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Hao M, Zhao D, Liu W, Yuan N, Tang T, Wang M, Zhai Y, Shi Y, Yang Y, Liu X, Li J, Zhou D, Liu W, Jin Y, Wang A. Deletion of the alr gene in Brucella suis S2 attenuates virulence by enhancing TLR4-NF-κB-NLRP3- mediated host inflammatory responses. Int Immunopharmacol 2024; 137:112443. [PMID: 38897124 DOI: 10.1016/j.intimp.2024.112443] [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: 03/01/2024] [Revised: 05/11/2024] [Accepted: 06/05/2024] [Indexed: 06/21/2024]
Abstract
Brucella is an intracellular parasitic bacterium lacking typical virulence factors, and its pathogenicity primarily relies on replication within host cells. In this study, we observed a significant increase in spleen weight in mice immunized with a Brucella strain deleted of the gene for alanine racemase (Alr), the enzyme responsible for alanine racemization (Δalr). However, the bacterial load in the spleen markedly decreased in the mutant strain. Concurrently, the ratio of white pulp to red pulp in the spleen was increased, serum IgG levels were elevated, but no significant damage to other organs was observed. In addition, the inflammatory response was potentiated and the NF-κB-NLRP3 signaling pathway was activated in macrophages (RAW264.7 Cells and Bone Marrow-Derived Cells) infect ed with the Δalr mutant. Further investigation revealed that the Δalr mutant released substantial amounts of protein in a simulated intracellular environment which resulted in heightened inflammation and activation of the TLR4-NF-κB-NLRP3 pathway in macrophages. The consequent cytoplasmic exocytosis reduced intracellular Brucella survival. In summary, cytoplasmic exocytosis products resulting from infection with a Brucella strain deleted of the alr gene effectively activated the TLR4-NFκB-NLRP3 pathway, triggered a robust inflammatory response, and reduced bacterial survival within host cells. Moreover, the Δalr strain exhibits lower toxicity and stronger immunogenicity in mice.
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Affiliation(s)
- Mingyue Hao
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Danyu Zhao
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Wei Liu
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Ningqiu Yuan
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Ting Tang
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Minghui Wang
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Yunyi Zhai
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Yong Shi
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Yuanhao Yang
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Xiaofang Liu
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Junmei Li
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Dong Zhou
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Wei Liu
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A &F University, Yangling, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, China.
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Wen J, Li Z, Lv Y, Ding S, Zhu Y, Yang J, Tang J, Zhu M, Zhao Y, Zhao W. A subunit vaccine based on Brucella rBP26 induces Th1 immune responses and M1 macrophage activation. Acta Biochim Biophys Sin (Shanghai) 2024; 56:879-891. [PMID: 38419498 PMCID: PMC11292127 DOI: 10.3724/abbs.2024023] [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: 12/02/2023] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
Brucellosis is a global zoonotic infection caused by Brucella bacteria, which poses a significant burden on society. While transmission prevention is currently the most effective method, the absence of a licenced vaccine for humans necessitates the urgent development of a safe and effective vaccine. Recombinant protein-based subunit vaccines are considered promising options, and in this study, the Brucella BP26 protein is expressed using prokaryotic expression systems. The immune responses are evaluated using the well-established adjuvant CpG-ODN. The results demonstrate that rBP26 supplemented with a CpG adjuvant induces M1 macrophage polarization and stimulates cellular immune responses mediated by Th1 cells and CD8 + T cells. Additionally, it generates high levels of rBP26-specific antibodies in immunized mice. Furthermore, rBP26 immunization activates, proliferates, and produces cytokines in T lymphocytes while also maintaining immune memory for an extended period of time. These findings shed light on the potential biological function of rBP26, which is crucial for understanding brucellosis pathogenesis. Moreover, rBP26 holds promise as an effective subunit vaccine candidate for use in endemic areas.
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Affiliation(s)
- Jia Wen
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- General Medicine DepartmentGeneral Hospital of Ningxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Zihua Li
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Yongxue Lv
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Shuqin Ding
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Yazhou Zhu
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Jihui Yang
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Jing Tang
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Mingxing Zhu
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Yinqi Zhao
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
| | - Wei Zhao
- School of Basic MedicineNingxia Medical UniversityYinchuan750004China
- Ningxia Key Laboratory of Prevention and Control of Common Infectious DiseasesNingxia Hui Autonomous RegionYinchuan750004China
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Loperena-Barber M, Elizalde-Bielsa A, Salvador-Bescós M, Ruiz-Rodríguez P, Pellegrini JM, Renau-Mínguez C, Lancaster R, Zúñiga-Ripa A, Iriarte M, Bengoechea JA, Coscollá M, Gorvel JP, Moriyón I, Conde-Álvarez R. "Phylogenomic insights into brucellaceae: The Pseudochrobactrum algeriensis case". INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024; 123:105625. [PMID: 38906517 DOI: 10.1016/j.meegid.2024.105625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/17/2024] [Accepted: 06/17/2024] [Indexed: 06/23/2024]
Abstract
The genus Pseudochrobactrum encompasses free-living bacteria phylogenetically close to Ochrobactrum opportunistic pathogens and to Brucella, facultative intracellular parasites causing brucellosis, a worldwide-extended and grave zoonosis. Recently, Pseudochrobactrum strains were isolated from Brucella natural hosts on Brucella selective media, potentially causing diagnostic confusions. Strikingly, P. algeriensis was isolated from cattle lymph nodes, organs that are inimical to bacteria. Here, we analyse P. algeriensis potential virulence factors in comparison with Ochrobactrum and Brucella. Consistent with genomic analyses, Western-Blot analyses confirmed that P. algeriensis lacks the ability to synthesize the N-formylperosamine O-polysaccharide characteristic of the lipopolysaccharide (LPS) of smooth Brucella core species. However, unlike other Pseudochrobactrum but similar to some early diverging brucellae, P. algeriensis carries genes potentially synthetizing a rhamnose-based O-polysaccharide LPS. Lipid A analysis by MALDI-TOF demonstrated that P. algeriensis LPS bears a lipid A with a reduced pathogen-associated molecular pattern, a trait shared with Ochrobactrum and Brucella that is essential to generate a highly stable outer membrane and to delay immune activation. Also, although not able to multiply intracellularly in macrophages, the analysis of P. algeriensis cell lipid envelope revealed the presence of large amounts of cationic aminolipids, which may account for the extremely high resistance of P. algeriensis to bactericidal peptides and could favor colonization of mucosae and transient survival in Brucella hosts. However, two traits critical in Brucella pathogenicity are either significantly different (T4SS [VirB]) or absent (erythritol catabolic pathway) in P. algeriensis. This work shows that, while diverging in other characteristics, lipidic envelope features relevant in Brucella pathogenicity are conserved in Brucellaceae. The constant presence of these features strongly suggests that reinforcement of the envelope integrity as an adaptive advantage in soil was maintained in Brucella because of the similarity of some environmental challenges, such as the action of cationic peptide antibiotics and host defense peptides. This information adds knowledge about the evolution of Brucellaceae, and also underlines the taxonomical differences of the three genera compared.
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Affiliation(s)
- Maite Loperena-Barber
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Aitor Elizalde-Bielsa
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Miriam Salvador-Bescós
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Paula Ruiz-Rodríguez
- Institute for Integrative Systems Biology, Universidad de Valencia-CSIC, Valencia, Spain
| | | | - Chantal Renau-Mínguez
- Institute for Integrative Systems Biology, Universidad de Valencia-CSIC, Valencia, Spain
| | - Rebecca Lancaster
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Amaia Zúñiga-Ripa
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Maite Iriarte
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Jose A Bengoechea
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Mireia Coscollá
- Institute for Integrative Systems Biology, Universidad de Valencia-CSIC, Valencia, Spain
| | - Jean-Pierre Gorvel
- Centre d'Immunologie de Marseille-Luminy, CNRS, INSERM, Aix-Marseille University, Marseille, France
| | - Ignacio Moriyón
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain
| | - Raquel Conde-Álvarez
- Instituto de Investigación Sanitaria de Navarra (IdISNA) and Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain.
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Yin Y, Fang T, Lian Z, Zuo D, Hu H, Zhang G, Ding C, Tian M, Yu S. Erythronate utilization activates VdtR regulating its metabolism to promote Brucella proliferation, inducing abortion in mice. Microbiol Spectr 2023; 11:e0207423. [PMID: 37671873 PMCID: PMC10580937 DOI: 10.1128/spectrum.02074-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/08/2023] [Indexed: 09/07/2023] Open
Abstract
Brucella is a facultative intracellular pathogen that preferentially colonizes reproductive organs and utilizes erythritol as a preferred carbon source for its survival and proliferation. In this study, we identified a virulence-related DeoR-family transcriptional regulator (VdtR) and an erythronate metabolic pathway responsible for four-carbon acid sugar metabolism of D-erythronate and L-threonate in Brucella. We found that VdtR plays an important role in Brucella intracellular survival and trafficking to the endoplasmic reticulum in RAW 264.7 macrophages and in virulence in a mouse model. More importantly, we found that VdtR negatively regulates the erythronate metabolic pathway to promote extracellular proliferation of Brucella, depending on utilization of D-erythronate, an oxidative product of erythritol in the host. In a pregnant mouse model, the erythronate metabolic pathway was shown to cooperate with erythritol metabolism and play a crucial role in Brucella proliferation in the placenta, inducing placentitis and finally resulting in abortion or stillbirth. Our results demonstrate that, in addition to erythritol, erythronate is a preferred carbon source for Brucella utilization to promote its extracellular proliferation. This discovery updates the information on the preferential colonization of reproductive organs by Brucella and provides a novel insight into the Brucella-associated induction of abortion in pregnant animals. IMPORTANCE Brucella is an intracellular parasitic bacterium causing zoonosis, which is distributed worldwide and mainly characterized by reproductive disorders. Erythritol is found in allantoic fluid, chorion, and placenta of aborted animals, preferentially utilized by Brucella to cause infertility and abortion. However, the erythritol metabolism-defected mutant was unable to function as a vaccine strain due to its residual virulence. Here, we found that erythronate, an oxidative product of erythritol in the host, was also preferentially utilized by Brucella relying on the function of a deoxyribonucleoside regulator-family transcriptional regulator VdtR. Erythronate utilization activates VdtR regulation of the erythronate metabolic pathway to promote Brucella extracellular proliferation, inducing placentitis/abortion in mice. Double mutations on Brucella erythritol and D-erythronate metabolisms significantly reduced bacterial virulence. This study revealed a novel mechanism of Brucella infection-induced abortion, thus providing a new clue for the study of safer Brucella attenuated vaccines.
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Affiliation(s)
- Yi Yin
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Tian Fang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Zhengmin Lian
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Dong Zuo
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Hai Hu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Guangdong Zhang
- 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
| | - Mingxing Tian
- 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
- Veterinary Bio-Pharmaceutical, Jiangsu Agri-Animal Husbandry Vocational College, Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Taizhou, Jiangsu, China
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5
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Corrêa JMM, de Oliveira MLG, de Souza PG, Filho PMS, de Macedo AN, Faria AF. Optimization of the first extraction protocol for metabolomic studies of Brucella abortus. Braz J Microbiol 2023; 54:2383-2392. [PMID: 37209273 PMCID: PMC10484873 DOI: 10.1007/s42770-023-01001-6] [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: 03/15/2023] [Accepted: 04/28/2023] [Indexed: 05/22/2023] Open
Abstract
Brucellosis is a zoonosis prevalent worldwide and very recurrent in less developed or developing regions. This zoonosis affects livestock, generating high financial losses to producers, in addition to transmitting diseases to humans through meat consumption or handling contaminated products and animals. In this study, five extraction methods for Brucella abortus intracellular metabolites, using different solvent compositions and cell membrane disruption procedures, were evaluated. Derivatized extracts were analyzed by GC-HRMS. Raw data were processed in XCMS Online and the results were evaluated through multivariate statistical analysis using the MetaboAnalyst platform. The identification of the extracted metabolites was performed by the Unknowns software using the NIST 17.L library. The extraction performance of each method was evaluated for thirteen representative metabolites, comprising four different chemical classes. Most of these compounds are reported in the cell membrane composition of Gram-negative bacteria. The method based on extraction with methanol/chloroform/water presented the best performance in the evaluation of the extracted compounds and in the statistical results. Therefore, this method was selected for extracting intracellular metabolites from cultures of Brucella abortus for untargeted metabolomics analysis.
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Affiliation(s)
- Joane M M Corrêa
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | | | - Patrícia G de Souza
- Laboratório Federal de Defesa Agropecuária em Minas Gerais, Ministério da Agricultura, Pecuária e Abastecimento, Pedro Leopoldo, MG, 33600-000, Brazil
| | - Paulo M S Filho
- Laboratório Federal de Defesa Agropecuária em Minas Gerais, Ministério da Agricultura, Pecuária e Abastecimento, Pedro Leopoldo, MG, 33600-000, Brazil
| | - Adriana N de Macedo
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
| | - Adriana F Faria
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
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Rivas-Solano O, Núñez-Montero K, Altamirano-Silva P, Ruiz-Villalobos N, Barquero-Calvo E, Moreno E, Chaves-Olarte E, Guzmán-Verri C. A bvrR/bvrS Non-Polar Brucella abortus Mutant Confirms the Role of the Two-Component System BvrR/BvrS in Virulence and Membrane Integrity. Microorganisms 2023; 11:2014. [PMID: 37630574 PMCID: PMC10459465 DOI: 10.3390/microorganisms11082014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/25/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Brucella abortus is a bacterial pathogen causing bovine brucellosis worldwide. This facultative extracellular-intracellular pathogen can be transmitted to humans, leading to a zoonotic disease. The disease remains a public health concern, particularly in regions where livestock farming is present. The two-component regulatory system BvrR/BvrS was described by isolating the attenuated transposition mutants bvrR::Tn5 and bvrS::Tn5, whose characterization led to the understanding of the role of the system in bacterial survival. However, a phenotypic comparison with deletion mutants has not been performed because their construction has been unsuccessful in brucellae and difficult in phylogenetically related Rhizobiales with BvrR/BvrS orthologs. Here, we used an unmarked gene excision strategy to generate a B. abortus mutant strain lacking both genes, called B. abortus ∆bvrRS. The deletion was verified through PCR, Southern blot, Western blot, Sanger sequencing, and whole-genome sequencing, confirming a clean mutation without further alterations at the genome level. B. abortus ∆bvrRS shared attenuated phenotypic traits with both transposition mutants, confirming the role of BvrR/BvrS in pathogenesis and membrane integrity. This B. abortus ∆bvrRS with a non-antimicrobial marker is an excellent tool for continuing studies on the role of BvrR/BvrS in the B. abortus lifestyle.
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Affiliation(s)
- Olga Rivas-Solano
- Centro de Investigación en Biotecnología, Instituto Tecnológico de Costa Rica, Cartago 30109, Costa Rica
| | - Kattia Núñez-Montero
- Laboratorio Facultad Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Temuco 4813003, Chile;
| | - Pamela Altamirano-Silva
- Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San Pedro de Montes de Oca, San José 2060, Costa Rica; (P.A.-S.); (E.C.-O.)
| | - Nazareth Ruiz-Villalobos
- Programa de Investigación en Enfermedades Tropicales, Universidad Nacional, Heredia 40104, Costa Rica; (N.R.-V.); (E.B.-C.); (E.M.); (C.G.-V.)
| | - Elías Barquero-Calvo
- Programa de Investigación en Enfermedades Tropicales, Universidad Nacional, Heredia 40104, Costa Rica; (N.R.-V.); (E.B.-C.); (E.M.); (C.G.-V.)
| | - Edgardo Moreno
- Programa de Investigación en Enfermedades Tropicales, Universidad Nacional, Heredia 40104, Costa Rica; (N.R.-V.); (E.B.-C.); (E.M.); (C.G.-V.)
| | - Esteban Chaves-Olarte
- Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San Pedro de Montes de Oca, San José 2060, Costa Rica; (P.A.-S.); (E.C.-O.)
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales, Universidad Nacional, Heredia 40104, Costa Rica; (N.R.-V.); (E.B.-C.); (E.M.); (C.G.-V.)
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7
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Gordon JL, Oliva Chavez AS, Martinez D, Vachiery N, Meyer DF. Possible biased virulence attenuation in the Senegal strain of Ehrlichia ruminantium by ntrX gene conversion from an inverted segmental duplication. PLoS One 2023; 18:e0266234. [PMID: 36800354 PMCID: PMC9937504 DOI: 10.1371/journal.pone.0266234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 03/16/2022] [Indexed: 02/18/2023] Open
Abstract
Ehrlichia ruminantium is a tick-borne intracellular pathogen of ruminants that causes heartwater, a disease present in Sub-saharan Africa, islands in the Indian Ocean and the Caribbean, inducing significant economic losses. At present, three avirulent strains of E. ruminantium (Gardel, Welgevonden and Senegal isolates) have been produced by a process of serial passaging in mammalian cells in vitro, but unfortunately their use as vaccines do not offer a large range of protection against other strains, possibly due to the genetic diversity present within the species. So far no genetic basis for virulence attenuation has been identified in any E. ruminantium strain that could offer targets to facilitate vaccine production. Virulence attenuated Senegal strains have been produced twice independently, and require many fewer passages to attenuate than the other strains. We compared the genomes of a virulent and attenuated Senegal strain and identified a likely attenuator gene, ntrX, a global transcription regulator and member of a two-component system that is linked to environmental sensing. This gene has an inverted partial duplicate close to the parental gene that shows evidence of gene conversion in different E. ruminantium strains. The pseudogenisation of the gene in the avirulent Senegal strain occurred by gene conversion from the duplicate to the parent, transferring a 4 bp deletion which is unique to the Senegal strain partial duplicate amongst the wild isolates. We confirmed that the ntrX gene is not expressed in the avirulent Senegal strain by RT-PCR. The inverted duplicate structure combined with the 4 bp deletion in the Senegal strain can explain both the attenuation and the faster speed of attenuation in the Senegal strain relative to other strains of E. ruminantium. Our results identify nrtX as a promising target for the generation of attenuated strains of E. ruminantium by random or directed mutagenesis that could be used for vaccine production.
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Affiliation(s)
- Jonathan L. Gordon
- CIRAD, UMR ASTRE, Petit-Bourg, Guadeloupe, France
- ASTRE, CIRAD, INRAe, Univ Montpellier, Montpellier, France
| | - Adela S. Oliva Chavez
- CIRAD, UMR ASTRE, Petit-Bourg, Guadeloupe, France
- ASTRE, CIRAD, INRAe, Univ Montpellier, Montpellier, France
| | | | | | - Damien F. Meyer
- CIRAD, UMR ASTRE, Petit-Bourg, Guadeloupe, France
- ASTRE, CIRAD, INRAe, Univ Montpellier, Montpellier, France
- * E-mail:
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8
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Guo X, Zeng H, Li M, Xiao Y, Gu G, Song Z, Shuai X, Guo J, Huang Q, Zhou B, Chu Y, Jiao H. The mechanism of chronic intracellular infection with Brucella spp. Front Cell Infect Microbiol 2023; 13:1129172. [PMID: 37143745 PMCID: PMC10151771 DOI: 10.3389/fcimb.2023.1129172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/31/2023] [Indexed: 05/06/2023] Open
Abstract
Globally, brucellosis is a widespread zoonotic disease. It is prevalent in more than 170 countries and regions. It mostly damages an animal's reproductive system and causes extreme economic losses to the animal husbandry industry. Once inside cells, Brucella resides in a vacuole, designated the BCV, which interacts with components of the endocytic and secretory pathways to ensure bacterial survival. Numerous studies conducted recently have revealed that Brucella's ability to cause a chronic infection depends on how it interacts with the host. This paper describes the immune system, apoptosis, and metabolic control of host cells as part of the mechanism of Brucella survival in host cells. Brucella contributes to both the body's non-specific and specific immunity during chronic infection, and it can aid in its survival by causing the body's immune system to become suppressed. In addition, Brucella regulates apoptosis to avoid being detected by the host immune system. The BvrR/BvrS, VjbR, BlxR, and BPE123 proteins enable Brucella to fine-tune its metabolism while also ensuring its survival and replication and improving its ability to adapt to the intracellular environment.
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Affiliation(s)
- Xiaoyi Guo
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Hui Zeng
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Mengjuan Li
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Yu Xiao
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Guojing Gu
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Zhenhui Song
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Xuehong Shuai
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Jianhua Guo
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Qingzhou Huang
- The College of Veterinary Medicine, Southwest University, Chongqing, China
| | - Bo Zhou
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, Jilin, China
- *Correspondence: Bo Zhou, ; Yuefeng Chu, ; Hanwei Jiao,
| | - Yuefeng Chu
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, China
- *Correspondence: Bo Zhou, ; Yuefeng Chu, ; Hanwei Jiao,
| | - Hanwei Jiao
- The College of Veterinary Medicine, Southwest University, Chongqing, China
- The Immunology Research Center, Medical Research Institute, Southwest University, Chongqing, China
- *Correspondence: Bo Zhou, ; Yuefeng Chu, ; Hanwei Jiao,
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9
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Fan Q, Zuo J, Wang H, Grenier D, Yi L, Wang Y. Contribution of quorum sensing to virulence and antibiotic resistance in zoonotic bacteria. Biotechnol Adv 2022; 59:107965. [PMID: 35487393 DOI: 10.1016/j.biotechadv.2022.107965] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/15/2022] [Accepted: 04/21/2022] [Indexed: 11/02/2022]
Abstract
Quorum sensing (QS), which is a key part of cell/cell communication, is widely distributed in microorganisms, especially in bacteria. Bacteria can produce and detect the presence of QS signal molecule, perceive the composition and density of microorganisms in their complex habitat, and then dynamically regulate their own gene expression to adapt to their environment. Among the many traits controlled by QS in pathogenic bacteria is the expression of virulence factors and antibiotic resistance. Many pathogenic bacteria rely on QS to govern the production of virulence factors and express drug-resistance, especially in zoonotic bacteria. The threat of antibiotic resistant zoonotic bacteria has called for alternative antimicrobial strategies that would mitigate the increase of classical resistance mechanism. Targeting QS has proven to be a promising alternative to conventional antibiotic for controlling infections. Here we review the QS systems in common zoonotic pathogenic bacteria and outline how QS may control the virulence and antibiotic resistance of zoonotic bacteria.
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Affiliation(s)
- Qingying Fan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Jing Zuo
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Haikun Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Daniel Grenier
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Canada
| | - Li Yi
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China; College of Life Science, Luoyang Normal University, Luoyang, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China.
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10
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The Retrospective on Atypical Brucella Species Leads to Novel Definitions. Microorganisms 2022; 10:microorganisms10040813. [PMID: 35456863 PMCID: PMC9025488 DOI: 10.3390/microorganisms10040813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/01/2023] Open
Abstract
The genus Brucella currently comprises twelve species of facultative intracellular bacteria with variable zoonotic potential. Six of them have been considered as classical, causing brucellosis in terrestrial mammalian hosts, with two species originated from marine mammals. In the past fifteen years, field research as well as improved pathogen detection and typing have allowed the identification of four new species, namely Brucella microti, Brucella inopinata, Brucella papionis, Brucella vulpis, and of numerous strains, isolated from a wide range of hosts, including for the first time cold-blooded animals. While their genome sequences are still highly similar to those of classical strains, some of them are characterized by atypical phenotypes such as higher growth rate, increased resistance to acid stress, motility, and lethality in the murine infection model. In our review, we provide an overview of state-of-the-art knowledge about these novel Brucella sp., with emphasis on their phylogenetic positions in the genus, their metabolic characteristics, acid stress resistance mechanisms, and their behavior in well-established in cellulo and in vivo infection models. Comparison of phylogenetic classification and phenotypical properties between classical and novel Brucella species and strains finally lead us to propose a more adapted terminology, distinguishing between core and non-core, and typical versus atypical brucellae, respectively.
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11
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Han AR, Kim H, Park JT, Kim JW. Characterization of a cold-adapted debranching enzyme and its role in glycogen metabolism and virulence of Vibrio vulnificus MO6-24/O. JOURNAL OF MICROBIOLOGY (SEOUL, KOREA) 2022; 60:375-386. [PMID: 35157220 DOI: 10.1007/s12275-022-1507-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 12/19/2022]
Abstract
Vibrio vulnificus MO6-24/O has three genes annotated as debranching enzymes or pullulanase genes. Among them, the gene encoded by VVMO6_03032 (vvde1) shares a higher similarity at the amino acid sequence level to the glycogen debranching enzymes, AmyX of Bacillus subtilis (40.5%) and GlgX of Escherichia coli (55.5%), than those encoded by the other two genes. The vvde1 gene encoded a protein with a molecular mass of 75.56 kDa and purified Vvde1 efficiently hydrolyzed glycogen and pullulan to shorter chains of maltodextrin and maltotriose (G3), respectively. However, it hydrolyzed amylopectin and soluble starch far less efficiently, and β-cyclodextrin (β-CD) only rarely. The optimal pH and temperature of Vvde1 was 6.5 and 25°C, respectively. Vvde1 was a cold-adapted debranching enzyme with more than 60% residual activity at 5°C. It could maintain stability for 2 days at 25°C and 1 day at 35°C, but it destabilized drastically at 40°C. The Vvde1 activity was inhibited considerably by Cu2+, Hg2+, and Zn2+, while it was slightly enhanced by Co2+, Ca2+, Ni2+, and Fe2+. The vvde1 knock-out mutant accumulated more glycogen than the wild-type in media supplemented with 1.0% maltodextrin; however, the side chain length distribution of glycogen was similar to that of the wild-type except G3, which was much more abundant in the mutant. Therefore, Vvde1 seemed to debranch glycogen with the degree of polymerization 3 (DP3) as the specific target branch length. Virulence of the pathogen against Caenorhabditis elegans was attenuated significantly by the vvde1 mutation. These results suggest that Vvde1 might be a unique glycogen debranching enzyme that is involved in both glycogen utilization and shaping of glycogen molecules, and contributes toward virulence of the pathogen.
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Affiliation(s)
- Ah-Reum Han
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea
| | - Haeyoung Kim
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea
| | - Jong-Tae Park
- Department of Food Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jung-Wan Kim
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea. .,Division of Bioengineering, Incheon National University, Incheon, 22102, Republic of Korea.
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12
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Pathogenicity and Its Implications in Taxonomy: The Brucella and Ochrobactrum Case. Pathogens 2022; 11:pathogens11030377. [PMID: 35335701 PMCID: PMC8954888 DOI: 10.3390/pathogens11030377] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/09/2022] [Accepted: 03/16/2022] [Indexed: 11/21/2022] Open
Abstract
The intracellular pathogens of the genus Brucella are phylogenetically close to Ochrobactrum, a diverse group of free-living bacteria with a few species occasionally infecting medically compromised patients. A group of taxonomists recently included all Ochrobactrum organisms in the genus Brucella based on global genome analyses and alleged equivalences with genera such as Mycobacterium. Here, we demonstrate that such equivalencies are incorrect because they overlook the complexities of pathogenicity. By summarizing Brucella and Ochrobactrum divergences in lifestyle, structure, physiology, population, closed versus open pangenomes, genomic traits, and pathogenicity, we show that when they are adequately understood, they are highly relevant in taxonomy and not unidimensional quantitative characters. Thus, the Ochrobactrum and Brucella differences are not limited to their assignments to different “risk-groups”, a biologically (and hence, taxonomically) oversimplified description that, moreover, does not support ignoring the nomen periculosum rule, as proposed. Since the epidemiology, prophylaxis, diagnosis, and treatment are thoroughly unrelated, merging free-living Ochrobactrum organisms with highly pathogenic Brucella organisms brings evident risks for veterinarians, medical doctors, and public health authorities who confront brucellosis, a significant zoonosis worldwide. Therefore, from taxonomical and practical standpoints, the Brucella and Ochrobactrum genera must be maintained apart. Consequently, we urge researchers, culture collections, and databases to keep their canonical nomenclature.
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13
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Brucella induces M1 to M2 polarization of macrophages through STAT6 signaling pathway to promote bacterial intracellular survival. Res Vet Sci 2022; 145:91-101. [DOI: 10.1016/j.rvsc.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 12/17/2021] [Accepted: 02/02/2022] [Indexed: 11/23/2022]
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14
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Yang J, He C, Zhang H, Liu M, Zhao H, Ren L, Wu D, Du F, Liu B, Han X, He S, Chen Z. Evaluation and Differential Diagnosis of a Genetic Marked Brucella Vaccine A19ΔvirB12 for Cattle. Front Immunol 2021; 12:679560. [PMID: 34163479 PMCID: PMC8215367 DOI: 10.3389/fimmu.2021.679560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/10/2021] [Indexed: 01/23/2023] Open
Abstract
Brucella abortus is an important zoonotic pathogen that causes severe economic loss to husbandry and poses a threat to human health. The B. abortus A19 live vaccine has been extensively used to prevent bovine brucellosis in China. However, it is difficult to distinguish the serological response induced by A19 from that induced by natural infection. In this study, a novel genetically marked vaccine, A19ΔvirB12, was generated and evaluated. The results indicated that A19ΔvirB12 was able to provide effective protection against B. abortus 2308 (S2308) challenge in mice. Furthermore, the safety and protective efficacy of A19ΔvirB12 have been confirmed in natural host cattle. Additionally, the VirB12 protein allowed for serological differentiation between the S2308 challenge/natural infection and A19ΔvirB12 vaccination. However, previous studies have found that the accuracy of the serological detection based on VirB12 needs to be improved. Therefore, we attempted to identify potential supplementary antigens with differential diagnostic functions by combining label-free quantitative proteomics and protein chip technology. Twenty-six proteins identified only in S2308 were screened; among them, five proteins were considered as potential supplementary antigens. Thus, the accuracy of the differential diagnosis between A19ΔvirB12 immunization and field infection may be improved through multi-antigen detection. In addition, we explored the possible attenuation factors of Brucella vaccine strain. Nine virulence factors were downregulated in A19ΔvirB12. The downregulation pathways of A19ΔvirB12 were significantly enriched in quorum sensing, ATP-binding cassette transporter, and metabolism. Several proteins related to cell division were significantly downregulated, while some proteins involved in transcription were upregulated in S2308. In conclusion, our results contribute to the control and eradication of brucellosis and provide insights into the mechanisms underlying the attenuation of A19ΔvirB12.
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Affiliation(s)
- Jianghua Yang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Chuanyu He
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,Tecon Biological Co. Ltd., Urumqi, China
| | - Huan Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | | | | | - Lisong Ren
- Tecon Biological Co. Ltd., Urumqi, China
| | | | - Fangyuan Du
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Baoshan Liu
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Xiaohu Han
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Sun He
- Tecon Biological Co. Ltd., Urumqi, China
| | - Zeliang Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, China.,Brucellosis Prevention and Treatment Engineering Technology Research Center of Inner Mongolia Autonomous Region, Inner Mongolia University for Nationalities, Tongliao, China.,School of Public Health, Sun Yat-sen University, Guangzhou, China
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15
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Sakata N, Ishiga T, Ishiga Y. Pseudmonas cannabina pv. alisalensis TrpA Is Required for Virulence in Multiple Host Plants. Front Microbiol 2021; 12:659734. [PMID: 33959115 PMCID: PMC8093880 DOI: 10.3389/fmicb.2021.659734] [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: 01/28/2021] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas cannabina pv. alisalensis (Pcal) causes bacterial leaf spot and blight of Brassicaceae and Poaceae. We previously identified several potential Pcal virulence factors with transposon mutagenesis. Among these a trpA mutant disrupted the tryptophan synthase alpha chain, and had an effect on disease symptom development and bacterial multiplication. To assess the importance of TrpA in Pcal virulence, we characterized the trpA mutant based on inoculation test and Pcal gene expression profiles. The trpA mutant showed reduced virulence when dip- and syringe-inoculated on cabbage and oat. Moreover, epiphytic bacterial populations of the trpA mutant were also reduced compared to the wild-type (WT). These results suggest that TrpA contributes to bacterial multiplication on the leaf surface and in the apoplast, and disease development. Additionally, several Brassicaceae (including Japanese radish, broccoli, and Chinese cabbage) also exhibited reduced symptom development when inoculated with the trpA mutant. Moreover, trpA disruption led to downregulation of bacterial virulence genes, including type three effectors (T3Es) and the phytotoxin coronatine (COR), and to upregulation of tryptophan biosynthesis genes. These results indicate that a trade-off between virulence factor production and Pcal multiplication with tryptophan might be regulated in the infection processes.
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Affiliation(s)
- Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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16
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Characterization of innate immune response to Brucella melitensis infection in goats with permissive or restrictive phenotype for Brucella intramacrophagic growth. Vet Immunol Immunopathol 2021; 234:110223. [PMID: 33711712 DOI: 10.1016/j.vetimm.2021.110223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 11/22/2022]
Abstract
Caprine brucellosis is a chronic, world-wide distributed disease which causes reproductive failure in goats and Brucella melitensis, its causative agent, bears a great zoonotic potential. There is evidence suggesting that some cattle and pigs have an innate ability to resist Brucella infection, but this has not yet been investigated in goats. In this study, we compared caprine macrophages that exhibit extreme restriction and permissiveness to B. melitensis' intracellular growth in vitro. Monocyte derived macrophages (MDMs) from 110 female goats were cultured and challenged in vitro with B. melitensis 16 M. After initial screening, 18 donor goats were selected based on their macrophages ability to restrict or allow bacterial intracellular growth and some elements of humoral and cellular immunity were studied in depth. MDMs that were able to restrict the pathogen's intracellular growth showed enhanced bacterial internalization, although there were no differences between groups in the production of reactive oxygen and nitrogen intermediates following 48 h treatment with heat-killed B. melitensis. Moreover, there were no differences between groups in the level of antibodies reacting with keyhole limpet hemocyanin (natural antibodies, NAbs) or with Brucella LPS antigens (cross-reacting antibodies, CrAbs), although a strong positive correlation between individual levels of IgM NAbs and IgM CrAbs was detected. Altogether, these results represent an initial step in understanding innate primary host response to B. melitensis, and deciphering which mechanisms may determine a successful outcome of the infection in goats.
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17
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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18
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Vizcaíno N, Pérez-Etayo L, Conde-Álvarez R, Iriarte M, Moriyón I, Zúñiga-Ripa A. Disruption of pyruvate phosphate dikinase in Brucella ovis PA CO 2-dependent and independent strains generates attenuation in the mouse model. Vet Res 2020; 51:101. [PMID: 32795361 PMCID: PMC7427901 DOI: 10.1186/s13567-020-00824-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 07/23/2020] [Indexed: 11/25/2022] Open
Abstract
Brucella ovis is a non-zoonotic rough Brucella that causes genital lesions, abortions and increased perinatal mortality in sheep and is responsible for important economic losses worldwide. Research on virulence factors of B. ovis is necessary for deciphering the mechanisms that enable this facultative intracellular pathogen to establish persistent infections and for developing a species-specific vaccine, a need in areas where the cross-protecting ovine smooth B. melitensis Rev1 vaccine is banned. Although several B. ovis virulence factors have been identified, there is little information on its metabolic abilities and their role in virulence. Here, we report that deletion of pyruvate phosphate dikinase (PpdK, catalyzing the bidirectional conversion pyruvate ⇌ phosphoenolpyruvate) in B. ovis PA (virulent and CO2-dependent) impaired growth in vitro. In cell infection experiments, although showing an initial survival higher than that of the parental strain, this ppdK mutant was unable to multiply. Moreover, when inoculated at high doses in mice, it displayed an initial spleen colonization higher than that of the parental strain followed by a marked comparative decrease, an unusual pattern of attenuation in mice. A homologous mutant was also obtained in a B. ovis PA CO2-independent construct previously proposed for developing B. ovis vaccines to solve the problem that CO2-dependence represents for large scale production. This CO2-independent ppdK mutant reproduced the growth defect in vitro and the multiplication/clearance pattern in mouse spleens, and is thus an interesting vaccine candidate for the immunoprophylaxis of B. ovis ovine brucellosis.
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Affiliation(s)
- Nieves Vizcaíno
- Departamento de Microbiología Y Genética, Edificio Departamental, Universidad de Salamanca, Edificio Departamental, Plaza Doctores de la Reina s/n, Salamanca, 37007, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Paseo de San Vicente 52-182, 37007, Salamanca, Spain
| | - Lara Pérez-Etayo
- Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Departamento de Microbiología y Parasitología, Universidad de Navarra, Calle Irunlarrea 1, 31008, Pamplona, Spain
| | - Raquel Conde-Álvarez
- Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Departamento de Microbiología y Parasitología, Universidad de Navarra, Calle Irunlarrea 1, 31008, Pamplona, Spain
| | - Maite Iriarte
- Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Departamento de Microbiología y Parasitología, Universidad de Navarra, Calle Irunlarrea 1, 31008, Pamplona, Spain
| | - Ignacio Moriyón
- Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Departamento de Microbiología y Parasitología, Universidad de Navarra, Calle Irunlarrea 1, 31008, Pamplona, Spain
| | - Amaia Zúñiga-Ripa
- Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Departamento de Microbiología y Parasitología, Universidad de Navarra, Calle Irunlarrea 1, 31008, Pamplona, Spain.
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19
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Brucella abortus Depends on l-Serine Biosynthesis for Intracellular Proliferation. Infect Immun 2020; 88:IAI.00840-19. [PMID: 31740531 DOI: 10.1128/iai.00840-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 11/11/2019] [Indexed: 01/15/2023] Open
Abstract
l-Serine is a nonessential amino acid and a key intermediate in several relevant metabolic pathways. In bacteria, the major source of l-serine is the phosphorylated pathway, which comprises three enzymes: d-3-phosphoglycerate dehydrogenase (PGDH; SerA), phosphoserine amino transferase (PSAT; SerC), and l-phosphoserine phosphatase (PSP; SerB). The Brucella abortus genome encodes two PGDHs (SerA-1 and SerA-2), involved in the first step in l-serine biosynthesis, and one PSAT and one PSP, responsible for the second and third steps, respectively. In this study, we demonstrate that the serA1 serA2 double mutant and the serC and serB single mutants are auxotrophic for l-serine. These auxotrophic mutants can be internalized but are unable to replicate in HeLa cells and in J774A.1 macrophage-like cells. Replication defects of auxotrophic mutants can be reverted by cell medium supplementation with l-serine at early times postinfection. In addition, the serB mutant is attenuated in the murine intraperitoneal infection model and has an altered lipid composition, since the lack of l-serine abrogates phosphatidylethanolamine synthesis in this strain. Taken together, these results reveal that limited availability of l-serine within the host cell impairs proliferation of the auxotrophic strains, highlighting the relevance of this biosynthetic pathway in Brucella pathogenicity.
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20
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Nayeri Fasaei B, Naserli S, Zahraei Salehi T, Saeedinia A, Behroozikhah A, Ashrafi Tamai I. New Brucella abortus S19 Mutant to Improve Distinction Between Infected and Vaccinated Animals. IRANIAN JOURNAL OF BIOTECHNOLOGY 2019; 17:e2159. [PMID: 32195284 PMCID: PMC7080968 DOI: 10.29252/ijb.2159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Background Using Brucella abortus Strain 19 (S19) to control bovine brucellosis is restricted due to induce antibodies to the O-side chain of the smooth lipopolysaccharide (LPS) which may be difficult to differentiate vaccinated and infected animals. Furthermore, it is virulent for humans and can induce abortion to cattle. Objectives The aim of this study was to employ gene knockout B. abortus S19 for the first time to eliminate diagnostic defects and obtain the attenuated mutant strain. Material and Methods The wbkA gene, which is one of the LPS O-chain coding genes, was knocked out in vaccinal Brucella abortus S19. The proliferative response and immunoglobulin M production were analyzed in wbkA deletion strain-infected BALB/c mice. Results The loss of wbkA gene function resulted in induction of the splenocyte proliferative response in mice infected by the mutant S19 strain compare to those induced by parental S19 and RB51 strains. Moreover, wbkA mutant did not induce any IgM antibody response using the enzyme-linked immunosorbent assay. Conclusions As a result, the new mutant S19 strain had deficiency in its LPS O-chain structure, besides cannot induce IgM response then, reduce mistakes to discriminate between vaccinated and infected animal, and also can be considered as a new vaccine candidate.
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Affiliation(s)
- Bahar Nayeri Fasaei
- Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Soulmaz Naserli
- Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Taghi Zahraei Salehi
- Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Alireza Saeedinia
- Department of Bioscience and Biotechnology, Malek-Ashtar University of Technology, Tehran, Iran
| | - Alimohammad Behroozikhah
- Department of Brucellosis, Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
| | - Iradj Ashrafi Tamai
- Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
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Salmon-Divon M, Zahavi T, Kornspan D. Transcriptomic Analysis of the Brucella melitensis Rev.1 Vaccine Strain in an Acidic Environment: Insights Into Virulence Attenuation. Front Microbiol 2019; 10:250. [PMID: 30837973 PMCID: PMC6382750 DOI: 10.3389/fmicb.2019.00250] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/30/2019] [Indexed: 12/12/2022] Open
Abstract
The live attenuated Brucella melitensis Rev.1 (Elberg-originated) vaccine strain is widely used to control the zoonotic infection brucellosis in small ruminants, but the molecular mechanisms underlying the attenuation of this strain have not been fully characterized. Following their uptake by the host cell, Brucella replicate inside a membrane-bound compartment—the Brucella-containing vacuole—whose acidification is essential for the survival of the pathogen. Therefore, identifying the genes that contribute to the survival of Brucella in acidic environments will greatly assist our understanding of its molecular pathogenic mechanisms and of the attenuated virulence of the Rev.1 strain. Here, we conducted a comprehensive comparative transcriptome analysis of the Rev.1 vaccine strain against the virulent reference strain 16M in cultures grown under either normal or acidic conditions. We found 403 genes that respond differently to acidic conditions in the two strains (FDR < 0.05, fold change ≥ 2). These genes are involved in crucial cellular processes, including metabolic, biosynthetic, and transport processes. Among the highly enriched genes that were downregulated in Rev.1 under acidic conditions were acetyl-CoA synthetase, aldehyde dehydrogenase, cell division proteins, a cold-shock protein, GroEL, and VirB3. The downregulation of these genes may explain the attenuated virulence of Rev.1 and provide new insights into the virulence mechanisms of Brucella.
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Affiliation(s)
- Mali Salmon-Divon
- Genomic Bioinformatics Laboratory, Department of Molecular Biology, Ariel University, Ariel, Israel
| | - Tamar Zahavi
- Genomic Bioinformatics Laboratory, Department of Molecular Biology, Ariel University, Ariel, Israel
| | - David Kornspan
- Department of Bacteriology, Kimron Veterinary Institute, Bet Dagan, Israel
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22
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Pérez-Etayo L, de Miguel MJ, Conde-Álvarez R, Muñoz PM, Khames M, Iriarte M, Moriyón I, Zúñiga-Ripa A. The CO 2-dependence of Brucella ovis and Brucella abortus biovars is caused by defective carbonic anhydrases. Vet Res 2018; 49:85. [PMID: 30185220 PMCID: PMC6126018 DOI: 10.1186/s13567-018-0583-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/03/2018] [Indexed: 12/14/2022] Open
Abstract
Brucella bacteria cause brucellosis, a major zoonosis whose control requires efficient diagnosis and vaccines. Identification of classical Brucella spp. has traditionally relied on phenotypic characterization, including surface antigens and 5–10% CO2 necessity for growth (CO2-dependence), a trait of Brucella ovis and most Brucella abortus biovars 1–4 strains. Although molecular tests are replacing phenotypic methods, CO2-dependence remains of interest as it conditions isolation and propagation and reflects Brucella metabolism, an area of active research. Here, we investigated the connection of CO2-dependence and carbonic anhydrases (CA), the enzymes catalyzing the hydration of CO2 to the bicarbonate used by anaplerotic and biosynthetic carboxylases. Based on the previous demonstration that B. suis carries two functional CAs (CAI and CAII), we analyzed the CA sequences of CO2-dependent and -independent brucellae and spontaneous mutants. The comparisons strongly suggested that CAII is not functional in CO2-dependent B. abortus and B. ovis, and that a modified CAII sequence explains the CO2-independent phenotype of spontaneous mutants. Then, by mutagenesis and heterologous plasmid complementation and chromosomal insertion we proved that CAI alone is enough to support CO2-independent growth of B. suis in rich media but not of B. abortus in rich media or B. suis in minimal media. Finally, we also found that insertion of a heterologous active CAII into B. ovis reverted the CO2-dependence but did not alter its virulence in the mouse model. These results allow a better understanding of central aspects of Brucella metabolism and, in the case of B. ovis, provide tools for large-scale production of diagnostic antigens and vaccines.
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Affiliation(s)
- Lara Pérez-Etayo
- Instituto de Salud Tropical y Departamento de Microbiología y Parasitología-IDISNA, Universidad de Navarra, 31008, Pamplona, Spain
| | - María Jesús de Miguel
- Unidad de Producción y Sanidad Animal del Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Instituto Agroalimentario de Aragón (IA2), Zaragoza, Spain
| | - Raquel Conde-Álvarez
- Instituto de Salud Tropical y Departamento de Microbiología y Parasitología-IDISNA, Universidad de Navarra, 31008, Pamplona, Spain
| | - Pilar M Muñoz
- Unidad de Producción y Sanidad Animal del Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Instituto Agroalimentario de Aragón (IA2), Zaragoza, Spain
| | - Mammar Khames
- Department of Biology, University of Medea, 26000, Medea, Algeria.,National Veterinary High School, Algiers, Algeria
| | - Maite Iriarte
- Instituto de Salud Tropical y Departamento de Microbiología y Parasitología-IDISNA, Universidad de Navarra, 31008, Pamplona, Spain
| | - Ignacio Moriyón
- Instituto de Salud Tropical y Departamento de Microbiología y Parasitología-IDISNA, Universidad de Navarra, 31008, Pamplona, Spain
| | - Amaia Zúñiga-Ripa
- Instituto de Salud Tropical y Departamento de Microbiología y Parasitología-IDISNA, Universidad de Navarra, 31008, Pamplona, Spain.
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23
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Boggiatto PM, Fitzsimmons D, Bayles DO, Alt D, Vrentas CE, Olsen SC. Coincidence cloning recovery of Brucella melitensis RNA from goat tissues: advancing the in vivo analysis of pathogen gene expression in brucellosis. BMC Mol Biol 2018; 19:10. [PMID: 30068312 PMCID: PMC6071331 DOI: 10.1186/s12867-018-0111-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 07/24/2018] [Indexed: 11/10/2022] Open
Abstract
Background Brucella melitensis bacteria cause persistent, intracellular infections in small ruminants as well as in humans, leading to significant morbidity and economic loss worldwide. The majority of experiments on the transcriptional responses of Brucella to conditions inside the host have been performed following invasion of cultured mammalian cells, and do not address gene expression patterns during long-term infection. Results Here, we examine the application of the previously developed coincidence cloning methodology to recover and characterize B. melitensis RNA from the supramammary lymph node of experimentally-infected goats. Using coincidence cloning, we successfully recovered Brucella RNA from supramammary lymph nodes of B. melitensis-infected goats at both short-term (4 weeks) and long-term (38 weeks) infection time points. Amplified nucleic acid levels were sufficient for analysis of Brucella gene expression patterns by RNA-sequencing, providing evidence of metabolic activity in both the short-term and the long-term samples. We developed a workflow for the use of sequence polymorphism analysis to confirm recovery of the inoculated strain in the recovered reads, and utilized clustering analysis to demonstrate a distinct transcriptional profile present in samples recovered in long-term infection. In this first look at B. melitensis gene expression patterns in vivo, the subset of Brucella genes that was highly upregulated in long-term as compared to short-term infection included genes linked to roles in murine infection, such as genes involved in proline utilization and signal transduction. Finally, we demonstrated the challenges of qPCR validation of samples with very low ratios of pathogen:host RNA, as is the case during in vivo brucellosis, and alternatively characterized intermediate products of the coincidence cloning reaction. Conclusions Overall, this study provides the first example of recovery plus characterization of B. melitensis RNA from in vivo lymph node infection, and demonstrates that the coincidence cloning technique is a useful tool for characterizing in vivo transcriptional changes in Brucella species. Genes upregulated in long-term infection in this data set, including many genes not previously demonstrated to be virulence factors in mice or macrophage experiments, are candidates of future interest for potential roles in Brucella persistence in natural host systems. Electronic supplementary material The online version of this article (10.1186/s12867-018-0111-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paola M Boggiatto
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Daniel Fitzsimmons
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - David Alt
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
| | - Catherine E Vrentas
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA.
| | - Steven C Olsen
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, 50010, USA
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24
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Osman AY, Saharee AA, Jesse FF, Kadir AA. Comparative experimental study of Brucella melitensis and its lipopolysaccharide in mouse model infected via subcutaneous route of exposure. Microb Pathog 2018; 116:318-327. [DOI: 10.1016/j.micpath.2018.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/02/2018] [Accepted: 01/07/2018] [Indexed: 01/18/2023]
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Zai X, Yang Q, Yin Y, Li R, Qian M, Zhao T, Li Y, Zhang J, Fu L, Xu J, Chen W. Relative Quantitative Proteomic Analysis of Brucella abortus Reveals Metabolic Adaptation to Multiple Environmental Stresses. Front Microbiol 2017; 8:2347. [PMID: 29238329 PMCID: PMC5712581 DOI: 10.3389/fmicb.2017.02347] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/15/2017] [Indexed: 11/19/2022] Open
Abstract
Brucella spp. are facultative intracellular pathogens that cause chronic brucellosis in humans and animals. The virulence of Brucella primarily depends on its successful survival and replication in host cells. During invasion of the host tissue, Brucella is simultaneously subjected to a variety of harsh conditions, including nutrient limitation, low pH, antimicrobial defenses, and extreme levels of reactive oxygen species (ROS) via the host immune response. This suggests that Brucella may be able to regulate its metabolic adaptation in response to the distinct stresses encountered during its intracellular infection of the host. An investigation into the differential proteome expression patterns of Brucella grown under the relevant stress conditions may contribute toward a better understanding of its pathogenesis and adaptive response. Here, we utilized a mass spectrometry-based label-free relative quantitative proteomics approach to investigate and compare global proteomic changes in B. abortus in response to eight different stress treatments. The 3 h short-term in vitro single-stress and multi-stress conditions mimicked the in vivo conditions of B. abortus under intracellular infection, with survival rates ranging from 3.17 to 73.17%. The proteomic analysis identified and quantified a total of 2,272 proteins and 74% of the theoretical proteome, thereby providing wide coverage of the B. abortus proteome. By including eight distinct growth conditions and comparing these with a control condition, we identified a total of 1,221 differentially expressed proteins (DEPs) that were significantly changed under the stress treatments. Pathway analysis revealed that most of the proteins were involved in oxidative phosphorylation, ABC transporters, two-component systems, biosynthesis of secondary metabolites, the citrate cycle, thiamine metabolism, and nitrogen metabolism; constituting major response mechanisms toward the reconstruction of cellular homeostasis and metabolic balance under stress. In conclusion, our results provide a better understanding of the global metabolic adaptations of B. abortus associated with distinct environmental stresses. The identification of proteins necessary for stress resistance is crucial toward elucidating the infectious process in order to control brucellosis, and may facilitate the discovery of novel therapeutic targets and effective vaccines.
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Affiliation(s)
- Xiaodong Zai
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Qiaoling Yang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ruihua Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Mengying Qian
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Taoran Zhao
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Yaohui Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Ling Fu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing, China
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26
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Mariappan V, Vellasamy KM, Vadivelu J. Host-Adaptation of Burkholderia pseudomallei Alters Metabolism and Virulence: a Global Proteome Analysis. Sci Rep 2017; 7:9015. [PMID: 28827633 PMCID: PMC5567125 DOI: 10.1038/s41598-017-09373-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/26/2017] [Indexed: 11/24/2022] Open
Abstract
Little is known about the evolution, adaptation and pathogenesis of Burkholderia pseudomallei within host during acute melioidosis infection. Melioidosis is a potential life threatening disease contracted through inhalation, ingestion, inoculation or direct entry of the organism into the blood stream via wounds or skin abrasions from contaminated soil and water. Environmental B. pseudomallei strain (BpMARAN), isolated during a melioidosis outbreak in Pahang, Malaysia was injected intra-peritoneally into a mouse and passaged strain was recovered from spleen (Bpmouse-adapted). A gel-based comparative proteomics profiling approach was used, to map and identify differentially expressed proteins (fold-change ≥ 2; p-value ≤ 0.05) between the strains. A total of 730 and 685 spots were visualised in the BpMARAN and Bpmouse-adapted strains, respectively. Of the 730 spots (BpMARAN as reference gel), 87 spots were differentially regulated (44 up- and 43 down-regulated). The identified proteins were classified as proteins related to metabolism, stress response, virulence, signal transduction, or adhesion. In comparison, it was found that those proteins related to adhesins, virulence factors and stress- response were up-regulated and could possibly explain the adaptation of the bacteria in the host. Investigating the differentially expressed proteins may provide better perspective of bacterial factors which aid survivability of B. pseudomallei in host.
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Affiliation(s)
- Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Kumutha Malar Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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27
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Suárez-Esquivel M, Baker KS, Ruiz-Villalobos N, Hernández-Mora G, Barquero-Calvo E, González-Barrientos R, Castillo-Zeledón A, Jiménez-Rojas C, Chacón-Díaz C, Cloeckaert A, Chaves-Olarte E, Thomson NR, Moreno E, Guzmán-Verri C. Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution. Genome Biol Evol 2017; 9:1901-1912. [PMID: 28854602 PMCID: PMC5554395 DOI: 10.1093/gbe/evx137] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2017] [Indexed: 12/31/2022] Open
Abstract
Intracellular bacterial pathogens probably arose when their ancestor adapted from a free-living environment to an intracellular one, leading to clonal bacteria with smaller genomes and less sources of genetic plasticity. Still, this plasticity is needed to respond to the challenges posed by the host. Members of the Brucella genus are facultative-extracellular intracellular bacteria responsible for causing brucellosis in a variety of mammals. The various species keep different host preferences, virulence, and zoonotic potential despite having 97-99% similarity at genome level. Here, we describe elements of genetic variation in Brucella ceti isolated from wildlife dolphins inhabiting the Pacific Ocean and the Mediterranean Sea. Comparison with isolates obtained from marine mammals from the Atlantic Ocean and the broader Brucella genus showed distinctive traits according to oceanic distribution and preferred host. Marine mammal isolates display genetic variability, represented by an important number of IS711 elements as well as specific IS711 and SNPs genomic distribution clustering patterns. Extensive pseudogenization was found among isolates from marine mammals as compared with terrestrial ones, causing degradation in pathways related to energy, transport of metabolites, and regulation/transcription. Brucella ceti isolates infecting particularly dolphin hosts, showed further degradation of metabolite transport pathways as well as pathways related to cell wall/membrane/envelope biogenesis and motility. Thus, gene loss through pseudogenization is a source of genetic variation in Brucella, which in turn, relates to adaptation to different hosts. This is relevant to understand the natural history of bacterial diseases, their zoonotic potential, and the impact of human interventions such as domestication.
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Affiliation(s)
- Marcela Suárez-Esquivel
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Kate S. Baker
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Institute for Integrative Biology, University of Liverpool, United Kingdom
| | - Nazareth Ruiz-Villalobos
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Gabriela Hernández-Mora
- Servicio Nacional de Salud Animal, Ministerio de Agricultura y Ganadería, Heredia, Costa Rica
| | - Elías Barquero-Calvo
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | | | - Amanda Castillo-Zeledón
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - César Jiménez-Rojas
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Carlos Chacón-Díaz
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Axel Cloeckaert
- ISP, INRA, Université François Rabelais de Tours, UMR 1282, Nouzilly, France
| | - Esteban Chaves-Olarte
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | | | - Edgardo Moreno
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
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Barbier T, Zúñiga-Ripa A, Moussa S, Plovier H, Sternon JF, Lázaro-Antón L, Conde-Álvarez R, De Bolle X, Iriarte M, Moriyón I, Letesson JJ. Brucella central carbon metabolism: an update. Crit Rev Microbiol 2017; 44:182-211. [PMID: 28604247 DOI: 10.1080/1040841x.2017.1332002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The brucellae are facultative intracellular pathogens causing brucellosis, an important zoonosis. Here, we review the nutritional, genetic, proteomic and transcriptomic studies on Brucella carbon uptake and central metabolism, information that is needed for a better understanding of Brucella virulence. There is no uniform picture across species but the studies suggest primary and/or secondary transporters for unknown carbohydrates, lactate, glycerol phosphate, erythritol, xylose, ribose, glucose and glucose/galactose, and routes for their incorporation to central metabolism, including an erythritol pathway feeding the pentose phosphate cycle. Significantly, all brucellae lack phosphoenolpyruvate synthase and phosphofructokinase genes, which confirms previous evidence on glycolysis absence, but carry all Entner-Doudoroff (ED) pathway and Krebs cycle (and glyoxylate pathway) genes. However, glucose catabolism proceeds through the pentose phosphate cycle in the classical species, and the ED pathway operates in some rodent-associated brucellae, suggesting an ancestral character for this pathway in this group. Gluconeogenesis is functional but does not rely exclusively on classical fructose bisphosphatases. Evidence obtained using infection models is fragmentary but suggests the combined or sequential use of hexoses/pentoses, amino acids and gluconeogenic substrates. We also discuss the role of the phosphotransferase system, stringent reponse, quorum sensing, BvrR/S and sRNAs in metabolism control, an essential aspect of the life style of facultative intracellular parasites.
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Affiliation(s)
- T Barbier
- a Unité de Recherche en Biologie des Microorganismes , Laboratoire d'Immunologie et de Microbiologie, NARILIS, Université de Namur , Namur , Belgium
| | - A Zúñiga-Ripa
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
| | - S Moussa
- a Unité de Recherche en Biologie des Microorganismes , Laboratoire d'Immunologie et de Microbiologie, NARILIS, Université de Namur , Namur , Belgium
| | - H Plovier
- a Unité de Recherche en Biologie des Microorganismes , Laboratoire d'Immunologie et de Microbiologie, NARILIS, Université de Namur , Namur , Belgium
| | - J F Sternon
- a Unité de Recherche en Biologie des Microorganismes , Laboratoire d'Immunologie et de Microbiologie, NARILIS, Université de Namur , Namur , Belgium
| | - L Lázaro-Antón
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
| | - R Conde-Álvarez
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
| | - X De Bolle
- a Unité de Recherche en Biologie des Microorganismes , Laboratoire d'Immunologie et de Microbiologie, NARILIS, Université de Namur , Namur , Belgium
| | - M Iriarte
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
| | - I Moriyón
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
| | - J J Letesson
- b Instituto de Salud Tropical (ISTUN), Instituto de Investigación Sanitaria de Navarra (IdISNA) and Depto. Microbiología y Parasitología , Universidad de Navarra, Edificio de Investigación , Pamplona , Spain
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29
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A Resource Allocation Trade-Off between Virulence and Proliferation Drives Metabolic Versatility in the Plant Pathogen Ralstonia solanacearum. PLoS Pathog 2016; 12:e1005939. [PMID: 27732672 PMCID: PMC5061431 DOI: 10.1371/journal.ppat.1005939] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 09/17/2016] [Indexed: 11/19/2022] Open
Abstract
Bacterial pathogenicity relies on a proficient metabolism and there is increasing evidence that metabolic adaptation to exploit host resources is a key property of infectious organisms. In many cases, colonization by the pathogen also implies an intensive multiplication and the necessity to produce a large array of virulence factors, which may represent a significant cost for the pathogen. We describe here the existence of a resource allocation trade-off mechanism in the plant pathogen R. solanacearum. We generated a genome-scale reconstruction of the metabolic network of R. solanacearum, together with a macromolecule network module accounting for the production and secretion of hundreds of virulence determinants. By using a combination of constraint-based modeling and metabolic flux analyses, we quantified the metabolic cost for production of exopolysaccharides, which are critical for disease symptom production, and other virulence factors. We demonstrated that this trade-off between virulence factor production and bacterial proliferation is controlled by the quorum-sensing-dependent regulatory protein PhcA. A phcA mutant is avirulent but has a better growth rate than the wild-type strain. Moreover, a phcA mutant has an expanded metabolic versatility, being able to metabolize 17 substrates more than the wild-type. Model predictions indicate that metabolic pathways are optimally oriented towards proliferation in a phcA mutant and we show that this enhanced metabolic versatility in phcA mutants is to a large extent a consequence of not paying the cost for virulence. This analysis allowed identifying candidate metabolic substrates having a substantial impact on bacterial growth during infection. Interestingly, the substrates supporting well both production of virulence factors and growth are those found in higher amount within the plant host. These findings also provide an explanatory basis to the well-known emergence of avirulent variants in R. solanacearum populations in planta or in stressful environments. Metabolic versatility is a critical element for pathogen’s virulence and their ability to survive in the host. Beyond the necessity to collect resources during infection, pathogens face a resource allocation dilemma: they have to use nutritional resources to proliferate inside the host, and in the other hand they need to mobilize matter and energy for the production of essential virulence factors. In this study, we provide evidence of that such a trade-off constrains antagonistically bacterial proliferation and virulence in the bacterial plant pathogen Ralstonia solanacearum. We determined the energetic cost required by R. solanacearum to produce and secrete exopolysaccharide, which is a major virulence factor required for wilting symptom appearance. We validated this result by showing that bacterial mutants defective for exopolysaccharide production or other virulence factor indeed have an increased growth rate compared to the wild-type strain. We provide evidence that this trade-off mechanism is orchestrated by the phcA master regulatory gene, which directly connects quorum-sensing regulation to metabolic versatility and virulence. Our results also support the view that R. solanacearum specializes towards a restricted number of substrates used during in planta growth.
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30
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Brissac T, Ziveri J, Ramond E, Tros F, Kock S, Dupuis M, Brillet M, Barel M, Peyriga L, Cahoreau E, Charbit A. Gluconeogenesis, an essential metabolic pathway for pathogenic Francisella. Mol Microbiol 2015; 98:518-34. [PMID: 26192619 DOI: 10.1111/mmi.13139] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2015] [Indexed: 01/23/2023]
Abstract
Intracellular multiplication and dissemination of the infectious bacterial pathogen Francisella tularensis implies the utilization of multiple host-derived nutrients. Here, we demonstrate that gluconeogenesis constitutes an essential metabolic pathway in Francisella pathogenesis. Indeed, inactivation of gene glpX, encoding the unique fructose 1,6-bisphosphatase of Francisella, severely impaired bacterial intracellular multiplication when cells were supplemented by gluconeogenic substrates such as glycerol or pyruvate. The ΔglpX mutant also showed a severe virulence defect in the mouse model, confirming the importance of this pathway during the in vivo life cycle of the pathogen. Isotopic profiling revealed the major role of the Embden-Meyerhof (glycolysis) pathway in glucose catabolism in Francisella and confirmed the importance of glpX in gluconeogenesis. Altogether, the data presented suggest that gluconeogenesis allows Francisella to cope with the limiting glucose availability it encounters during its infectious cycle by relying on host amino acids. Hence, targeting the gluconeogenic pathway might constitute an interesting therapeutic approach against this pathogen.
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Affiliation(s)
- Terry Brissac
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Jason Ziveri
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Elodie Ramond
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Fabiola Tros
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Stephanie Kock
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Marion Dupuis
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Magali Brillet
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Monique Barel
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
| | - Lindsay Peyriga
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, Toulouse, 31077, France.,INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, 31400, France.,CNRS, UMR5504, Toulouse, 31400, France
| | - Edern Cahoreau
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, Toulouse, 31077, France.,INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, 31400, France.,CNRS, UMR5504, Toulouse, 31400, France
| | - Alain Charbit
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France.,INSERM U1151 - CNRS UMR 8253, Institut Necker-Enfants Malades, Equipe 11: Pathogénie des Infections Systémiques, Paris, France
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Oh YT, Lee KM, Bari W, Raskin DM, Yoon SS. (p)ppGpp, a Small Nucleotide Regulator, Directs the Metabolic Fate of Glucose in Vibrio cholerae. J Biol Chem 2015; 290:13178-90. [PMID: 25882848 DOI: 10.1074/jbc.m115.640466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 12/20/2022] Open
Abstract
When V. cholerae encounters nutritional stress, it activates (p)ppGpp-mediated stringent response. The genes relA and relV are involved in the production of (p)ppGpp, whereas the spoT gene encodes an enzyme that hydrolyzes it. Herein, we show that the bacterial capability to produce (p)ppGpp plays an essential role in glucose metabolism. The V. cholerae mutants defective in (p)ppGpp production (i.e. ΔrelAΔrelV and ΔrelAΔrelVΔspoT mutants) lost their viability because of uncontrolled production of organic acids, when grown with extra glucose. In contrast, the ΔrelAΔspoT mutant, a (p)ppGpp overproducer strain, exhibited better growth in the presence of the same glucose concentration. An RNA sequencing analysis demonstrated that transcriptions of genes consisting of an operon for acetoin biosynthesis were markedly elevated in N16961, a seventh pandemic O1 strain, but not in its (p)ppGpp(0) mutant during glucose-stimulated growth. Transposon insertion in acetoin biosynthesis gene cluster resulted in glucose-induced loss of viability of the ΔrelAΔspoT mutant, further suggesting the crucial role of acetoin production in balanced growth under glucose-rich environments. Additional deletion of the aphA gene, encoding a negative regulator for acetoin production, failed to rescue the (p)ppGpp(0) mutant from the defective glucose-mediated growth, suggesting that (p)ppGpp-mediated acetoin production occurs independent of the presence of AphA. Overall, our results reveal that (p)ppGpp, in addition to its well known role as a stringent response mediator, positively regulates acetoin production that contributes to the successful glucose metabolism and consequently the proliferation of V. cholerae cells under a glucose-rich environment, a condition that may mimic the human intestine.
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Affiliation(s)
- Young Taek Oh
- From the Department of Microbiology and Immunology, Brain Korea 21 PLUS Project for Medical Science and
| | - Kang-Mu Lee
- From the Department of Microbiology and Immunology, Brain Korea 21 PLUS Project for Medical Science and
| | - Wasimul Bari
- From the Department of Microbiology and Immunology, Brain Korea 21 PLUS Project for Medical Science and
| | - David M Raskin
- the Marian University College of Osteopathic Medicine, Indianapolis, Indiana 46222
| | - Sang Sun Yoon
- From the Department of Microbiology and Immunology, Brain Korea 21 PLUS Project for Medical Science and the Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, 120-752, Korea and
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Li Z, Fu Q, Wang Z, Li T, Zhang H, Guo F, Wang Y, Zhang J, Chen C. TceSR two-component regulatory system of Brucella melitensis 16M is involved in invasion, intracellular survival and regulated cytotoxicity for macrophages. Lett Appl Microbiol 2015; 60:565-71. [PMID: 25721466 DOI: 10.1111/lam.12408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/21/2015] [Accepted: 02/17/2015] [Indexed: 11/29/2022]
Abstract
The mechanisms of invasion and intracellular survival of Brucella are still poorly understood. Previous studies showed that the two-component regulatory systems (TCSs) play an important role in the intracellular survival of Brucella. To investigate if TCSs involve in the virulence and cytotoxicity of Brucella melitensis, we introduced a mutation into one of the TCSs in chromosome II in Br. melitensis 16M strain, and generated 16MΔTceSR, a mutant of Br. melitensis 16M strain. In vitro infection experiments using murine macrophage cell line (RAW 264.7) showed that the survival of 16MΔTceSR mutant in macrophages decreased 0·91-log compared with that of wild type Br. melitensis 16M strain at 2 h postinfection, replication of 16MΔTceSR mutant in macrophages was 5·65-log, which was much lower than that wild type strain. Results of lactate dehydrogenase cytotoxicity assays in macrophages demonstrated high dose infection with wide type strain produced high level cytotoxicity to macrophages, but 16MΔTceSR mutant had very low level cytotoxicity, indicating mutation of TCSs impaired the cytotoxicity of Br. melitensis to macrophages. Animal experiments showed that the spleen colonization of 16MΔTceSR was significantly reduced compared with its wild type strains. The lower levels of survival of 16MΔTceSR in various stress conditions suggested that the mutation of the TCSs of Br. melitensis was the causative factor of its reduced resistance to stress conditions. Taken together, our results demonstrated TCS TceSR involves in the intracellular survival, virulence and cytotoxicity of Br. melitensis during its infection. Significance and impact of the study: Two-component systems (TCSs) are predominant bacterial signal transduction mechanisms. The pathogenicity of Brucella is due to its ability to adapt to the intracellular environment including low levels of acidic pH, high-salt and heat shock. TCSs are designed to sense diverse stimuli, transfer signals and enact an appropriate adaptive physiological response. Here, we show that Br. meilitensis TCS TceSR is not only involved in regulation of Br. meilitensis virulence and adaptation of environmental stresses, but also can regulate cytotoxicity in macrophages.
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Affiliation(s)
- Z Li
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
| | - Q Fu
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
| | - Z Wang
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
| | - T Li
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
| | - H Zhang
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
| | - F Guo
- College of Medicine, Shihezi University, Shihezi, China
| | - Y Wang
- College of Medicine, Shihezi University, Shihezi, China
| | - J Zhang
- College of Biology, Agriculture and Forestry, Tongren University, Tongren, Guizhou, China
| | - C Chen
- College of Animal Science and Technology/Co-Innovation Center for Zoonotic Infectious Diseases in the western region, Shihezi University, Shihezi, China
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Ralstonia solanacearum uses inorganic nitrogen metabolism for virulence, ATP production, and detoxification in the oxygen-limited host xylem environment. mBio 2015; 6:e02471. [PMID: 25784703 PMCID: PMC4453514 DOI: 10.1128/mbio.02471-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Genomic data predict that, in addition to oxygen, the bacterial plant pathogen Ralstonia solanacearum can use nitrate (NO3−), nitrite (NO2−), nitric oxide (NO), and nitrous oxide (N2O) as terminal electron acceptors (TEAs). Genes encoding inorganic nitrogen reduction were highly expressed during tomato bacterial wilt disease, when the pathogen grows in xylem vessels. Direct measurements found that tomato xylem fluid was low in oxygen, especially in plants infected by R. solanacearum. Xylem fluid contained ~25 mM NO3−, corresponding to R. solanacearum’s optimal NO3− concentration for anaerobic growth in vitro. We tested the hypothesis that R. solanacearum uses inorganic nitrogen species to respire and grow during pathogenesis by making deletion mutants that each lacked a step in nitrate respiration (ΔnarG), denitrification (ΔaniA, ΔnorB, and ΔnosZ), or NO detoxification (ΔhmpX). The ΔnarG, ΔaniA, and ΔnorB mutants grew poorly on NO3− compared to the wild type, and they had reduced adenylate energy charge levels under anaerobiosis. While NarG-dependent NO3− respiration directly enhanced growth, AniA-dependent NO2− reduction did not. NO2− and NO inhibited growth in culture, and their removal depended on denitrification and NO detoxification. Thus, NO3− acts as a TEA, but the resulting NO2− and NO likely do not. None of the mutants grew as well as the wild type in planta, and strains lacking AniA (NO2− reductase) or HmpX (NO detoxification) had reduced virulence on tomato. Thus, R. solanacearum exploits host NO3− to respire, grow, and cause disease. Degradation of NO2− and NO is also important for successful infection and depends on denitrification and NO detoxification systems. The plant-pathogenic bacterium Ralstonia solanacearum causes bacterial wilt, one of the world’s most destructive crop diseases. This pathogen’s explosive growth in plant vascular xylem is poorly understood. We used biochemical and genetic approaches to show that R. solanacearum rapidly depletes oxygen in host xylem but can then respire using host nitrate as a terminal electron acceptor. The microbe uses its denitrification pathway to detoxify the reactive nitrogen species nitrite (a product of nitrate respiration) and nitric oxide (a plant defense signal). Detoxification may play synergistic roles in bacterial wilt virulence by converting the host’s chemical weapon into an energy source. Mutant bacterial strains lacking elements of the denitrification pathway could not grow as well as the wild type in tomato plants, and some mutants were also reduced in virulence. Our results show how a pathogen’s metabolic activity can alter the host environment in ways that increase pathogen success.
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Lee JJ, Simborio HL, Reyes AWB, Kim DG, Hop HT, Min W, Her M, Jung SC, Yoo HS, Kim S. Immunoproteomic identification of immunodominant antigens independent of the time of infection in Brucella abortus 2308-challenged cattle. Vet Res 2015; 46:17. [PMID: 25885057 PMCID: PMC4345015 DOI: 10.1186/s13567-015-0147-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 01/13/2015] [Indexed: 11/27/2022] Open
Abstract
Brucellosis is a vital zoonotic disease caused by Brucella, which infects a wide range of animals and humans. Accurate diagnosis and reliable vaccination can control brucellosis in domestic animals. This study examined novel immunogenic proteins that can be used to detect Brucella abortus infection or as an effective subcellular vaccine. In an immunoproteomic assay, 55 immunodominant proteins from B. abortus 544 were observed using two dimensional electrophoresis (2DE) and immunoblot profiles with antisera from B. abortus-infected cattle at the early (week 3), middle (week 7), and late (week 10) periods, after excluding protein spots reacting with antisera from Yersinia enterocolitica O:9-infected and non-infected cattle. Twenty-three selected immunodominant proteins whose spots were observed at all three infection periods were identified using MALDI-MS/MS. Most of these proteins identified by immunoblot and mass spectrometry were determined by their subcellular localization and predicted function. We suggest that the detection of prominent immunogenic proteins during the infection period can support the development of advanced diagnostic methods with high specificity and accuracy; subsidiarily, these proteins can provide supporting data to aid in developing novel vaccine candidates.
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Affiliation(s)
- Jin Ju Lee
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-757, Republic of Korea.
| | - Hannah Leah Simborio
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
| | - Alisha Wehdnesday Bernardo Reyes
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
| | - Dae Geun Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
| | - Huynh Tan Hop
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
| | - Wongi Min
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
| | - Moon Her
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-757, Republic of Korea.
| | - Suk Chan Jung
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-757, Republic of Korea.
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, 151-742, Republic of Korea.
| | - Suk Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea. .,Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
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35
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Challacombe JF, Stubben CJ, Klimko CP, Welkos SL, Kern SJ, Bozue JA, Worsham PL, Cote CK, Wolfe DN. Interrogation of the Burkholderia pseudomallei genome to address differential virulence among isolates. PLoS One 2014; 9:e115951. [PMID: 25536074 PMCID: PMC4275268 DOI: 10.1371/journal.pone.0115951] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 12/01/2014] [Indexed: 11/18/2022] Open
Abstract
Infection by the Gram-negative pathogen Burkholderia pseudomallei results in the disease melioidosis, acquired from the environment in parts of southeast Asia and northern Australia. Clinical symptoms of melioidosis range from acute (fever, pneumonia, septicemia, and localized infection) to chronic (abscesses in various organs and tissues, most commonly occurring in the lungs, liver, spleen, kidney, prostate and skeletal muscle), and persistent infections in humans are difficult to cure. Understanding the basic biology and genomics of B. pseudomallei is imperative for the development of new vaccines and therapeutic interventions. This formidable task is becoming more tractable due to the increasing number of B. pseudomallei genomes that are being sequenced and compared. Here, we compared three B. pseudomallei genomes, from strains MSHR668, K96243 and 1106a, to identify features that might explain why MSHR668 is more virulent than K96243 and 1106a in a mouse model of B. pseudomallei infection. Our analyses focused on metabolic, virulence and regulatory genes that were present in MSHR668 but absent from both K96243 and 1106a. We also noted features present in K96243 and 1106a but absent from MSHR668, and identified genomic differences that may contribute to variations in virulence noted among the three B. pseudomallei isolates. While this work contributes to our understanding of B. pseudomallei genomics, more detailed experiments are necessary to characterize the relevance of specific genomic features to B. pseudomallei metabolism and virulence. Functional analyses of metabolic networks, virulence and regulation shows promise for examining the effects of B. pseudomallei on host cell metabolism and will lay a foundation for future prediction of the virulence of emerging strains. Continued emphasis in this area will be critical for protection against melioidosis, as a better understanding of what constitutes a fully virulent Burkholderia isolate may provide for better diagnostic and medical countermeasure strategies.
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Affiliation(s)
- Jean F. Challacombe
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, NM, United States of America
- * E-mail:
| | - Chris J. Stubben
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, NM, United States of America
| | - Christopher P. Klimko
- US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, Fort Detrick, MD, United States of America
| | - Susan L. Welkos
- US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, Fort Detrick, MD, United States of America
| | - Steven J. Kern
- US Army Medical Research Institute of Infectious Diseases, Biostatistics Division, Fort Detrick, MD, United States of America
| | - Joel A. Bozue
- US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, Fort Detrick, MD, United States of America
| | - Patricia L. Worsham
- US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, Fort Detrick, MD, United States of America
| | - Christopher K. Cote
- US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, Fort Detrick, MD, United States of America
| | - Daniel N. Wolfe
- Defense Threat Reduction Agency, Chemical and Biological Technologies Department, Fort Belvoir, VA, United States of America
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Ronneau S, Moussa S, Barbier T, Conde-Álvarez R, Zuniga-Ripa A, Moriyon I, Letesson JJ. Brucella, nitrogen and virulence. Crit Rev Microbiol 2014; 42:507-25. [PMID: 25471320 DOI: 10.3109/1040841x.2014.962480] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.
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Affiliation(s)
| | - Simon Moussa
- a UNamur, URBM 61 rue de Bruxelles , Namur , Belgium and
| | | | - Raquel Conde-Álvarez
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Amaia Zuniga-Ripa
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Ignacio Moriyon
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
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37
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Metabolic sensor governing bacterial virulence in Staphylococcus aureus. Proc Natl Acad Sci U S A 2014; 111:E4981-90. [PMID: 25368190 DOI: 10.1073/pnas.1411077111] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An effective metabolism is essential to all living organisms, including the important human pathogen Staphylococcus aureus. To establish successful infection, S. aureus must scavenge nutrients and coordinate its metabolism for proliferation. Meanwhile, it also must produce an array of virulence factors to interfere with host defenses. However, the ways in which S. aureus ties its metabolic state to its virulence regulation remain largely unknown. Here we show that citrate, the first intermediate of the tricarboxylic acid (TCA) cycle, binds to and activates the catabolite control protein E (CcpE) of S. aureus. Using structural and site-directed mutagenesis studies, we demonstrate that two arginine residues (Arg145 and Arg256) within the putative inducer-binding cavity of CcpE are important for its allosteric activation by citrate. Microarray analysis reveals that CcpE tunes the expression of 126 genes that comprise about 4.7% of the S. aureus genome. Intriguingly, although CcpE is a major positive regulator of the TCA-cycle activity, its regulon consists predominantly of genes involved in the pathogenesis of S. aureus. Moreover, inactivation of CcpE results in increased staphyloxanthin production, improved ability to acquire iron, increased resistance to whole-blood-mediated killing, and enhanced bacterial virulence in a mouse model of systemic infection. This study reveals CcpE as an important metabolic sensor that allows S. aureus to sense and adjust its metabolic state and subsequently to coordinate the expression of virulence factors and bacterial virulence.
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38
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Brucella abortus depends on pyruvate phosphate dikinase and malic enzyme but not on Fbp and GlpX fructose-1,6-bisphosphatases for full virulence in laboratory models. J Bacteriol 2014; 196:3045-57. [PMID: 24936050 DOI: 10.1128/jb.01663-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The brucellae are the etiological agents of brucellosis, a worldwide-distributed zoonosis. These bacteria are facultative intracellular parasites and thus are able to adjust their metabolism to the extra- and intracellular environments encountered during an infectious cycle. However, this aspect of Brucella biology is imperfectly understood, and the nutrients available in the intracellular niche are unknown. Here, we investigated the central pathways of C metabolism used by Brucella abortus by deleting the putative fructose-1,6-bisphosphatase (fbp and glpX), phosphoenolpyruvate carboxykinase (pckA), pyruvate phosphate dikinase (ppdK), and malic enzyme (mae) genes. In gluconeogenic but not in rich media, growth of ΔppdK and Δmae mutants was severely impaired and growth of the double Δfbp-ΔglpX mutant was reduced. In macrophages, only the ΔppdK and Δmae mutants showed reduced multiplication, and studies with the ΔppdK mutant confirmed that it reached the replicative niche. Similarly, only the ΔppdK and Δmae mutants were attenuated in mice, the former being cleared by week 10 and the latter persisting longer than 12 weeks. We also investigated the glyoxylate cycle. Although aceA (isocitrate lyase) promoter activity was enhanced in rich medium, aceA disruption had no effect in vitro or on multiplication in macrophages or mouse spleens. The results suggest that B. abortus grows intracellularly using a limited supply of 6-C (and 5-C) sugars that is compensated by glutamate and possibly other amino acids entering the Krebs cycle without a critical role of the glyoxylate shunt.
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Moreno E. Retrospective and prospective perspectives on zoonotic brucellosis. Front Microbiol 2014; 5:213. [PMID: 24860561 PMCID: PMC4026726 DOI: 10.3389/fmicb.2014.00213] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 04/23/2014] [Indexed: 11/13/2022] Open
Abstract
Members of the genus Brucella are pathogenic bacteria exceedingly well adapted to their hosts. The bacterium is transmitted by direct contact within the same host species or accidentally to secondary hosts, such as humans. Human brucellosis is strongly linked to the management of domesticated animals and ingestion of their products. Since the domestication of ungulates and dogs in the Fertile Crescent and Asia in 12000 and 33000 ya, respectively, a steady supply of well adapted emergent Brucella pathogens causing zoonotic disease has been provided. Likewise, anthropogenic modification of wild life may have also impacted host susceptibility and Brucella selection. Domestication and human influence on wild life animals are not neutral phenomena. Consequently, Brucella organisms have followed their hosts’ fate and have been selected under conditions that favor high transmission rate. The “arm race” between Brucella and their preferred hosts has been driven by genetic adaptation of the bacterium confronted with the evolving immune defenses of the host. Management conditions, such as clustering, selection, culling, and vaccination of Brucella preferred hosts have profound influences in the outcome of brucellosis and in the selection of Brucella organisms. Countries that have controlled brucellosis systematically used reliable smooth live vaccines, consistent immunization protocols, adequate diagnostic tests, broad vaccination coverage and sustained removal of the infected animals. To ignore and misuse tools and strategies already available for the control of brucellosis may promote the emergence of new Brucella variants. The unrestricted use of low-efficacy vaccines may promote a “false sense of security” and works towards selection of Brucella with higher virulence and transmission potential.
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Affiliation(s)
- Edgardo Moreno
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional Heredia, Costa Rica ; Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica San José, Costa Rica
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40
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Alva-Pérez J, Arellano-Reynoso B, Hernández-Castro R, Suárez-Güemes F. The invA gene of Brucella melitensis is involved in intracellular invasion and is required to establish infection in a mouse model. Virulence 2014; 5:563-74. [PMID: 24667775 DOI: 10.4161/viru.28589] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Some of the mechanisms underlying the invasion and intracellular survival of B. melitensis are still unknown, including the role of a subfamily of NUDIX enzymes, which have been described in other bacterial species as invasins and are present in Brucella spp. We have generated a mutation in the coding gene of one of these proteins, the invA gene (BMEI0215) of B. melitensis strain 133, to understand its role in virulence. HeLa cell invasion results showed that mutant strain survival was decreased 5-fold compared with that of the parental strain at 2 h pi (P<0.001). In a goat macrophage infection assay, mutant strain replication was 8-fold less than in the parental strain at 24 h pi (P<0.001); yet, at 48 h pi, no significant differences in intracellular replication were observed. Additionally, colocalization of the invA mutant with calregulin was significantly lower at 24 h pi compared with that of the parental strain. Furthermore, the mutant strain exhibited a low level of colocalization with cathepsin D, which was similar to the parental strain colocalization at 24 h pi. In vivo infection results demonstrated that spleen colonization was significantly lower with the mutant than with the parental strain. The immune response, measured in terms of antibody switching and IFN-γ transcription, was similar for Rev1 and infection with the mutant, although it was lower than the immune response elicited by the parental strain. Consequently, these results indicate that the invA gene is important during invasion but not for intracellular replication. Additionally, mutation of the invA gene results in in vivo attenuation.
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Affiliation(s)
- Jorge Alva-Pérez
- Department of Microbiology and Immunology; College of Veterinary Medicine; National Autonomous University of Mexico; Mexico DF, Mexico
| | - Beatriz Arellano-Reynoso
- Department of Microbiology and Immunology; College of Veterinary Medicine; National Autonomous University of Mexico; Mexico DF, Mexico
| | - Rigoberto Hernández-Castro
- Department of Ecology of Pathogen Agents; General Hospital "Dr. Manuel Gea González"; National Health Department; Mexico DF, Mexico
| | - Francisco Suárez-Güemes
- Department of Microbiology and Immunology; College of Veterinary Medicine; National Autonomous University of Mexico; Mexico DF, Mexico
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41
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Wattam AR, Foster JT, Mane SP, Beckstrom-Sternberg SM, Beckstrom-Sternberg JM, Dickerman AW, Keim P, Pearson T, Shukla M, Ward DV, Williams KP, Sobral BW, Tsolis RM, Whatmore AM, O'Callaghan D. Comparative phylogenomics and evolution of the Brucellae reveal a path to virulence. J Bacteriol 2014; 196:920-30. [PMID: 24336939 PMCID: PMC3957692 DOI: 10.1128/jb.01091-13] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/04/2013] [Indexed: 11/20/2022] Open
Abstract
Brucella species include important zoonotic pathogens that have a substantial impact on both agriculture and human health throughout the world. Brucellae are thought of as "stealth pathogens" that escape recognition by the host innate immune response, modulate the acquired immune response, and evade intracellular destruction. We analyzed the genome sequences of members of the family Brucellaceae to assess its evolutionary history from likely free-living soil-based progenitors into highly successful intracellular pathogens. Phylogenetic analysis split the genus into two groups: recently identified and early-dividing "atypical" strains and a highly conserved "classical" core clade containing the major pathogenic species. Lateral gene transfer events brought unique genomic regions into Brucella that differentiated them from Ochrobactrum and allowed the stepwise acquisition of virulence factors that include a type IV secretion system, a perosamine-based O antigen, and systems for sequestering metal ions that are absent in progenitors. Subsequent radiation within the core Brucella resulted in lineages that appear to have evolved within their preferred mammalian hosts, restricting their virulence to become stealth pathogens capable of causing long-term chronic infections.
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Affiliation(s)
- Alice R. Wattam
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Jeffrey T. Foster
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
| | | | - Stephen M. Beckstrom-Sternberg
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - James M. Beckstrom-Sternberg
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - Allan W. Dickerman
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Paul Keim
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
- Translational Genomics Research Institute, Pathogen Genomics Division, Phoenix, Arizona, USA
| | - Talima Pearson
- Center for Microbial Genetics & Genomics, Northern Arizona University, Flagstaff, Arizona, USA
| | - Maulik Shukla
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Doyle V. Ward
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Kelly P. Williams
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Bruno W. Sobral
- Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, USA
| | - Renee M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, California, USA
| | - Adrian M. Whatmore
- Department of Bacteriology, Animal Health & Veterinary Laboratories Agency, Addlestone, United Kingdom
| | - David O'Callaghan
- INSERM U1047, UFR Médecine, Nîmes, France
- Université Montpellier 1, UFR Médecine, Nîmes, France
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42
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Han X, Sun X, Shan X, Zhang M, Song J, Tian M, Fan G, Wang S, Tong Y, Ding C, Yu S. In vivo-induced argininosuccinate lyase plays a role in the replication of Brucella abortus in RAW264.7 cells. MICROBIOLOGY-SGM 2014; 160:567-575. [PMID: 24421405 DOI: 10.1099/mic.0.072926-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Brucellosis caused by Brucella species is a zoonotic disease with a serious impact on public health and the livestock industry. To better understand the pathogenesis of the disease, in vivo-induced antigen technology (IVIAT) was used to investigate the in vivo-induced antigens of Brucella abortus in this study. A genomic expression library of B. abortus was constructed and screened using pooled bovine B. abortus-positive sera by IVIAT. In total, 33 antigens were identified. Five antigens were further expressed and tested for their seroreactivity against 33 individual bovine B. abortus-positive sera by Western blot analysis. The results showed a highest positive rate of 32/33 for argininosuccinate lyase (ASL), indicating that ASL may be used as a candidate marker for serodiagnosis of brucellosis. Furthermore, an asl gene-deleted mutant strain S2308ΔASL was constructed, and the intracellular survival and replication of the mutant strain in RAW264.7 cells were investigated. Interestingly, the numbers of bacteria recovered from cells infected with mutant strain S2308ΔASL were similar at all time points observed from 0 h to 96 h post-infection, suggesting the asl gene plays an important role in the bacterial replication in RAW264.7 cells. Real-time quantitative PCR (qPCR) analysis showed that the mRNA levels in S2308ΔASL were decreased for BvrR, BvrS and virB5 when compared with those in S2308 (P<0.05). Our results not only expand the knowledge of Brucella intracellular replication but also expand the list of candidates for serodiagnostic markers of brucellosis.
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Affiliation(s)
- Xiangan Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Xiaoqing Sun
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Xueqing Shan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Min Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Jun Song
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Mingxing Tian
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Guobo Fan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Shaohui Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Yongliang Tong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China
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43
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Terwagne M, Mirabella A, Lemaire J, Deschamps C, De Bolle X, Letesson JJ. Quorum sensing and self-quorum quenching in the intracellular pathogen Brucellamelitensis. PLoS One 2013; 8:e82514. [PMID: 24349302 PMCID: PMC3859601 DOI: 10.1371/journal.pone.0082514] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 10/24/2013] [Indexed: 11/19/2022] Open
Abstract
Brucella quorum sensing has been described as an important regulatory system controlling crucial virulence determinants such as the VirB type IV secretion system and the flagellar genes. However, the basis of quorum sensing, namely the production of autoinducers in Brucella has been questioned. Here, we report data obtained from the use of a genetic tool allowing the in situ detection of long-chain N-acyl-homoserine lactones (AHL) activity at single bacterium level in Brucella melitensis. These data are consistent with an intrinsic production of AHL by B. melitensis in low concentration both during in vitro growth and macrophage infection. Moreover, we identified a protein, named AibP, which is homologous to the AHL-acylases of various bacterial species. In vitro and during infection, expression of aibP coincided with a decrease in endogenous AHL activity within B. melitensis, suggesting that AibP could efficiently impair AHL accumulation. Furthermore, we showed that deletion of aibP in B. melitensis resulted in enhanced virB genes expression and VirB8 production as well as in a reduced flagellar genes expression and production of FlgE (hook protein) and FliC (flagellin) in vitro. Altogether, these results suggest that AHL-dependent quorum sensing and AHL-quorum quenching coexist in Brucella, at least to regulate its virulence.
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Affiliation(s)
| | | | - Julien Lemaire
- URBM, Department of Biology, University of Namur, Namur, Belgium
| | | | - Xavier De Bolle
- URBM, Department of Biology, University of Namur, Namur, Belgium
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44
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Xavier MN, Winter MG, Spees AM, den Hartigh AB, Nguyen K, Roux CM, Silva TMA, Atluri VL, Kerrinnes T, Keestra AM, Monack DM, Luciw PA, Eigenheer RA, Bäumler AJ, Santos RL, Tsolis RM. PPARγ-mediated increase in glucose availability sustains chronic Brucella abortus infection in alternatively activated macrophages. Cell Host Microbe 2013; 14:159-70. [PMID: 23954155 PMCID: PMC3777723 DOI: 10.1016/j.chom.2013.07.009] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 05/17/2013] [Accepted: 06/20/2013] [Indexed: 01/16/2023]
Abstract
Eradication of persistent intracellular bacterial pathogens with antibiotic therapy is often slow or incomplete. However, strategies to augment antibiotics are hampered by our poor understanding of the nutritional environment that sustains chronic infection. Here we show that the intracellular pathogen Brucella abortus survives and replicates preferentially in alternatively activated macrophages (AAMs), which are more abundant during chronic infection. A metabolic shift induced by peroxisome proliferator-activated receptor γ (PPARγ), which increases intracellular glucose availability, is identified as a causal mechanism promoting enhanced bacterial survival in AAMs. Glucose uptake was crucial for increased replication of B. abortus in AAMs, and for chronic infection, as inactivation of the bacterial glucose transporter gluP reduced both intracellular survival in AAMs and persistence in mice. Thus, a shift in intracellular nutrient availability induced by PPARγ promotes chronic persistence of B. abortus within AAMs, and targeting this pathway may aid in eradicating chronic infection.
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Affiliation(s)
- Mariana N. Xavier
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Alanna M. Spees
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Andreas B. den Hartigh
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Kim Nguyen
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Christelle M. Roux
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Teane M. A. Silva
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Vidya L. Atluri
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Tobias Kerrinnes
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - A. Marijke Keestra
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Denise M. Monack
- Department of Microbiology & Immunology, School of Medicine, Stanford University, Palo Alto, CA, 94305, USA
| | - Paul A. Luciw
- Center for Comparative Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Richard A. Eigenheer
- Proteomics Core Facility, University of California at Davis Genome Center, Davis, CA, 95616, USA
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
| | - Renato L. Santos
- Departamento de Clinica e Cirurgia Veterinarias, Escola de Veterinaria, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Renée M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, 95616, USA
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45
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Bad & breakfast. Interview by Sophia Häfner. Microbes Infect 2013; 15:531-3. [PMID: 23624106 DOI: 10.1016/j.micinf.2013.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 04/16/2013] [Indexed: 11/23/2022]
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46
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Erythritol triggers expression of virulence traits in Brucella melitensis. Microbes Infect 2013; 15:440-9. [PMID: 23421980 DOI: 10.1016/j.micinf.2013.02.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/29/2013] [Accepted: 02/05/2013] [Indexed: 11/21/2022]
Abstract
Erythritol is a four-carbon sugar preferentially utilized by Brucella spp. The presence of erythritol in the placentas of goats, cows, and pigs has been used to explain the localization of Brucella to these sites and the subsequent accumulation of large amounts of bacteria, eventually leading to abortion. Here we show that Brucella melitensis will also localize to an artificial site of erythritol within a mouse, providing a potential model system to study the pathogenesis of Brucella abortion. Immunohistological staining of the sites of erythritol within infected mice indicated a higher than expected proportion of extracellular bacteria. Ensuing experiments suggested intracellular B. melitensis was unable to replicate within macrophages in the presence of erythritol and that erythritol was able to reach the site of intracellular bacteria. The intracellular inhibition of growth was found to encourage the bacteria to replicate extracellularly rather than intracellularly, a particularly interesting development in Brucella pathogenesis. To determine the effect of erythritol on expression of B. melitensis genes, bacteria grown either with or without erythritol were analyzed by microarray. Two major virulence pathways were up-regulated in response to exposure to erythritol (the type IV secretion system VirB and flagellar proteins), suggesting a role for erythritol in virulence.
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47
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Erni B. The bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS): an interface between energy and signal transduction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2012. [DOI: 10.1007/s13738-012-0185-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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48
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Evaluation of the effects of erythritol on gene expression in Brucella abortus. PLoS One 2012; 7:e50876. [PMID: 23272076 PMCID: PMC3522698 DOI: 10.1371/journal.pone.0050876] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/25/2012] [Indexed: 11/19/2022] Open
Abstract
Bacteria of the genus Brucella have the unusual capability to catabolize erythritol and this property has been associated with their virulence mainly because of the presence of erythritol in bovine foetal tissues and because the attenuated S19 vaccine strain is the only Brucella strain unable to oxydize erythritol. In this work we have analyzed the transcriptional changes produced in Brucella by erythritol by means of two high throughput approaches: RNA hybridization against a microarray containing most of Brucella ORF's constructed from the Brucella ORFeome and next generation sequencing of Brucella mRNA in an Illumina GAIIx platform. The results obtained showed the overexpression of a group of genes, many of them in a single cluster around the ery operon, able to co-ordinately mediate the transport and degradation of erythritol into three carbon atoms intermediates that will be then converted into fructose-6P (F6P) by gluconeogenesis. Other induced genes participating in the nonoxidative branch of the pentose phosphate shunt and the TCA may collaborate with the ery genes to conform an efficient degradation of sugars by this route. On the other hand, several routes of amino acid and nucleotide biosynthesis are up-regulated whilst amino acid transport and catabolism genes are down-regulated. These results corroborate previous descriptions indicating that in the presence of erythritol, this sugar was used preferentially over other compounds and provides a neat explanation of the the reported stimulation of growth induced by erythritol.
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49
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Brucella melitensis MucR, an orthologue of Sinorhizobium meliloti MucR, is involved in resistance to oxidative, detergent, and saline stresses and cell envelope modifications. J Bacteriol 2012; 195:453-65. [PMID: 23161025 DOI: 10.1128/jb.01336-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Brucella spp. and Sinorhizobium meliloti are alphaproteobacteria that share not only an intracellular lifestyle in their respective hosts, but also a crucial requirement for cell envelope components and their timely regulation for a successful infectious cycle. Here, we report the characterization of Brucella melitensis mucR, which encodes a zinc finger transcriptional regulator that has previously been shown to be involved in cellular and mouse infections at early time points. MucR modulates the surface properties of the bacteria and their resistance to environmental stresses (i.e., oxidative stress, cationic peptide, and detergents). We show that B. melitensis mucR is a functional orthologue of S. meliloti mucR, because it was able to restore the production of succinoglycan in an S. meliloti mucR mutant, as detected by calcofluor staining. Similar to S. meliloti MucR, B. melitensis MucR also represses its own transcription and flagellar gene expression via the flagellar master regulator ftcR. More surprisingly, we demonstrate that MucR regulates a lipid A core modification in B. melitensis. These changes could account for the attenuated virulence of a mucR mutant. These data reinforce the idea that there is a common conserved circuitry between plant symbionts and animal pathogens that regulates the relationship they have with their hosts.
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50
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Abstract
Brucella strains encounter oxygen deprivation during their intracellular replication in host cells, and the capacity of these bacteria to utilize NO(3) as an alternative electron acceptor for respiration plays an important role in their successful adaption to their intracellular niche. In this issue of Molecular Microbiology, Carrica et al (2012). report that NtrY and NtrX comprise a redox-responsive two-component regulator in Brucella abortus 2308 that responds to decreasing levels of O(2) and induces the expression of this strain's denitrification genes. Thus, NtrYX joins the increasing number of genetic regulators that contribute to the metabolic versatility required for the virulence of Brucella strains in their mammalian hosts.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
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