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Prajapati A, Hemanth RA, Namrutha MR, Bindu S, Yogisharadhya R, Mohanty NN, Chanda MM, Shivachandra SB. Production of highly soluble and immuno-reactive recombinant flagellin protein of Clostridium chauvoei. Anaerobe 2024; 89:102899. [PMID: 39142535 DOI: 10.1016/j.anaerobe.2024.102899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 06/02/2024] [Accepted: 08/10/2024] [Indexed: 08/16/2024]
Abstract
OBJECTIVE Flagellin protein, an integral component of flagella, provides motility to several bacterial species and also acts as a candidate antigen in diagnostics and subunit vaccines. The bulk production of flagellin with retention of all conformational epitopes using recombinant protein technology is of paramount importance in the development of pathogen-specific immuno-assays and vaccines. We describe the production of highly soluble and immuno-reactive rFliA(C) protein of Clostridium chauvoei, a causative agent of blackleg or black quarter (BQ) affecting cattle and small ruminants worldwide. The bacterium is known to possess peritrichous flagella that provide motility and also act as a virulence factor with high protective antigenicity. METHODS Upon sequence and structural analysis, a partial fliA(C) gene from Clostridium chauvoei was cloned and the recombinant mature protein with N- and C- terminal truncation was over-expressed as a His-tagged fusion protein (∼25 kDa) in Escherichia coli. Subsequently, rFliA(C) protein was purified by single-step affinity chromatography and characterized for its immuno-reactivity in laboratory animals, Western blot, and indirect-ELISA format. RESULTS rFliA(C) was highly soluble and was purified in high quantity and quality. rFliA(C) elicited antigen-specific conformational polyclonal antibodies in rabbit and guinea pig models, as well as anti-Clostridium chauvoei-specific antibodies being specifically detected in BQ-vaccinated and convalescent sera of bovines in Western blot and in indirect-ELISA format. Further, no cross reactivity was noted with antibodies against major bovine diseases (e.g., foot-and-mouth disease, IBR, LSDV, hemorrhagic septicaemia, brucellosis, and leptospirosis). CONCLUSION The study indicated the production of conformational recombinant flagellin-rFliA(C)-antigen and its potential utility in development of diagnostics for detection of Clostridium chauvoei-specific antibodies in BQ-recovered and/or vaccinated animals.
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Affiliation(s)
- Awadhesh Prajapati
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India
| | - Roopa Anandamurthy Hemanth
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India
| | - Mandira Ramakrishna Namrutha
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India
| | - Suresh Bindu
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India
| | - Revanaiah Yogisharadhya
- ICAR-Krishi Vigyan Kendra (KVK), ICAR-Research Complex for NEH Region, Hailakandi, 788152, Assam, India
| | - Nihar Nalini Mohanty
- CCS-National Institute of Animal Health (NIAH), Baghpat, 250609, Uttar Pradesh (UP), India
| | - Mohammed Mudassar Chanda
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India
| | - Sathish Bhadravati Shivachandra
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India.
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Waszczuk W, Czajkowska J, Dutkiewicz A, Klasa B, Carolak E, Aleksandrowicz A, Grzymajlo K. It takes two to attach - endo-1,3-β-d-glucanase as a potential receptor of mannose-independent, FimH-dependent Salmonella Typhimurium binding to spinach leaves. Food Microbiol 2024; 121:104519. [PMID: 38637081 DOI: 10.1016/j.fm.2024.104519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 04/20/2024]
Abstract
Currently, fresh, unprocessed food has become a relevant element of the chain of transmission of enteropathogenic infections. To survive on a plant surface and further spread the infections, pathogens like Salmonella have to attach stably to the leaf surface. Adhesion, driven by various virulence factors, including the most abundant fim operon encoding type 1 fimbriae, is usually an initial step of infection, preventing physical removal of the pathogen. Adhesion properties of Salmonella's type 1 fimbriae and its FimH adhesin were investigated intensively in the past. However, there is a lack of knowledge regarding its role in interaction with plant cells. Understanding the mechanisms and structures involved in such interaction may facilitate efforts to decrease the risk of contamination and increase fresh food safety. Here, we applied Salmonella genome site-directed mutagenesis, adhesion assays, protein-protein interactions, and biophysics methods based on surface plasmon resonance to unravel the role of FimH adhesin in interaction with spinach leaves. We show that FimH is at least partially responsible for Salmonella binding to spinach leaves, and this interaction occurs in a mannose-independent manner. Importantly, we identified a potential FimH receptor as endo-1,3-β-d-Glucanase and found that this interaction is strong and specific, with a dissociation constant in the nanomolar range. This research advances our comprehension of Salmonella's interactions with plant surfaces, offering insights that can aid in minimizing contamination risks and improving the safety of fresh, unprocessed foods.
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Affiliation(s)
- Wiktoria Waszczuk
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Joanna Czajkowska
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Agata Dutkiewicz
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Beata Klasa
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Ewa Carolak
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Adrianna Aleksandrowicz
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
| | - Krzysztof Grzymajlo
- Wrocław University of Environmental and Life Sciences, Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Poland.
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Halte M, Popp PF, Hathcock D, Severn J, Fischer S, Goosmann C, Ducret A, Charpentier E, Tu Y, Lauga E, Erhardt M, Renault TT. Bacterial motility depends on a critical flagellum length and energy-optimised assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.599820. [PMID: 38979141 PMCID: PMC11230379 DOI: 10.1101/2024.06.28.599820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The flagellum is the most complex macromolecular structure known in bacteria and comprised of around two dozen distinct proteins. The main building block of the long, external flagellar filament, flagellin, is secreted through the flagellar type-III secretion system at a remarkable rate of several tens of thousands amino acids per second, significantly surpassing the rates achieved by other pore-based protein secretion systems. The evolutionary implications and potential benefits of this high secretion rate for flagellum assembly and function, however, have remained elusive. In this study, we provide both experimental and theoretical evidence that the flagellar secretion rate has been evolutionarily optimized to facilitate rapid and efficient construction of a functional flagellum. By synchronizing flagellar assembly, we found that a minimal filament length of 2.5 µm was required for swimming motility. Biophysical modelling revealed that this minimal filament length threshold resulted from an elasto-hydrodynamic instability of the whole swimming cell, dependent on the filament length. Furthermore, we developed a stepwise filament labeling method combined with electron microscopy visualization to validate predicted flagellin secretion rates of up to 10,000 amino acids per second. A biophysical model of flagellum growth demonstrates that the observed high flagellin secretion rate efficiently balances filament elongation and energy consumption, thereby enabling motility in the shortest amount of time. Taken together, these insights underscore the evolutionary pressures that have shaped the development and optimization of the flagellum and type-III secretion system, illuminating the intricate interplay between functionality and efficiency in assembly of large macromolecular structures. Significance statement Our study demonstrates how protein secretion of the bacterial flagellum is finely tuned to optimize filament assembly rate and flagellum function while minimizing energy consumption. By measuring flagellar filament lengths and bacterial swimming after initiation of flag-ellum assembly, we were able to establish the minimal filament length necessary for swimming motility, which we rationalized physically as resulting from an elasto-hydrodynamic instability of the swimming cell. Our bio-physical model of flagellum growth further illustrates how the physiological flagellin secretion rate is optimized to maximize filament elongation while conserving energy. These findings illuminate the evolutionary pressures that have shaped the function of the bacterial flagellum and type-III secretion system, driving improvements in bacterial motility and overall fitness.
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Neamah M, Mahdi E, Sameir M, Hussein S, Saber A. Clustered Regularly Interspaced Short Palindromic Repeat-1 (CRISPR-1) Locus as a Tool for Tracing the Zoonotic History of Salmonella enterica Strains. Cureus 2024; 16:e62050. [PMID: 38989365 PMCID: PMC11235391 DOI: 10.7759/cureus.62050] [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] [Accepted: 06/10/2024] [Indexed: 07/12/2024] Open
Abstract
Background Salmonella enterica is a significant foodborne pathogen that causes considerable illness and death in humans and animals. The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) system in bacteria acts as an adaptive immune defense against invasive genetic elements by incorporating short intergenic spacers (IGSs) into CRISPR loci. These loci serve as molecular records of past interactions with phages and plasmids, providing insights into the transmission and evolution of bacterial strains across different hosts. Aim This study aimed to investigate the diversity of IGSs in the CRISPR-1 locus of S. enterica isolates from humans and camels. The objective was to assess the potential of IGSs to distinguish strains, track sources, and understand patterns of zoonotic transmission. Materials and methods Genomic DNA was extracted from multiple strains of S. enterica, and the CRISPR-1 locus was polymerase chain reaction (PCR) amplified and sequenced. The sequences were compared to identify distinct patterns of IGSs and potential host-specific characteristics. Sanger sequencing and bioinformatics tools were used to classify the IGSs and determine their similarity to known sequences in the National Center for Biotechnology Information (NCBI) database. Results Sequence analysis revealed five distinct CRISPR-1 types among S. enterica isolates from humans and three among camel isolates. The presence of shared IGSs between human and camel S. enterica isolates suggested zoonotic or reverse-zoonotic transmission events. Additionally, host-specific unknown IGSs (UIGS) were identified. Importantly, camel isolates initially identified as S. enterica subspecies enterica serovar Enteritidis based on rrnH gene sequencing were reclassified as S. enterica serovar Enteritidis based on CRISPR-1 profiling, demonstrating the higher resolution of CRISPR-based genotyping. Conclusion The diversity of IGSs in the CRISPR-1 locus effectively differentiated S. enterica strains and provided insights into their evolutionary origins and transmission dynamics. CRISPR-based genotyping proves to be a promising tool to complement traditional serotyping methods, enhancing the molecular epidemiology of salmonellosis and potentially leading to better management and control strategies for this pathogen.
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Affiliation(s)
- Maan Neamah
- Department of Medical Biotechnology, Al-Qasim Green University, Babil, IRQ
| | - Evan Mahdi
- Department of Medical Laboratory Techniques, Altoosi University College, Najaf, IRQ
| | - Muhammed Sameir
- Hammurabi College of Medicine, University of Babylon, Babil, IRQ
| | - Safin Hussein
- Department of Biology, University of Raparin, Sulaymaniyah, IRQ
| | - Abdulmalik Saber
- Department of Psychiatric and Mental Health Nursing, Hawler Medical University, Erbil, IRQ
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Fields JL, Zhang H, Bellis NF, Petersen HA, Halder SK, Rich-New ST, Wu H, Wang F. Structural diversity and clustering of bacterial flagellar outer domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585621. [PMID: 38562817 PMCID: PMC10983879 DOI: 10.1101/2024.03.18.585621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Supercoiled flagellar filaments function as mechanical propellers within the bacterial flagellum complex, playing a crucial role in motility. Flagellin, the building block of the filament, features a conserved inner D0/D1 core domain across different bacterial species. In contrast, approximately half of the flagellins possess additional, highly divergent outer domain(s), suggesting varied functional potential. In this study, we elucidate atomic structures of flagellar filaments from three distinct bacterial species: Cupriavidus gilardii , Stenotrophomonas maltophilia , and Geovibrio thiophilus . Our findings reveal that the flagella from the facultative anaerobic G. thiophilus possesses a significantly more negatively charged surface, potentially enabling adhesion to positively charged minerals. Furthermore, we analyzed all AlphaFold predicted structures for annotated bacterial flagellins, categorizing the flagellin outer domains into 682 structural clusters. This classification provides insights into the prevalence and experimental verification of these outer domains. Remarkably, two of the flagellar structures reported herein belong to a previously unexplored cluster, indicating new opportunities on the study of the functional diversity of flagellar outer domains. Our findings underscore the complexity of bacterial flagellins and open up possibilities for future studies into their varied roles beyond motility.
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Wang G, Wang Y, Ma F. Exploiting bacterial-origin immunostimulants for improved vaccination and immunotherapy: current insights and future directions. Cell Biosci 2024; 14:24. [PMID: 38368397 PMCID: PMC10874560 DOI: 10.1186/s13578-024-01207-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 02/06/2024] [Indexed: 02/19/2024] Open
Abstract
Vaccination is a valid strategy to prevent and control newly emerging and reemerging infectious diseases in humans and animals. However, synthetic and recombinant antigens are poor immunogenic to stimulate efficient and protective host immune response. Immunostimulants are indispensable factors of vaccines, which can promote to trigger fast, robust, and long-lasting immune responses. Importantly, immunotherapy with immunostimulants is increasing proved to be an effective and promising treatment of cancer, which could enhance the function of the immune system against tumor cells. Pattern recognition receptors (PRRs) play vital roles in inflammation and are central to innate and adaptive immune responses. Toll-like receptors (TLRs)-targeting immunostimulants have become one of the hotspots in adjuvant research and cancer therapy. Bacterial-origin immunoreactive molecules are usually the ligands of PRRs, which could be fast recognized by PRRs and activate immune response to eliminate pathogens. Varieties of bacterial immunoreactive molecules and bacterial component-mimicking molecules have been successfully used in vaccines and clinical therapy so far. This work provides a comprehensive review of the development, current state, mechanisms, and applications of bacterial-origin immunostimulants. The exploration of bacterial immunoreactive molecules, along with their corresponding mechanisms, holds immense significance in deepening our understanding of bacterial pathogenicity and in the development of promising immunostimulants.
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Affiliation(s)
- Guangyu Wang
- College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing, Jiangsu, 210023, China
| | - Yongkang Wang
- College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing, Jiangsu, 210023, China
| | - Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
- GuoTai (Taizhou) Center of Technology Innovation for Veterinary Biologicals, Taizhou, 225300, China.
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He B, Zhu TT, Liang Y, Wei HJ, Huang ZL, Liang LJ, Zhong JH, Luo Y, Lian XL, Zhao DH, Liao XP, Liu YH, Ren H, Sun J. Adaptive evolution in asymptomatic host confers MDR Salmonella with enhanced environmental persistence and virulence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168340. [PMID: 37931815 DOI: 10.1016/j.scitotenv.2023.168340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/03/2023] [Accepted: 11/03/2023] [Indexed: 11/08/2023]
Abstract
As a common cause for food-borne diseases, the Salmonella spp. are generally prevalent among livestock, whereby they are likely to be transmitted to human via environmental contamination. To explore the potential mechanism for prevalence of MDR Salmonella and its risk for dissemination via contaminated environments, we profiled the colonization dynamics of MDR Salmonella in chicken, herein we found that an adaptive evolution, driven by mutagenesis in a small protein-encoding gene (STM14_1829), conferred the multidrug resistant (MDR) Salmonella with increased fitness in asymptomatic host. Then the mechanistic study demonstrated that only one amino acid substitution in small protein STM14_1829 rendered MDR Salmonella capable to better invade and persist in phagocytotic cells by modulating bacterial flagella overexpression. Concerningly, the evolved Salmonella was also more resilient to the potential stressors generally found in environments and food processing, including heat, cold, adverse pH and oxidations. It implied that the evolved subpopulations are plausibly more persistent in environments once they contaminated through animal manure or human excreta. Moreover, the evolution promoted the pathogenesis caused by MDR Salmonella in susceptible hosts, resulting in higher risk for dissemination of pathogens via contaminated environments. Together, our data provided the novel insights into that in vivo adaptive evolution benefits Salmonella colonization, persistence and pathogenesis, by promoting bacterial tolerance via modulating flagella expression. These findings may explain the rationale behind the increasing prevalence of certain MDR Salmonella clones in livestock and associated environment, and underscoring the need for advanced strategies to tackle the possible evolution of such zoonotic pathogens.
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Affiliation(s)
- Bing He
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Ting-Ting Zhu
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Yin Liang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Hai-Jing Wei
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Zi-Lei Huang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Li-Jie Liang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Jia-Hao Zhong
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Yang Luo
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Xin-Lei Lian
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Dong-Hao Zhao
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Xiao-Ping Liao
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China
| | - Ya-Hong Liu
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, PR China
| | - Hao Ren
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China.
| | - Jian Sun
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, PR China.
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Zhang S, Ren L, Zhang C, Cao Q, Ye H, Dong Z, Feng D, Zuo J, Wang W. Research Note: Xylooligosaccharide directly attenuates Salmonella Typhimurium colonization and its induction of impairments in intestinal barrier and growth performance of broilers. Poult Sci 2024; 103:103184. [PMID: 37918306 PMCID: PMC10624967 DOI: 10.1016/j.psj.2023.103184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/25/2023] [Accepted: 10/06/2023] [Indexed: 11/04/2023] Open
Abstract
Xylooligosaccharide (XOS) is known as a prebiotic, however, it is unknown whether XOS can directly protect against bacterial infection. This study aimed to investigate the direct inhibitory effects of XOS on Salmonella Typhimurium colonization and the inductive impairments in gut health and growth performance in broilers. We first probed the inhibitory effects of XOS on S. Typhimurium adhesion and its induction of intestinal epithelial cell (IPEC-J2) injuries. Afterward, 168 one-day-old yellow-feathered broilers were randomly divided into 3 groups (7 replicates/group): negative control (NC, received a basal diet), positive control (PC, received a basal diet with S. Typhimurium challenge) and XOS group (PC birds + 1,500 mg/kg XOS). All birds except those in NC were orally challenged with S. Typhimurium from 8 to 10 d of age. Parameters were analyzed on d 11. The results showed that XOS inhibited S. Typhimurium adhesion and the inductive injuries of IPEC-J2 cells by lowering (P < 0.05) certain adhesion-related genes expression of this bacterium. It also alleviated S. Typhimurium-induced increase (P < 0.05) in the expression of certain inflammatory cytokines and tight junction (TJ) proteins of IPEC-J2 cells. Supplementing XOS to S. Typhimurium-challenged broilers attenuated the elevations (P < 0.05) in S. Typhimurium colonization of ileal mucosa and its translocation to the liver and spleen, as well as increased (P < 0.05) certain TJ proteins expression of ileum. Besides, XOS addition normalized S. Typhimurium-induced impairments (P < 0.05) in ileal morphology, final body weight and average daily gain in broilers. Collectively, supplemental XOS directly suppressed intestinal colonization of S. Typhimurium by diminishing its adhesiveness and subsequently mitigated destructions in intestinal barriers, thus contributing to weaken growth retardation in challenged broilers. Our findings provide a new insight into the mechanisms of XOS limiting Salmonella infection in chickens.
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Affiliation(s)
- Shuming Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Lulu Ren
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Changming Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Qingyun Cao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Hui Ye
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Zemin Dong
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Dingyuan Feng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Jianjun Zuo
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Weiwei Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
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Minamino T, Kinoshita M. Structure, Assembly, and Function of Flagella Responsible for Bacterial Locomotion. EcoSal Plus 2023; 11:eesp00112023. [PMID: 37260402 PMCID: PMC10729930 DOI: 10.1128/ecosalplus.esp-0011-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/14/2023] [Indexed: 01/28/2024]
Abstract
Many motile bacteria use flagella for locomotion under a variety of environmental conditions. Because bacterial flagella are under the control of sensory signal transduction pathways, each cell is able to autonomously control its flagellum-driven locomotion and move to an environment favorable for survival. The flagellum of Salmonella enterica serovar Typhimurium is a supramolecular assembly consisting of at least three distinct functional parts: a basal body that acts as a bidirectional rotary motor together with multiple force generators, each of which serves as a transmembrane proton channel to couple the proton flow through the channel with torque generation; a filament that functions as a helical propeller that produces propulsion; and a hook that works as a universal joint that transmits the torque produced by the rotary motor to the helical propeller. At the base of the flagellum is a type III secretion system that transports flagellar structural subunits from the cytoplasm to the distal end of the growing flagellar structure, where assembly takes place. In recent years, high-resolution cryo-electron microscopy (cryoEM) image analysis has revealed the overall structure of the flagellum, and this structural information has made it possible to discuss flagellar assembly and function at the atomic level. In this article, we describe what is known about the structure, assembly, and function of Salmonella flagella.
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Affiliation(s)
- Tohru Minamino
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Miki Kinoshita
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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Grzymajło K, Dutkiewicz A, Czajkowska J, Carolak E, Aleksandrowicz A, Waszczuk W. Salmonella adhesion is decreased by hypoxia due to adhesion and motility structure crosstalk. Vet Res 2023; 54:99. [PMID: 37875985 PMCID: PMC10598919 DOI: 10.1186/s13567-023-01233-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/28/2023] [Indexed: 10/26/2023] Open
Abstract
Initial stages of Salmonella Typhimurium infection involve a series of coordinated events aimed at reaching, attaching to, and invading host cells. Virulence factors such as flagella, fimbriae, and secretion systems play crucial roles in these events and are regulated in response to the host environment. The first point of contact between the pathogen and host is the intestinal epithelial layer, which normally serves as a barrier against invading pathogens, but can also be an entry site for pathogens. The integrity of this barrier can be modulated by the hypoxic environment of the intestines, created by the presence of trillions of microbes. Variable oxygen concentrations can strongly affect many functions of the gut, including secretion of cytokines and growth factors from the host site and affect the ability of Salmonella to persist, invade, and replicate. In this study, we investigated the first stages of Salmonella Typhimurium infection under hypoxic conditions in vitro and found that low oxygen levels significantly decreased bacterial adhesion. Using adhesion and motility assays, biofilm formation tests, as well as gene expression and cytokine secretion analysis, we identified a hypoxia-specific cross-talk between the expression of type 1 fimbriae and flagella, suggesting that altered flagellin expression levels affect the motility of bacteria and further impact their adhesion level, biofilm formation ability, and innate immune response. Overall, understanding how Salmonella interacts with its variable host environment provides insights into the virulence mechanisms of the bacterium and information regarding strategies for preventing or treating infections. Further research is required to fully understand the complex interplay between Salmonella and its host environment.
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Affiliation(s)
- Krzysztof Grzymajło
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
| | - Agata Dutkiewicz
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Joanna Czajkowska
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Ewa Carolak
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Adrianna Aleksandrowicz
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Wiktoria Waszczuk
- Faculty of Veterinary Medicine, Department of Biochemistry and Molecular Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
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11
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Genthe E, Miletic S, Tekkali I, Hennell James R, Marlovits TC, Heuser P. PickYOLO: Fast deep learning particle detector for annotation of cryo electron tomograms. J Struct Biol 2023; 215:107990. [PMID: 37364763 DOI: 10.1016/j.jsb.2023.107990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 05/31/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
Particle localization (picking) in digital tomograms is a laborious and time-intensive step in cryogenic electron tomography (cryoET) analysis often requiring considerable user involvement, thus becoming a bottleneck for automated cryoET subtomogram averaging (STA) pipelines. In this paper, we introduce a deep learning framework called PickYOLO to tackle this problem. PickYOLO is a super-fast, universal particle detector based on the deep-learning real-time object recognition system YOLO (You Only Look Once), and tested on single particles, filamentous structures, and membrane-embedded particles. After training with the centre coordinates of a few hundred representative particles, the network automatically detects additional particles with high yield and reliability at a rate of 0.24-3.75 s per tomogram. PickYOLO can automatically detect number of particles comparable to those manually selected by experienced microscopists. This makes PickYOLO a valuable tool to substantially reduce the time and manual effort needed to analyse cryoET data for STA, greatly aiding in high-resolution cryoET structure determination.
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Affiliation(s)
- Erik Genthe
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Sean Miletic
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany; CSSB Centre for Structural Systems Biology, Notkestr. 85, 22607 Hamburg, Germany; University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
| | - Indira Tekkali
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany; Helmholtz Imaging, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Rory Hennell James
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany; CSSB Centre for Structural Systems Biology, Notkestr. 85, 22607 Hamburg, Germany; University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
| | - Thomas C Marlovits
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany; CSSB Centre for Structural Systems Biology, Notkestr. 85, 22607 Hamburg, Germany; University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.
| | - Philipp Heuser
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany; Helmholtz Imaging, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
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12
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Sanchez JC, Montemayor EJ, Ploscariu NT, Parrell D, Baumgardt JK, Yang JE, Sibert B, Cai K, Wright ER. Atomic-level architecture of Caulobacter crescentus flagellar filaments provide evidence for multi-flagellin filament stabilization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548443. [PMID: 37503001 PMCID: PMC10369909 DOI: 10.1101/2023.07.10.548443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Flagella are dynamic, ion-powered machines with assembly pathways that are optimized for efficient flagella production. In bacteria, dozens of genes are coordinated at specific times in the cell lifecycle to generate each component of the flagellum. This is the case for Caulobacter crescentus, but little is known about why this species encodes six different flagellin genes. Furthermore, little is known about the benefits multi-flagellin species possess over single flagellin species, if any, or what molecular properties allow for multi-flagellin filaments to assemble. Here we present an in-depth analysis of several single flagellin filaments from C. crescentus, including an extremely well-resolved structure of a bacterial flagellar filament. We highlight key molecular interactions that differ between each bacterial strain and speculate how these interactions may alleviate or impose helical strain on the overall architecture of the filament. We detail conserved residues within the flagellin subunit that allow for the synthesis of multi-flagellin filaments. We further comment on how these molecular differences impact bacterial motility and highlight how no single flagellin filament achieves wild-type levels of motility, suggesting C. crescentus has evolved to produce a filament optimized for motility comprised of six flagellins. Finally, we highlight an ordered arrangement of glycosylation sites on the surface of the filaments and speculate how these sites may protect the β-hairpin located on the surface exposed domain of the flagellin subunit.
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Affiliation(s)
- Juan C. Sanchez
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | - Eric J. Montemayor
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | | | - Daniel Parrell
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI USA
| | - Joseph K. Baumgardt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | - Jie E. Yang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
| | - Bryan Sibert
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
| | - Kai Cai
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
| | - Elizabeth R. Wright
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI 53706
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI USA
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Morgridge Institute for Research, UW-Madison, Madison, WI, 53715, USA
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13
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Saleh DO, Horstmann JA, Giralt-Zúñiga M, Weber W, Kaganovitch E, Durairaj AC, Klotzsch E, Strowig T, Erhardt M. SPI-1 virulence gene expression modulates motility of Salmonella Typhimurium in a proton motive force- and adhesins-dependent manner. PLoS Pathog 2023; 19:e1011451. [PMID: 37315106 DOI: 10.1371/journal.ppat.1011451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
Both the bacterial flagellum and the evolutionary related injectisome encoded on the Salmonella pathogenicity island 1 (SPI-1) play crucial roles during the infection cycle of Salmonella species. The interplay of both is highlighted by the complex cross-regulation that includes transcriptional control of the flagellar master regulatory operon flhDC by HilD, the master regulator of SPI-1 gene expression. Contrary to the HilD-dependent activation of flagellar gene expression, we report here that activation of HilD resulted in a dramatic loss of motility, which was dependent on the presence of SPI-1. Single cell analyses revealed that HilD-activation triggers a SPI-1-dependent induction of the stringent response and a substantial decrease in proton motive force (PMF), while flagellation remains unaffected. We further found that HilD activation enhances the adhesion of Salmonella to epithelial cells. A transcriptome analysis revealed a simultaneous upregulation of several adhesin systems, which, when overproduced, phenocopied the HilD-induced motility defect. We propose a model where the SPI-1-dependent depletion of the PMF and the upregulation of adhesins upon HilD-activation enable flagellated Salmonella to rapidly modulate their motility during infection, thereby enabling efficient adhesion to host cells and delivery of effector proteins.
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Affiliation(s)
- Doaa Osama Saleh
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Julia A Horstmann
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - María Giralt-Zúñiga
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Willi Weber
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Eugen Kaganovitch
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Abilash Chakravarthy Durairaj
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Enrico Klotzsch
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Till Strowig
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Marc Erhardt
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
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14
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Nedeljković M, Kreutzberger MAB, Postel S, Bonsor D, Xing Y, Jacob N, Schuler WJ, Egelman EH, Sundberg EJ. An unbroken network of interactions connecting flagellin domains is required for motility in viscous environments. PLoS Pathog 2023; 19:e1010979. [PMID: 37253071 PMCID: PMC10256154 DOI: 10.1371/journal.ppat.1010979] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 06/09/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023] Open
Abstract
In its simplest form, bacterial flagellar filaments are composed of flagellin proteins with just two helical inner domains, which together comprise the filament core. Although this minimal filament is sufficient to provide motility in many flagellated bacteria, most bacteria produce flagella composed of flagellin proteins with one or more outer domains arranged in a variety of supramolecular architectures radiating from the inner core. Flagellin outer domains are known to be involved in adhesion, proteolysis and immune evasion but have not been thought to be required for motility. Here we show that in the Pseudomonas aeruginosa PAO1 strain, a bacterium that forms a ridged filament with a dimerization of its flagellin outer domains, motility is categorically dependent on these flagellin outer domains. Moreover, a comprehensive network of intermolecular interactions connecting the inner domains to the outer domains, the outer domains to one another, and the outer domains back to the inner domain filament core, is required for motility. This inter-domain connectivity confers PAO1 flagella with increased stability, essential for its motility in viscous environments. Additionally, we find that such ridged flagellar filaments are not unique to Pseudomonas but are, instead, present throughout diverse bacterial phyla.
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Affiliation(s)
- Marko Nedeljković
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Mark A. B. Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Sandra Postel
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Daniel Bonsor
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Yingying Xing
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Neil Jacob
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - William J. Schuler
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Edward H. Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Eric J. Sundberg
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
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15
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Teklemariam AD, Al-Hindi RR, Albiheyri RS, Alharbi MG, Alghamdi MA, Filimban AAR, Al Mutiri AS, Al-Alyani AM, Alseghayer MS, Almaneea AM, Albar AH, Khormi MA, Bhunia AK. Human Salmonellosis: A Continuous Global Threat in the Farm-to-Fork Food Safety Continuum. Foods 2023; 12:foods12091756. [PMID: 37174295 PMCID: PMC10178548 DOI: 10.3390/foods12091756] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
Salmonella is one of the most common zoonotic foodborne pathogens and a worldwide public health threat. Salmonella enterica is the most pathogenic among Salmonella species, comprising over 2500 serovars. It causes typhoid fever and gastroenteritis, and the serovars responsible for the later disease are known as non-typhoidal Salmonella (NTS). Salmonella transmission to humans happens along the farm-to-fork continuum via contaminated animal- and plant-derived foods, including poultry, eggs, fish, pork, beef, vegetables, fruits, nuts, and flour. Several virulence factors have been recognized to play a vital role in attaching, invading, and evading the host defense system. These factors include capsule, adhesion proteins, flagella, plasmids, and type III secretion systems that are encoded on the Salmonella pathogenicity islands. The increased global prevalence of NTS serovars in recent years indicates that the control approaches centered on alleviating the food animals' contamination along the food chain have been unsuccessful. Moreover, the emergence of antibiotic-resistant Salmonella variants suggests a potential food safety crisis. This review summarizes the current state of the knowledge on the nomenclature, microbiological features, virulence factors, and the mechanism of antimicrobial resistance of Salmonella. Furthermore, it provides insights into the pathogenesis and epidemiology of Salmonella infections. The recent outbreaks of salmonellosis reported in different clinical settings and geographical regions, including Africa, the Middle East and North Africa, Latin America, Europe, and the USA in the farm-to-fork continuum, are also highlighted.
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Affiliation(s)
- Addisu D Teklemariam
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Rashad R Al-Hindi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Raed S Albiheyri
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Centre of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Mona G Alharbi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Mashail A Alghamdi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Amani A R Filimban
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Abdullah S Al Mutiri
- Laboratory Department, Saudi Food and Drug Authority, Riyadh 12843, Saudi Arabia
| | - Abdullah M Al-Alyani
- Laboratory Department, Saudi Food and Drug Authority, Jeddah 22311, Saudi Arabia
| | - Mazen S Alseghayer
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Monitoring and Risk Assessment Department, Saudi Food and Drug Authority, Riyadh 13513, Saudi Arabia
| | - Abdulaziz M Almaneea
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Monitoring and Risk Assessment Department, Saudi Food and Drug Authority, Riyadh 13513, Saudi Arabia
| | - Abdulgader H Albar
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Department of Microbiology and Medical Parasitology, Faculty of Medicine, Jeddah University, Jeddah 23218, Saudi Arabia
| | - Mohsen A Khormi
- Department of Biological Sciences, Faculty of Sciences, Jazan University, Jazan 82817, Saudi Arabia
| | - Arun K Bhunia
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
- Purdue University Interdisciplinary Life Science Program (PULSe), West Lafayette, IN 47907, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
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16
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Development and application of a multiplex PCR method to differentiate Salmonella enterica serovar Typhimurium from its monophasic variants in pig farms. Food Microbiol 2023; 109:104135. [DOI: 10.1016/j.fm.2022.104135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/19/2022]
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17
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Gabbert AD, Mydosh JL, Talukdar PK, Gloss LM, McDermott JE, Cooper KK, Clair GC, Konkel ME. The Missing Pieces: The Role of Secretion Systems in Campylobacter jejuni Virulence. Biomolecules 2023; 13:135. [PMID: 36671522 PMCID: PMC9856085 DOI: 10.3390/biom13010135] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/29/2022] [Accepted: 01/05/2023] [Indexed: 01/10/2023] Open
Abstract
Campylobacter jejuni is likely the most common bacterial cause of gastroenteritis worldwide, responsible for millions of cases of inflammatory diarrhea characterized by severe abdominal cramps and blood in the stool. Further, C. jejuni infections are associated with post-infection sequelae in developed countries and malnutrition and growth-stunting in low- and middle-income countries. Despite the increasing prevalence of the disease, campylobacteriosis, and the recognition that this pathogen is a serious health threat, our understanding of C. jejuni pathogenesis remains incomplete. In this review, we focus on the Campylobacter secretion systems proposed to contribute to host-cell interactions and survival in the host. Moreover, we have applied a genomics approach to defining the structural and mechanistic features of C. jejuni type III, IV, and VI secretion systems. Special attention is focused on the flagellar type III secretion system and the prediction of putative effectors, given that the proteins exported via this system are essential for host cell invasion and the inflammatory response. We conclude that C. jejuni does not possess a type IV secretion system and relies on the type III and type VI secretion systems to establish a niche and potentiate disease.
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Affiliation(s)
- Amber D. Gabbert
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Jennifer L. Mydosh
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ 85721, USA
| | - Prabhat K. Talukdar
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Lisa M. Gloss
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Jason E. McDermott
- Integrative Omics, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Kerry K. Cooper
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ 85721, USA
| | - Geremy C. Clair
- Integrative Omics, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Michael E. Konkel
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
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18
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Flagellar Phenotypes Impact on Bacterial Transport and Deposition Behavior in Porous Media: Case of Salmonella enterica Serovar Typhimurium. Int J Mol Sci 2022; 23:ijms232214460. [PMID: 36430938 PMCID: PMC9698738 DOI: 10.3390/ijms232214460] [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: 10/06/2022] [Revised: 11/11/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022] Open
Abstract
Bacterial contamination of groundwater has always been an ecological problem worthy of attention. In this study, Salmonella enterica serovar Typhimurium with different flagellar phenotypes mainly characterized during host-pathogen interaction were analyzed for their transport and deposition behavior in porous media. Column transport experiments and a modified mobile-immobile model were applicated on different strains with flagellar motility (wild-type) or without motility (ΔmotAB), without flagella (ΔflgKL), methylated and unmethylated flagellin (ΔfliB), and different flagella phases (fliCON, fljBON). Results showed that flagella motility could promote bacterial transport and deposition due to their biological advantages of moving and attaching to surfaces. We also found that the presence of non-motile flagella improved bacterial adhesion according to a higher retention rate of the ΔmotAB strain compared to the ΔflgKL strain. This indicated that bacteria flagella and motility both had promoting effects on bacterial deposition in sandy porous media. Flagella phases influenced the bacterial movement; the fliCON strain went faster through the column than the fljBON strain. Moreover, flagella methylation was found to favor bacterial transport and deposition. Overall, flagellar modifications affect Salmonella enterica serovar Typhimurium transport and deposition behavior in different ways in environmental conditions.
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19
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Martins Morasi R, Zimbardi da Silva A, Thais Alves Dantas S, Faganello C, Cristina Bastos Juliano L, Lúcia Mores Rall V, Ribeiro Tiba-Casas M, Pantoja JC, Ferreira Amarante A, Cristina Cirone Silva N. Overview of antimicrobial resistance and virulence factors in Salmonella spp. isolated in the last two decades from chicken in Brazil. Food Res Int 2022; 162:111955. [DOI: 10.1016/j.foodres.2022.111955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/29/2022] [Accepted: 09/16/2022] [Indexed: 11/29/2022]
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20
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Wang H, Tang Z, Xue B, Lu Q, Liu X, Zou Q. Salmonella Regulator STM0347 Mediates Flagellar Phase Variation via Hin Invertase. Int J Mol Sci 2022; 23:ijms23158481. [PMID: 35955615 PMCID: PMC9368917 DOI: 10.3390/ijms23158481] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 12/04/2022] Open
Abstract
Salmonella enterica is one of the most important food-borne pathogens, whose motility and virulence are highly related to flagella. Flagella alternatively express two kinds of surface antigen flagellin, FliC and FljB, in a phenomenon known as flagellar phase variation. The molecular mechanisms by which the switching orientation of the Hin-composed DNA segment mediates the expression of the fljBA promoter have been thoroughly illustrated. However, the precise regulators that control DNA strand exchange are barely understood. In this study, we found that a putative response regulator, STM0347, contributed to the phase variation of flagellin in S. Typhimurium. With quantitative proteomics and secretome profiling, a lack of STM0347 was confirmed to induce the transformation of flagellin from FliC to FljB. Real-time PCR and in vitro incubation of SMT0347 with the hin DNA segment suggested that STM0347 disturbed Hin-catalyzed DNA reversion via hin degradation, and the overexpression of Hin was sufficient to elicit flagellin variation. Subsequently, the Δstm0347 strain was outcompeted by its parental strain in HeLa cell invasion. Collectively, our results reveal the crucial role of STM0347 in Salmonella virulence and flagellar phase variation and highlight the complexity of the regulatory network of Hin-modulated flagellum phase variation in Salmonella.
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Affiliation(s)
- Hongou Wang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; (H.W.); (Z.T.); (Q.L.)
| | - Zhiheng Tang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; (H.W.); (Z.T.); (Q.L.)
| | - Baoshuai Xue
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130012, China;
| | - Qinghui Lu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; (H.W.); (Z.T.); (Q.L.)
| | - Xiaoyun Liu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; (H.W.); (Z.T.); (Q.L.)
- Correspondence: (X.L.); (Q.Z.); Tel.: +86-10-82805673 (X.L.); +86-10-8280-5070 (Q.Z.)
| | - Qinghua Zou
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; (H.W.); (Z.T.); (Q.L.)
- Correspondence: (X.L.); (Q.Z.); Tel.: +86-10-82805673 (X.L.); +86-10-8280-5070 (Q.Z.)
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21
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Fatty Acid Homeostasis Tunes Flagellar Motility by Activating Phase 2 Flagellin Expression, Contributing to Salmonella Gut Colonization. Infect Immun 2022; 90:e0018422. [PMID: 35652649 DOI: 10.1128/iai.00184-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Long-chain-fatty-acid (LCFA) metabolism is a fundamental cellular process in bacteria that is involved in lipid homeostasis, energy production, and infection. However, the role of LCFA metabolism in Salmonella enterica serovar Typhimurium (S. Tm) gut infection remains unclear. Here, using a murine gastroenteritis infection model, we demonstrate involvement of LCFA metabolism in S. Tm gut colonization. The LCFA metabolism-associated transcriptional regulator FadR contributes to S. Tm gut colonization. fadR deletion alters the gene expression profile and leads to aberrant flagellar motility of S. Tm. Colonization defects in the fadR mutant are attributable to altered swimming behavior characterized by less frequently smooth swimming, resulting from reduced expression of the phase 2 flagellin FljB. Notably, changes in lipid LCFA composition by fadR deletion lead to reduced expression of fljB, which is restored by exogenous LCFA. Therefore, LCFA homeostasis may maintain proper flagellar motility by activating fljB expression, contributing to S. Tm gut colonization. Our findings improve the understanding of the effect of luminal LCFA on the virulence of enteric pathogens.
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22
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Ek V, Fattinger SA, Florbrant A, Hardt WD, Di Martino ML, Eriksson J, Sellin ME. A Motile Doublet Form of Salmonella Typhimurium Diversifies Target Search Behaviour at the Epithelial Surface. Mol Microbiol 2022; 117:1156-1172. [PMID: 35332598 PMCID: PMC9325389 DOI: 10.1111/mmi.14898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/24/2022] [Accepted: 03/21/2022] [Indexed: 12/01/2022]
Abstract
The behaviors of infectious bacteria are commonly studied in bulk. This is effective to define the general properties of a given isolate, but insufficient to resolve subpopulations and unique single‐microbe behaviors within the bacterial pool. We here employ microscopy to study single‐bacterium characteristics among Salmonella enterica serovar Typhimurium (S.Tm), as they prepare for and launch invasion of epithelial host cells. We find that during the bacterial growth cycle, S.Tm populations switch gradually from fast planktonic growth to a host cell‐invasive phenotype, characterized by flagellar motility and expression of the Type‐three‐secretion‐system‐1. The indistinct nature of this shift leads to the establishment of a transient subpopulation of S.Tm “doublets”—waist‐bearing bacteria anticipating cell division—which simultaneously express host cell invasion machinery. In epithelial cell culture infections, these S.Tm doublets outperform their “singlet” brethren and represent a hyperinvasive subpopulation. Atop both glass and enteroid‐derived monolayers, doublets swim along markedly straighter trajectories than singlets, thereby diversifying search patterns and improving the surface exploration capacity of the total bacterial population. The straighter swimming, combined with an enhanced cell‐adhesion propensity, suffices to account for the hyperinvasive doublet phenotype. This work highlights bacterial cell length heterogeneity as a key determinant of target search patterns atop epithelia.
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Affiliation(s)
- Viktor Ek
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Stefan A Fattinger
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden.,Institute of Microbiology, Department of Biology, ETH, Zurich, Zurich, Switzerland
| | - Alexandra Florbrant
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH, Zurich, Zurich, Switzerland
| | - Maria Letizia Di Martino
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Jens Eriksson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
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23
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Lack of N-Terminal Segment of the Flagellin Protein Results in the Production of a Shortened Polar Flagellum in the Deep-Sea Sedimentary Bacterium Pseudoalteromonas sp. Strain SM9913. Appl Environ Microbiol 2021; 87:e0152721. [PMID: 34406825 DOI: 10.1128/aem.01527-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial polar flagella, comprised of flagellin, are essential for bacterial motility. Pseudoalteromonas sp. strain SM9913 is a bacterium isolated from deep-sea sediments. Unlike other Pseudoalteromonas strains that have a long polar flagellum, strain SM9913 has an abnormally short polar flagellum. Here, we investigated the underlying reason for the short flagellum and found that a single-base mutation was responsible for the altered flagellar assembly. This mutation leads to the fragmentation of the flagellin gene into two genes, PSM_A2281, encoding the core segment and the C-terminal segment, and PSM_A2282, encoding the N-terminal segment, and only gene PSM_A2281 is involved in the production of the short polar flagellum. When a chimeric gene of PSM_A2281 and PSM_A2282 encoding an intact flagellin, A2281::82, was expressed, a long polar flagellum was produced, indicating that the N-terminal segment of flagellin contributes to the production of a polar flagellum of a normal length. Analyses of the simulated structures of A2281 and A2281::82 and that of the flagellar filament assembled with A2281::82 indicate that due to the lack of two α-helices, the core of the flagellar filament assembled with A2281 is incomplete and is likely too weak to support the stability and movement of a long flagellum. This mutation in strain SM9913 had little effect on its growth and only a small effect on its swimming motility, implying that strain SM9913 can live well with this mutation in natural sedimentary environments. This study provides a better understanding of the assembly and production of bacterial flagella. IMPORTANCE Polar flagella, which are essential organelles for bacterial motility, are comprised of multiple flagellin subunits. A flagellin molecule contains an N-terminal segment, a core segment, and a C-terminal segment. The results of this investigation of the deep-sea sedimentary bacterium Pseudoalteromonas sp. strain SM9913 demonstrate that a single-base mutation in the flagellin gene leads to the production of an incomplete flagellin without the N-terminal segment and that the loss of the N-terminal segment of the flagellin protein results in the production of a shortened polar flagellar filament. Our results shed light on the important function of the N-terminal segment of flagellin in the assembly and stability of bacterial flagellar filament.
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24
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Structure of the molecular bushing of the bacterial flagellar motor. Nat Commun 2021; 12:4469. [PMID: 34294704 PMCID: PMC8298488 DOI: 10.1038/s41467-021-24715-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/29/2021] [Indexed: 12/15/2022] Open
Abstract
The basal body of the bacterial flagellum is a rotary motor that consists of several rings (C, MS and LP) and a rod. The LP ring acts as a bushing supporting the distal rod for its rapid and stable rotation without much friction. Here, we use electron cryomicroscopy to describe the LP ring structure around the rod, at 3.5 Å resolution, from Salmonella Typhimurium. The structure shows 26-fold rotational symmetry and intricate intersubunit interactions of each subunit with up to six partners, which explains the structural stability. The inner surface is charged both positively and negatively. Positive charges on the P ring (the part of the LP ring that is embedded within the peptidoglycan layer) presumably play important roles in its initial assembly around the rod with a negatively charged surface. In the basal body of the bacterial flagellum, the LP ring acts as a bushing supporting the distal rod for its rapid and stable rotation. Here, Yamaguchi et al. present the electron cryomicroscopy structure of the LP ring around the rod, shedding light into potential mechanisms involved in stability and assembly of the structure.
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25
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Recent Advances in the Bacterial Flagellar Motor Study. Biomolecules 2021; 11:biom11050741. [PMID: 34067523 PMCID: PMC8156572 DOI: 10.3390/biom11050741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 11/17/2022] Open
Abstract
The bacterial flagellum is a supramolecular motility machine that allows bacterial cells to swim in liquid environments [...].
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26
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Morimoto YV, Minamino T. Architecture and Assembly of the Bacterial Flagellar Motor Complex. Subcell Biochem 2021; 96:297-321. [PMID: 33252734 DOI: 10.1007/978-3-030-58971-4_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
One of the central systems responsible for bacterial motility is the flagellum. The bacterial flagellum is a macromolecular protein complex that is more than five times the cell length. Flagella-driven motility is coordinated via a chemosensory signal transduction pathway, and so bacterial cells sense changes in the environment and migrate towards more desirable locations. The flagellum of Salmonella enterica serovar Typhimurium is composed of a bi-directional rotary motor, a universal joint and a helical propeller. The flagellar motor, which structurally resembles an artificial motor, is embedded within the cell envelop and spins at several hundred revolutions per second. In contrast to an artificial motor, the energy utilized for high-speed flagellar motor rotation is the inward-directed proton flow through a transmembrane proton channel of the stator unit of the flagellar motor. The flagellar motor realizes efficient chemotaxis while performing high-speed movement by an ingenious directional switching mechanism of the motor rotation. To build the universal joint and helical propeller structures outside the cell body, the flagellar motor contains its own protein transporter called a type III protein export apparatus. In this chapter we summarize the structure and assembly of the Salmonella flagellar motor complex.
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Affiliation(s)
- Yusuke V Morimoto
- Department of Physics and Information Technology, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan
| | - Tohru Minamino
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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27
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Flagellar Structures from the Bacterium Caulobacter crescentus and Implications for Phage ϕ CbK Predation of Multiflagellin Bacteria. J Bacteriol 2021; 203:JB.00399-20. [PMID: 33288623 DOI: 10.1128/jb.00399-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023] Open
Abstract
Caulobacter crescentus is a Gram-negative alphaproteobacterium that commonly lives in oligotrophic fresh- and saltwater environments. C. crescentus is a host to many bacteriophages, including ϕCbK and ϕCbK-like bacteriophages, which require interaction with the bacterial flagellum and pilus complexes during adsorption. It is commonly thought that the six paralogs of the flagellin gene present in C. crescentus are important for bacteriophage evasion. Here, we show that deletion of specific flagellins in C. crescentus can indeed attenuate ϕCbK adsorption efficiency, although no single deletion completely ablates ϕCbK adsorption. Thus, the bacteriophage ϕCbK likely recognizes a common motif among the six known flagellins in C. crescentus with various degrees of efficiency. Interestingly, we observe that most deletion strains still generate flagellar filaments, with the exception of a strain that contains only the most divergent flagellin, FljJ, or a strain that contains only FljN and FljO. To visualize the surface residues that are likely recognized by ϕCbK, we determined two high-resolution structures of the FljK filament, with and without an amino acid substitution that induces straightening of the filament. We observe posttranslational modifications on conserved surface threonine residues of FljK that are likely O-linked glycans. The possibility of interplay between these modifications and ϕCbK adsorption is discussed. We also determined the structure of a filament composed of a heterogeneous mixture of FljK and FljL, the final resolution of which was limited to approximately 4.6 Å. Altogether, this work builds a platform for future investigations of how phage ϕCbK infects C. crescentus at the molecular level.IMPORTANCE Bacterial flagellar filaments serve as an initial attachment point for many bacteriophages to bacteria. Some bacteria harbor numerous flagellin genes and are therefore able to generate flagellar filaments with complex compositions, which is thought to be important for evasion from bacteriophages. This study characterizes the importance of the six flagellin genes in C. crescentus for infection by bacteriophage ϕCbK. We find that filaments containing the FljK flagellin are the preferred substrate for bacteriophage ϕCbK. We also present a high-resolution structure of a flagellar filament containing only the FljK flagellin, which provides a platform for future studies on determining how bacteriophage ϕCbK attaches to flagellar filaments at the molecular level.
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28
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Structural Conservation and Adaptation of the Bacterial Flagella Motor. Biomolecules 2020; 10:biom10111492. [PMID: 33138111 PMCID: PMC7693769 DOI: 10.3390/biom10111492] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 02/07/2023] Open
Abstract
Many bacteria require flagella for the ability to move, survive, and cause infection. The flagellum is a complex nanomachine that has evolved to increase the fitness of each bacterium to diverse environments. Over several decades, molecular, biochemical, and structural insights into the flagella have led to a comprehensive understanding of the structure and function of this fascinating nanomachine. Notably, X-ray crystallography, cryo-electron microscopy (cryo-EM), and cryo-electron tomography (cryo-ET) have elucidated the flagella and their components to unprecedented resolution, gleaning insights into their structural conservation and adaptation. In this review, we focus on recent structural studies that have led to a mechanistic understanding of flagellar assembly, function, and evolution.
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29
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Terahara N, Namba K, Minamino T. Dynamic exchange of two types of stator units in Bacillus subtilis flagellar motor in response to environmental changes. Comput Struct Biotechnol J 2020; 18:2897-2907. [PMID: 33163150 PMCID: PMC7595845 DOI: 10.1016/j.csbj.2020.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 11/23/2022] Open
Abstract
Bacteria can migrate towards more suitable environments by rotating flagella that are under the control of sensory signal transduction networks. The bacterial flagellum is composed of the long helical filament functioning as a propeller, the flexible hook as a universal joint and the basal body as a rotary motor powered by ion motive force across the cell membrane. The flagellar motor consists of a rotor and multiple stator units, each of which couples the ion flow through its ion channel with force generation. The flagellar building blocks and motor proteins are highly conserved among bacterial species, but structural and functional diversity of flagella has also been revealed. It has been reported that the structure and function of the flagellar motor of a Gram-positive bacterium, Bacillus subtilis, differ from those of Escherichia coli and Salmonella. The flagellar motor of the B. subtilis BR151MA strain possesses two distinct types of stator complexes, H+-type MotAB and Na+-type MotPS, around the rotor. These two types of stator units dynamically assemble to and disassemble from the rotor in response to environmental changes such as viscosity and external Na+ concentrations. In this mini-review article, we describe our recent understanding of the structure and dynamics of the B. subtilis flagellar motor.
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Affiliation(s)
- Naoya Terahara
- Department of Physics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Keiichi Namba
- Graduate School of Frontier Bioscience, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- RIKEN Spring-8 Center and Center for Biosystems Dynamics Research, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tohru Minamino
- Graduate School of Frontier Bioscience, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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30
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Kreutzberger MAB, Ewing C, Poly F, Wang F, Egelman EH. Atomic structure of the Campylobacter jejuni flagellar filament reveals how ε Proteobacteria escaped Toll-like receptor 5 surveillance. Proc Natl Acad Sci U S A 2020; 117:16985-16991. [PMID: 32641510 PMCID: PMC7382276 DOI: 10.1073/pnas.2010996117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vertebrates, from zebra fish to humans, have an innate immune recognition of many bacterial flagellins. This involves a conserved eight-amino acid epitope in flagellin recognized by the Toll-like receptor 5 (TLR5). Several important human pathogens, such as Helicobacter pylori and Campylobacter jejuni, have escaped TLR5 activation by mutations in this epitope. When such mutations were introduced into Salmonella flagellin, motility was abolished. It was previously argued, using very low-resolution cryoelectron microscopy (cryo-EM), that C. jejuni accommodated these mutations by forming filaments with 7 protofilaments, rather than the 11 found in other bacteria. We have now determined the atomic structure of the C. jejuni G508A flagellar filament from a 3.5-Å-resolution cryo-EM reconstruction, and show that it has 11 protofilaments. The residues in the C. jejuni TLR5 epitope have reduced contacts with the adjacent subunit compared to other bacterial flagellar filament structures. The weakening of the subunit-subunit interface introduced by the mutations in the TLR5 epitope is compensated for by extensive interactions between the outer domains of the flagellin subunits. In other bacteria, these outer domains can be nearly absent or removed without affecting motility. Furthermore, we provide evidence for the stabilization of these outer domain interactions through glycosylation of key residues. These results explain the essential role of glycosylation in C. jejuni motility, and show how the outer domains have evolved to play a role not previously found in other bacteria.
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Affiliation(s)
- Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903
| | - Cheryl Ewing
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Frederic Poly
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903;
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31
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Thompson MC, Yeates TO, Rodriguez JA. Advances in methods for atomic resolution macromolecular structure determination. F1000Res 2020; 9:F1000 Faculty Rev-667. [PMID: 32676184 PMCID: PMC7333361 DOI: 10.12688/f1000research.25097.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/25/2020] [Indexed: 12/13/2022] Open
Abstract
Recent technical advances have dramatically increased the power and scope of structural biology. New developments in high-resolution cryo-electron microscopy, serial X-ray crystallography, and electron diffraction have been especially transformative. Here we highlight some of the latest advances and current challenges at the frontiers of atomic resolution methods for elucidating the structures and dynamical properties of macromolecules and their complexes.
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Affiliation(s)
- Michael C. Thompson
- Department of Chemistry and Chemical Biology, University of California, Merced, CA, USA
| | - Todd O. Yeates
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA, USA
| | - Jose A. Rodriguez
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA, USA
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32
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Zarkani AA, López-Pagán N, Grimm M, Sánchez-Romero MA, Ruiz-Albert J, Beuzón CR, Schikora A. Salmonella Heterogeneously Expresses Flagellin during Colonization of Plants. Microorganisms 2020; 8:microorganisms8060815. [PMID: 32485895 PMCID: PMC7355505 DOI: 10.3390/microorganisms8060815] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 12/19/2022] Open
Abstract
Minimally processed or fresh fruits and vegetables are unfortunately linked to an increasing number of food-borne diseases, such as salmonellosis. One of the relevant virulence factors during the initial phases of the infection process is the bacterial flagellum. Although its function is well studied in animal systems, contradictory results have been published regarding its role during plant colonization. In this study, we tested the hypothesis that Salmonella's flagellin plays a versatile function during the colonization of tomato plants. We have assessed the persistence in plant tissues of a Salmonella enterica wild type strain, and of a strain lacking the two flagellins, FljB and FliC. We detected no differences between these strains concerning their respective abilities to reach distal, non-inoculated parts of the plant. Analysis of flagellin expression inside the plant, at both the population and single cell levels, shows that the majority of bacteria down-regulate flagellin production, however, a small fraction of the population continues to express flagellin at a very high level inside the plant. This heterogeneous expression of flagellin might be an adaptive strategy to the plant environment. In summary, our study provides new insights on Salmonella adaption to the plant environment through the regulation of flagellin expression.
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Affiliation(s)
- Azhar A. Zarkani
- Julius Kühn-Institut Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104 Braunschweig, Germany; (A.A.Z.); (M.G.)
- Department of Biotechnology, College of Science, University of Baghdad, 10071 Baghdad, Iraq
| | - Nieves López-Pagán
- Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Dpto. Biología Celular, Genética y Fisiología, Campus de Teatinos, 29071 Malaga, Spain; (N.L.-P.); (J.R.-A.); (C.R.B.)
| | - Maja Grimm
- Julius Kühn-Institut Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104 Braunschweig, Germany; (A.A.Z.); (M.G.)
| | - María Antonia Sánchez-Romero
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Apartado 1095, 41080 Seville, Spain;
- Current address: Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Calle Profesor García González 2, 41012 Seville, Spain
| | - Javier Ruiz-Albert
- Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Dpto. Biología Celular, Genética y Fisiología, Campus de Teatinos, 29071 Malaga, Spain; (N.L.-P.); (J.R.-A.); (C.R.B.)
| | - Carmen R. Beuzón
- Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Dpto. Biología Celular, Genética y Fisiología, Campus de Teatinos, 29071 Malaga, Spain; (N.L.-P.); (J.R.-A.); (C.R.B.)
| | - Adam Schikora
- Julius Kühn-Institut Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104 Braunschweig, Germany; (A.A.Z.); (M.G.)
- Correspondence:
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33
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Methylation of Salmonella Typhimurium flagella promotes bacterial adhesion and host cell invasion. Nat Commun 2020; 11:2013. [PMID: 32332720 PMCID: PMC7181671 DOI: 10.1038/s41467-020-15738-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 03/13/2020] [Indexed: 11/09/2022] Open
Abstract
The long external filament of bacterial flagella is composed of several thousand copies of a single protein, flagellin. Here, we explore the role played by lysine methylation of flagellin in Salmonella, which requires the methylase FliB. We show that both flagellins of Salmonella enterica serovar Typhimurium, FliC and FljB, are methylated at surface-exposed lysine residues by FliB. A Salmonella Typhimurium mutant deficient in flagellin methylation is outcompeted for gut colonization in a gastroenteritis mouse model, and methylation of flagellin promotes bacterial invasion of epithelial cells in vitro. Lysine methylation increases the surface hydrophobicity of flagellin, and enhances flagella-dependent adhesion of Salmonella to phosphatidylcholine vesicles and epithelial cells. Therefore, posttranslational methylation of flagellin facilitates adhesion of Salmonella Typhimurium to hydrophobic host cell surfaces, and contributes to efficient gut colonization and host infection. Flagellin proteins of Salmonella flagella are methylated. Here, the authors show that flagellin methylation facilitates adhesion of Salmonella to hydrophobic host-cell surfaces, and contributes to efficient gut colonization and host infection.
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