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Rocha ST, Shah DD, Shrivastava A. Ecological, beneficial, and pathogenic functions of the Type 9 Secretion System. Microb Biotechnol 2024; 17:e14516. [PMID: 38924452 PMCID: PMC11205867 DOI: 10.1111/1751-7915.14516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
The recently discovered Type 9 Secretion System (T9SS) is present in bacteria of the Fibrobacteres-Bacteroidetes-Chlorobi superphylum, which are key constituents of diverse microbiomes. T9SS is instrumental in the extracellular secretion of over 270,000 proteins, including peptidases, sugar hydrolases, metal ion-binding proteins, and metalloenzymes. These proteins are essential for the interaction of bacteria with their environment. This mini-review explores the extensive array of proteins secreted by the T9SS. It highlights the diverse functions of these proteins, emphasizing their roles in pathogenesis, bacterial interactions, host colonization, and the overall health of the ecosystems inhabited by T9SS-containing bacteria.
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Affiliation(s)
- Sofia T. Rocha
- Biodesign InstituteArizona State UniversityTempeArizonaUSA
- School of Life SciencesArizona State UniversityTempeArizonaUSA
| | - Dhara D. Shah
- Biodesign InstituteArizona State UniversityTempeArizonaUSA
- School of Mathematical and Natural SciencesArizona State UniversityGlendaleArizonaUSA
| | - Abhishek Shrivastava
- Biodesign InstituteArizona State UniversityTempeArizonaUSA
- School of Life SciencesArizona State UniversityTempeArizonaUSA
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2
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Thunes NC, Evenhuis JP, Lipscomb RS, Pérez-Pascual D, Stevick RJ, Birkett C, Ghigo JM, McBride MJ. Gliding motility proteins GldJ and SprB contribute to Flavobacterium columnare virulence. J Bacteriol 2024; 206:e0006824. [PMID: 38517170 PMCID: PMC11025331 DOI: 10.1128/jb.00068-24] [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: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/23/2024] Open
Abstract
Flavobacterium columnare causes columnaris disease in fish. Columnaris disease is incompletely understood, and adequate control measures are lacking. The type IX secretion system (T9SS) is required for F. columnare gliding motility and virulence. The T9SS and gliding motility machineries share some, but not all, components. GldN (required for gliding and for secretion) and PorV (involved in secretion but not required for gliding) are both needed for virulence, implicating T9SS-mediated secretion in virulence. The role of motility in virulence is uncertain. We constructed and analyzed sprB, sprF, and gldJ mutants that were defective for motility but that maintained T9SS function to understand the role of motility in virulence. Wild-type cells moved rapidly and formed spreading colonies. In contrast, sprB and sprF deletion mutants were partially defective in gliding and formed nonspreading colonies. Both mutants exhibited reduced virulence in rainbow trout fry. A gldJ deletion mutant was nonmotile, secretion deficient, and avirulent in rainbow trout fry. To separate the roles of GldJ in secretion and in motility, we generated gldJ truncation mutants that produce nearly full-length GldJ. Mutant gldJ563, which produces GldJ truncated at amino acid 563, was defective for gliding but was competent for secretion as measured by extracellular proteolytic activity. This mutant displayed reduced virulence in rainbow trout fry, suggesting that motility contributes to virulence. Fish that survived exposure to the sprB deletion mutant or the gldJ563 mutant exhibited partial resistance to later challenge with wild-type cells. The results aid our understanding of columnaris disease and may suggest control strategies.IMPORTANCEFlavobacterium columnare causes columnaris disease in many species of freshwater fish in the wild and in aquaculture systems. Fish mortalities resulting from columnaris disease are a major problem for aquaculture. F. columnare virulence is incompletely understood, and control measures are inadequate. Gliding motility and protein secretion have been suggested to contribute to columnaris disease, but evidence directly linking motility to disease was lacking. We isolated and analyzed mutants that were competent for secretion but defective for motility. Some of these mutants exhibited decreased virulence. Fish that had been exposed to these mutants were partially protected from later exposure to the wild type. The results contribute to our understanding of columnaris disease and may aid development of control strategies.
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Affiliation(s)
- Nicole C. Thunes
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Jason P. Evenhuis
- National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, USDA, Kearneysville, West Virginia, USA
| | - Ryan S. Lipscomb
- National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, USDA, Kearneysville, West Virginia, USA
| | - David Pérez-Pascual
- Institut Pasteur, Université Paris-Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Rebecca J. Stevick
- Institut Pasteur, Université Paris-Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Clayton Birkett
- National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, USDA, Kearneysville, West Virginia, USA
| | - Jean-Marc Ghigo
- Institut Pasteur, Université Paris-Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Mark J. McBride
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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3
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Liu J, Hao D, Ding X, Shi M, Wang Q, He H, Cheng B, Wang M, Wang Q, Xiang Y, Chen L. Epidemiological investigation and β-lactam antibiotic resistance of Riemerella anatipestifer isolates with waterfowl origination in Anhui Province, China. Poult Sci 2024; 103:103490. [PMID: 38387287 PMCID: PMC10899037 DOI: 10.1016/j.psj.2024.103490] [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: 12/01/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 02/24/2024] Open
Abstract
Riemerella anatipestifer (R. anatipestifer) is a highly pathogenic and complex serotypes waterfowl pathogen with inherent resistance to multiple antibiotics. This study was aimed to investigate the antibiotic resistance characteristics and genomic features of R. anatipestifer isolates in Anhui Province, China in 2023. A total of 287 cases were analysed from duck farms and goose farms, and the R. anatipestifer isolates were subjected to drug resistance tests for 30 antimicrobials. Whole genome sequencing (WGS) and bioinformatics analysis were performed on the bacterial genomes, targeting the β-lactam resistance genes. The results showed that a total of 74 isolates of R. anatipestifer were isolated from 287 cases, with a prevalence of 25.8%. The antimicrobial susceptibility testing (AST) revealed that all the 74 isolates were resistant to multiple drugs, ranging from 13 to 26 kinds of drugs. Notably, these isolates showed significant resistance to aminoglycosides and macrolides, which are also commonly used in clinical practices. Data revealed the presence of several β-lactamase-related genes among the isolates, including a novel blaRASA-1 variant (16.2%), the class A extended-spectrum β-lactamase blaRAA-1 (12.2%), and a blaOXA-209 variant (98.6%). Functional analysis of the variants blaRASA-1 and blaOXA-209 showed that the blaRASA-1 variant exhibited activity against various β-lactam antibiotics while their occurrence in R. anatipestifer were not common. The blaOXA-209 variant, on the other hand, did not perform any β-lactam antibiotic resistance. Furthermore, we observed that blaRAA-1 could undergo horizontal transmission among different bacteria via the insertion sequence IS982. In conclusion, this study delves into the high prevalence of R. anatipestifer infection in waterfowl in Anhui, China. The isolated strains exhibit severe drug resistance issues, closely associated with the prevalence of antibiotic resistance genes (ARG). Additionally, our research investigates the β-lactam antibiotic resistance mechanism in R. anatipestifer.
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Affiliation(s)
- Junfeng Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou City 450000, China; Anhui Qiangying Food Group, Suzhou City 234000, Anhui Province, China
| | - Dongmin Hao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Henan Key Laboratory of Animal Food Safety Zhengzhou City 450000, Henan Province, China; Anhui Qiangying Food Group, Suzhou City 234000, Anhui Province, China
| | - Xueyan Ding
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou City 450000, China
| | - Mingzhen Shi
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou City 450000, China
| | - Qiaojun Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou City 225000, Jiangsu Province, China
| | - Hengxu He
- College of Veterinary Medicine, Yangzhou University, Yangzhou City 225000, Jiangsu Province, China
| | - Binghua Cheng
- Anhui Qiangying Food Group, Suzhou City 234000, Anhui Province, China
| | - Mengping Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China
| | - Qingxiu Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China
| | - Yuqiang Xiang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou City 450000, China
| | - Liying Chen
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou City 450000, Henan Province, China; Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Zhengzhou City 450000, China; Henan Key Laboratory of Animal Food Safety Zhengzhou City 450000, Henan Province, China.
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4
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Li S, Wang Y, Yang R, Zhu X, Bai H, Deng X, Bai J, Zhang Y, Xiao Y, Li Z, Liu Z, Zhou Z. Outer membrane protein OMP76 of Riemerella anatipestifer contributes to complement evasion and virulence by binding to duck complement factor vitronectin. Virulence 2023; 14:2223060. [PMID: 37326479 PMCID: PMC10281475 DOI: 10.1080/21505594.2023.2223060] [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: 03/21/2023] [Revised: 05/26/2023] [Accepted: 06/05/2023] [Indexed: 06/17/2023] Open
Abstract
Riemerella anatipestifer is an important bacterial pathogen in poultry. Pathogenic bacteria recruit host complement factors to resist the bactericidal effect of serum complement. Vitronectin (Vn) is a complementary regulatory protein that inhibits the formation of the membrane attack complex (MAC). Microbes use outer membrane proteins (OMPs) to hijack Vn for complement evasion. However, the mechanism by which R. anatipestifer achieves evasion is unclear. This study aimed to characterise OMPs of R. anatipestifer which interact with duck Vn (dVn) during complement evasion. Far-western assays and comparison of wild-type and mutant strains that were treated with dVn and duck serum demonstrated particularly strong binding of OMP76 to dVn. These data were confirmed with Escherichia coli strains expressing and not expressing OMP76. Combining tertiary structure analysis and homology modelling, truncated and knocked-out fragments of OMP76 showed that a cluster of critical amino acids in an extracellular loop of OMP76 mediate the interaction with dVn. Moreover, binding of dVn to R. anatipestifer inhibited MAC deposition on the bacterial surface thereby enhancing survival in duck serum. Virulence of the mutant strain ΔOMP76 was attenuated significantly relative to the wild-type strain. Furthermore, adhesion and invasion abilities of ΔOMP76 decreased, and histopathological changes showed that ΔOMP76 was less virulent in ducklings. Thus, OMP76 is a key virulence factor of R. anatipestifer. The identification of OMP76-mediated evasion of complement by recruitment of dVn contributes significantly to the understanding of the molecular mechanism by which R. anatipestifer escapes host innate immunity and provides a new target for the development of subunit vaccines.
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Affiliation(s)
- Sen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Yanhua Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Rongkun Yang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Xiaotong Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Hongying Bai
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Xiaojian Deng
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jiao Bai
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yang Zhang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zhengfei Liu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
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5
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Zheng X, Xu S, Wang Z, Tao X, Liu Y, Dai L, Li Y, Zhang W. Sifting through the core-genome to identify putative cross-protective antigens against Riemerella anatipestifer. Appl Microbiol Biotechnol 2023; 107:3085-3098. [PMID: 36941438 DOI: 10.1007/s00253-023-12479-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/27/2023] [Accepted: 03/06/2023] [Indexed: 03/23/2023]
Abstract
Infectious serositis of ducks, caused by Riemerella anatipestifer, is one of the main infectious diseases that harm commercial ducks. Whole-strain-based vaccines with no or few cross-protection were observed between different serotypes of R. anatipestifer, and so far, control of infection is hampered by a lack of effective vaccines, especially subunit vaccines with cross-protection. Since the concept of reverse vaccinology was introduced, it has been widely used to screen for protective antigens in important pathogens. In this study, pan-genome binding reverse vaccinology, an emerging approach to vaccine candidate screening, was used to screen for cross-protective antigens against R. anatipestifer. Thirty proteins were identified from the core-genome as potential cross-protective antigens. Three of these proteins were recombinantly expressed, and their immunoreactivity with five antisera (anti-serotypes 1, 2, 6, 10, and 11) was demonstrated by Western blotting. Our study established a method for high-throughput screening of cross-protective antigens against R. anatipestifer in silico, which will lay the foundation for the development of a cross-protective subunit vaccine controlling R. anatipestifer infection. KEY POINTS: • Pan-genome binding reverse vaccine approach was first established in R. anatipestifer to screen for subunit vaccine candidates. • Thirty potential cross-protective antigens against R. anatipestifer were identified by this method. • The reliability of the method was verified preliminarily by the results of Western blotting of three of these potential antigens.
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Affiliation(s)
- Xiangkuan Zheng
- The Sanya Institute of Nanjing Agriculture University, Sanya, 572024, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, 210095, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Sixiang Xu
- The Sanya Institute of Nanjing Agriculture University, Sanya, 572024, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, 210095, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhuohao Wang
- The Sanya Institute of Nanjing Agriculture University, Sanya, 572024, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, 210095, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xingyu Tao
- The Sanya Institute of Nanjing Agriculture University, Sanya, 572024, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, 210095, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuqing Liu
- Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, Shandong Province, 250100, China
| | - Lei Dai
- Hainan Animal Disease Prevention and Control Center, 16 Xingdan Road, Haikou, 571100, China
| | - Yubao Li
- Agricultural Science and Engineering School, Liaocheng University, Liaocheng, China.
| | - Wei Zhang
- The Sanya Institute of Nanjing Agriculture University, Sanya, 572024, China.
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.
- OIE Reference Lab for Swine Streptococcosis, Nanjing, 210095, China.
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
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Riemerella anatipestifer GldG is necessary for secretion of effectors by type IX secretion system. Vet Microbiol 2023; 276:109628. [PMID: 36508857 DOI: 10.1016/j.vetmic.2022.109628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Riemerella anatipestifer secretes proteins through the type IX secretion system (T9SS). Recent studies have shown that the R. anatipestifer T9SS component proteins GldM and GldK also act as crucial virulence factors. In our previous study, the disruption of AS87_RS00460 gene, which encodes the predicted protein GldG, significantly reduced the bacterial virulence of R. anatipestifer wild-type strain Yb2, but the mechanism was unclear. In this study, we investigated the function of the GldG in bacterial virulence and protein secretion using the mutant strain Yb2ΔgldG and complementation strain cYb2ΔgldG. Our results demonstrate that the gldG gene encodes a gliding-motility-associated ABC transporter substrate-binding protein GldG, which was localized to the bacterial membrane in an immunoblotting analysis, and functions in the bacterium's adherence to and invasion of host cells and its survival in host blood. The resistance of mutant strain Yb2ΔgldG to complement-dependent killing was significantly reduced. Yb2ΔgldG displayed reduced gliding motility and deficient protein secretion. Label-free quantification (LFQ) with liquid chromatography-mass spectrometry (LC-MS) showed that 10 proteins with a conserved T9SS C-terminal domain were differentially secreted by Yb2ΔgldG and Yb2. The secretion levels of those 10 proteins were determined with immunoblotting, and the results were consistent with the LFQ LC-MS data. All of these effects were rescued by complementation with a plasmid encoding Yb2 gldG. Our results demonstrate that the R. anatipestifer gldG gene encodes the protein GldG, which is involved in bacterial virulence and protein secretion.
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Li J, Zhang Y, Wang Y, Zhang Y, Shi B, Gan L, Yu S, Jia X, Yang K, Li Z. Immunogenicity of live phoP gene deletion strain of Riemerella anatipestifer serotype 1. Poult Sci 2022; 102:102294. [PMID: 36436377 PMCID: PMC9706625 DOI: 10.1016/j.psj.2022.102294] [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: 06/02/2022] [Revised: 10/08/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022] Open
Abstract
Duck infectious serositis is an acute and infectious disease caused by Riemerella anatipestifer (R. anatipestifer) that leads to perihepatitis, pericarditis, meningitis, and airbag inflammation in ducks, which causes serious economic losses to the global duck industry. The phoP/phoR is a novel 2-component signal transduction system first reported in gram-negative bacteria, of which phoP acts as a global regulator and virulence factor. In this study, the phoP gene from the R. anatipestifer YM strain was knocked out using homologous recombination technology and replaced with the spectinomycin resistance gene (Spec). The virulence of the R. anatipestifer YMΔphoP strain was reduced by approximately 47,000 times compared to that of the wild-type R. anatipestifer YM strain. Ducks were immunized with live R. anatipestifer YMΔphoP strain by subcutaneous inoculation at a dose of 106 to 107 CFU (0.2 mL per duck) and challenged with the wild-type R. anatipestifer YM strain 14 days later. The protection rate in the immunized group was 100%. The growth characteristics of ducks in the immunized and negative control groups were normal, and the research demonstrated R. anatipestifer YMΔphoP strain have suitable immunogenicity and protective effects. Thus, the study findings suggest that the novel R. anatipestifer YMΔphoP strain may provide a candidate for the development of a gene deletion activated vaccine against duck infectious serositis.
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Affiliation(s)
- Jian Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yanhao Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ying Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yang Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Baolan Shi
- Sinopharm Animal Health Corporation Ltd., Wuhan, 430070, China
| | - Luoxin Gan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuang Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiangchao Jia
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Kang Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zili Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, 430070, China,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, 430070, China,Corresponding author:
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8
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Zhang Y, Zhang R, Sy SKB, Li Z, Zhu S, Zhou M, Song C, Zhang J, Lv Z, Liu J, Qin L, Yu M. Florfenicol/Chlortetracycline Effect on Pharmacodynamic Indices for Mutant Selection of Riemerella anatipestifer in Ducks. Microb Drug Resist 2022; 28:832-840. [PMID: 35723674 DOI: 10.1089/mdr.2022.0008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Riemerella anatipestifer can cause septicemia and death in ducks and geese, leading to significant economic losses to animal farms. The emergence of resistance of R. anatipestifer to commonly used antibiotics increases the difficulty of treating R. anatipestifer infection. The aim of this study was to evaluate the utility of antibiotic combination to restrict mutant selection of multidrug-resistant (MDR) R. anatipestifer isolates. Pharmacokinetics of florfenicol and chlortetracycline in Pekin ducks were evaluated using both noncompartmental analysis and population pharmacokinetic models. The areas under the curve of florfenicol and chlortetracycline after single 20 and 10 mg/kg oral administration were 49.3 and 6.84 mg*h/L, respectively. Chlortetracycline exhibited high apparent clearance and low systemic exposure. Minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) values of the two antibiotics were determined in 10 and 2 MDR R. anatipestifer isolates, respectively, to derive fTMSW (the fraction of time over 24 hours wherein the free drug concentration was within the mutant selection window [MSW]) and fT>MPC (the fraction of time that the free drug concentration was above the MPC). Both fTMSW and fT>MPC were estimated from simulated concentration-time profiles relative to MIC and MPC. Florfenicol and chlortetracycline combination have additive activities against R. anatipestifer in majority of isolates and could significantly decrease monotherapy MPC of florfenicol and chlortetracycline, as well as optimize both fTMSW and fT>MPC parameters, provided that the bioavailability of chlortetracycline is improved. The application of pharmacokinetic/pharmacodynamic analyses to MPC concepts to restrict selection of mutant bacterial strains can help improve short- and long-term outcomes of antibiotic treatment in animal farms.
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Affiliation(s)
- Yicong Zhang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China
| | - Ruili Zhang
- Shandong New Hope Liuhe Group Co., Ltd., Qingdao, P.R. China.,Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao, P.R. China
| | - Sherwin K B Sy
- Department of Statistics, State University of Maringá, Maringá, Brazil
| | - Zhizhong Li
- Shandong New Hope Liuhe Group Co., Ltd., Qingdao, P.R. China.,Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao, P.R. China
| | - Shixing Zhu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China
| | - Meichen Zhou
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China
| | - Chu Song
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China
| | - Jiayuan Zhang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China
| | - Zhihua Lv
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China.,Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, P.R. China
| | - Jinsong Liu
- Zhejiang Vegamax Biological Technology Co., Ltd., Hangzhou, China
| | - Liting Qin
- Shandong New Hope Liuhe Group Co., Ltd., Qingdao, P.R. China.,Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao, P.R. China
| | - Mingming Yu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, P.R. China.,Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, P.R. China
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9
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Structures of the Type IX Secretion/Gliding Motility Motor from across the Phylum Bacteroidetes. mBio 2022; 13:e0026722. [PMID: 35446127 PMCID: PMC9239094 DOI: 10.1128/mbio.00267-22] [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] [Indexed: 11/28/2022] Open
Abstract
Gliding motility using cell surface adhesins, and export of proteins by the type IX secretion system (T9SS) are two phylum-specific features of the Bacteroidetes. Both of these processes are energized by the GldLM motor complex, which transduces the proton motive force at the inner membrane into mechanical work at the outer membrane. We previously used cryo-electron microscopy to solve the structure of the GldLM motor core from Flavobacterium johnsoniae at 3.9-Å resolution (R. Hennell James, J. C. Deme, A. Kjaer, F. Alcock, et al., Nat Microbiol 6:221–233, 2021, https://dx.doi.org/10.1038/s41564-020-00823-6). Here, we present structures of homologous complexes from a range of pathogenic and environmental Bacteroidetes species at up to 3.0-Å resolution. These structures show that the architecture of the GldLM motor core is conserved across the Bacteroidetes phylum, although there are species-specific differences at the N terminus of GldL. The resolution improvements reveal a cage-like structure that ties together the membrane-proximal cytoplasmic region of GldL and influences gliding function. These findings add detail to our structural understanding of bacterial ion-driven motors that drive the T9SS and gliding motility.
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10
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Type IX secretion system effectors and virulence of the model Flavobacterium columnare strain MS-FC-4. Appl Environ Microbiol 2021; 88:e0170521. [PMID: 34818105 DOI: 10.1128/aem.01705-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Flavobacterium columnare causes columnaris disease in wild and cultured freshwater fish and is a major problem for sustainable aquaculture worldwide. The F. columnare type IX secretion system (T9SS) secretes many proteins and is required for virulence. The T9SS component GldN is required for secretion and for gliding motility over surfaces. Genetic manipulation of F. columnare is inefficient, which has impeded identification of secreted proteins that are critical for virulence. Here we identified a virulent wild-type F. columnare strain (MS-FC-4) that is highly amenable to genetic manipulation. This facilitated isolation and characterization of two deletion mutants lacking core components of the T9SS. Deletion of gldN disrupted protein secretion and gliding motility and eliminated virulence in zebrafish and rainbow trout. Deletion of porV disrupted secretion and virulence but not motility. Both mutants exhibited decreased extracellular proteolytic, hemolytic, and chondroitin sulfate lyase activities. They also exhibited decreased biofilm formation and decreased attachment to fish fins and to other surfaces. Using genomic and proteomic approaches, we identified proteins secreted by the T9SS. We deleted ten genes encoding secreted proteins and characterized the virulence of mutants lacking individual or multiple secreted proteins. A mutant lacking two genes encoding predicted peptidases exhibited reduced virulence in rainbow trout, and mutants lacking a predicted cytolysin showed reduced virulence in zebrafish and rainbow trout. The results establish F. columnare strain MS-FC-4 as a genetically amenable model to identify virulence factors. This may aid development of measures to control columnaris disease and impact fish health and sustainable aquaculture. IMPORTANCE: Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish and is a major problem for aquaculture. Little is known regarding the virulence factors involved in this disease and control measures are inadequate. The type IX secretion system (T9SS) secretes many proteins and is required for virulence, but the secreted virulence factors are not known. We identified a strain of F. columnare (MS-FC-4) that is well suited for genetic manipulation. The components of the T9SS and the proteins secreted by this system were identified. Deletion of core T9SS genes eliminated virulence. Genes encoding ten secreted proteins were deleted. Deletion of two peptidase-encoding genes resulted in decreased virulence in rainbow trout, and deletion of a cytolysin-encoding gene resulted in decreased virulence in rainbow trout and zebrafish. Secreted peptidases and cytolysins are likely virulence factors and are targets for the development of control measures.
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11
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Zhao D, Song W, Wang S, Zhang W, Zhao Y, Lu X. Identification of the Type IX Secretion System Component, PorV (CHU_3238), Involved in Secretion and Localization of Proteins in Cytophaga hutchinsonii. Front Microbiol 2021; 12:742673. [PMID: 34745042 PMCID: PMC8564354 DOI: 10.3389/fmicb.2021.742673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/22/2021] [Indexed: 11/29/2022] Open
Abstract
Cytophaga hutchinsonii can efficiently degrade cellulose and rapidly glide over surfaces, but the underlying mechanisms remain unclear. The type IX secretion system (T9SS) is involved in protein secretion and gliding motility, which is unique to the phylum Bacteroidetes. In this study, we deleted a homologous gene of PorV (chu_3238), a shuttle protein in the T9SS. The Δ3238 mutant caused cellulolytic and gliding defects, while the porV deletion mutants in other Bacteroidetes could glide normally. Adding Ca2+ and K+ improved growth in the PY6 medium, suggesting a potential role of chu_3238 in ion uptake. A proteomic analysis showed an increase in the number of extracellular proteins in the Δ3238 mutant and a decrease in the outer membrane proteins compared to the wild type (WT). Endoglucanase activity in the Δ3238 intact cells was reduced by approximately 70% compared to that of the WT. These results indicate that the secreted proteins could not attach to the cell surface but were released into the extracellular space in the Δ3238 mutant. However, the cargo proteins accumulated in the periplasm of other reported porV deletion mutants. In addition, the homologs of the translocon SprA and a Plug protein were pulled down by co-immunoprecipitation in the 3238-FLAG strain, which are involved in protein transport in the T9SS of Flavobacterium johnsoniae. The integrity of the lipopolysaccharide (LPS) was also affected in the Δ3238 mutant, which may be the reason for the sensitivity of the cell to toxic reagents. The functional diversity of CHU_3238 suggests its important role in the T9SS of C. hutchinsonii and highlights the functional differences of PorV in the T9SS among the Bacteroidetes.
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Affiliation(s)
- Dong Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,School of Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Wenxia Song
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Sen Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Weican Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yue Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xuemei Lu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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12
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A Riemerella anatipestifer Metallophosphoesterase That Displays Phosphatase Activity and Is Associated with Virulence. Appl Environ Microbiol 2021; 87:AEM.00086-21. [PMID: 33741629 DOI: 10.1128/aem.00086-21] [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] [Received: 01/13/2021] [Accepted: 02/27/2021] [Indexed: 11/20/2022] Open
Abstract
Riemerella anatipestifer is an important pathogen of waterfowl, causing septicemic and exudative diseases. In our previous study, we demonstrated that bacterial virulence and secretion proteins of the type IX secretion system (T9SS) mutant strains Yb2ΔgldK and Yb2ΔgldM were significantly reduced, in comparison to those of wild-type strain Yb2. In this study, the T9SS secretion protein AS87_RS00980, which is absent from the secretion proteins of Yb2ΔgldK and Yb2ΔgldM, was investigated by construction of gene mutation and complementation strains. The virulence assessment showed >1,000-fold attenuated virulence and significantly reduced bacterial loads in the blood of ducks infected with Yb2Δ00980, the AS87_RS00980 gene deletion mutant strain. Bacterial virulence was recovered in complementation strain cYb2Δ00980 Further study indicated that the T9SS secretion protein AS87_RS00980 is a metallophosphoesterase (MPPE), which displayed phosphatase activity and was cytomembrane localized. Moreover, the optimal reactive pH and temperature were determined to be 7.0 and 60°C, respectively, and the Km and V max were determined to be 3.53 mM and 198.1 U/mg. The rMPPE activity was activated by Zn2+ and Cu2+ but inhibited by Fe3+, Fe2+, and EDTA. There are five conserved sites, namely, N267, H268 H351, H389, and H391, in the metallophosphatase domain. Mutant proteins Y267-rMPPE and Y268-rMPPE retained 29.30% and 19.81% relative activity, respectively, and mutant proteins Y351-rMPPE, Y389-rMPPE, and Y391-rMPPE lost almost all MPPE activity. Taken together, these results indicate that the R. anatipestifer AS87_RS00980 gene encodes an MPPE that is a secretion protein of T9SS that plays an important role in bacterial virulence.IMPORTANCE Riemerella anatipestifer T9SS was recently discovered to be associated with bacterial gliding motility and secretion of virulence factors. Several T9SS genes have been identified, but no effector has been reported in R. anatipestifer to date. In this study, we identified the T9SS secretion protein AS87_RS00980 as an MPPE that displays phosphatase activity and is associated with bacterial virulence. The enzymatic activity of the rMPPE was determined, and the Km and V max were 3.53 mM and 198.1 U/mg, respectively. Five conserved sites were also identified. The AS87_RS00980 gene deletion mutant strain was attenuated >1,000-fold, indicating that MPPE is an important virulence factor. In summary, we identified that the R. anatipestifer AS87_RS00980 gene encodes an important T9SS effector, MPPE, which plays an important role in bacterial virulence.
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13
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Identification by MALDI-TOF MS and Antibiotic Resistance of Riemerella anatipestifer, Isolated from a Clinical Case in Commercial Broiler Chickens. Vet Sci 2021; 8:vetsci8020029. [PMID: 33671477 PMCID: PMC7922512 DOI: 10.3390/vetsci8020029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 11/17/2022] Open
Abstract
The Gram-negative bacterium Riemerella anatipestifer (RA) is known to cause clinical disease with severe economic impacts primarily in ducks and less frequently in geese and turkeys. RA was isolated and identified in broiler chickens, from a clinical case in a commercial broiler farm located in the southwest mainland of Greece. The morbidity and the mortality in the broiler house were estimated at 10% and 5% respectively. The observed clinical signs appeared at the age of 30 to 42 days with respiratory distress (dyspnea), white fluid feces and stunting. Post-mortem examinations displayed serositis, pericarditis, perihepatitis and airsacculitis. Edematous swelling around the tibio-tarsal joints was observed in some birds. Tissue samples from lesions were streaked on selective media. Three bacterial isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Moreover, an antibiogram analysis was performed for the three RA strains, using a pattern of 16 common antibiotics to advocate the most effective drugs for a proper treatment. All the RA isolates were sensitive to ceftiofur, sulphamethoxazole-trimethoprim and amoxicillin, whereas all were resistant to gentamicin, tylosin, tetracyclin, colistin sulphate, spectinomycin, lincomycin and oxytetracycline.
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14
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The Type IX Secretion System Is Required for Virulence of the Fish Pathogen Flavobacterium psychrophilum. Appl Environ Microbiol 2020; 86:AEM.00799-20. [PMID: 32532872 DOI: 10.1128/aem.00799-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/06/2020] [Indexed: 12/15/2022] Open
Abstract
Flavobacterium psychrophilum causes bacterial cold-water disease in wild and aquaculture-reared fish and is a major problem for salmonid aquaculture. The mechanisms responsible for cold-water disease are not known. It was recently demonstrated that the related fish pathogen, Flavobacterium columnare, requires a functional type IX protein secretion system (T9SS) to cause disease. T9SSs secrete cell surface adhesins, gliding motility proteins, peptidases, and other enzymes, any of which may be virulence factors. The F. psychrophilum genome has genes predicted to encode components of a T9SS. Here, we used a SacB-mediated gene deletion technique recently adapted for use in the Bacteroidetes to delete a core F. psychrophilum T9SS gene, gldN The ΔgldN mutant cells were deficient for secretion of many proteins in comparison to wild-type cells. Complementation of the mutant with wild-type gldN on a plasmid restored secretion. Compared to wild-type and complemented strains, the ΔgldN mutant was deficient in adhesion, gliding motility, and extracellular proteolytic and hemolytic activities. The ΔgldN mutant exhibited reduced virulence in rainbow trout and complementation restored virulence, suggesting that the T9SS plays an important role in the disease.IMPORTANCE Bacterial cold-water disease, caused by F. psychrophilum, is a major problem for salmonid aquaculture. Little is known regarding the virulence factors involved in this disease, and control measures are inadequate. A targeted gene deletion method was adapted to F. psychrophilum and used to demonstrate the importance of the T9SS in virulence. Proteins secreted by this system are likely virulence factors and targets for the development of control measures.
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15
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Gorasia DG, Veith PD, Reynolds EC. The Type IX Secretion System: Advances in Structure, Function and Organisation. Microorganisms 2020; 8:microorganisms8081173. [PMID: 32752268 PMCID: PMC7463736 DOI: 10.3390/microorganisms8081173] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 12/24/2022] Open
Abstract
The type IX secretion system (T9SS) is specific to the Bacteroidetes phylum. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilises the T9SS to transport many proteins—including its gingipain virulence factors—across the outer membrane and attach them to the cell surface. Additionally, the T9SS is also required for gliding motility in motile organisms, such as Flavobacterium johnsoniae. At least nineteen proteins have been identified as components of the T9SS, including the three transcription regulators, PorX, PorY and SigP. Although the components are known, the overall organisation and the molecular mechanism of how the T9SS operates is largely unknown. This review focusses on the recent advances made in the structure, function, and organisation of the T9SS machinery to provide further insight into this highly novel secretion system.
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16
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Wang Y, Zhang Y, Cui Y, Sun Z, Zhou Z, Hu S, Li S, Liu M, Meng X, Xiao Y, Shi D, Bi D, Li Z. Identification of an Integrase That Responsible for Precise Integration and Excision of Riemerella anatipestifer Genomic Island. Front Microbiol 2019; 10:2099. [PMID: 31616389 PMCID: PMC6764341 DOI: 10.3389/fmicb.2019.02099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/26/2019] [Indexed: 12/19/2022] Open
Abstract
Riemerella anatipestifer is a Gram-negative, pathogenic bacterium, which is harmful to poultry. However, the genomic islands (GIs) in R. anatipestifer are not well-studied. In this study, a 10K genomic island was predicted by the bioinformatics analysis of R. anatipestifer ATCC 11845, which is widely found in other R. anatipestifer genomes. We had first reported the genomic island integration and excision function in R. anatipestifer. We successfully constructed the integration plasmid by using the integrase and 53 bp attP elements. The 10K GI was found integrated at the 53 bp attB located in the Arg-tRNA of the R. anatipestifer RA-YM chromosome. We identified an integrase that helped in the precise integration and excision in R. anatipestifer and elucidated the molecular mechanism of the 10K genomic island integration and excision. Furthermore, we provided a new method for the gene expression and construction of complementary strain.
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Affiliation(s)
- Ying Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yang Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yijie Cui
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Zhijian Sun
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Zutao Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Sishun Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Shaowen Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Mei Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Xianrong Meng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Yuncai Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Deshi Shi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Dingren Bi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Zili Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
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17
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The Carboxy-Terminal Region of Flavobacterium johnsoniae SprB Facilitates Its Secretion by the Type IX Secretion System and Propulsion by the Gliding Motility Machinery. J Bacteriol 2019; 201:JB.00218-19. [PMID: 31262839 DOI: 10.1128/jb.00218-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/26/2019] [Indexed: 12/18/2022] Open
Abstract
Flavobacterium johnsoniae SprB moves rapidly along the cell surface, resulting in gliding motility. SprB secretion requires the type IX secretion system (T9SS). Proteins secreted by the T9SS typically have conserved C-terminal domains (CTDs) belonging to the type A CTD or type B CTD family. Attachment of 70- to 100-amino-acid type A CTDs to a foreign protein allows its secretion. Type B CTDs are common but have received little attention. Secretion of the foreign protein superfolder green fluorescent protein (sfGFP) fused to regions spanning the SprB type B CTD (sfGFP-CTDSprB) was analyzed. CTDs of 218 amino acids or longer resulted in secretion of sfGFP, whereas a 149-amino-acid region did not. Some sfGFP was secreted in soluble form, whereas the rest was attached on the cell surface. Surface-attached sfGFP was rapidly propelled along the cell, suggesting productive interaction with the motility machinery. This did not result in rapid cell movement, which apparently requires additional regions of SprB. Secretion of sfGFP-CTDSprB required coexpression with sprF, which lies downstream of sprB SprF is similar in sequence to Porphyromonas gingivalis PorP. Most F. johnsoniae genes encoding proteins with type B CTDs lie immediately upstream of porP/sprF-like genes. sfGFP was fused to the type B CTD from one such protein (Fjoh_3952). This resulted in secretion of sfGFP only when it was coexpressed with its cognate PorP/SprF-like protein. These results highlight the need for extended regions of type B CTDs and for coexpression with the appropriate PorP/SprF-like protein for efficient secretion and cell surface localization of cargo proteins.IMPORTANCE The F. johnsoniae gliding motility adhesin SprB is delivered to the cell surface by the type IX secretion system (T9SS) and is rapidly propelled along the cell by the motility machinery. How this 6,497-amino-acid protein interacts with the secretion and motility machines is not known. Fusion of the C-terminal 218 amino acids of SprB to a foreign cargo protein resulted in its secretion, attachment to the cell surface, and rapid movement by the motility machinery. Efficient secretion of SprB required coexpression with the outer membrane protein SprF. Secreted proteins that have sequence similarity to SprB in their C-terminal regions are common in the phylum Bacteroidetes and may have roles in adhesion, motility, and virulence.
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18
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Chen Z, Wang X, Ren X, Han W, Malhi KK, Ding C, Yu S. Riemerella anatipestifer GldM is required for bacterial gliding motility, protein secretion, and virulence. Vet Res 2019; 50:43. [PMID: 31164171 PMCID: PMC6549377 DOI: 10.1186/s13567-019-0660-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 04/12/2019] [Indexed: 12/02/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Genetic analyses suggest that this pathogen has a novel protein secretion system, known as the “type IX secretion system” (T9SS). We previously reported that deletion of the AS87_RS08465 gene significantly reduced the bacterial virulence of the R. anatipestifer strain Yb2, but the mechanism remained unclear. The AS87_RS08465 gene is predicted to encode the gliding motility protein GldM (GldM) protein, a key component of the T9SS complex. In this study, Western blotting analysis demonstrated that R. anatipestifer GldM was localized to the cytomembrane. Further study revealed that the adhesion and invasion capacities of the mutant strain RA2281 (designated Yb2ΔgldM) in Vero cells and the bacterial loads in the blood of infected ducks were significantly reduced. RNA-Seq and PCR analyses showed that six genes were upregulated and five genes were downregulated in the mutant strain Yb2ΔgldM and that these genes were mainly involved in the secretion of proteins. Yb2ΔgldM was also found to be defective in gliding motility and protein secretion. Liquid chromatography–tandem mass spectrometry analysis revealed that nine of the proteins had a conserved T9SS C-terminal domain and were differentially secreted by Yb2ΔgldM compared to Yb2. The complementation strain cYb2ΔgldM recovered the adhesion and invasion capacities in Vero cells and the bacterial loads in the blood of infected ducks as well as the bacterial gliding motility and most protein secretion in the mutant strain Yb2ΔgldM to the levels of the wild-type strain Yb2. Taken together, these results indicate that R. anatipestifer GldM is associated with T9SS and is important in bacterial virulence.
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Affiliation(s)
- Zongchao Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaolan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaomei Ren
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Wenlong Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Kanwar Kumar Malhi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China. .,Jiangsu Agri-animal Husbandry Vocational College, Veterinary Bio-pharmaceutical, Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Taizhou, Jiangsu, China.
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19
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Yuan H, Huang L, Wang M, Jia R, Chen S, Liu M, Zhao X, Yang Q, Wu Y, Zhang S, Liu Y, Zhang L, Yu Y, You Y, Chen X, Zhu D, Cheng A. Role of the gldK gene in the virulence of Riemerella anatipestifer. Poult Sci 2019; 98:2414-2421. [DOI: 10.3382/ps/pez028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/10/2019] [Indexed: 01/09/2023] Open
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20
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Malhi KK, Wang X, Chen Z, Ding C, Yu S. Riemerella anatipestifer gene AS87_08785 encodes a functional component, GldK, of the type IX secretion system. Vet Microbiol 2019; 231:93-99. [PMID: 30955831 DOI: 10.1016/j.vetmic.2019.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 11/25/2022]
Abstract
Riemerella anatipestifer is an important pathogen of waterfowl, causing septicemic and exudative diseases. In our previous study, we demonstrated that the deletion of the AS87_08785 gene significantly reduced the virulence of R. anatipestifer strain Yb2, but the mechanism remained unclear. In this study, R. anatipestifer strains with mutated or complemented AS87_08785 genes were constructed and characterized. A sequence analysis indicated that the AS87_08785 gene encoded a putative GldK protein, which localized to the membrane fraction in a western blotting analysis. The mutant strain Yb2ΔgldK displayed defective gliding motility on agar plates, reduced protease activity, and a reduced capacity for protein secretion. RNA sequencing and quantitative PCR analyses indicated that the transcription of 13 genes was downregulated in mutant Yb2ΔgldK. Animal experiments showed that the bacterial loads in the blood of Yb2ΔgldK-infected ducks were significantly reduced relative to those in wild-type strain Yb2 infected ducks. Most of the defective biological properties of the mutant were restored in complementation strain cYb2ΔgldK. Our results demonstrated that R. anatipestifer gene AS87_08785 encoded a component of the type IX secretion system, GldK, which functioned in bacterial gliding motility, protein secretion, and bacterial virulence.
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Affiliation(s)
- Kanwar Kumar Malhi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaolan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Zongchao Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China; Jiangsu Agri-Animal Husbandry Vocational College, Veterinary Bio-Pharmaceutical, Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Taizhou, Jiangsu, China.
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21
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Hu D, Guo Y, Guo J, Wang Y, Pan Z, Xiao Y, Wang X, Hu S, Liu M, Li Z, Bi D, Zhou Z. Deletion of the Riemerella anatipestifer type IX secretion system gene sprA results in differential expression of outer membrane proteins and virulence. Avian Pathol 2019; 48:191-203. [PMID: 30640518 DOI: 10.1080/03079457.2019.1566594] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Riemerella anatipestifer (RA), the causative agent of infectious serositis that targets ducklings and other poultry, secretes protein via the type IX secretion system (T9SS). The proteins transported by T9SS are located on the bacterial cell surface or secreted into the extracellular milieu. In this study, a sprA deletion mutant was constructed encoding a core protein of T9SS to investigate its influence on outer membrane protein expression and its role in virulence. Compared with the wild-type RA-YM strain, the deletion mutant ΔsprA failed to digest gelatin, showed the same growth rate in the logarithmic phase and exhibited greater sensitivity to the bactericidal activity of duck sera, whereas the complemented strain restored these phenotypes. The outer membrane proteome of RA-YM and the ΔsprA mutant were analyzed by Tandem Mass Tags, which revealed 198 proteins with predicted localization to the cell envelope. Sixty-three of these proteins were differentially expressed in the outer membrane, with 43 up-regulated and 20 down-regulated. Among the twelve outer membrane proteins which were secreted by T9SS, four proteins were up-regulated and one protein was down-regulated. Animal experiments demonstrated that the median lethal dose of the mutant strain ΔsprA was about 500 times higher than that of the wild-type RA-YM strain, and bacterial loads in blood, brain, heart, liver and spleen of the ΔsprA-infected ducks were significantly reduced. Our results indicate that the SprA is a virulence-associated factor of RA, and its absence results in altered abundance of outer membrane proteins, and secretion disorders associated with some of the T9SS effector proteins.
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Affiliation(s)
- Di Hu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Yunqing Guo
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Jie Guo
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Ying Wang
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zhe Pan
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Yuncai Xiao
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Xiliang Wang
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Sishun Hu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Mei Liu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zili Li
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Dingren Bi
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zutao Zhou
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
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22
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Abstract
ABSTRACT
Members of the phylum
Bacteroidetes
have many unique features, including gliding motility and the type IX protein secretion system (T9SS).
Bacteroidetes
gliding and T9SSs are common in, but apparently confined to, this phylum. Most, but not all, members of the phylum secrete proteins using the T9SS, and most also exhibit gliding motility. T9SSs secrete cell surface components of the gliding motility machinery and also secrete many extracellular or cell surface enzymes, adhesins, and virulence factors. The components of the T9SS are novel and are unrelated to those of other bacterial secretion systems. Proteins secreted by the T9SS rely on the Sec system to cross the cytoplasmic membrane, and they use the T9SS for delivery across the outer membrane. Secreted proteins typically have conserved C-terminal domains that target them to the T9SS. Some of the T9SS components were initially identified as proteins required for gliding motility. Gliding does not involve flagella or pili and instead relies on the rapid movement of motility adhesins, such as SprB, along the cell surface by the gliding motor. Contact of the adhesins with the substratum provides the traction that results in cell movement. SprB and other motility adhesins are delivered to the cell surface by the T9SS. Gliding and the T9SS appear to be intertwined, and components of the T9SS that span the cytoplasmic membrane may energize both gliding and protein secretion. The functions of the individual proteins in each process are the subject of ongoing investigations.
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23
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Chen Q, Gong X, Zheng F, Ji G, Li S, Stipkovits L, Szathmary S, Liu Y. Interplay Between the Phenotype and Genotype, and Efflux Pumps in Drug-Resistant Strains of Riemerella anatipestifer. Front Microbiol 2018; 9:2136. [PMID: 30327640 PMCID: PMC6174861 DOI: 10.3389/fmicb.2018.02136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/21/2018] [Indexed: 12/05/2022] Open
Abstract
The number of multidrug-resistant strains of Riemerella anatipestifer continues to increase, and new strategies for the treatment of associated infections are necessary. Recently, numerous studies have shown that efflux pumps (EPs) play key roles in universal bacterial mechanisms that contribute to antibiotic resistance. In addition, studies have shown that the effects of antibiotics that are subjected to efflux can be reinforced by their combined use with efflux pump inhibitors (EPIs). Unfortunately, the role of the efflux system in R. anatipestifer remains barely understood. In this study, we evaluated the role of EPs and resistance genes in the resistance generated by clinical strains of R. anatipestifer to antibiotics. A set of 10 R. anatipestifer strains were characterized by drug resistance, associated resistance genes, and antibiotic profiles in the presence and absence of EPIs. Efflux activity was studied on a real time basis through a fluorometric method. Quantification of the levels of mRNA transcription of efflux pump genes (EPGs) was determined by RT-qPCR. Several approaches (detection of resistance genes, drug susceptibility testing, and growth kinetics analysis) were used to assess the correlation between the effect of the EPIs and the resistance levels. Analysis of the R. anatipestifer growth inhibition tests showed that the antibiotic activity was enhanced by the synergy of EPIs. Among the various resistance genes that confer antibiotic resistance, different minimum inhibitory concentrations (MICs) were observed. The different levels of resistance were reduced by EPIs. Real time fluorometry showed that all the R. anatipestifer strains presented inherent efflux activity, conferring varying levels of inhibition in the presence of EPIs. Moreover, 15 EPGs were overexpressed in the presence of antibiotics. The addition of EPIs to antibiotics led to downregulation in the expression of some EPGs and a simultaneous increase in drug resistance and sensitivity. These results demonstrated the contribution of these EPs in the resistant phenotype of the clinical strains of R. anatipestifer that are under investigation, independently of the resistant genotype of the respective strains. Intrinsic efflux activity was possibly linked to the evolution of resistance in multidrug-resistant isolates of R. anatipestifer. Furthermore, the inhibition of EPs by EPIs could enhance the clinical effects of antibiotics.
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Affiliation(s)
- Qiwei Chen
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xiaowei Gong
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Fuying Zheng
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Guo Ji
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Shengdou Li
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | | | | | - Yongsheng Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
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