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Kolodziejek AM, Bearden SW, Maes S, Montenieri JM, Gage KL, Hovde CJ, Minnich SA. Yersinia pestis Δ ail Mutants Are Not Susceptible to Human Complement Bactericidal Activity in the Flea. Appl Environ Microbiol 2023; 89:e0124422. [PMID: 36744930 PMCID: PMC9973026 DOI: 10.1128/aem.01244-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 01/09/2023] [Indexed: 02/07/2023] Open
Abstract
Ail confers serum resistance in humans and is a critical virulence factor of Y. pestis, the causative agent of plague. Here, the contribution of Ail for Y. pestis survival in the flea vector was examined. Rat or human but not mouse sera were bactericidal against a Y. pestis Δail mutant at 28°C in vitro. Complement components deposited rapidly on the Y. pestis surface as measured by immunofluorescent microscopy. Ail reduced the amount of active C3b on the Y. pestis surface. Human sera retained bactericidal activity against a Y. pestis Δail mutant in the presence of mouse sera. However, in the flea vector, the serum protective properties of Ail were not required. Flea colonization studies using murine sera and Y. pestis KIM6+ wild type, a Δail mutant, and the Δail/ail+ control showed no differences in bacterial prevalence or numbers during the early stage of flea colonization. Similarly, flea studies with human blood showed Ail was not required for serum resistance. Finally, a variant of Ail (AilF100V E108_S109insS) from a human serum-sensitive Y. pestis subsp. microtus bv. Caucasica 1146 conferred resistance to human complement when expressed in the Y. pestis KIM6+ Δail mutant. This indicated that Ail activity was somehow blocked, most likely by lipooligosaccharide, in this serum sensitive strain. IMPORTANCE This work contributes to our understanding of how highly virulent Y. pestis evolved from its innocuous enteric predecessor. Among identified virulence factors is the attachment invasion locus protein, Ail, that is required to protect Y. pestis from serum complement in all mammals tested except mice. Murine sera is not bactericidal. In this study, we asked, is bactericidal sera from humans active in Y. pestis colonized fleas? We found it was not. The importance of this observation is that it identifies a protective niche for the growth of serum sensitive and nonsensitive Y. pestis strains.
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Affiliation(s)
- Anna M. Kolodziejek
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott W. Bearden
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Sarah Maes
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - John M. Montenieri
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Kenneth L. Gage
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Carolyn J. Hovde
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott A. Minnich
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
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Kolodziejek AM, Hovde CJ, Minnich SA. Contributions of Yersinia pestis outer membrane protein Ail to plague pathogenesis. Curr Opin Infect Dis 2022; 35:188-195. [PMID: 35665712 PMCID: PMC9186061 DOI: 10.1097/qco.0000000000000830] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Pathogenic Yersinia have been a productive model system for studying bacterial pathogenesis. Hallmark contributions of Yersinia research to medical microbiology are legion and include: (i) the first identification of the role of plasmids in virulence, (ii) the important mechanism of iron acquisition from the host, (iii) the first identification of bacterial surface proteins required for host cell invasion, (iv) the archetypical type III secretion system, and (v) elucidation of the role of genomic reduction in the evolutionary trajectory from a fairly innocuous pathogen to a highly virulent species. RECENT FINDINGS The outer membrane (OM) protein Ail (attachment invasion locus) was identified over 30 years ago as an invasin-like protein. Recent work on Ail continues to provide insights into Gram-negative pathogenesis. This review is a synopsis of the role of Ail in invasion, serum resistance, OM stability, thermosensing, and vaccine development. SUMMARY Ail is shown to be an essential virulence factor with multiple roles in pathogenesis. The recent adaptation of Yersinia pestis to high virulence, which included genomic reduction to eliminate redundant protein functions, is a model to understand the emergence of new bacterial pathogens.
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Affiliation(s)
- Anna M. Kolodziejek
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Carolyn J. Hovde
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott A. Minnich
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
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George A, Ravi R, Tiwari PB, Srivastava SR, Jain V, Mahalakshmi R. Engineering a Hyperstable Yersinia pestis Outer Membrane Protein Ail Using Thermodynamic Design. J Am Chem Soc 2022; 144:1545-1555. [DOI: 10.1021/jacs.1c05964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anjana George
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
| | - Roshika Ravi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
| | - Pankaj Bharat Tiwari
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
| | - Shashank Ranjan Srivastava
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
| | - Vikas Jain
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal - 462066, India
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Tn-Seq Analysis Identifies Genes Important for Yersinia pestis Adherence during Primary Pneumonic Plague. mSphere 2020; 5:5/4/e00715-20. [PMID: 32759339 PMCID: PMC7407073 DOI: 10.1128/msphere.00715-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Colonization of the lung by Yersinia pestis is a critical first step in establishing infection during primary pneumonic plague, a disease characterized by high lethality. However, the mechanisms by which Y. pestis adheres in the lung after inhalation remain elusive. Here, we used Tn-seq to identify Y. pestis genes important for adherence early during primary pneumonic plague. Our mutant enrichment strategy resulted in the identification of genes important for regulation and assembly of genes and proteins rather than adhesin genes themselves. These results reveal that there may be multiple Y. pestis adhesins or redundancy among adhesins. Identifying the adhesins regulated by the genes identified in our enrichment screen may reveal novel therapeutic targets for preventing Y. pestis adherence and the subsequent development of pneumonic plague. Following inhalation, Yersinia pestis rapidly colonizes the lung to establish infection during primary pneumonic plague. Although several adhesins have been identified in Yersinia spp., the factors mediating early Y. pestis adherence in the lung remain unknown. To identify genes important for Y. pestis adherence during primary pneumonic plague, we used transposon insertion sequencing (Tn-seq). Wild-type and capsule mutant (Δcaf1) Y. pestis transposon mutant libraries were serially passaged in vivo to enrich for nonadherent mutants in the lung using a mouse model of primary pneumonic plague. Sequencing of the passaged libraries revealed six mutants that were significantly enriched in both the wild-type and Δcaf1Y. pestis backgrounds. The enriched mutants had insertions in genes that encode transcriptional regulators, chaperones, an endoribonuclease, and YPO3903, a hypothetical protein. Using single-strain infections and a transcriptional analysis, we identified a significant role for YPO3903 in Y. pestis adherence in the lung and showed that YPO3903 regulated transcript levels of psaA, which encodes a fimbria previously implicated in Y. pestis adherence in vitro. Deletion of psaA had a minor effect on Y. pestis adherence in the lung, suggesting that YPO3903 regulates other adhesins in addition to psaA. By enriching for mutations in genes that regulate the expression or assembly of multiple genes or proteins, we obtained screen results indicating that there may be not just one dominant adhesin but rather several factors that contribute to early Y. pestis adherence during primary pneumonic plague. IMPORTANCE Colonization of the lung by Yersinia pestis is a critical first step in establishing infection during primary pneumonic plague, a disease characterized by high lethality. However, the mechanisms by which Y. pestis adheres in the lung after inhalation remain elusive. Here, we used Tn-seq to identify Y. pestis genes important for adherence early during primary pneumonic plague. Our mutant enrichment strategy resulted in the identification of genes important for regulation and assembly of genes and proteins rather than adhesin genes themselves. These results reveal that there may be multiple Y. pestis adhesins or redundancy among adhesins. Identifying the adhesins regulated by the genes identified in our enrichment screen may reveal novel therapeutic targets for preventing Y. pestis adherence and the subsequent development of pneumonic plague.
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Krukonis ES, Thomson JJ. Complement evasion mechanisms of the systemic pathogens Yersiniae and Salmonellae. FEBS Lett 2020; 594:2598-2620. [DOI: 10.1002/1873-3468.13771] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 01/12/2023]
Affiliation(s)
- Eric S. Krukonis
- Division of Integrated Biomedical Sciences University of Detroit Mercy School of Dentistry Detroit MI USA
| | - Joshua J. Thomson
- Division of Integrated Biomedical Sciences University of Detroit Mercy School of Dentistry Detroit MI USA
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Bohn E, Sonnabend M, Klein K, Autenrieth IB. Bacterial adhesion and host cell factors leading to effector protein injection by type III secretion system. Int J Med Microbiol 2019; 309:344-350. [DOI: 10.1016/j.ijmm.2019.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/02/2019] [Accepted: 05/31/2019] [Indexed: 01/14/2023] Open
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Thomson JJ, Plecha SC, Krukonis ES. Ail provides multiple mechanisms of serum resistance to Yersinia pestis. Mol Microbiol 2018; 111:82-95. [PMID: 30260060 DOI: 10.1111/mmi.14140] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2018] [Indexed: 02/06/2023]
Abstract
Ail, a multifunctional outer membrane protein of Yersinia pestis, confers cell binding, Yop delivery and serum resistance activities. Resistance to complement proteins in serum is critical for the survival of Y. pestis during the septicemic stage of plague infections. Bacteria employ a variety of tactics to evade the complement system, including recruitment of complement regulatory factors, such as factor H, C4b-binding protein (C4BP) and vitronectin (Vn). Y. pestis Ail interacts with the regulatory factors Vn and C4BP, and Ail homologs from Y. enterocolitica and Y. pseudotuberculosis recruit factor H. Using co-sedimentation assays, we demonstrate that two surface-exposed amino acids, F80 and F130, are required for the interaction of Y. pestis Ail with Vn, factor H and C4BP. However, although Ail-F80A/F130A fails to interact with these complement regulatory proteins, it still confers 10,000-fold more serum resistance than a Δail strain and prevents C9 polymerization, potentially by directly interfering with MAC assembly. Using site-directed mutagenesis, we further defined this additional mechanism of complement evasion conferred by Ail. Finally, we find that at Y. pestis concentrations reflective of early-stage septicemic plague, Ail weakly recruits Vn and fails to recruit factor H, suggesting that this alternative mechanism of serum resistance may be essential during plague infection.
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Affiliation(s)
- Joshua J Thomson
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA
| | - Sarah C Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA
| | - Eric S Krukonis
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA.,Department of Immunology, Microbiology, and Biochemistry, Wayne State University School of Medicine, Detroit, MI, USA.,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
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Abstract
Many bacteria, both environmental and pathogenic, exhibit the property of autoaggregation. In autoaggregation (sometimes also called autoagglutination or flocculation), bacteria of the same type form multicellular clumps that eventually settle at the bottom of culture tubes. Autoaggregation is generally mediated by self-recognising surface structures, such as proteins and exopolysaccharides, which we term collectively as autoagglutinins. Although a widespread phenomenon, in most cases the function of autoaggregation is poorly understood, though there is evidence to show that aggregating bacteria are protected from environmental stresses or host responses. Autoaggregation is also often among the first steps in forming biofilms. Here, we review the current knowledge on autoaggregation, the role of autoaggregation in biofilm formation and pathogenesis, and molecular mechanisms leading to aggregation using specific examples.
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Affiliation(s)
- Thomas Trunk
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Hawzeen S Khalil
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jack C Leo
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
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