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Liu J, Yin F, Liu T, Li S, Tan C, Li L, Zhou R, Huang Q. The Tat system and its dependent cell division proteins are critical for virulence of extra-intestinal pathogenic Escherichia coli. Virulence 2020; 11:1279-1292. [PMID: 32962530 PMCID: PMC7549933 DOI: 10.1080/21505594.2020.1817709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/23/2020] [Accepted: 08/28/2020] [Indexed: 11/29/2022] Open
Abstract
The twin-arginine translocation (Tat) system is involved in a variety of important bacterial physiological processes. Conserved among bacteria and crucial for virulence, the Tat system is deemed as a promising anti-microbial drug target. However, the mechanism of how the Tat system functions in bacterial pathogenesis has not been fully understood. In this study, we showed that the Tat system was critical for the virulence of an extra-intestinal pathogenic E. coli (ExPEC) strain PCN033. A total of 20 Tat-related mutant strains were constructed, and competitive infection assays were performed to evaluate the relative virulence of these mutants. The results demonstrated that several Tat substrate mutants, including the ΔsufI, ΔamiAΔamiC double mutant as well as each single mutant, ΔyahJ, ΔcueO, and ΔnapG, were significantly outcompeted by the WT strain, among which the ΔsufI and ΔamiAΔamiC strains showed the lowest competitive index (CI) value. Results of individual mouse infection assay, in vitro cell adhesion assay, whole blood bactericidal assay, and serum bactericidal assay further confirmed the virulence attenuation phenotype of the ΔsufI and ΔamiAΔamiC strains. Moreover, the two mutants displayed chained morphology in the log phase resembling the Δtat and were defective in stress response. Our results suggest that the Tat system and its dependent cell division proteins SufI, AmiA, and AmiC play critical roles during ExPEC pathogenesis.
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Affiliation(s)
- Jinjin Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Fan Yin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Te Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Shaowen Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of China, Wuhan, China
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of China, Wuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of China, Wuhan, China
| | - Qi Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of China, Wuhan, China
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Hughes ER, Winter MG, Duerkop BA, Spiga L, Furtado de Carvalho T, Zhu W, Gillis CC, Büttner L, Smoot MP, Behrendt CL, Cherry S, Santos RL, Hooper LV, Winter SE. Microbial Respiration and Formate Oxidation as Metabolic Signatures of Inflammation-Associated Dysbiosis. Cell Host Microbe 2017; 21:208-219. [PMID: 28182951 DOI: 10.1016/j.chom.2017.01.005] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 11/16/2016] [Accepted: 01/03/2017] [Indexed: 12/16/2022]
Abstract
Intestinal inflammation is frequently associated with an alteration of the gut microbiota, termed dysbiosis, which is characterized by a reduced abundance of obligate anaerobic bacteria and an expansion of facultative Proteobacteria such as commensal E. coli. The mechanisms enabling the outgrowth of Proteobacteria during inflammation are incompletely understood. Metagenomic sequencing revealed bacterial formate oxidation and aerobic respiration to be overrepresented metabolic pathways in a chemically induced murine model of colitis. Dysbiosis was accompanied by increased formate levels in the gut lumen. Formate was of microbial origin since no formate was detected in germ-free mice. Complementary studies using commensal E. coli strains as model organisms indicated that formate dehydrogenase and terminal oxidase genes provided a fitness advantage in murine models of colitis. In vivo, formate served as electron donor in conjunction with oxygen as the terminal electron acceptor. This work identifies bacterial formate oxidation and oxygen respiration as metabolic signatures for inflammation-associated dysbiosis.
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Affiliation(s)
- Elizabeth R Hughes
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maria G Winter
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Breck A Duerkop
- Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Luisella Spiga
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tatiane Furtado de Carvalho
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, 31270 Brazil
| | - Wenhan Zhu
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Caroline C Gillis
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lisa Büttner
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Madeline P Smoot
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Cassie L Behrendt
- Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sara Cherry
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Renato L Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, 31270 Brazil
| | - Lora V Hooper
- Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sebastian E Winter
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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