its function through RsmA in PAO1(∆rtcB∆retS). Quantification of c-di-GMP showed an elevated intracellular levels in PAO1(∆rtcB), which likely drove the switch between T6SS and T3SS, and contributed to the altered phenotypes and characteristics observed. Our data demonstrate a pivotal role of RtcB in the virulence of P. aeruginosa by controlling multiple virulence determinants, such as biofilm formation, motility, pyocyanin production, T3SS, and T6SS secretion systems towards eukaryotic and prokaryotic cells. These findings suggest RtcB as a potential target for controlling P. aeruginosa colonization, establishment, and pathogenicity.
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Affiliation(s)
- Maryam Dadashi
- Department of Oral Biology, Rady Faculty of Health Sciences, Dr. Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, MB R3E 0W2, Canada;
| | - Lin Chen
- College of Life Sciences, Northwest University, Xi’an 710069, China;
| | - Ahmad Nasimian
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 0W2, Canada; (A.N.); (S.G.)
| | - Saeid Ghavami
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 0W2, Canada; (A.N.); (S.G.)
| | - Kangmin Duan
- Department of Oral Biology, Rady Faculty of Health Sciences, Dr. Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, MB R3E 0W2, Canada;
- Department of Medical Microbiology and Infectious Disease, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
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Boluk G, Arizala D, Dobhal S, Zhang J, Hu J, Alvarez AM, Arif M. Genomic and Phenotypic Biology of Novel Strains of Dickeya zeae Isolated From Pineapple and Taro in Hawaii: Insights Into Genome Plasticity, Pathogenicity, and Virulence Determinants. FRONTIERS IN PLANT SCIENCE 2021; 12:663851. [PMID: 34456933 PMCID: PMC8386352 DOI: 10.3389/fpls.2021.663851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/30/2021] [Indexed: 05/04/2023]
Abstract
Dickeya zeae, a bacterial plant pathogen of the family Pectobacteriaceae, is responsible for a wide range of diseases on potato, maize, rice, banana, pineapple, taro, and ornamentals and significantly reduces crop production. D. zeae causes the soft rot of taro (Colocasia esculenta) and the heart rot of pineapple (Ananas comosus). In this study, we used Pacific Biosciences single-molecule real-time (SMRT) sequencing to sequence two high-quality complete genomes of novel strains of D. zeae: PL65 (size: 4.74997 MB; depth: 701x; GC: 53.6%) and A5410 (size: 4.7792 MB; depth: 558x; GC: 53.5%) isolated from economically important Hawaiian crops, taro, and pineapple, respectively. Additional complete genomes of D. zeae representing three additional hosts (philodendron, rice, and banana) and other species used for a taxonomic comparison were retrieved from the NCBI GenBank genome database. Genomic analyses indicated the truncated type III and IV secretion systems (T3SS and T4SS) in the taro strain, which only harbored one and two genes of T3SS and T4SS, respectively, and showed high heterogeneity in the type VI secretion system (T6SS). Unlike strain EC1, which was isolated from rice and recently reclassified as D. oryzae, neither the genome PL65 nor A5410 harbors the zeamine biosynthesis gene cluster, which plays a key role in virulence of other Dickeya species. The percentages of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the two genomes were 94.47 and 57.00, respectively. In this study, we compared the major virulence factors [plant cell wall-degrading extracellular enzymes and protease (Prt)] produced by D. zeae strains and evaluated the virulence on taro corms and pineapple leaves. Both strains produced Prts, pectate lyases (Pels), and cellulases but no significant quantitative differences were observed (p > 0.05) between the strains. All the strains produced symptoms on taro corms and pineapple leaves, but the strain PL65 produced symptoms more rapidly than others. Our study highlights the genetic constituents of pathogenicity determinants and genomic heterogeneity that will help to understand the virulence mechanisms and aggressiveness of this plant pathogen.
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Affiliation(s)
- Gamze Boluk
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Dario Arizala
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Shefali Dobhal
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Jingxin Zhang
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - John Hu
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Anne M. Alvarez
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Mohammad Arif
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United States
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Fernandes C, Martins L, Teixeira M, Blom J, Pothier JF, Fonseca NA, Tavares F. Comparative Genomics of Xanthomonas euroxanthea and Xanthomonas arboricola pv. juglandis Strains Isolated from a Single Walnut Host Tree. Microorganisms 2021; 9:microorganisms9030624. [PMID: 33803052 PMCID: PMC8003016 DOI: 10.3390/microorganisms9030624] [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: 02/16/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 11/20/2022] Open
Abstract
The recent report of distinct Xanthomonas lineages of Xanthomonas arboricola pv. juglandis and Xanthomonas euroxanthea within the same walnut tree revealed that this consortium of walnut-associated Xanthomonas includes both pathogenic and nonpathogenic strains. As the implications of this co-colonization are still poorly understood, in order to unveil niche-specific adaptations, the genomes of three X. euroxanthea strains (CPBF 367, CPBF 424T, and CPBF 426) and of an X. arboricola pv. juglandis strain (CPBF 427) isolated from a single walnut tree in Loures (Portugal) were sequenced with two different technologies, Illumina and Nanopore, to provide consistent single scaffold chromosomal sequences. General genomic features showed that CPBF 427 has a genome similar to other X. arboricola pv. juglandis strains, regarding its size, number, and content of CDSs, while X. euroxanthea strains show a reduction regarding these features comparatively to X. arboricola pv. juglandis strains. Whole genome comparisons revealed remarkable genomic differences between X. arboricola pv. juglandis and X. euroxanthea strains, which translates into different pathogenicity and virulence features, namely regarding type 3 secretion system and its effectors and other secretory systems, chemotaxis-related proteins, and extracellular enzymes. Altogether, the distinct genomic repertoire of X. euroxanthea may be particularly useful to address pathogenicity emergence and evolution in walnut-associated Xanthomonas.
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Affiliation(s)
- Camila Fernandes
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; (L.M.); (M.T.); (N.A.F.)
- FCUP—Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
- Unidade Estratégica de Investigação e Serviços de Sistemas Agrários e Florestais e Sanidade Vegetal, INIAV, Avenida da República, Quinta do Marquês, 2780-157 Oeiras, Portugal
- Correspondence: (C.F.); (F.T.)
| | - Leonor Martins
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; (L.M.); (M.T.); (N.A.F.)
- FCUP—Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Miguel Teixeira
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; (L.M.); (M.T.); (N.A.F.)
- FCUP—Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig University Giessen, Ludwigstraße 23, 35390 Giessen, Germany;
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research Group, Institute for Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland;
| | - Nuno A. Fonseca
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; (L.M.); (M.T.); (N.A.F.)
| | - Fernando Tavares
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; (L.M.); (M.T.); (N.A.F.)
- FCUP—Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
- Correspondence: (C.F.); (F.T.)
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Yegorov Y, Sendersky E, Zilberman S, Nagar E, Waldman Ben-Asher H, Shimoni E, Simkovsky R, Golden SS, LiWang A, Schwarz R. A Cyanobacterial Component Required for Pilus Biogenesis Affects the Exoproteome. mBio 2021; 12:e03674-20. [PMID: 33727363 PMCID: PMC8092324 DOI: 10.1128/mbio.03674-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/02/2021] [Indexed: 12/23/2022] Open
Abstract
Protein secretion as well as the assembly of bacterial motility appendages are central processes that substantially contribute to fitness and survival. This study highlights distinctive features of the mechanism that serves these functions in cyanobacteria, which are globally prevalent photosynthetic prokaryotes that significantly contribute to primary production. Our studies of biofilm development in the cyanobacterium Synechococcus elongatus uncovered a novel component required for the biofilm self-suppression mechanism that operates in this organism. This protein, which is annotated as "hypothetical," is denoted EbsA (essential for biofilm self-suppression A) here. EbsA homologs are highly conserved and widespread in diverse cyanobacteria but are not found outside this clade. We revealed a tripartite complex of EbsA, Hfq, and the ATPase homolog PilB (formerly called T2SE) and demonstrated that each of these components is required for the assembly of the hairlike type IV pili (T4P) appendages, for DNA competence, and affects the exoproteome in addition to its role in biofilm self-suppression. These data are consistent with bioinformatics analyses that reveal only a single set of genes in S. elongatus to serve pilus assembly or protein secretion; we suggest that a single complex is involved in both processes. A phenotype resulting from the impairment of the EbsA homolog in the cyanobacterium Synechocystis sp. strain PCC 6803 implies that this feature is a general cyanobacterial trait. Moreover, comparative exoproteome analyses of wild-type and mutant strains of S. elongatus suggest that EbsA and Hfq affect the exoproteome via a process that is independent of PilB, in addition to their involvement in a T4P/secretion machinery.IMPORTANCE Cyanobacteria, environmentally prevalent photosynthetic prokaryotes, contribute ∼25% of global primary production. Cyanobacterial biofilms elicit biofouling, thus leading to substantial economic losses; however, these microbial assemblages can also be beneficial, e.g., in wastewater purification processes and for biofuel production. Mechanistic aspects of cyanobacterial biofilm development were long overlooked, and genetic and molecular information emerged only in recent years. The importance of this study is 2-fold. First, it identifies novel components of cyanobacterial biofilm regulation, thus contributing to the knowledge of these processes and paving the way for inhibiting detrimental biofilms or promoting beneficial ones. Second, the data suggest that cyanobacteria may employ the same complex for the assembly of the motility appendages, type 4 pili, and protein secretion. A shared pathway was previously shown in only a few cases of heterotrophic bacteria, whereas numerous studies demonstrated distinct systems for these functions. Thus, our study broadens the understanding of pilus assembly/secretion in diverse bacteria and furthers the aim of controlling the formation of cyanobacterial biofilms.
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Affiliation(s)
- Yevgeni Yegorov
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Shaul Zilberman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Elad Nagar
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Hiba Waldman Ben-Asher
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Susan S Golden
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, California, USA
| | - Andy LiWang
- Center for Circadian Biology, University of California, San Diego, La Jolla, California, USA
- Department of Chemistry and Chemical Biology, University of California, Merced, Merced, California, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, California, USA
- Health Sciences Research Institute, University of California, Merced, Merced, California, USA
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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18
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Secrete or perish: The role of secretion systems in Xanthomonas biology. Comput Struct Biotechnol J 2020; 19:279-302. [PMID: 33425257 PMCID: PMC7777525 DOI: 10.1016/j.csbj.2020.12.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/13/2020] [Accepted: 12/13/2020] [Indexed: 12/22/2022] Open
Abstract
Bacteria of the Xanthomonas genus are mainly phytopathogens of a large variety of crops of economic importance worldwide. Xanthomonas spp. rely on an arsenal of protein effectors, toxins and adhesins to adapt to the environment, compete with other microorganisms and colonize plant hosts, often causing disease. These protein effectors are mainly delivered to their targets by the action of bacterial secretion systems, dedicated multiprotein complexes that translocate proteins to the extracellular environment or directly into eukaryotic and prokaryotic cells. Type I to type VI secretion systems have been identified in Xanthomonas genomes. Recent studies have unravelled the diverse roles played by the distinct types of secretion systems in adaptation and virulence in xanthomonads, unveiling new aspects of their biology. In addition, genome sequence information from a wide range of Xanthomonas species and pathovars have become available recently, uncovering a heterogeneous distribution of the distinct families of secretion systems within the genus. In this review, we describe the architecture and mode of action of bacterial type I to type VI secretion systems and the distribution and functions associated with these important nanoweapons within the Xanthomonas genus.
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Llanos Salinas SP, Castillo Sánchez LO, Castañeda Miranda G, Rodríguez Reyes EA, Ordoñez López L, Mena Bañuelos R, Alcaraz Sosa LE, Núñez Carrera MG, José Manuel RO, Carmona Gasca CA, Matsunaga J, Haake DA, Candanosa Aranda IE, de la Peña-Moctezuma A. GspD, The Type II Secretion System Secretin of Leptospira, Protects Hamsters against Lethal Infection with a Virulent L. interrogans Isolate. Vaccines (Basel) 2020; 8:vaccines8040759. [PMID: 33327369 PMCID: PMC7768463 DOI: 10.3390/vaccines8040759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/28/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022] Open
Abstract
The wide variety of pathogenic Leptospira serovars and the weak protection offered by the available vaccines encourage the search for protective immunogens against leptospirosis. We found that the secretin GspD of the type II secretion system (T2S) of Leptospira interrogans serovar Canicola was highly conserved amongst pathogenic serovars and was expressed in vivo during infection, as shown by immunohistochemistry. Convalescent sera of hamsters, dogs, and cows showed the presence of IgG antibodies, recognizing a recombinant version of this protein expressed in Escherichia coli (rGspDLC) in Western blot assays. In a pilot vaccination study, a group of eight hamsters was immunized on days zero and 14 with 50 µg of rGspDLC mixed with Freund’s incomplete adjuvant (FIA). On day 28 of the study, 1,000 LD50 (Lethal Dose 50%) of a virulent strain of Leptospira interrogans serovar Canicola (LOCaS46) were inoculated by an intraoral submucosal route (IOSM). Seventy-five percent protection against disease (p = 0.017573, Fisher’s exact test) and 50% protection against infection were observed in this group of vaccinated hamsters. In contrast, 85% of non-vaccinated hamsters died six to nine days after the challenge. These results suggest the potential usefulness of the T2S secretin GspD of Leptospira as a protective recombinant vaccine against leptospirosis.
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Affiliation(s)
- Samantha Paulina Llanos Salinas
- Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico; (S.P.L.S.); (G.C.M.); (I.E.C.A.)
| | - Luz Olivia Castillo Sánchez
- Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Nayarit, Tepic 63155, Mexico; (L.O.C.S.); (C.A.C.G.)
| | - Giselle Castañeda Miranda
- Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico; (S.P.L.S.); (G.C.M.); (I.E.C.A.)
| | | | - Liliana Ordoñez López
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico; (L.O.L.); (R.M.B.); (R.O.J.M.)
| | - Rodrigo Mena Bañuelos
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico; (L.O.L.); (R.M.B.); (R.O.J.M.)
| | - Luz Elena Alcaraz Sosa
- Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana, Tlalpan 14387, Mexico;
| | - María Guadalupe Núñez Carrera
- Facultad de Medicina Veterinaria y Zootecnia, Benemérita Universidad Autónoma de Puebla, Centro Histórico 72000, Mexico;
| | - Ramírez Ortega José Manuel
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico; (L.O.L.); (R.M.B.); (R.O.J.M.)
| | - Carlos Alfredo Carmona Gasca
- Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Nayarit, Tepic 63155, Mexico; (L.O.C.S.); (C.A.C.G.)
| | - James Matsunaga
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA; (J.M.); (D.A.H.)
| | - David A. Haake
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA; (J.M.); (D.A.H.)
| | - Irma Eugenia Candanosa Aranda
- Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico; (S.P.L.S.); (G.C.M.); (I.E.C.A.)
| | - Alejandro de la Peña-Moctezuma
- Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico; (S.P.L.S.); (G.C.M.); (I.E.C.A.)
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico; (L.O.L.); (R.M.B.); (R.O.J.M.)
- Correspondence: ; Tel.:+52-414-291-8100
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Perlaza-Jiménez L, Wu Q, Torres VVL, Zhang X, Li J, Rocker A, Lithgow T, Zhou T, Vijaykrishna D. Forensic genomics of a novel Klebsiella quasipneumoniae type from a neonatal intensive care unit in China reveals patterns of colonization, evolution and epidemiology. Microb Genom 2020; 6:mgen000433. [PMID: 32931409 PMCID: PMC7660260 DOI: 10.1099/mgen.0.000433] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
During March 2017, a neonatal patient with severe diarrhoea subsequently developed septicaemia and died, with Klebsiella isolated as the causative microorganism. In keeping with infection control protocols, the coincident illness of an attending staff member and three other neonates with Klebsiella infection triggered an outbreak response, leading to microbiological assessment of isolates collected from the staff member and all 21 co-housed neonates. Multilocus sequence typing and genomic sequencing identified that the isolates from the 21 neonates were of a new Klebsiella sequence type, ST2727, and taxonomically belonged to K. quasipneumoniae subsp. similipneumoniae (formerly referred to as KpIIB). Genomic characterization showed that the isolated ST2727 strains had diverged from other K. quasipneumoniae subsp. similipneumoniae strains at least 90 years ago, whereas the neonatal samples were highly similar with a genomic divergence of 3.6 months. There was no relationship to the Klebsiella isolate from the staff member. This demonstrates that no transmission occurred from staff to patient or between patients. Rather, the data suggest that ST2727 colonized each neonate from a common hospital source. Sequence-based analysis of the genomes revealed several genes for antimicrobial resistance and some virulence features, but suggest that ST2727 is neither extremely-drug resistant nor hypervirulent. Our results highlight the clinical significance and genomic properties of ST2727 and urge genome-based measures be implemented for diagnostics and surveillance within hospital environments. Additionally, the present study demonstrates the need to scale the power of genomic analysis in retrospective studies where relatively few samples are available.
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Affiliation(s)
| | - Qing Wu
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, PR China
| | - Von Vergel L. Torres
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - Xiaoxiao Zhang
- Women’s Hospital School of Medicine Zhejiang University, Hangzhou, PR China
| | - Jiahui Li
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, PR China
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - Andrea Rocker
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - Trevor Lithgow
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - Tieli Zhou
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, PR China
| | - Dhanasekaran Vijaykrishna
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, PR China
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
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21
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Garita-Cambronero J, Sena-Vélez M, Ferragud E, Sabuquillo P, Redondo C, Cubero J. Xanthomonas citri subsp. citri and Xanthomonas arboricola pv. pruni: Comparative analysis of two pathogens producing similar symptoms in different host plants. PLoS One 2019; 14:e0219797. [PMID: 31318915 PMCID: PMC6639005 DOI: 10.1371/journal.pone.0219797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/01/2019] [Indexed: 01/06/2023] Open
Abstract
Comparative studies in Xanthomonas have provided a vast amount of data that enabled to deepen in the knowledge of those factors associated with virulence and Xanthomonas plant interaction. The species of this genus present a wide range of host plants and a large number of studies have been focused to elucidate which mechanism are involved in this characteristic. In this study, comparative genomic and phenotypic analysis were performed between X. citri subsp. citri (Xcc), one of the most studied pathogens within Xanthomonas, and X. arboricola pv. pruni (Xap), a pathogen which has aroused great interest in recent time. The work was aimed to find those elements that contribute to their host divergence despite the convergence in the symptoms that each species cause on Citrus spp. and Prunus spp., respectively. This study reveals a set of genes that could be putatively associated with the adaptation of these pathogens to their hosts, being the most remarkable those involved in environmental sensing systems such as the case of the TonB-dependent transporters, the sensors of the two-component system and the methyl accepting chemotaxis proteins. Other important variants were found in processes related to the decomposition of the cell wall as could be appreciated by their dissimilar set of cell-wall degrading enzymes. Type three effectors, as one of the most important factors in delineating the host specificity in Xanthomonas, also showed a different array when comparing both species, being some of them unique to each pathogen. On the other hand, only small variations could be connected to other features such as the motility appendages and surface adhesion proteins, but these differences were accompanied by a dissimilar capacity to attach on host and non-host leaf surface. The molecular factors found in this work provide the basis to perform a more in-depth functional analyses that unveil those actual factors associated with pathogenesis and host specificity in Xcc and Xap.
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Affiliation(s)
- Jerson Garita-Cambronero
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain.,Centro de Investigación de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León (ITACyL), Villarejo de Órbigo, Leon, Spain
| | - Marta Sena-Vélez
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain.,Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Elisa Ferragud
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Pilar Sabuquillo
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Cristina Redondo
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Jaime Cubero
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
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22
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Li L, Yuan L, Shi Y, Xie X, Chai A, Wang Q, Li B. Comparative genomic analysis of Pectobacterium carotovorum subsp. brasiliense SX309 provides novel insights into its genetic and phenotypic features. BMC Genomics 2019; 20:486. [PMID: 31195968 PMCID: PMC6567464 DOI: 10.1186/s12864-019-5831-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 05/23/2019] [Indexed: 12/20/2022] Open
Abstract
Background Pectobacterium carotovorum subsp. brasiliense is a broad host range bacterial pathogen, which causes blackleg of potatoes and bacterial soft rot of vegetables worldwide. Production of plant cell wall degrading enzymes is usually critical for Pectobacterium infection. However, other virulence factors and the mechanisms of genetic adaptation still need to be studied in detail. Results In this study, the complete genome of P. carotovorum subsp. brasiliense strain SX309 isolated from cucumber was compared with eight other pathogenic bacteria belonging to the Pectobacterium genus, which were isolated from various host plants. Genome comparison revealed that most virulence genes are highly conserved in the Pectobacterium strains, especially for the key virulence determinants involved in the biosynthesis of extracellular enzymes and others including the type II and III secretion systems, quorum sensing system, flagellar and chemotactic genes. Nevertheless, some variable regions of the T6SS and the CRISP-Cas immune system are unique for P. carotovorum subsp. brasiliense. Conclusions The extensive comparative genomics analysis revealed highly conserved virulence genes in the Pectobacterium strains. However, several variable regions of type VI secretion system and two subtype Cas mechanism-Cas immune systems possibly contribute to the process of Pectobacterium infection and adaptive immunity. Electronic supplementary material The online version of this article (10.1186/s12864-019-5831-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lei Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Lifang Yuan
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.,Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Yanxia Shi
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xuewen Xie
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ali Chai
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Qi Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Baoju Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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23
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White RC, Cianciotto NP. Assessing the impact, genomics and evolution of type II secretion across a large, medically important genus: the Legionella type II secretion paradigm. Microb Genom 2019; 5. [PMID: 31166887 PMCID: PMC6617341 DOI: 10.1099/mgen.0.000273] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The type II secretion system (T2SS) plays a major role in promoting bacterial survival in the environment and in human hosts. One of the best characterized T2SS is that of Legionella pneumophila, the agent of Legionnaires’ disease. Secreting at least 25 proteins, including degradative enzymes, eukaryotic-like proteins and novel effectors, this T2SS contributes to the ability of L. pneumophila to grow at low temperatures, infect amoebal and macrophage hosts, damage lung tissue, evade the immune system, and undergo sliding motility. The genes encoding the T2SS are conserved across the genus Legionella, which includes 62 species and >30 pathogens in addition to L. pneumophila. The vast majority of effectors associated with L. pneumophila are shared by a large number of Legionella species, hinting at a critical role for them in the ecology of Legionella as a whole. However, no other species has the same repertoire as L. pneumophila, with, as a general rule, phylogenetically more closely related species sharing similar sets of effectors. T2SS effectors that are involved in infection of a eukaryotic host(s) are more prevalent throughout Legionella, indicating that they are under stronger selective pressure. The Legionella T2SS apparatus is closest to that of Aquicella (another parasite of amoebae), and a significant number of L. pneumophila effectors have their closest homologues in Aquicella. Thus, the T2SS of L. pneumophila probably originated within the order Legionellales, with some of its effectors having arisen within that Aquicella-like progenitor, while other effectors derived from the amoebal host, mimiviruses, fungi and less closely related bacteria.
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Affiliation(s)
- Richard C White
- 1 Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
| | - Nicholas P Cianciotto
- 1 Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
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24
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Arora P, Riyaz-Ul-Hassan S. Endohyphal bacteria; the prokaryotic modulators of host fungal biology. FUNGAL BIOL REV 2019. [DOI: 10.1016/j.fbr.2018.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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25
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Arifuzzaman M, Mitra S, Jahan SI, Jakaria M, Abeda T, Absar N, Dash R. A Computational workflow for the identification of the potent inhibitor of type II secretion system traffic ATPase of Pseudomonas aeruginosa. Comput Biol Chem 2018; 76:191-201. [DOI: 10.1016/j.compbiolchem.2018.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/30/2018] [Accepted: 07/10/2018] [Indexed: 01/04/2023]
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26
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Structural insight into the assembly of the type II secretion system pilotin–secretin complex from enterotoxigenic Escherichia coli. Nat Microbiol 2018; 3:581-587. [DOI: 10.1038/s41564-018-0148-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 03/07/2018] [Indexed: 12/29/2022]
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27
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Kinsella RL, Lopez J, Palmer LD, Salinas ND, Skaar EP, Tolia NH, Feldman MF. Defining the interaction of the protease CpaA with its type II secretion chaperone CpaB and its contribution to virulence in Acinetobacter species. J Biol Chem 2017; 292:19628-19638. [PMID: 28982978 PMCID: PMC5712607 DOI: 10.1074/jbc.m117.808394] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/02/2017] [Indexed: 11/06/2022] Open
Abstract
Acinetobacter baumannii, Acinetobacter nosocomialis, and Acinetobacter pittii are a frequent cause of multidrug-resistant, healthcare-associated infections. Our previous work demonstrated that A. nosocomialis M2 possesses a functional type II secretion system (T2SS) that is required for full virulence. Further, we identified the metallo-endopeptidase CpaA, which has been shown previously to cleave human Factor V and deregulate blood coagulation, as the most abundant type II secreted effector protein. We also demonstrated that its secretion is dependent on CpaB, a membrane-bound chaperone. In this study, we show that CpaA expression and secretion are conserved across several medically relevant Acinetobacter species. Additionally, we demonstrate that deletion of cpaA results in attenuation of A. nosocomialis M2 virulence in moth and mouse models. The virulence defects resulting from the deletion of cpaA were comparable with those observed upon abrogation of T2SS activity. The virulence defects resulting from the deletion of cpaA are comparable with those observed upon abrogation of T2SS activity. We also show that CpaA and CpaB strongly interact, forming a complex in a 1:1 ratio. Interestingly, deletion of the N-terminal transmembrane domain of CpaB results in robust secretion of CpaA and CpaB, indicating that the transmembrane domain is dispensable for CpaA secretion and likely functions to retain CpaB inside the cell. Limited proteolysis of spheroplasts revealed that the C-terminal domain of CpaB is exposed to the periplasm, suggesting that this is the site where CpaA and CpaB interact in vivo Last, we show that CpaB does not abolish the proteolytic activity of CpaA against human Factor V. We conclude that CpaA is, to the best of our knowledge, the first characterized, bona fide virulence factor secreted by Acinetobacter species.
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Affiliation(s)
- Rachel L Kinsella
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
- the Department of Biological Sciences, University of Alberta, Edmonton T6G 2E9, Alberta, Canada, and
| | - Juvenal Lopez
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Lauren D Palmer
- the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Nichole D Salinas
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Eric P Skaar
- the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Niraj H Tolia
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Mario F Feldman
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110,
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28
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Anti-Salmonella Activity Modulation of Mastoparan V1-A Wasp Venom Toxin-Using Protease Inhibitors, and Its Efficient Production via an Escherichia coli Secretion System. Toxins (Basel) 2017; 9:toxins9100321. [PMID: 29027924 PMCID: PMC5666368 DOI: 10.3390/toxins9100321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 12/27/2022] Open
Abstract
A previous study highlighted that mastoparan V1 (MP-V1), a mastoparan from the venom of the social wasp Vespula vulgaris, is a potent antimicrobial peptide against Salmonella infection, which causes enteric diseases. However, there exist some limits for its practical application due to the loss of its activity in an increased bacterial density and the difficulty of its efficient production. In this study, we first modulated successfully the antimicrobial activity of synthetic MP-V1 against an increased Salmonella population using protease inhibitors, and developed an Escherichia coli secretion system efficiently producing active MP-V1. The protease inhibitors used, except pepstatin A, significantly increased the antimicrobial activity of the synthetic MP-V1 at minimum inhibitory concentrations (determined against 10⁶ cfu/mL of population) against an increased population (10⁸ cfu/mL) of three different Salmonella serotypes, Gallinarum, Typhimurium and Enteritidis. Meanwhile, the E. coli strain harboring OmpA SS::MP-V1 was identified to successfully secrete active MP-V1 into cell-free supernatant, whose antimicrobial activity disappeared in the increased population (10⁸ cfu/mL) of Salmonella Typhimurium recovered by adding a protease inhibitor cocktail. Therefore, it has been concluded that our challenge using the E. coli secretion system with the protease inhibitors is an attractive strategy for practical application of peptide toxins, such as MP-V1.
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29
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Chen L, Wang M, Huang L, Zhang Z, Liu F, Lu G. XC_0531 encodes a c-type cytochrome biogenesis protein and is required for pathogenesis in Xanthomonas campestris pv. campestris. BMC Microbiol 2017; 17:142. [PMID: 28655353 PMCID: PMC5488342 DOI: 10.1186/s12866-017-1056-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/21/2017] [Indexed: 11/13/2022] Open
Abstract
Background The phytopathogenic Xanthomonas campestris pv.campestris is a gram-negative bacterium and the causal agent of black-rot disease of cruciferous crops. Many gram-negative bacteria possess a family of proteins, called Dsbs, which are involved in disulfide bond formation in certain periplasmic proteins. In our preliminary screening of the virulence to the plants we identified that gene XC_0531 which annotated gene dsbD of Xanthomonas campestris pv. campestris (Xcc) is related to the virulence to the host plants. Results Here, we found XC_0531 encoded a DsbD like protein. Its deletion is sensitive to DTT and copper, decreased accumulation of free thiols in periplasm. Its deletion also affected heme synthesis, position of Soret band and the production of peak c550. This suggests that XC_0531 is related to c-type cytochromes biogenesis. XC_0531 mutation decreased the utilization of different carbon sources (such as galactose, xylose, maltose, saccharose and glucose), reduced extracellular polysaccharide (EPS) production, decreased extracellular enzyme activities (protease, cellulose and amylase), slowed down growth rate of Xcc and weakened virulence to the plants. These results suggest that these phenotypes caused by XC_0531 mutation is possibly due to deficient biosynthesis of c-type cytochromes in respiration chain and the formation of disulfide bonds. Our work confirmed the function of XC_0531 and provide theory basis for scientists working on molecular mechanisms of cytochrome c biogenesis, pathogenesis of Xcc, development of EPS commercial values and protecting plant from black rot. Conclusion We confirmed the function of gene XC_0531, which encodes a DsbD like protein, a protein correlated with c-type cytochrome biogenesis. This gene is related to the virulence to plants by affecting funtion of cytochromes c and probably disulfide bonds modification of proteins in type II secretion system (T2SS). Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-1056-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lei Chen
- State Key Laboratory for Conservation and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, The Key Laboratory ofMinistry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, China.,Key Laboratory of Coastal Biology and Biological Resources Utilization, Yantai Institute of Coastal Zone Research, Yantai, China
| | - Mingpeng Wang
- Key Laboratory of Coastal Biology and Biological Resources Utilization, Yantai Institute of Coastal Zone Research, Yantai, China
| | - Li Huang
- State Key Laboratory for Conservation and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, The Key Laboratory ofMinistry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, China
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Fanghua Liu
- Key Laboratory of Coastal Biology and Biological Resources Utilization, Yantai Institute of Coastal Zone Research, Yantai, China
| | - Guangtao Lu
- State Key Laboratory for Conservation and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, The Key Laboratory ofMinistry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, China.
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30
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Karlsen C, Hjerde E, Klemetsen T, Willassen NP. Pan genome and CRISPR analyses of the bacterial fish pathogen Moritella viscosa. BMC Genomics 2017; 18:313. [PMID: 28427330 PMCID: PMC5399434 DOI: 10.1186/s12864-017-3693-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/06/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Winter-ulcer Moritella viscosa infections continue to be a significant burden in Atlantic salmon (Salmo salar L.) farming. M. viscosa comprises two main clusters that differ in genetic variation and phenotypes including virulence. Horizontal gene transfer through acquisition and loss of mobile genetic elements (MGEs) is a major driving force of bacterial diversification. To gain insight into genomic traits that could affect sublineage evolution within this bacterium we examined the genome sequences of twelve M. viscosa strains. Matches between M. viscosa clustered, regularly interspaced, short palindromic, repeats and associated cas genes (CRISPR-Cas) were analysed to correlate CRISPR-Cas with adaptive immunity against MGEs. RESULTS The comparative genomic analysis of M. viscosa isolates from across the North Atlantic region and from different fish species support delineation of M. viscosa into four phylogenetic lineages. The results showed that M. viscosa carries two distinct variants of the CRISPR-Cas subtype I-F systems and that CRISPR features follow the phylogenetic lineages. A subset of the spacer content match prophage and plasmid genes dispersed among the M. viscosa strains. Further analysis revealed that prophage and plasmid-like element distribution were reflected in the content of the CRISPR-spacer profiles. CONCLUSIONS Our data suggests that CRISPR-Cas mediated interactions with MGEs impact genome properties among M. viscosa, and that patterns in spacer and MGE distributions are linked to strain relationships.
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Affiliation(s)
- Christian Karlsen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences (NMBU), Pb 8146 Dep., 0033, Oslo, Norway. .,Present address: Nofima AS, Division of Aquaculture, PO Box 210, Ås, N-1431, Norway.
| | - Erik Hjerde
- Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway
| | - Terje Klemetsen
- Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway
| | - Nils Peder Willassen
- Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway.,The Norwegian Structural Biology Centre, University of Tromsø, N-9037, Tromsø, Norway
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Garita-Cambronero J, Palacio-Bielsa A, López MM, Cubero J. Pan-Genomic Analysis Permits Differentiation of Virulent and Non-virulent Strains of Xanthomonas arboricola That Cohabit Prunus spp. and Elucidate Bacterial Virulence Factors. Front Microbiol 2017; 8:573. [PMID: 28450852 PMCID: PMC5389983 DOI: 10.3389/fmicb.2017.00573] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/20/2017] [Indexed: 01/17/2023] Open
Abstract
Xanthomonas arboricola is a plant-associated bacterial species that causes diseases on several plant hosts. One of the most virulent pathovars within this species is X. arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruit trees and almond. Recently, a non-virulent Xap-look-a-like strain isolated from Prunus was characterized and its genome compared to pathogenic strains of Xap, revealing differences in the profile of virulence factors, such as the genes related to the type III secretion system (T3SS) and type III effectors (T3Es). The existence of this atypical strain arouses several questions associated with the abundance, the pathogenicity, and the evolutionary context of X. arboricola on Prunus hosts. After an initial characterization of a collection of Xanthomonas strains isolated from Prunus bacterial spot outbreaks in Spain during the past decade, six Xap-look-a-like strains, that did not clustered with the pathogenic strains of Xap according to a multi locus sequence analysis, were identified. Pathogenicity of these strains was analyzed and the genome sequences of two Xap-look-a-like strains, CITA 14 and CITA 124, non-virulent to Prunus spp., were obtained and compared to those available genomes of X. arboricola associated with this host plant. Differences were found among the genomes of the virulent and the Prunus non-virulent strains in several characters related to the pathogenesis process. Additionally, a pan-genomic analysis that included the available genomes of X. arboricola, revealed that the atypical strains associated with Prunus were related to a group of non-virulent or low virulent strains isolated from a wide host range. The repertoire of the genes related to T3SS and T3Es varied among the strains of this cluster and those strains related to the most virulent pathovars of the species, corylina, juglandis, and pruni. This variability provides information about the potential evolutionary process associated to the acquisition of pathogenicity and host specificity in X. arboricola. Finally, based in the genomic differences observed between the virulent and the non-virulent strains isolated from Prunus, a sensitive and specific real-time PCR protocol was designed to detect and identify Xap strains. This method avoids miss-identifications due to atypical strains of X. arboricola that can cohabit Prunus.
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Affiliation(s)
- Jerson Garita-Cambronero
- Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
| | - Ana Palacio-Bielsa
- Unidad de Sanidad Vegetal, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto Agroalimentario de Aragón, Universidad de ZaragozaZaragoza, Spain
| | - María M. López
- Departamento de Bacteriología, Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones AgrariasValencia, Spain
| | - Jaime Cubero
- Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
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32
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Garita-Cambronero J, Palacio-Bielsa A, López MM, Cubero J. Pan-Genomic Analysis Permits Differentiation of Virulent and Non-virulent Strains of Xanthomonas arboricola That Cohabit Prunus spp. and Elucidate Bacterial Virulence Factors. Front Microbiol 2017; 8:573. [PMID: 28450852 DOI: 10.3389/fmicb.2017.00573.ecollection2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/20/2017] [Indexed: 05/24/2023] Open
Abstract
Xanthomonas arboricola is a plant-associated bacterial species that causes diseases on several plant hosts. One of the most virulent pathovars within this species is X. arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruit trees and almond. Recently, a non-virulent Xap-look-a-like strain isolated from Prunus was characterized and its genome compared to pathogenic strains of Xap, revealing differences in the profile of virulence factors, such as the genes related to the type III secretion system (T3SS) and type III effectors (T3Es). The existence of this atypical strain arouses several questions associated with the abundance, the pathogenicity, and the evolutionary context of X. arboricola on Prunus hosts. After an initial characterization of a collection of Xanthomonas strains isolated from Prunus bacterial spot outbreaks in Spain during the past decade, six Xap-look-a-like strains, that did not clustered with the pathogenic strains of Xap according to a multi locus sequence analysis, were identified. Pathogenicity of these strains was analyzed and the genome sequences of two Xap-look-a-like strains, CITA 14 and CITA 124, non-virulent to Prunus spp., were obtained and compared to those available genomes of X. arboricola associated with this host plant. Differences were found among the genomes of the virulent and the Prunus non-virulent strains in several characters related to the pathogenesis process. Additionally, a pan-genomic analysis that included the available genomes of X. arboricola, revealed that the atypical strains associated with Prunus were related to a group of non-virulent or low virulent strains isolated from a wide host range. The repertoire of the genes related to T3SS and T3Es varied among the strains of this cluster and those strains related to the most virulent pathovars of the species, corylina, juglandis, and pruni. This variability provides information about the potential evolutionary process associated to the acquisition of pathogenicity and host specificity in X. arboricola. Finally, based in the genomic differences observed between the virulent and the non-virulent strains isolated from Prunus, a sensitive and specific real-time PCR protocol was designed to detect and identify Xap strains. This method avoids miss-identifications due to atypical strains of X. arboricola that can cohabit Prunus.
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Affiliation(s)
- Jerson Garita-Cambronero
- Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
| | - Ana Palacio-Bielsa
- Unidad de Sanidad Vegetal, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto Agroalimentario de Aragón, Universidad de ZaragozaZaragoza, Spain
| | - María M López
- Departamento de Bacteriología, Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones AgrariasValencia, Spain
| | - Jaime Cubero
- Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
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Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits. PLoS One 2016; 11:e0161977. [PMID: 27571391 PMCID: PMC5003339 DOI: 10.1371/journal.pone.0161977] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/15/2016] [Indexed: 02/07/2023] Open
Abstract
Xanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola.
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Parnasa R, Nagar E, Sendersky E, Reich Z, Simkovsky R, Golden S, Schwarz R. Small secreted proteins enable biofilm development in the cyanobacterium Synechococcus elongatus. Sci Rep 2016; 6:32209. [PMID: 27558743 PMCID: PMC4997328 DOI: 10.1038/srep32209] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/03/2016] [Indexed: 11/18/2022] Open
Abstract
Small proteins characterized by a double-glycine (GG) secretion motif, typical of secreted bacterial antibiotics, are encoded by the genomes of diverse cyanobacteria, but their functions have not been investigated to date. Using a biofilm-forming mutant of Synechococcus elongatus PCC 7942 and a mutational approach, we demonstrate the involvement of four small secreted proteins and their GG-secretion motifs in biofilm development. These proteins are denoted EbfG1-4 (enable biofilm formation with a GG-motif). Furthermore, the conserved cysteine of the peptidase domain of the Synpcc7942_1133 gene product (dubbed PteB for peptidase transporter essential for biofilm) is crucial for biofilm development and is required for efficient secretion of the GG-motif containing proteins. Transcriptional profiling of ebfG1-4 indicated elevated transcript levels in the biofilm-forming mutant compared to wild type (WT). However, these transcripts decreased, acutely but transiently, when the mutant was cultured in extracellular fluids from a WT culture, and biofilm formation was inhibited. We propose that WT cells secrete inhibitor(s) that suppress transcription of ebfG1-4, whereas secretion of the inhibitor(s) is impaired in the biofilm-forming mutant, leading to synthesis and secretion of EbfG1-4 and supporting the formation of biofilms.
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Affiliation(s)
- Rami Parnasa
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Elad Nagar
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Ziv Reich
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan Golden
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
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Jani M, Mathee K, Azad RK. Identification of Novel Genomic Islands in Liverpool Epidemic Strain of Pseudomonas aeruginosa Using Segmentation and Clustering. Front Microbiol 2016; 7:1210. [PMID: 27536294 PMCID: PMC4971588 DOI: 10.3389/fmicb.2016.01210] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/20/2016] [Indexed: 02/03/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen implicated in a myriad of infections and a leading pathogen responsible for mortality in patients with cystic fibrosis (CF). Horizontal transfers of genes among the microorganisms living within CF patients have led to highly virulent and multi-drug resistant strains such as the Liverpool epidemic strain of P. aeruginosa, namely the LESB58 strain that has the propensity to acquire virulence and antibiotic resistance genes. Often these genes are acquired in large clusters, referred to as "genomic islands (GIs)." To decipher GIs and understand their contributions to the evolution of virulence and antibiotic resistance in P. aeruginosa LESB58, we utilized a recursive segmentation and clustering procedure, presented here as a genome-mining tool, "GEMINI." GEMINI was validated on experimentally verified islands in the LESB58 strain before examining its potential to decipher novel islands. Of the 6062 genes in P. aeruginosa LESB58, 596 genes were identified to be resident on 20 GIs of which 12 have not been previously reported. Comparative genomics provided evidence in support of our novel predictions. Furthermore, GEMINI unraveled the mosaic structure of islands that are composed of segments of likely different evolutionary origins, and demonstrated its ability to identify potential strain biomarkers. These newly found islands likely have contributed to the hyper-virulence and multidrug resistance of the Liverpool epidemic strain of P. aeruginosa.
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Affiliation(s)
- Mehul Jani
- Department of Biological Sciences, University of North Texas Denton, TX, USA
| | - Kalai Mathee
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine Global Health Consortium, and Biomolecular Sciences Institute, Florida International University Miami, FL, USA
| | - Rajeev K Azad
- Department of Biological Sciences, University of North TexasDenton, TX, USA; Department of Mathematics, University of North TexasDenton, TX, USA
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Wagner S, Sommer R, Hinsberger S, Lu C, Hartmann RW, Empting M, Titz A. Novel Strategies for the Treatment of Pseudomonas aeruginosa Infections. J Med Chem 2016; 59:5929-69. [DOI: 10.1021/acs.jmedchem.5b01698] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Stefanie Wagner
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Roman Sommer
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Stefan Hinsberger
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Cenbin Lu
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Rolf W. Hartmann
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Martin Empting
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Alexander Titz
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
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Knapp A, Voget S, Gao R, Zaburannyi N, Krysciak D, Breuer M, Hauer B, Streit WR, Müller R, Daniel R, Jaeger KE. Mutations improving production and secretion of extracellular lipase by Burkholderia glumae PG1. Appl Microbiol Biotechnol 2016; 100:1265-1273. [PMID: 26476653 PMCID: PMC4717159 DOI: 10.1007/s00253-015-7041-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/15/2015] [Accepted: 09/24/2015] [Indexed: 01/05/2023]
Abstract
Burkholderia glumae is a Gram-negative phytopathogenic bacterium known as the causative agent of rice panicle blight. Strain B. glumae PG1 is used for the production of a biotechnologically relevant lipase, which is secreted into the culture supernatant via a type II secretion pathway. We have comparatively analyzed the genome sequences of B. glumae PG1 wild type and a lipase overproducing strain obtained by classical strain mutagenesis. Among a total number of 72 single nucleotide polymorphisms (SNPs) identified in the genome of the production strain, two were localized in front of the lipAB operon and were analyzed in detail. Both mutations contribute to a 100-fold overproduction of extracellular lipase in B. glumae PG1 by affecting transcription of the lipAB operon and efficiency of lipase secretion. We analyzed each of the two SNPs separately and observed a stronger influence of the promoter mutation than of the signal peptide modification but also a cumulative effect of both mutations. Furthermore, fusion of the mutated LipA signal peptide resulted in a 2-fold increase in secretion of the heterologous reporter alkaline phosphatase from Escherichia coli.
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Affiliation(s)
- Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sonja Voget
- Institute of Microbiology and Genetics, Department of Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Göttingen, Germany
| | - Rong Gao
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Nestor Zaburannyi
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Dagmar Krysciak
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Michael Breuer
- BASF SE, Biocatalysis and Fine Chemicals Research, Ludwigshafen, Germany
| | - Bernhard Hauer
- BASF SE, Biocatalysis and Fine Chemicals Research, Ludwigshafen, Germany
- Institute of Technical Biochemistry, University of Stuttgart, Stuttgart, Germany
| | - Wolfgang R Streit
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Rolf Daniel
- Institute of Microbiology and Genetics, Department of Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Göttingen, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences IBG-1: Biotechnology, Jülich, Germany.
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Panteli JT, Forkus BA, Van Dessel N, Forbes NS. Genetically modified bacteria as a tool to detect microscopic solid tumor masses with triggered release of a recombinant biomarker. Integr Biol (Camb) 2015; 7:423-34. [PMID: 25737274 DOI: 10.1039/c5ib00047e] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Current tomographic methods of cancer detection have limited sensitivity and are unable to detect malignant masses smaller than half a centimeter in diameter. Mortality from tumor recurrence and metastatic disease would be reduced if small lesions could be detected earlier. To overcome this limitation, we created a detection system that combines the specificity of tumor-targeting bacteria with the sensitivity of a synthetic biomarker. Bacteria, specifically Salmonella, preferentially accumulate in tumors and microscopic metastases as small as five cell layers thick. To create tumor detecting bacteria, an attenuated strain of Salmonella was engineered to express and release the fluorescent protein ZsGreen. A single-layer antibody method was developed to measure low concentrations of ZsGreen. Engineered bacteria were administered to a microfluidic tumor-on-a-chip device to measure protein production. In culture, half of produced ZsGreen was released by viable bacteria at a rate of 87.6 fg bacterium(-1) h(-1). Single-layer antibody dots were able to detect bacterially produced ZsGreen at concentrations down to 4.5 ng ml(-1). Bacteria colonized in 0.12 mm(3) of tumor tissue in the microfluidic device released ZsGreen at a rate of 23.9 μg h(-1). This release demonstrates that ZsGreen readily diffuses through tissue and accumulates at detectable concentrations. Based on a mathematical pharmacokinetic model, the measured rate of release would enable detection of 0.043 mm(3) tumor masses, which is 2600 times smaller than the current limit of tomographic techniques. Tumor-detecting bacteria would provide a sensitive, minimally invasive method to detect tumor recurrence, monitor treatment efficacy, and identify the onset of metastatic disease.
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Affiliation(s)
- Jan T Panteli
- Department of Chemical Engineering, University of Massachusetts Amherst, 159 Goessmann Laboratory, 686 North Pleasant Street, Amherst, MA 01003-9303, USA.
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Scales BS, Erb-Downward JR, Huffnagle IM, LiPuma JJ, Huffnagle GB. Comparative genomics of Pseudomonas fluorescens subclade III strains from human lungs. BMC Genomics 2015; 16:1032. [PMID: 26644001 PMCID: PMC4672498 DOI: 10.1186/s12864-015-2261-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/30/2015] [Indexed: 12/22/2022] Open
Abstract
Background While the taxonomy and genomics of environmental strains from the P. fluorescens species-complex has been reported, little is known about P. fluorescens strains from clinical samples. In this report, we provide the first genomic analysis of P. fluorescens strains in which human vs. environmental isolates are compared. Results Seven P. fluorescens strains were isolated from respiratory samples from cystic fibrosis (CF) patients. The clinical strains could grow at a higher temperature (>34 °C) than has been reported for environmental strains. Draft genomes were generated for all of the clinical strains, and multi-locus sequence analysis placed them within subclade III of the P. fluorescens species-complex. All strains encoded type- II, −III, −IV, and -VI secretion systems, as well as the widespread colonization island (WCI). This is the first description of a WCI in P. fluorescens strains. All strains also encoded a complete I2/PfiT locus and showed evidence of horizontal gene transfer. The clinical strains were found to differ from the environmental strains in the number of genes involved in metal resistance, which may be a possible adaptation to chronic antibiotic exposure in the CF lung. Conclusions This is the largest comparative genomics analysis of P. fluorescens subclade III strains to date and includes the first clinical isolates. At a global level, the clinical P. fluorescens subclade III strains were largely indistinguishable from environmental P. fluorescens subclade III strains, supporting the idea that identifying strains as ‘environmental’ vs ‘clinical’ is not a phenotypic trait. Rather, strains within P. fluorescens subclade III will colonize and persist in any niche that provides the requirements necessary for growth. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2261-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brittan S Scales
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA. .,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - John R Erb-Downward
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ian M Huffnagle
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - John J LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Gary B Huffnagle
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA. .,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
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Versatile plasmid-based expression systems for Gram-negative bacteria—General essentials exemplified with the bacterium Ralstonia eutropha H16. N Biotechnol 2015; 32:552-8. [DOI: 10.1016/j.nbt.2015.03.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 03/12/2015] [Accepted: 03/20/2015] [Indexed: 12/13/2022]
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Bedoui A, Tigini V, Ghedira K, Varese GC, Chekir Ghedira L. Evaluation of an eventual ecotoxicity induced by textile effluents using a battery of biotests. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:16700-16708. [PMID: 26087930 DOI: 10.1007/s11356-015-4862-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 06/08/2015] [Indexed: 06/04/2023]
Abstract
Textile industry is considered as one of the important factors of the economic growth in Tunisia. However, this prominent role has certainly some drawbacks mainly represented by the huge amounts of textile wastewaters generated that become a real menace to nature. Many previous studies showed the purifying potential of some activated sludge and bacteria (Pseudomonas putida) to decolourize textile effluents. However, in many cases, decolourization of wastewaters is not necessary associated with detoxification, generating a real risk for the ecosystem in general. We evaluated in this work the induced toxicity of a textile effluent before and after its treatment with activated sludge followed by P. putida, using a battery of biotests. This study proved the detoxifying power of the activated sludge according to most of ecotoxicity tests. The treatment with P. putida did not improve the quality of the effluent; on the contrary, it could increase its toxicity. Daphnia magna and Raphidocelis subcapitata appear to be the most sensitive organisms in assessing eventual toxicity caused by this kind of wastewaters.
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Affiliation(s)
- Ahmed Bedoui
- Unité de substances Naturelles Bioactives et Biotechnologie, UR12ES12, Faculté de Pharmacie de Monastir, Université de Monastir, Rue Avicenne, 5000, Monastir, Tunisia
| | - Valeria Tigini
- Department of Life Sciences and Systems Biology, University of Turin, viale Mattioli 25, 10125, Turin, Italy
| | - Kamel Ghedira
- Unité de substances Naturelles Bioactives et Biotechnologie, UR12ES12, Faculté de Pharmacie de Monastir, Université de Monastir, Rue Avicenne, 5000, Monastir, Tunisia
| | - Giovanna Cristina Varese
- Department of Life Sciences and Systems Biology, University of Turin, viale Mattioli 25, 10125, Turin, Italy
| | - Leila Chekir Ghedira
- Unité de substances Naturelles Bioactives et Biotechnologie, UR12ES12, Faculté de Pharmacie de Monastir, Université de Monastir, Rue Avicenne, 5000, Monastir, Tunisia.
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté de Médecine Dentaire, Université de Monastir, Rue Avicenne, 5000, Monastir, Tunisia.
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Park J, Zhang Y, Chen C, Dudley EG, Harvill ET. Diversity of secretion systems associated with virulence characteristics of the classical bordetellae. MICROBIOLOGY-SGM 2015; 161:2328-40. [PMID: 26459829 DOI: 10.1099/mic.0.000197] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Secretion systems are key virulence factors, modulating interactions between pathogens and the host's immune response. Six potential secretion systems (types 1-6; T1SS-T6SS) have been discussed in classical bordetellae, respiratory commensals/pathogens of mammals. The prototypical Bordetella bronchiseptica strain RB50 genome seems to contain all six systems, whilst two human-restricted subspecies, Bordetella parapertussis and Bordetella pertussis, have lost different subsets of these. This implicates secretion systems in the divergent evolutionary histories that have led to their success in different niches. Based on our previous work demonstrating that changes in secretion systems are associated with virulence characteristics, we hypothesized there would be substantial divergence of the loci encoding each amongst sequenced strains. Here, we describe extensive differences in secretion system loci; 10 of the 11 sequenced strains had lost subsets of genes or one entire secretion system locus. These loci contained genes homologous to those present in the respective loci in distantly related organisms, as well as genes unique to bordetellae, suggesting novel and/or auxiliary functions. The high degree of conservation of the T3SS locus, a complex machine with interdependent parts that must be conserved, stands in dramatic contrast to repeated loss of T5aSS 'autotransporters', which function as an autonomous unit. This comparative analysis provided insights into critical aspects of each pathogen's adaptation to its different niche, and the relative contributions of recombination, mutation and horizontal gene transfer. In addition, the relative conservation of various secretion systems is an important consideration in the ongoing search for more highly conserved protective antigens for the next generation of pertussis vaccines.
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Affiliation(s)
- Jihye Park
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA 2 Graduate Program in Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, USA
| | - Ying Zhang
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
| | - Chun Chen
- 3 Department of Food Science, Pennsylvania State University, University Park, PA, USA
| | - Edward G Dudley
- 3 Department of Food Science, Pennsylvania State University, University Park, PA, USA
| | - Eric T Harvill
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA 4 Singapore Centre on Environmental Life Sciences Engineering, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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Ravichandran A, Ramachandran M, Suriyanarayanan T, Wong CC, Swarup S. Global Regulator MorA Affects Virulence-Associated Protease Secretion in Pseudomonas aeruginosa PAO1. PLoS One 2015; 10:e0123805. [PMID: 25894344 PMCID: PMC4404142 DOI: 10.1371/journal.pone.0123805] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/06/2015] [Indexed: 11/18/2022] Open
Abstract
Bacterial invasion plays a critical role in the establishment of Pseudomonas aeruginosa infection and is aided by two major virulence factors--surface appendages and secreted proteases. The second messenger cyclic diguanylate (c-di-GMP) is known to affect bacterial attachment to surfaces, biofilm formation and related virulence phenomena. Here we report that MorA, a global regulator with GGDEF and EAL domains that was previously reported to affect virulence factors, negatively regulates protease secretion via the type II secretion system (T2SS) in P. aeruginosa PAO1. Infection assays with mutant strains carrying gene deletion and domain mutants show that host cell invasion is dependent on the active domain function of MorA. Further investigations suggest that the MorA-mediated c-di-GMP signaling affects protease secretion largely at a post-translational level. We thus report c-di-GMP second messenger system as a novel regulator of T2SS function in P. aeruginosa. Given that T2SS is a central and constitutive pump, and the secreted proteases are involved in interactions with the microbial surroundings, our data broadens the significance of c-di-GMP signaling in P. aeruginosa pathogenesis and ecological fitness.
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Affiliation(s)
- Ayshwarya Ravichandran
- Metabolites Biology Lab, Department of Biological Sciences, National University of Singapore, Singapore 117543
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411
| | - Malarmathy Ramachandran
- Metabolites Biology Lab, Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Tanujaa Suriyanarayanan
- Metabolites Biology Lab, Department of Biological Sciences, National University of Singapore, Singapore 117543
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University 60 Nanyang Drive, SBS-01N-27 Singapore 637551
| | - Chui Ching Wong
- Metabolites Biology Lab, Department of Biological Sciences, National University of Singapore, Singapore 117543
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411
| | - Sanjay Swarup
- Metabolites Biology Lab, Department of Biological Sciences, National University of Singapore, Singapore 117543
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411
- NUS Environmental Research Institute (NERI), National University of Singapore, 5A Engineering Drive 1, Singapore 117411
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University 60 Nanyang Drive, SBS-01N-27 Singapore 637551
- * E-mail:
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Redzej A, Waksman G, V Orlova E. Structural studies of T4S systems by electron microscopy. AIMS BIOPHYSICS 2015. [DOI: 10.3934/biophy.2015.2.184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Cabezón E, Ripoll-Rozada J, Peña A, de la Cruz F, Arechaga I. Towards an integrated model of bacterial conjugation. FEMS Microbiol Rev 2014; 39:81-95. [PMID: 25154632 DOI: 10.1111/1574-6976.12085] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bacterial conjugation is one of the main mechanisms for horizontal gene transfer. It constitutes a key element in the dissemination of antibiotic resistance and virulence genes to human pathogenic bacteria. DNA transfer is mediated by a membrane-associated macromolecular machinery called Type IV secretion system (T4SS). T4SSs are involved not only in bacterial conjugation but also in the transport of virulence factors by pathogenic bacteria. Thus, the search for specific inhibitors of different T4SS components opens a novel approach to restrict plasmid dissemination. This review highlights recent biochemical and structural findings that shed new light on the molecular mechanisms of DNA and protein transport by T4SS. Based on these data, a model for pilus biogenesis and substrate transfer in conjugative systems is proposed. This model provides a renewed view of the mechanism that might help to envisage new strategies to curb the threating expansion of antibiotic resistance.
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Affiliation(s)
- Elena Cabezón
- Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC, (Universidad de Cantabria, CSIC) Santander, Spain
| | - Jorge Ripoll-Rozada
- Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC, (Universidad de Cantabria, CSIC) Santander, Spain
| | - Alejandro Peña
- Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC, (Universidad de Cantabria, CSIC) Santander, Spain
| | - Fernando de la Cruz
- Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC, (Universidad de Cantabria, CSIC) Santander, Spain
| | - Ignacio Arechaga
- Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC, (Universidad de Cantabria, CSIC) Santander, Spain
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Characterization and localization of the Campylobacter jejuni transformation system proteins CtsE, CtsP, and CtsX. J Bacteriol 2014; 197:636-45. [PMID: 25448813 DOI: 10.1128/jb.02434-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The human pathogen Campylobacter jejuni is naturally competent for transformation with its own DNA. Genes required for efficient transformation in C. jejuni include those similar to components of type II secretion systems found in many Gram-negative bacteria (R. S. Wiesner, D. R. Hendrixson, and V. J. DiRita, J Bacteriol 185:5408-5418, 2003, http://dx.doi.org/10.1128/JB.185.18.5408-5418.2003). Two of these, ctsE and ctsP, encode proteins annotated as putative nucleotide binding nucleoside triphosphatases (NTPases) or nucleoside triphosphate (NTP) binding proteins. Here we demonstrate that the nucleotide binding motifs of both proteins are essential for their function in transformation of C. jejuni. Localization experiments demonstrated that CtsE is a soluble protein while CtsP is membrane associated in C. jejuni. A bacterial two-hybrid screen identified an interaction between CtsP and CtsX, an integral membrane protein also required for transformation. Topological analysis of CtsX by the use of LacZ and PhoA fusions demonstrated it to be a bitopic, integral membrane protein with a cytoplasmic amino terminus and a periplasmic carboxyl terminus. Notwithstanding its interaction with membrane-localized CtsX, CtsP inherently associates with the membrane, requiring neither CtsX nor several other Cts proteins for this association.
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Moebius N, Üzüm Z, Dijksterhuis J, Lackner G, Hertweck C. Active invasion of bacteria into living fungal cells. eLife 2014; 3:e03007. [PMID: 25182414 PMCID: PMC4166002 DOI: 10.7554/elife.03007] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/29/2014] [Indexed: 12/12/2022] Open
Abstract
The rice seedling blight fungus Rhizopus microsporus and its endosymbiont Burkholderia rhizoxinica form an unusual, highly specific alliance to produce the highly potent antimitotic phytotoxin rhizoxin. Yet, it has remained a riddle how bacteria invade the fungal cells. Genome mining for potential symbiosis factors and functional analyses revealed that a type 2 secretion system (T2SS) of the bacterial endosymbiont is required for the formation of the endosymbiosis. Comparative proteome analyses show that the T2SS releases chitinolytic enzymes (chitinase, chitosanase) and chitin-binding proteins. The genes responsible for chitinolytic proteins and T2SS components are highly expressed during infection. Through targeted gene knock-outs, sporulation assays and microscopic investigations we found that chitinase is essential for bacteria to enter hyphae. Unprecedented snapshots of the traceless bacterial intrusion were obtained using cryo-electron microscopy. Beyond unveiling the pivotal role of chitinolytic enzymes in the active invasion of a fungus by bacteria, these findings grant unprecedented insight into the fungal cell wall penetration and symbiosis formation.
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Affiliation(s)
- Nadine Moebius
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Zerrin Üzüm
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | | | - Gerald Lackner
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
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48
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Nagar E, Schwarz R. To be or not to be planktonic? Self-inhibition of biofilm development. Environ Microbiol 2014; 17:1477-86. [DOI: 10.1111/1462-2920.12583] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 07/23/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Elad Nagar
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan 5290002 Israel
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan 5290002 Israel
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49
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Lu C, Korotkov KV, Hol WGJ. Crystal structure of the full-length ATPase GspE from the Vibrio vulnificus type II secretion system in complex with the cytoplasmic domain of GspL. J Struct Biol 2014; 187:223-235. [PMID: 25092625 DOI: 10.1016/j.jsb.2014.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 11/15/2022]
Abstract
The type II secretion system (T2SS) is present in many Gram-negative bacteria and is responsible for secreting a large number of folded proteins, including major virulence factors, across the outer membrane. The T2SS consists of 11-15 different proteins most of which are present in multiple copies in the assembled secretion machinery. The ATPase GspE, essential for the functioning of the T2SS, contains three domains (N1E, N2E and CTE) of which the N1E domain is associated with the cytoplasmic domain of the inner membrane protein GspL. Here we describe and analyze the structure of the GspE•cyto-GspL complex from Vibrio vulnificus in the presence of an ATP analog, AMPPNP. There are three such ∼83 kDa complexes per asymmetric unit with essentially the same structure. The N2E and CTE domains of a single V. vulnificus GspE subunit adopt a mutual orientation that has not been seen before in any of the previous GspE structures, neither in structures of related ATPases from other secretion systems. This underlines the tremendous conformational flexibility of the T2SS secretion ATPase. Cyto-GspL interacts not only with the N1E domain, but also with the CTE domain and is even in contact with AMPPNP. Moreover, the cyto-GspL domains engage in two types of mutual interactions, resulting in two essentially identical, but crystallographically independent, "cyto-GspL rods" that run throughout the crystal. Very similar rods are present in previous crystals of cyto-GspL and of the N1E•cyto-GspL complex. This arrangement, now seen four times in three entirely different crystal forms, involves contacts between highly conserved residues suggesting a role in the biogenesis or the secretion mechanism or both of the T2SS.
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Affiliation(s)
- Connie Lu
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, United States
| | - Konstantin V Korotkov
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, United States
| | - Wim G J Hol
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, United States.
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50
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Li B, Ibrahim M, Ge M, Cui Z, Sun G, Xu F, Kube M. Transcriptome analysis of Acidovorax avenae subsp. avenae cultivated in vivo and co-culture with Burkholderia seminalis. Sci Rep 2014; 4:5698. [PMID: 25027476 PMCID: PMC4099980 DOI: 10.1038/srep05698] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 06/23/2014] [Indexed: 12/28/2022] Open
Abstract
Response of bacterial pathogen to environmental bacteria and its host is critical for understanding of microbial adaption and pathogenesis. Here, we used RNA-Seq to comprehensively and quantitatively assess the transcriptional response of Acidovorax avenae subsp. avenae strain RS-1 cultivated in vitro, in vivo and in co-culture with rice rhizobacterium Burkholderia seminalis R456. Results revealed a slight response to other bacteria, but a strong response to host. In particular, a large number of virulence associated genes encoding Type I to VI secretion systems, 118 putative non-coding RNAs, and 7 genomic islands (GIs) were differentially expressed in vivo based on comparative genomic and transcriptomic analyses. Furthermore, the loss of virulence for knockout mutants of 11 differentially expressed T6SS genes emphasized the importance of these genes in bacterial pathogenicity. In addition, the reliability of expression data obtained by RNA-Seq was supported by quantitative real-time PCR of the 25 selected T6SS genes. Overall, this study highlighted the role of differentially expressed genes in elucidating bacterial pathogenesis based on combined analysis of RNA-Seq data and knockout of T6SS genes.
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Affiliation(s)
- Bin Li
- 1] State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 310058, Hangzhou, China [2]
| | - Muhammad Ibrahim
- 1] State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 310058, Hangzhou, China [2]
| | - Mengyu Ge
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 310058, Hangzhou, China
| | - Zhouqi Cui
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 310058, Hangzhou, China
| | - Guochang Sun
- State Key Laboratory Breeding Base for Zhejiang Sustainable Plant Pest and Disease Control, Key Laboratory of Detection for Pesticide Residues, Ministry of Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Fei Xu
- Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Michael Kube
- Faculty of Agriculture and Horticulture, Humboldt-Universität zu Berlin, 14195 Berlin, Germany
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