1
|
Chen X. DISSyphilis and the risk of HIV infection: A Mendelian randomization study. AIDS Res Hum Retroviruses 2024. [PMID: 39086230 DOI: 10.1089/aid.2024.0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024] Open
Abstract
OBJECTION To assess the causal effect of syphilis on HIV infection by Mendelian randomization analysis. METHODS The data of syphilis and HIV infection were obtained from genome-wide association studies, Mendelian randomization analyses were conducted using methods such as weighted median, MR Egger, and inverse variance to evaluate the causal relationship between syphilis and HIV infection. Gene expression data of persons living with HIV (PLWH) and single-cell RNA sequencing profiles were obtained from the GEO database. Analysis involved the identification of key molecules and relevant signaling pathways. RESULTS MR analysis showed a significant causal relationship between syphilis and HIV infection (WM, OR: 1.098, 95%CI: 1.033-1.217, P = 0.003; IVW, OR: 1.095, 95%CI: 1.048-1.145, P < 0.001). We discovered that rs138697742, a genetic variant related to the RPAIN gene, is associated with HIV infection, and influences the expression of RPAIN, possibly contributing to the progression of the disease. Moreover, single-cell data analysis revealed the cellular communication patterns within PLWH, with monocytes appearing to play a crucial role. CONCLUSION In summary, our study reveals a direct causal relationship between syphilis and HIV infection. Additionally, the upregulation of RPAIN gene expression resulting from genetic mutations may serve as a key factor in promoting the progression of HIV infection. Targeting the RPAIN/GALECTIN merges as a promising novel therapeutic target for managing HIV infection.
Collapse
Affiliation(s)
- Xinye Chen
- Shanghai Licheng Bio-Technique Co Ltd, Lane 2999, Hutai Road, Baoshan District, Shanghai, China, 201900;
| |
Collapse
|
2
|
Lynch MJ, Deshpande M, Kurniyati K, Zhang K, James M, Miller M, Zhang S, Passalia FJ, Wunder EA, Charon NW, Li C, Crane BR. Lysinoalanine cross-linking is a conserved post-translational modification in the spirochete flagellar hook. PNAS NEXUS 2023; 2:pgad349. [PMID: 38047041 PMCID: PMC10691653 DOI: 10.1093/pnasnexus/pgad349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023]
Abstract
Spirochetes cause Lyme disease, leptospirosis, syphilis, and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by the action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) and Lyme disease pathogen Borreliella burgdorferi (Bb) form covalent lysinoalanine (Lal) cross-links between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. In Td, Lal is unnecessary for hook assembly but is required for motility, presumably due to the stabilizing effect of the cross-link. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal cross-linked peptides in recombinant and in vivo-derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp. As was observed with Td, a mutant strain of Bb unable to form the cross-link has greatly impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans FlgE also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveal that the Lal cross-link is a conserved and necessary posttranslational modification across the spirochete phylum and may thus represent an effective target for the development of spirochete-specific antimicrobials.
Collapse
Affiliation(s)
- Michael J Lynch
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Maithili Deshpande
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Kurni Kurniyati
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, VA 23298, USA
| | - Kai Zhang
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, VA 23298, USA
| | - Milinda James
- Department of Microbiology, Immunology, and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Michael Miller
- Department of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Sheng Zhang
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY 14853, USA
| | - Felipe J Passalia
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06510, USA
| | - Elsio A Wunder
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06510, USA
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA
| | - Nyles W Charon
- Department of Microbiology, Immunology, and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Chunhao Li
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, VA 23298, USA
| | - Brian R Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
3
|
Lynch MJ, Deshpande M, Kyrniyati K, Zhang K, James M, Miller M, Zhang S, Passalia FJ, Wunder EA, Charon NW, Li C, Crane BR. Lysinoalanine crosslinking is a conserved post-translational modification in the spirochete flagellar hook. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.13.544825. [PMID: 37398457 PMCID: PMC10312707 DOI: 10.1101/2023.06.13.544825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Spirochete bacteria cause Lyme disease, leptospirosis, syphilis and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) catalyzes the formation of covalent lysinoalanine (Lal) crosslinks between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. Although not necessary for hook assembly, Lal is required for motility of Td, presumably due to the stabilizing effect of the crosslink. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal crosslinked peptides in recombinant and in vivo -derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp.. Like with Td, a mutant strain of the Lyme disease pathogen Borreliella burgdorferi unable to form the crosslink has impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveals that the Lal crosslink is a conserved and necessary post-translational modification across the spirochete phylum and may thus represent an effective target for spirochete-specific antimicrobials. Significance Statement The phylum Spirochaetota contains bacterial pathogens responsible for a variety of diseases, including Lyme disease, syphilis, periodontal disease, and leptospirosis. Motility of these pathogens is a major virulence factor that contributes to infectivity and host colonization. The oral pathogen Treponema denticola produces a post-translational modification (PTM) in the form of a lysinoalanine (Lal) crosslink between neighboring subunits of the flagellar hook protein FlgE. Herein, we demonstrate that representative spirochetes species across the phylum all form Lal in their flagellar hooks. T. denticola and B. burgdorferi cells incapable of forming the crosslink are non-motile, thereby establishing the general role of the Lal PTM in the unusual type of flagellar motility evolved by spirochetes.
Collapse
|
4
|
Ávila-Nieto C, Pedreño-López N, Mitjà O, Clotet B, Blanco J, Carrillo J. Syphilis vaccine: challenges, controversies and opportunities. Front Immunol 2023; 14:1126170. [PMID: 37090699 PMCID: PMC10118025 DOI: 10.3389/fimmu.2023.1126170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
Syphilis is a sexually or vertically (mother to fetus) transmitted disease caused by the infection of Treponema pallidum subspecie pallidum (TPA). The incidence of syphilis has increased over the past years despite the fact that this bacterium is an obligate human pathogen, the infection route is well known, and the disease can be successfully treated with penicillin. As complementary measures to preventive campaigns and early treatment of infected individuals, development of a syphilis vaccine may be crucial for controlling disease spread and/or severity, particularly in countries where the effectiveness of the aforementioned measures is limited. In the last century, several vaccine prototypes have been tested in preclinical studies, mainly in rabbits. While none of them provided protection against infection, some prototypes prevented bacteria from disseminating to distal organs, attenuated lesion development, and accelerated their healing. In spite of these promising results, there is still some controversy regarding the identification of vaccine candidates and the characteristics of a syphilis-protective immune response. In this review, we describe what is known about TPA immune response, and the main mechanisms used by this pathogen to evade it. Moreover, we emphasize the importance of integrating this knowledge, in conjunction with the characterization of outer membrane proteins (OMPs), to expedite the development of a syphilis vaccine that can protect against TPA infection.
Collapse
Affiliation(s)
- Carlos Ávila-Nieto
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Autonomous University of Barcelona, Cerdanyola del Vallès, Catalonia, Spain
| | | | - Oriol Mitjà
- Skin Neglected Tropical Diseases and Sexually Transmitted Infections Department, Germans Trias i Pujol Hospital, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
| | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Julià Blanco
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Jorge Carrillo
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| |
Collapse
|
5
|
You Y, Ye F, Mao W, Yang H, Lai J, Deng S. An overview of the structure and function of the flagellar hook FlgE protein. World J Microbiol Biotechnol 2023; 39:126. [PMID: 36941455 DOI: 10.1007/s11274-023-03568-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/04/2023] [Indexed: 03/23/2023]
Abstract
The flagellum is an important organelle for the survival of bacteria and consists of a basal body, hook, and filament. The FlgE protein is the subunit of the hook that connects the basal body and the filament and determines the motility of bacteria. Also, flgE gene plays an essential role in flagellar biosynthesis, swimming ability and biofilm formation. Although the intact flagella and the major component filament have been extensively studied, so far, little is known about the comprehensive understanding of flagellar hook and FlgE. Here in this review, we summarize the structures of flagellar hook and its subunit FlgE in various species and physiological functions of FlgE, including the hook assembly, the structural characteristics of flagellar hook, the mechanical properties of hook, and the similarities and differences between FlgE (hook) and FlgG (distal rod), with special attention on the interaction of FlgE with other molecules, the antigenicity and pro-inflammatory effect of FlgE, and cross-linking of FlgE in spirochetes. We hope our summary of this review could provide a better understanding of the FlgE protein and provide some useful information for developing new effective antibacterial drugs in the future work.
Collapse
Affiliation(s)
- Yu You
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Fei Ye
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Wei Mao
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Hong Yang
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jijia Lai
- Department of Laboratory Medicine, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Chengdu, 610041, China
| | - Shun Deng
- Sichuan Province Orthopedic Hospital, 132 West First Section First Ring Road, Chengdu, 610041, China
| |
Collapse
|
6
|
Cai CX, Li SL, Lin HL, Wei ZH, Xie L, Lin LR, Niu JJ, Yang TC. Treponema pallidum protein Tp0136 promoting MMPs/TIMPs imbalance via PI3K, MAPK and NF-κB signalling pathways in HDVSMCs. Heliyon 2022; 8:e12065. [PMID: 36561703 PMCID: PMC9763734 DOI: 10.1016/j.heliyon.2022.e12065] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/17/2022] [Accepted: 11/25/2022] [Indexed: 12/12/2022] Open
Abstract
The invasive capability of Treponema. pallidum is central to its infection process. Matrix metalloproteinases (MMPs), which are specifically inhibited by the tissue inhibitors of metalloproteinases (TIMPs), play a pivotal role in promoting pathogenic invasion by destroying tissue barriers within the body. This study aimed to explore the effect of T. pallidum protein Tp0136 on the balance of MMPs/TIMPs in human dermal vascular smooth muscle cells (HDVSMCs) and the related underlying mechanisms. A number of in vitro studies were conducted to access the impact of recombinant Tp0136 protein on the balance of MMPs/TIMPs in HDVSMCs. The involvement of the PI3K, MAPK, and NF-κB signaling pathways in this process was also investigated. Tp0136 induced the mRNA and protein expressions of MMP1 in HDVSMCs in a concentration-dependent way. In addition, MMP1/TIMP1 and MMP1/TIMP2 ratios were also increased. Furthermore, the study demonstrated that treatment of HDVSMCs with Tp0136 activated the PI3K, MAPK, and NF-κB signaling pathways. Inhibition of PI3K, JNK, P38, and NF-κB, suppressed MMP1 expression and reduced the induction of MMP1/TIMP1 and MMP1/TIMP2 ratios by Tp0136. These findings demonstrate that Tp0136 enhanced the expression of MMP1 involving the PI3K, MAPK, and NF-κB signaling pathways in HDVSMCs, and thus generated the unbalance of MMPs/TIMP, which could contribute to the early spread of T. pallidum and pathogenesis of syphilis.
Collapse
Affiliation(s)
- Chun-Xiang Cai
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China,Xiamen Center for Disease Control and Prevention, Xiamen, China
| | - Shu-Lian Li
- Department of Gynaecology and Obstetrics, Xiamen Huli District Maternity and Child Care Hospital, Xiamen, China
| | - Hui-Ling Lin
- Department of Gynaecology and Obstetrics, Xiamen Huli District Maternity and Child Care Hospital, Xiamen, China
| | - Zi-Han Wei
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Lin Xie
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Rong Lin
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China,Corresponding author.
| | - Jian-Jun Niu
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China,Corresponding author.
| | - Tian-Ci Yang
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China,Corresponding author.
| |
Collapse
|
7
|
Tang Y, Zhou Y, He B, Cao T, Zhou X, Ning L, Chen E, Li Y, Xie X, Peng B, Hu Y, Liu S. Investigation of the immune escape mechanism of Treponema pallidum. Infection 2022; 51:305-321. [PMID: 36260281 DOI: 10.1007/s15010-022-01939-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Syphilis is a chronic sexually transmitted disease caused by Treponema pallidum subspecies pallidum (T. pallidum), which is a public health problem that seriously affects human health worldwide. T. pallidum is characterized by early transmission and immune escape and is therefore termed an "invisible pathogen". METHODS This review systematically summarizes the host's innate and adaptive immune responses to T. pallidum infection as well as the escape mechanisms of T. pallidum. PURPOSE To lay the foundation for assessing the pathogenic mechanism and the systematic prevention and treatment of syphilis. CONCLUSION The immune escape mechanism of T. pallidum plays an important role in its survival. Exploring the occurrence and development of these mechanisms has laid the foundation for the development of syphilis vaccine.
Collapse
Affiliation(s)
- Yun Tang
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yingjie Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Bisha He
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Ting Cao
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiangping Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Lichang Ning
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - En Chen
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yumeng Li
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiaoping Xie
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Binfeng Peng
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yibao Hu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Shuangquan Liu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China.
| |
Collapse
|
8
|
Serag AM, Abdel-Sabour MS, El-Hadidi M, Maged M, Magdy M, Ramadan MF, Refaat MH. Comparative 16S Metabarcoding of Nile Tilapia Gut Microbiota from the Northern Lakes of Egypt. Appl Biochem Biotechnol 2022; 194:2168-2182. [PMID: 35048279 DOI: 10.1007/s12010-021-03750-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 11/08/2021] [Indexed: 11/24/2022]
Abstract
Nile tilapia, Oreochromis niloticus, is the principal fish bred in Egypt. A pilot study was designed to analyze the bacterial composition of the Nile tilapia fish guts from two saltwater lakes in Northern Egypt. Fish samples were obtained from two Delta lakes: Manzala (ML) and Borollus (BL). DNA was extracted, and the bacterial communities in the stomach content were classified (down to the species level) using the 16S rRNA-based analysis. From the two metagenomics libraries in this study, 1,426,740 reads of the amplicon sequence corresponding to 508 total taxonomic operational units were recorded. The most prevalent bacterial phyla were Proteobacteria, Firmicutes, Actinobacteria, and Synergistetes in all samples. Some of the strains identified belong to classes of pathogenic zoonotic bacteria. A notable difference was observed between gut bacteria of Nile tilapia fish obtained from BL and ML. There is a remarkable indication that Nile tilapia fish living in BL is heavily burdened with pathogenic microbes most remarkably those involved with methylation of mercury and its accumulation in fish organs. These pathogenic microbes could have clinical implications and correlated with many diseases. This result was also consistent with the metagenomic data's functional prediction that indicated that Nile tilapia species harboring these two Egyptian northern lakes may be exposed to numerous anthropogenic pollutants. The findings show that the host environment has a significant impact on the composition of its microbiota. The first step towards exploring the better management of this profit-making fish is recognizing the structure of the microbiome.
Collapse
Affiliation(s)
- Ahmed M Serag
- Department of Genetics and Genetic Engineering, Faculty of Agriculture, Benha University, Benha, Egypt. .,Moshtohor Research Park, Molecular Biology Lab, Benha University, Benha, Egypt.
| | - Mohamed S Abdel-Sabour
- Department of Genetics and Genetic Engineering, Faculty of Agriculture, Benha University, Benha, Egypt
| | - Mohamed El-Hadidi
- Bioinformatics Group, Center of Informatics Science (CIS), Nile University, Giza, Egypt
| | - Mohamad Maged
- School of Life and Medical Sciences, University of Hertfordshire, Hosted By Global Academic Foundation (GAF), New Administrative Capital, Egypt
| | - Mahmoud Magdy
- Department of Genetics, Faculty of Agriculture, Ain Shams University, Cairo, Egypt
| | - Mohamed Fawzy Ramadan
- Deanship of Scientific Research, Umm Al-Qura University, Makkah, Saudi Arabia. .,Department of Agricultural Biochemistry, Faculty of Agriculture, Zagazig University, Zagazig, 44519, Egypt.
| | - Mohamed H Refaat
- Department of Genetics and Genetic Engineering, Faculty of Agriculture, Benha University, Benha, Egypt.,Moshtohor Research Park, Molecular Biology Lab, Benha University, Benha, Egypt
| |
Collapse
|
9
|
Furtado JM, Simões M, Vasconcelos-Santos D, Oliver GF, Tyagi M, Nascimento H, Gordon DL, Smith JR. Ocular syphilis. Surv Ophthalmol 2021; 67:440-462. [PMID: 34147542 DOI: 10.1016/j.survophthal.2021.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/01/2023]
Abstract
Multiple studies around the world suggest that syphilis is re-emerging. Ocular syphilis - with a wide range of presentations, most of which are subtypes of uveitis - has become an increasingly common cause of ocular inflammation over the past 20 years. Its rising incidence, diagnostic complexity, and manifestations that have only recently been characterized make ocular syphilis relevant from the public health, clinical, and scientific perspectives. We review the demographics, epidemiology, clinical features, ocular imaging findings, diagnosis, and medical management of this condition.
Collapse
Affiliation(s)
- João M Furtado
- Divisão de Oftalmologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
| | - Milena Simões
- Divisão de Oftalmologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Daniel Vasconcelos-Santos
- Departamento de Oftalmologia e Otorrinolaringologia, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Genevieve F Oliver
- Flinders University College of Medicine and Public Health, Adelaide, Australia
| | - Mudit Tyagi
- Ocular Inflammation and Immunology Services, LV Prasad Eye Institute, Hyderabad, India
| | - Heloisa Nascimento
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil; Instituto Paulista de Estudos e Pesquisas em Oftalmologia-IPEPO, São Paulo, Brazil
| | - David L Gordon
- Flinders University College of Medicine and Public Health, Adelaide, Australia; SA Pathology, Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia
| | - Justine R Smith
- Flinders University College of Medicine and Public Health, Adelaide, Australia
| |
Collapse
|
10
|
Velho Rodrigues MF, Lisicki M, Lauga E. The bank of swimming organisms at the micron scale (BOSO-Micro). PLoS One 2021; 16:e0252291. [PMID: 34111118 PMCID: PMC8191957 DOI: 10.1371/journal.pone.0252291] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 05/13/2021] [Indexed: 12/24/2022] Open
Abstract
Unicellular microscopic organisms living in aqueous environments outnumber all other creatures on Earth. A large proportion of them are able to self-propel in fluids with a vast diversity of swimming gaits and motility patterns. In this paper we present a biophysical survey of the available experimental data produced to date on the characteristics of motile behaviour in unicellular microswimmers. We assemble from the available literature empirical data on the motility of four broad categories of organisms: bacteria (and archaea), flagellated eukaryotes, spermatozoa and ciliates. Whenever possible, we gather the following biological, morphological, kinematic and dynamical parameters: species, geometry and size of the organisms, swimming speeds, actuation frequencies, actuation amplitudes, number of flagella and properties of the surrounding fluid. We then organise the data using the established fluid mechanics principles for propulsion at low Reynolds number. Specifically, we use theoretical biophysical models for the locomotion of cells within the same taxonomic groups of organisms as a means of rationalising the raw material we have assembled, while demonstrating the variability for organisms of different species within the same group. The material gathered in our work is an attempt to summarise the available experimental data in the field, providing a convenient and practical reference point for future studies.
Collapse
Affiliation(s)
- Marcos F. Velho Rodrigues
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom
| | - Maciej Lisicki
- Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Eric Lauga
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
11
|
Abstract
Lyme disease (Lyme borreliosis) is a tick-borne, zoonosis of adults and children caused by genospecies of the Borrelia burgdorferi sensu lato complex. The ailment, widespread throughout the Northern Hemisphere, continues to increase globally due to multiple environmental factors, coupled with increased incursion of humans into habitats that harbor the spirochete. B. burgdorferi sensu lato is transmitted by ticks from the Ixodes ricinus complex. In North America, B. burgdorferi causes nearly all infections; in Europe, B. afzelii and B. garinii are most associated with human disease. The spirochete's unusual fragmented genome encodes a plethora of differentially expressed outer surface lipoproteins that play a seminal role in the bacterium's ability to sustain itself within its enzootic cycle and cause disease when transmitted to its incidental human host. Tissue damage and symptomatology (i.e., clinical manifestations) result from the inflammatory response elicited by the bacterium and its constituents. The deposition of spirochetes into human dermal tissue generates a local inflammatory response that manifests as erythema migrans (EM), the hallmark skin lesion. If treated appropriately and early, the prognosis is excellent. However, in untreated patients, the disease may present with a wide range of clinical manifestations, most commonly involving the central nervous system, joints, or heart. A small percentage (~10%) of patients may go on to develop a poorly defined fibromyalgia-like illness, post-treatment Lyme disease (PTLD) unresponsive to prolonged antimicrobial therapy. Below we integrate current knowledge regarding the ecologic, epidemiologic, microbiologic, and immunologic facets of Lyme disease into a conceptual framework that sheds light on the disorder that healthcare providers encounter.
Collapse
Affiliation(s)
- Justin D. Radolf
- Department of Medicine, UConn Health, Farmington, CT 06030, USA
- Department of Pediatrics, UConn Health, Farmington, CT 06030, USA
- Departments of Genetics and Genome Sciences, UConn Health, Farmington, CT 06030, USA
- Departments of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030, USA
- Department of Immunology, UConn Health, Farmington, CT 06030, USA
| | - Klemen Strle
- Division of Infectious Diseases, Wadsworth Center, NY Department of Health, Albany NY, 12208, USA
| | - Jacob E. Lemieux
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Franc Strle
- Department of Infectious Diseases, University Medical Center Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
12
|
Abe K, Kuribayashi T, Takabe K, Nakamura S. Implications of back-and-forth motion and powerful propulsion for spirochetal invasion. Sci Rep 2020; 10:13937. [PMID: 32811890 PMCID: PMC7434897 DOI: 10.1038/s41598-020-70897-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/06/2020] [Indexed: 12/18/2022] Open
Abstract
The spirochete Leptospira spp. can move in liquid and on a solid surface using two periplasmic flagella (PFs), and its motility is an essential virulence factor for the pathogenic species. Mammals are infected with the spirochete through the wounded dermis, which implies the importance of behaviors on the boundary with such viscoelastic milieu; however, the leptospiral pathogenicity involving motility remains unclear. We used a glass chamber containing a gel area adjoining the leptospiral suspension to resemble host dermis exposed to contaminated water and analyzed the motility of individual cells at the liquid-gel border. Insertion of one end of the cell body to the gel increased switching of the swimming direction. Moreover, the swimming force of Leptospira was also measured by trapping single cells using an optical tweezer. It was found that they can generate [Formula: see text] 17 pN of force, which is [Formula: see text] 30 times of the swimming force of Escherichia coli. The force-speed relationship suggested the load-dependent force enhancement and showed that the power (the work per unit time) for the propulsion is [Formula: see text] 3.1 × 10-16 W, which is two-order of magnitudes larger than the propulsive power of E. coli. The powerful and efficient propulsion of Leptospira using back-and-forth movements could facilitate their invasion.
Collapse
Affiliation(s)
- Keigo Abe
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Toshiki Kuribayashi
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Kyosuke Takabe
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Shuichi Nakamura
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan.
| |
Collapse
|
13
|
Spirochete Flagella and Motility. Biomolecules 2020; 10:biom10040550. [PMID: 32260454 PMCID: PMC7225975 DOI: 10.3390/biom10040550] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/03/2020] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
Spirochetes can be distinguished from other flagellated bacteria by their long, thin, spiral (or wavy) cell bodies and endoflagella that reside within the periplasmic space, designated as periplasmic flagella (PFs). Some members of the spirochetes are pathogenic, including the causative agents of syphilis, Lyme disease, swine dysentery, and leptospirosis. Furthermore, their unique morphologies have attracted attention of structural biologists; however, the underlying physics of viscoelasticity-dependent spirochetal motility is a longstanding mystery. Elucidating the molecular basis of spirochetal invasion and interaction with hosts, resulting in the appearance of symptoms or the generation of asymptomatic reservoirs, will lead to a deeper understanding of host-pathogen relationships and the development of antimicrobials. Moreover, the mechanism of propulsion in fluids or on surfaces by the rotation of PFs within the narrow periplasmic space could be a designing base for an autonomously driving micro-robot with high efficiency. This review describes diverse morphology and motility observed among the spirochetes and further summarizes the current knowledge on their mechanisms and relations to pathogenicity, mainly from the standpoint of experimental biophysics.
Collapse
|
14
|
Xu M, Xie Y, Tan M, Zheng K, Xiao Y, Jiang C, Zhao F, Zeng T, Wu Y. The N-terminal D1 domain of Treponema pallidum flagellin binding to TLR5 is required but not sufficient in activation of TLR5. J Cell Mol Med 2019; 23:7490-7504. [PMID: 31493340 PMCID: PMC6815820 DOI: 10.1111/jcmm.14617] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 08/02/2019] [Accepted: 08/09/2019] [Indexed: 12/18/2022] Open
Abstract
Syphilis is a chronic bacterial infection caused by Treponema pallidum (T pallidum) and the pathogenesis that T pallidum infection induces immunopathological damages in skin and other tissues remains unclear. We have previously reported that recombinant flagellins of T pallidum can elicit IL‐6 and IL‐8 transcriptions via TLR5 pathway. To identify the domains which induced the pro‐inflammatory activity and the importance of the interactions between TLR5 and domains, homology‐based modelling and comparative structural analyses revealed that Tpflagellins can combine with TLR5 directly. Deletion mutations showed that the ND1 domain binding to TLR5 is required but not sufficient in TLR5 activation. Moreover, site‐directed mutagenesis analysis indicated that the arginine residue (Tpflagellins R89) of the ND1 domain and its adjacent residues (Tpflagellins L93 and E113) constitute a hot spot that elicits IL‐6, IL‐8 transcriptions and TLR5 activation, and affects the binding of Tpflagellins to TLR5. Taken together, these results give insight into the pathogenesis of T pallidum and may contribute to the future design of Tpflagellins‐based therapeutics and syphilis vaccine.
Collapse
Affiliation(s)
- Man Xu
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yafeng Xie
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China.,Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Manyi Tan
- Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Kang Zheng
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yongjian Xiao
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Chuanhao Jiang
- Department of Laboratory Medicine, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Feijun Zhao
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| |
Collapse
|
15
|
Church B, Wall E, Webb JR, Cameron CE. Interaction of Treponema pallidum, the syphilis spirochete, with human platelets. PLoS One 2019; 14:e0210902. [PMID: 30657796 PMCID: PMC6338379 DOI: 10.1371/journal.pone.0210902] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/03/2019] [Indexed: 02/06/2023] Open
Abstract
Extracellular bacteria that spread via the vasculature employ invasive mechanisms that mirror those of metastatic tumor cells, including intravasation into the bloodstream and survival during hematogenous dissemination, arrestation despite blood flow, and extravasation into distant tissue sites. Several invasive bacteria have been shown to exploit normal platelet function during infection. Due to their inherent ability to interact with and influence other cell types, platelets play a critical role in alteration of endothelial barrier permeability, and their role in cancer metastasis has been well established. The highly invasive bacterium and causative agent of syphilis, Treponema pallidum subspecies pallidum, readily crosses the endothelial, blood-brain and placental barriers. However, the mechanisms underlying this unusual and important aspect of T. pallidum pathogenesis are incompletely understood. In this study we use darkfield microscopy in combination with flow cytometry to establish that T. pallidum interacts with platelets. We also investigate the dynamics of this interaction and show T. pallidum is able to activate platelets and preferentially interacts with activated platelets. Platelet-interacting treponemes consistently exhibit altered kinematic (movement) parameters compared to free treponemes, and T. pallidum-platelet interactions are reversible. This study provides insight into host cell interactions at play during T. pallidum infection and suggests that T. pallidum may exploit platelet function to aid in establishment of disseminated infection.
Collapse
Affiliation(s)
- Brigette Church
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Erika Wall
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - John R. Webb
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Trev and Joyce Deeley Research Centre, British Columbia Cancer Agency, Victoria, BC, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
16
|
Sklodowska K, Debski PR, Michalski JA, Korczyk PM, Dolata M, Zajac M, Jakiela S. Simultaneous Measurement of Viscosity and Optical Density of Bacterial Growth and Death in a Microdroplet. MICROMACHINES 2018; 9:E251. [PMID: 30424184 PMCID: PMC6187717 DOI: 10.3390/mi9050251] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 02/07/2023]
Abstract
Herein, we describe a novel method for the assessment of droplet viscosity moving inside microfluidic channels. The method allows for the monitoring of the rate of the continuous growth of bacterial culture. It is based on the analysis of the hydrodynamic resistance of a droplet that is present in a microfluidic channel, which affects its motion. As a result, we were able to observe and quantify the change in the viscosity of the dispersed phase that is caused by the increasing population of interacting bacteria inside a size-limited system. The technique allows for finding the correlation between the viscosity of the medium with a bacterial culture and its optical density. These features, together with the high precision of the measurement, make our viscometer a promising tool for various experiments in the field of analytical chemistry and microbiology, where the rigorous control of the conditions of the reaction and the monitoring of the size of bacterial culture are vital.
Collapse
Affiliation(s)
- Karolina Sklodowska
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
- Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Pawel R Debski
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Jacek A Michalski
- Faculty of Civil Engineering, Mechanics and Petrochemistry, Warsaw University of Technology, 17 Lukasiewicza Street, 09400 Plock, Poland.
| | - Piotr M Korczyk
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02106 Warsaw, Poland.
| | - Miroslaw Dolata
- Department of Econophysics and Physics Application, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Miroslaw Zajac
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Slawomir Jakiela
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| |
Collapse
|
17
|
Abstract
Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.
Collapse
Affiliation(s)
- Rosanna W Peeling
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David Mabey
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Mary L Kamb
- Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xiang-Sheng Chen
- National Center for STD Control, Chinese Academy of Medical Sciences and Peking Union Medical College Institute of Dermatology, Nanjing, China
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Adele S Benzaken
- Department of Surveillance, Prevention and Control of STI, HIV/AIDS and Viral Hepatitis, Ministry of Health, Brasília, Brazil
| |
Collapse
|
18
|
Kumar B, Miller K, Charon NW, Legleiter J. Periplasmic flagella in Borrelia burgdoferi function to maintain cellular integrity upon external stress. PLoS One 2017; 12:e0184648. [PMID: 28898274 PMCID: PMC5595309 DOI: 10.1371/journal.pone.0184648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 08/28/2017] [Indexed: 12/15/2022] Open
Abstract
Tapping mode atomic force microscopy (AFM) in solution was used to analyze the role of the internally located periplasmic flagella (PFs) of the Lyme disease spirochete Borrelia burgdorferi in withstanding externally applied cellular stresses. By systematically imaging immobilized spirochetes with increasing tapping forces, we found that mutants that lack PFs are more readily compressed and damaged by the imaging process compared to wild-type cells. This finding suggest that the PFs, aside from being essential for motility and involved in cell shape, play a cytoskeletal role in dissipating energy and maintaining cellular integrity in the presence of external stress.
Collapse
Affiliation(s)
- Bharath Kumar
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Kelly Miller
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia, United States of America
| | - Nyles W. Charon
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia, United States of America
- WVU nanoSAFE, West Virginia University, Morgantown, West Virginia, United States of America
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
- WVU nanoSAFE, West Virginia University, Morgantown, West Virginia, United States of America
- Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, West Virginia, United States of America
- * E-mail:
| |
Collapse
|
19
|
Harman MW, Hamby AE, Boltyanskiy R, Belperron AA, Bockenstedt LK, Kress H, Dufresne ER, Wolgemuth CW. Vancomycin Reduces Cell Wall Stiffness and Slows Swim Speed of the Lyme Disease Bacterium. Biophys J 2017; 112:746-754. [PMID: 28256234 DOI: 10.1016/j.bpj.2016.12.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/23/2016] [Accepted: 12/27/2016] [Indexed: 11/19/2022] Open
Abstract
Borrelia burgdorferi, the spirochete that causes Lyme disease, is a tick-transmitted pathogen that requires motility to invade and colonize mammalian and tick hosts. These bacteria use a unique undulating flat-wave shape to penetrate and propel themselves through host tissues. Previous mathematical modeling has suggested that the morphology and motility of these spirochetes depends crucially on the flagellar/cell wall stiffness ratio. Here, we test this prediction using the antibiotic vancomycin to weaken the cell wall. We found that low to moderate doses of vancomycin (≤2.0 μg/mL for 24 h) produced small alterations in cell shape and that as the dose was increased, cell speed decreased. Vancomycin concentrations >1.0 μg/mL also inhibited cell growth and led to bleb formation on a fraction of the cells. To quantitatively assess how vancomycin affects cell stiffness, we used optical traps to bend unflagellated mutants of B. burgdorferi. We found that in the presence of vancomycin, cell wall stiffness gradually decreased over time, with a 40% reduction in the bending stiffness after 36 h. Under the same conditions, the swimming speed of wild-type B. burgdorferi slowed by ∼15%, with only marginal changes to cell morphology. Interestingly, our biophysical model for the swimming dynamics of B. burgdorferi suggested that cell speed should increase with decreasing cell stiffness. We show that this discrepancy can be resolved if the periplasmic volume decreases as the cell wall becomes softer. These results provide a testable hypothesis for how alterations of cell wall stiffness affect periplasmic volume regulation. Furthermore, since motility is crucial to the virulence of B. burgdorferi, the results suggest that sublethal doses of antibiotics could negatively impact spirochete survival by impeding their swim speed, thereby enabling their capture and elimination by phagocytes.
Collapse
Affiliation(s)
- Michael W Harman
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona
| | - Alex E Hamby
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona
| | - Ross Boltyanskiy
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut
| | - Alexia A Belperron
- Department of Internal Medicine, Yale University, New Haven, Connecticut
| | | | - Holger Kress
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut; Department of Physics, University of Bayreuth, Bayreuth, Bavaria, Germany
| | - Eric R Dufresne
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut
| | - Charles W Wolgemuth
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona; Department of Physics, University of Arizona, Tucson, Arizona.
| |
Collapse
|
20
|
van Teeseling MCF, de Pedro MA, Cava F. Determinants of Bacterial Morphology: From Fundamentals to Possibilities for Antimicrobial Targeting. Front Microbiol 2017; 8:1264. [PMID: 28740487 PMCID: PMC5502672 DOI: 10.3389/fmicb.2017.01264] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Bacterial morphology is extremely diverse. Specific shapes are the consequence of adaptive pressures optimizing bacterial fitness. Shape affects critical biological functions, including nutrient acquisition, motility, dispersion, stress resistance and interactions with other organisms. Although the characteristic shape of a bacterial species remains unchanged for vast numbers of generations, periodical variations occur throughout the cell (division) and life cycles, and these variations can be influenced by environmental conditions. Bacterial morphology is ultimately dictated by the net-like peptidoglycan (PG) sacculus. The species-specific shape of the PG sacculus at any time in the cell cycle is the product of multiple determinants. Some morphological determinants act as a cytoskeleton to guide biosynthetic complexes spatiotemporally, whereas others modify the PG sacculus after biosynthesis. Accumulating evidence supports critical roles of morphogenetic processes in bacteria-host interactions, including pathogenesis. Here, we review the molecular determinants underlying morphology, discuss the evidence linking bacterial morphology to niche adaptation and pathogenesis, and examine the potential of morphological determinants as antimicrobial targets.
Collapse
Affiliation(s)
- Muriel C F van Teeseling
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
| | - Miguel A de Pedro
- Centro de Biología Molecular "Severo Ochoa" - Consejo Superior de Investigaciones Científicas, Universidad Autónoma de MadridMadrid, Spain
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
| |
Collapse
|
21
|
Yoshida K, Onoe H. Functionalized core-shell hydrogel microsprings by anisotropic gelation with bevel-tip capillary. Sci Rep 2017; 7:45987. [PMID: 28378803 PMCID: PMC5380988 DOI: 10.1038/srep45987] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/07/2017] [Indexed: 11/09/2022] Open
Abstract
This study describes a novel microfluidic-based method for the synthesis of hydrogel microsprings that are capable of encapsulating various functional materials. A continuous flow of alginate pre-gel solution can spontaneously form a hydrogel microspring by anisotropic gelation around the bevel-tip of the capillary. This technique allows fabrication of hydrogel microsprings using only simple capillaries and syringe pumps, while their complex compartmentalization characterized by a laminar flow inside the capillary can contribute to the optimization of the microspring internal structure and functionality. Encapsulation of several functional materials including magnetic-responsive nanoparticles or cell dispersed collagen for tissue scaffold was demonstrated to functionalize the microsprings. Our core-shell hydrogel microsprings have immense potential for application in a number of fields, including biological/chemical microsensors, biocompatible soft robots/microactuators, drug release, self-assembly of 3D structures and tissue engineering.
Collapse
Affiliation(s)
- Koki Yoshida
- Center for Multidisciplinary and Design Science, Graduate School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Hiroaki Onoe
- Center for Multidisciplinary and Design Science, Graduate School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| |
Collapse
|
22
|
Takabe K, Tahara H, Islam MS, Affroze S, Kudo S, Nakamura S. Viscosity-dependent variations in the cell shape and swimming manner of Leptospira. MICROBIOLOGY-SGM 2017; 163:153-160. [PMID: 28036244 DOI: 10.1099/mic.0.000420] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spirochaetes are spiral or flat-wave-shaped Gram-negative bacteria that have periplasmic flagella between the peptidoglycan layer and outer membrane. Rotation of the periplasmic flagella transforms the cell body shape periodically, allowing the cell to swim in aqueous environments. Because the virulence of motility-deficient mutants of pathogenic species is drastically attenuated, motility is thought to be an essential virulence factor in spirochaetes. However, it remains unknown how motility practically contributes to the infection process. We show here that the cell body configuration and motility of the zoonotic spirochaete Leptospira changes depending on the viscosity of the medium. Leptospira swim and reverse the swimming direction by transforming the cell body. Motility analysis showed that the frequency of cell shape transformation was increased by increasing the viscosity of the medium. The increased cell body transformation induced highly frequent reversal of the swimming direction. A simple kinetic model based on the experimental results shows that the viscosity-induced increase in reversal limits cell migration, resulting in the accumulation of cells in high-viscosity regions. This behaviour could facilitate the colonization of the spirochaete on host tissues covered with mucosa.
Collapse
Affiliation(s)
- Kyosuke Takabe
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Hajime Tahara
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Md Shafiqul Islam
- Present address: Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.,Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Samia Affroze
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Seishi Kudo
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Shuichi Nakamura
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| |
Collapse
|
23
|
Wirth R, Ugele M, Wanner G. Motility and Ultrastructure of Spirochaeta thermophila. Front Microbiol 2016; 7:1609. [PMID: 27790206 PMCID: PMC5064287 DOI: 10.3389/fmicb.2016.01609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/26/2016] [Indexed: 12/19/2022] Open
Abstract
We analyze here for the first time the swimming behavior of a thermophilic, strictly anaerobic Spirochete, namely Spirochaeta thermophila using high temperature light microscopy. Our data show that S. thermophila very rapidly can change its morphology during swimming, resulting in cells appearing nearly linear, in cells possessing three different spiral forms, and in cells being linear at one end and spiral at the other end. In addition cells can rapidly bend by up to 180°, with their ends coming into close contact. We combine electron with light microscopy to explain these various cell morphologies. Swimming speeds for cells with the various morphologies did not differ significantly: the average speed was 33 (± 8) μm/s, with minimal and maximal speeds of 19 and 59 μm/s, respectively. Addition of gelling agents like polyvinylpyrrolidone or methyl cellulose to the growth medium resulted in lower and not higher swimming speeds, arguing against the idea that the highly unusual cell body plan of S. thermophila enables cells to swim more efficiently in gel-like habitats.
Collapse
Affiliation(s)
- Reinhard Wirth
- Faculty of Biology, University of Regensburg Regensburg, Germany
| | - Matthias Ugele
- In-Vitro DX and Bioscience, Department of Strategy and Innovation, Siemens Healthcare GmbH Erlangen, Germany
| | - Gerhard Wanner
- Department of Biology I, Ludwig-Maximilian-University Munich, Germany
| |
Collapse
|
24
|
Osbak KK, Houston S, Lithgow KV, Meehan CJ, Strouhal M, Šmajs D, Cameron CE, Van Ostade X, Kenyon CR, Van Raemdonck GA. Characterizing the Syphilis-Causing Treponema pallidum ssp. pallidum Proteome Using Complementary Mass Spectrometry. PLoS Negl Trop Dis 2016; 10:e0004988. [PMID: 27606673 PMCID: PMC5015957 DOI: 10.1371/journal.pntd.0004988] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/19/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The spirochete bacterium Treponema pallidum ssp. pallidum is the etiological agent of syphilis, a chronic multistage disease. Little is known about the global T. pallidum proteome, therefore mass spectrometry studies are needed to bring insights into pathogenicity and protein expression profiles during infection. METHODOLOGY/PRINCIPAL FINDINGS To better understand the T. pallidum proteome profile during infection, we studied T. pallidum ssp. pallidum DAL-1 strain bacteria isolated from rabbits using complementary mass spectrometry techniques, including multidimensional peptide separation and protein identification via matrix-assisted laser desorption ionization-time of flight (MALDI-TOF/TOF) and electrospray ionization (ESI-LTQ-Orbitrap) tandem mass spectrometry. A total of 6033 peptides were detected, corresponding to 557 unique T. pallidum proteins at a high level of confidence, representing 54% of the predicted proteome. A previous gel-based T. pallidum MS proteome study detected 58 of these proteins. One hundred fourteen of the detected proteins were previously annotated as hypothetical or uncharacterized proteins; this is the first account of 106 of these proteins at the protein level. Detected proteins were characterized according to their predicted biological function and localization; half were allocated into a wide range of functional categories. Proteins annotated as potential membrane proteins and proteins with unclear functional annotations were subjected to an additional bioinformatics pipeline analysis to facilitate further characterization. A total of 116 potential membrane proteins were identified, of which 16 have evidence supporting outer membrane localization. We found 8/12 proteins related to the paralogous tpr gene family: TprB, TprC/D, TprE, TprG, TprH, TprI and TprJ. Protein abundance was semi-quantified using label-free spectral counting methods. A low correlation (r = 0.26) was found between previous microarray signal data and protein abundance. CONCLUSIONS This is the most comprehensive description of the global T. pallidum proteome to date. These data provide valuable insights into in vivo T. pallidum protein expression, paving the way for improved understanding of the pathogenicity of this enigmatic organism.
Collapse
Affiliation(s)
- Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Conor J Meehan
- Unit of Mycobacteriology, Institute of Tropical Medicine, Antwerp, Belgium
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
| |
Collapse
|
25
|
Wolgemuth CW. Flagellar motility of the pathogenic spirochetes. Semin Cell Dev Biol 2015; 46:104-12. [PMID: 26481969 DOI: 10.1016/j.semcdb.2015.10.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/08/2015] [Accepted: 10/12/2015] [Indexed: 01/13/2023]
Abstract
Bacterial pathogens are often classified by their toxicity and invasiveness. The invasiveness of a given bacterium is determined by how capable the bacterium is at invading a broad range of tissues in its host. Of mammalian pathogens, some of the most invasive come from a group of bacteria known as the spirochetes, which cause diseases, such as syphilis, Lyme disease, relapsing fever and leptospirosis. Most of the spirochetes are characterized by their distinct shapes and unique motility. They are long, thin bacteria that can be shaped like flat-waves, helices, or have more irregular morphologies. Like many other bacteria, the spirochetes use long, helical appendages known as flagella to move; however, the spirochetes enclose their flagella in the periplasm, the narrow space between the inner and outer membranes. Rotation of the flagella in the periplasm causes the entire cell body to rotate and/or undulate. These deformations of the bacterium produce the force that drives the motility of these organisms, and it is this unique motility that likely allows these bacteria to be highly invasive in mammals. This review will describe the current state of knowledge on the motility and biophysics of these organisms and provide evidence on how this knowledge can inform our understanding of spirochetal diseases.
Collapse
Affiliation(s)
- Charles W Wolgemuth
- University of Connecticut Health Center, Department of Cell Biology and Center for Cell Analysis and Modeling, Farmington, CT 06030-3505, United States; University of Arizona, Department of Physics and Molecular and Cellular Biology, Tucson, AZ 85721, United States.
| |
Collapse
|
26
|
Nakamura S. [Morphology and motility of the spirochetes]. Nihon Saikingaku Zasshi 2015; 69:527-38. [PMID: 25186643 DOI: 10.3412/jsb.69.527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Spirochetes have flagella within the cell body and swim by wriggling the spiral cell body. Besides they have been known to be critical agents causing various infectious diseases, their eccentric appearances and motilities have been attracting many scientists in a wide variety of fields other than bacteriologists. Unlike externally flagellated bacteria that swim by using flagella as a screw propeller, spirochetes progress in a liquid by changing their cell shapes. To understand the unique motion mechanism of spirochetes, many experiments and theoretical studies are being carried out. In this review, I will summarize morphological and motile properties of various species of spirochete, such as Borrelia, Treponema and Brachyspira. I will also expound on the motion mechanism of Leptospira with our latest results obtained by high-resolution optical photometry.
Collapse
Affiliation(s)
- Shuichi Nakamura
- Department of Applied Physics, Graduate School of Engineering, Tohoku University
| |
Collapse
|
27
|
Meriläinen L, Herranen A, Schwarzbach A, Gilbert L. Morphological and biochemical features of Borrelia burgdorferi pleomorphic forms. MICROBIOLOGY-SGM 2015; 161:516-27. [PMID: 25564498 PMCID: PMC4339653 DOI: 10.1099/mic.0.000027] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The spirochaete bacterium Borrelia burgdorferi sensu lato is the causative agent of Lyme disease, the most common tick-borne infection in the northern hemisphere. There is a long-standing debate regarding the role of pleomorphic forms in Lyme disease pathogenesis, while very little is known about the characteristics of these morphological variants. Here, we present a comprehensive analysis of B. burgdorferi pleomorphic formation in different culturing conditions at physiological temperature. Interestingly, human serum induced the bacterium to change its morphology to round bodies (RBs). In addition, biofilm-like colonies in suspension were found to be part of B. burgdorferi’s normal in vitro growth. Further studies provided evidence that spherical RBs had an intact and flexible cell envelope, demonstrating that they are not cell wall deficient, or degenerative as previously implied. However, the RBs displayed lower metabolic activity compared with spirochaetes. Furthermore, our results indicated that the different pleomorphic variants were distinguishable by having unique biochemical signatures. Consequently, pleomorphic B. burgdorferi should be taken into consideration as being clinically relevant and influence the development of novel diagnostics and treatment protocols.
Collapse
Affiliation(s)
- Leena Meriläinen
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Anni Herranen
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| | | | - Leona Gilbert
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
28
|
Initial characterization of the FlgE hook high molecular weight complex of Borrelia burgdorferi. PLoS One 2014; 9:e98338. [PMID: 24859001 PMCID: PMC4032328 DOI: 10.1371/journal.pone.0098338] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 05/01/2014] [Indexed: 11/20/2022] Open
Abstract
The spirochete periplasmic flagellum has many unique attributes. One unusual characteristic is the flagellar hook. This structure serves as a universal joint coupling rotation of the membrane-bound motor to the flagellar filament. The hook is comprised of about 120 FlgE monomers, and in most bacteria these structures readily dissociate to monomers (∼ 50 kDa) when treated with heat and detergent. However, in spirochetes the FlgE monomers form a large mass of over 250 kDa [referred to as a high molecular weight complex (HMWC)] that is stable to these and other denaturing conditions. In this communication, we examined specific aspects with respect to the formation and structure of this complex. We found that the Lyme disease spirochete Borrelia burgdorferi synthesized the HMWC throughout the in vitro growth cycle, and also in vivo when implanted in dialysis membrane chambers in rats. The HMWC was stable to formic acid, which supports the concept that the stability of the HMWC is dependent on covalent cross-linking of individual FlgE subunits. Mass spectrometry analysis of the HMWC from both wild type periplasmic flagella and polyhooks from a newly constructed ΔfliK mutant indicated that other proteins besides FlgE were not covalently joined to the complex, and that FlgE was the sole component of the complex. In addition, mass spectrometry analysis also indicated that the HMWC was composed of a polymer of the FlgE protein with both the N- and C-terminal regions remaining intact. These initial studies set the stage for a detailed characterization of the HMWC. Covalent cross-linking of FlgE with the accompanying formation of the HMWC we propose strengthens the hook structure for optimal spirochete motility.
Collapse
|