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Yang X, Goodwin ZI, Bhagyaraj E, Hoffman C, Pascual DW. Parenteral Vaccination with a Live Brucella melitensis Mutant Protects against Wild-Type B. melitensis 16M Challenge. Microorganisms 2024; 12:169. [PMID: 38257995 PMCID: PMC10820470 DOI: 10.3390/microorganisms12010169] [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: 12/05/2023] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Susceptibility to brucellosis remains prevalent, even in herds vaccinated with conventional vaccines. Efforts are underway to develop an improved brucellosis vaccine, and possibly a universal vaccine, given that Brucella species are highly homologous. To this end, two B. melitensis mutants were developed, znBM-lacZ (znBMZ) and znBM-mCherry (znBM-mC), and were tested for their ability to confer systemic immunity against virulent B. melitensis challenge. To assess the extent of their attenuation, bone-marrow-derived macrophages and human TF-1 myeloid cells were infected with both mutants, and the inability to replicate within these cells was noted. Mice infected with varying doses of znBM-mC cleared the brucellae within 6-10 weeks. To test for efficacy against systemic disease, groups of mice were vaccinated once by the intraperitoneal route with either znBMZ or B. abortus S19 vaccine. Relative to the PBS-dosed mice, znBMZ vaccination greatly reduced splenic brucellae colonization by ~25,000-fold compared to 700-fold for S19-vaccinated mice. Not surprisingly, both znBMZ and S19 strains induced IFN-γ+ CD4+ T cells, yet only znBMZ induced IFN-γ+ CD8+ T cells. While both strains induced CD4+ effector memory T cells (Tems), only znBMZ induced CD8+ Tems. Thus, these results show that the described znBM mutants are safe, able to elicit CD4+ and CD8+ T cell immunity without a boost, and highly effective, rendering them promising vaccine candidates for livestock.
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Affiliation(s)
| | | | | | | | - David W. Pascual
- Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; (X.Y.); (Z.I.G.); (E.B.); (C.H.)
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Zhang H, Sun T, Cao X, Wang Y, Ma Z, Wang Y, Yang N, Xu M, Deng X, Li H, Wang B, Yi J, Wang Z, Zhang Q, Chen C. Scanning iron response regulator binding sites using Dap-seq in the Brucella genome. PLoS Negl Trop Dis 2023; 17:e0011481. [PMID: 37459300 PMCID: PMC10374146 DOI: 10.1371/journal.pntd.0011481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 07/27/2023] [Accepted: 06/26/2023] [Indexed: 07/28/2023] Open
Abstract
Iron is an essential element required for all organisms. Iron response regulator (Irr) is a crucial transcriptional regulator and can affect the growth and iron uptake of Brucella. The growth rate of Brucella melitensis M5-90 irr mutant was significantly lower than that of B. melitensis M5-90 under normal or iron-sufficient conditions, however, the growth rate of the B. melitensis M5-90 irr mutant was significantly higher than that of B. melitensis M5-90 under iron-limited conditions. In addition, irr mutation significantly reduced iron uptake under iron-limited conditions. Previous studies suggested that the Irr protein has multiple target genes in the Brucella genome that are involved in iron metabolism. Therefore, in the present study, a Dap-seq approach was used to investigate the other iron metabolism genes that are also regulated by the Irr protein in Brucella. A total of seven genes were identified as target genes for Irr in this study and the expression levels of these seven genes was identified using qRT-PCR. The electrophoretic mobility shift assay confirmed that six out of the seven genes, namely rirA (BME_RS13665), membrane protein (BME_RS01725), hypothetical protein (BME_RS09560), ftrA (BME_RS14525), cation-transporting P-type ATPase (zntA) (BME_RS10660), and 2Fe-2S binding protein (BME_RS13655), interact with the Irr protein. Furthermore, the iron utilization and growth assay experiments confirmed that rirA was involve in iron metabolism and growth of Brucella. In summary, our results identified six genes regulated by the Irr protein that may participate in iron metabolism, and the rirA was identified as a regulon of Irr and it also plays a role in iron metabolism of Brucella. Collectively, these results provide valuable insights for the exploration of Brucella iron metabolism.
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Affiliation(s)
- Huan Zhang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Tianhao Sun
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xudong Cao
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- School of Medicine, HeXi University, Zhangye City, Gansu, China
| | - Yifan Wang
- State key Laboratory of Agricultural Microbiology/College of Veterinary Medicine Huazhong Agricultural University 1 Wuhan, China
| | - Zhongchen Ma
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Yueli Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Ningning Yang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Mingguo Xu
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xiaoyu Deng
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Honghuan Li
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Benben Wang
- School of Life Science, Shihezi University, Shihezi City, Xinjiang, China
| | - Jihai Yi
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Zhen Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Qian Zhang
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agriculture and Reclamation Science,Shihezi, Xinjiang, China
| | - Chuangfu Chen
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
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Wang H, Clapp B, Hoffman C, Yang X, Pascual DW. A Single Nasal Dose Vaccination with a Brucella abortus Mutant Potently Protects against Pulmonary Infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:1576-1588. [PMID: 37036290 PMCID: PMC10159994 DOI: 10.4049/jimmunol.2300071] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/14/2023] [Indexed: 04/11/2023]
Abstract
The Brucella abortus double-mutant (ΔznuA ΔnorD Brucella abortus-lacZ [znBAZ]) was assessed for its protective efficacy after vaccination with a single nasal dose. Superior protection was achieved in znBAZ-vaccinated mice against pulmonary, wild-type B. abortus 2308 challenge when compared with conventional livestock Brucella abortus vaccines, the smooth S19 (smooth B. abortus strain 19 vaccine) and rough RB51 (rough mutant vaccine strain of B. abortus) strains. Nasal znBAZ vaccination reduced splenic and lung colonization by wild-type brucellae by >3-4 logs. In contrast, S19 reduced lung colonization by only 32-fold, and RB51 failed to reduce colonization. One profound attribute of znBAZ vaccination was the >3-fold increase in pulmonary CD8+ T cells when compared with other vaccinated groups. S19 vaccination increased only CD4+ T cells. All vaccines induced IFN-γ and TNF-α production by CD4+ T cells, but only znBAZ vaccination enhanced the recruitment of polyfunctional CD8+ T cells, by >100-fold. IL-17 by both CD4+ and CD8+ T cells was also induced by subsequent znBAZ vaccination. These results demonstrate that, in addition to achieving protective immunity by CD4+ T cells, CD8+ T cells, specifically resident memory T cells, also confer protection against brucellosis. The protection obtained by znBAZ vaccination was attributed to IFN-γ-producing CD8+ T cells, because depletion of CD8+ T cells throughout vaccination and challenge phases abrogated protection. The stimulation of only CD4+ T cells by RB51- and S19-vaccinated mice proved insufficient in protecting against pulmonary B. abortus 2308 challenge. Thus, nasal znBAZ vaccination offers an alternative means to elicit protection against brucellosis.
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Affiliation(s)
- Hongbin Wang
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL
| | - Beata Clapp
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL
| | - Carol Hoffman
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL
| | - Xinghong Yang
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL
| | - David W. Pascual
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL
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Pascual DW, Goodwin ZI, Bhagyaraj E, Hoffman C, Yang X. Activation of mucosal immunity as a novel therapeutic strategy for combating brucellosis. Front Microbiol 2022; 13:1018165. [PMID: 36620020 PMCID: PMC9814167 DOI: 10.3389/fmicb.2022.1018165] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Brucellosis is a disease of livestock that is commonly asymptomatic until an abortion occurs. Disease in humans results from contact of infected livestock or consumption of contaminated milk or meat. Brucella zoonosis is primarily caused by one of three species that infect livestock, Bacillus abortus in cattle, B. melitensis in goats and sheep, and B. suis in pigs. To aid in disease prophylaxis, livestock vaccines are available, but are only 70% effective; hence, improved vaccines are needed to mitigate disease, particularly in countries where disease remains pervasive. The absence of knowing which proteins confer complete protection limits development of subunit vaccines. Instead, efforts are focused on developing new and improved live, attenuated Brucella vaccines, since these mimic attributes of wild-type Brucella, and stimulate host immune, particularly T helper 1-type responses, required for protection. In considering their development, the new mutants must address Brucella's defense mechanisms normally active to circumvent host immune detection. Vaccination approaches should also consider mode and route of delivery since disease transmission among livestock and humans is believed to occur via the naso-oropharyngeal tissues. By arming the host's mucosal immune defenses with resident memory T cells (TRMs) and by expanding the sources of IFN-γ, brucellae dissemination from the site of infection to systemic tissues can be prevented. In this review, points of discussion focus on understanding the various immune mechanisms involved in disease progression and which immune players are important in fighting disease.
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da Silva GC, Rossi CC, Rosa JN, Sanches NM, Cardoso DL, Li Y, Witney AA, Gould KA, Fontes PP, Callaghan AJ, Bossé JT, Langford PR, Bazzolli DMS. Identification of small RNAs associated with RNA chaperone Hfq reveals a new stress response regulator in Actinobacillus pleuropneumoniae. Front Microbiol 2022; 13:1017278. [PMID: 36267174 PMCID: PMC9577009 DOI: 10.3389/fmicb.2022.1017278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
The RNA chaperone Hfq promotes the association of small RNAs (sRNAs) with cognate mRNAs, controlling the expression of bacterial phenotype. Actinobacillus pleuropneumoniae hfq mutants strains are attenuated for virulence in pigs, impaired in the ability to form biofilms, and more susceptible to stress, but knowledge of the extent of sRNA involvement is limited. Here, using A. pleuropneumoniae strain MIDG2331 (serovar 8), 14 sRNAs were identified by co-immunoprecipitation with Hfq and the expression of eight, identified as trans-acting sRNAs, were confirmed by Northern blotting. We focused on one of these sRNAs, named Rna01, containing a putative promoter for RpoE (stress regulon) recognition. Knockout mutants of rna01 and a double knockout mutant of rna01 and hfq, both had decreased biofilm formation and hemolytic activity, attenuation for virulence in Galleria mellonella, altered stress susceptibility, and an altered outer membrane protein profile. Rna01 affected extracellular vesicle production, size and toxicity in G. mellonella. qRT-PCR analysis of rna01 and putative cognate mRNA targets indicated that Rna01 is associated with the extracytoplasmic stress response. This work increases our understanding of the multilayered and complex nature of the influence of Hfq-dependent sRNAs on the physiology and virulence of A. pleuropneumoniae.
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Affiliation(s)
- Giarlã Cunha da Silva
- Laboratório de Genética Molecular de Bactérias, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária—Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Ciro César Rossi
- Laboratório de Genética Molecular de Bactérias, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária—Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Jéssica Nogueira Rosa
- Laboratório de Genética Molecular de Bactérias, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária—Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Newton Moreno Sanches
- Laboratório de Genética Molecular de Bactérias, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária—Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Daniela Lopes Cardoso
- School of Biological Sciences and Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Yanwen Li
- Section of Pediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Adam A. Witney
- Institute for Infection and Immunity, St. George’s, University of London, London, United Kingdom
| | - Kate A. Gould
- Institute for Infection and Immunity, St. George’s, University of London, London, United Kingdom
| | | | - Anastasia J. Callaghan
- School of Biological Sciences and Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Janine Thérèse Bossé
- Section of Pediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Paul Richard Langford
- Section of Pediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Denise Mara Soares Bazzolli
- Laboratório de Genética Molecular de Bactérias, Departamento de Microbiologia, Instituto de Biotecnologia Aplicada à Agropecuária—Bioagro, Universidade Federal de Viçosa, Viçosa, Brazil
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Goodwin ZI, Yang X, Hoffman C, Pascual DW. Live mucosal vaccination stimulates potent protection via varied CD4+ and CD8+ T cell subsets against wild-type Brucella melitensis 16M challenge. Front Immunol 2022; 13:995327. [PMID: 36263034 PMCID: PMC9574439 DOI: 10.3389/fimmu.2022.995327] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/31/2022] [Indexed: 12/01/2022] Open
Abstract
Re-emerging zoonotic pathogen Brucella spp. continues to impact developing countries and persists in expanding populations of wildlife species in the US, constantly threatening infection of our domestic herds. The development of improved animal and human vaccines remains a priority. In this study, immunity to a novel live attenuated B. melitensis strain, termed znBM-mC, was characterized. An oral prime, intranasal (IN) boost strategy conferred exquisite protection against pulmonary challenge, with wild-type (wt) B. melitensis providing nearly complete protection in the lungs and spleens from brucellae colonization. Vaccination with znBM-mC showed an IFN-γ+ CD8+ T-cell bias in the lungs as opposed to Rev 1-vaccinated mice showing IFN-γ+ CD4+ T-cell inclination. Lung CD4+ and CD8+ effector memory T cells (TEMs) increased over 200-fold; and lung CD4+ and CD8+ resident memory T cells (TRMs) increased more than 250- and 150-fold, respectively. These T cells served as the primary producers of IFN-γ in the lungs, which was essential for vaccine clearance and the predominant cytokine generated pre-and post-challenge with wt B. melitensis 16M; znBM-mC growth could not be arrested in IFN-γ−/− mice. Increases in lung TNF-α and IL-17 were also induced, with IL-17 being mostly derived from CD4+ T cells. Vaccination of CD4−/−, CD8−/−, and B6 mice with znBM-mC conferred full protection in the lungs and spleens post-pulmonary challenge with virulent B. melitensis; vaccination of IL-17−/− mice resulted in the protection of the lungs, but not the spleen. These data demonstrate the efficacy of mucosal vaccine administration for the generation of protective memory T cells against wt B. melitensis.
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Yan X, Gu C, Yu Z, Ding L, He M, Xiao W, Zhao M, Qing Y, He L. Comprehensive analysis of transcriptome and metabolome analysis reveal new targets of Glaesserella parasuis glucose-specific enzyme IIBC (PtsG). Microb Pathog 2022; 172:105785. [PMID: 36150554 DOI: 10.1016/j.micpath.2022.105785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 10/31/2022]
Abstract
The ptsG (hpIIBCGlc) gene, belonging to the glucose-specific phosphotransferase system, encodes the bacterial glucose-specific enzyme IIBC. In this study, the effects of a deletion of the ptsG gene were investigated by metabolome and transcriptome analyses. At the transcriptional level, we identified 970 differentially expressed genes between ΔptsG and sc1401 (Padj<0.05) and 2072 co-expressed genes. Among these genes, those involved in methane metabolism, amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, pyruvate metabolism, phosphotransferase system (PTS), biotin metabolism, Two-component system and Terpenoid backbone biosynthesis showed significant changes in the ΔptsG mutant strain. Metabolome analysis revealed that a total of 310 metabolites were identified, including 20 different metabolites (p < 0.05). Among them, 15 metabolites were upregulated and 5 were downregulated in ΔptsG mutant strain. Statistical analysis revealed there were 115 individual metabolites having correlation, of which 89 were positive and 26 negative. These metabolites include amino acids, phosphates, amines, esters, nucleotides, benzoic acid and adenosine, among which amino acids and phosphate metabolites dominate. However, not all of these changes were attributable to changes in mRNA levels and must also be caused by post-transcriptional regulatory processes. The knowledge gained from this lays the foundation for further study on the role of ptsG in the pathogenic process of Glaesserella parasuis (G.parasuis).
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Affiliation(s)
- Xuefeng Yan
- School of Physical Education, Southwest Medical University, Luzhou, China
| | - Congwei Gu
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China
| | - Zehui Yu
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China
| | - Lingqiang Ding
- School of Life Science and Engineering, Hexi University, Zhangye, China
| | - Manli He
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China
| | - Wudian Xiao
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China
| | - Mingde Zhao
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China
| | - Yunfeng Qing
- Animal Disease Prevention and Control Center of Zhaohua District, Guangyuan, China
| | - Lvqin He
- Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou, China; Model Animal and Human Disease Research of Luzhou Key Laboratory, Luzhou, China.
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Akhtar AA, Turner DP. The role of bacterial ATP-binding cassette (ABC) transporters in pathogenesis and virulence: Therapeutic and vaccine potential. Microb Pathog 2022; 171:105734. [PMID: 36007845 DOI: 10.1016/j.micpath.2022.105734] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022]
Abstract
The ATP-binding cassette (ABC) transporter superfamily is found in all domains of life, facilitating critical biological processes through the translocation of a wide variety of substrates from, ions to proteins, across cellular membranes in an ATP-coupled process. The role of ABC transporters in eukaryotes has been well established: the facilitation of genetic diseases and multi-drug resistance (MDR) in cancer patients. In contrast, the role of ABC transporters in prokaryotes has been ambiguous due to their diverse functions and the sheer number of organisms in which they reside. This review examines the role of bacterial ABC transporters in pathogenesis and virulence, and their potential for therapeutic and vaccine application. We demonstrate how ABC transporters play a vital role in the virulence and pathogenesis of several pathogenic bacteria through the import of essential molecules, such as metal ions, amino acids, peptides, vitamins and osmoprotectants, as well as, the export of virulent determinants involved in glycoconjugate biosynthesis and Type I secretion. Furthermore, ABC exporters facilitate the persistence of pathogenic bacteria through the export of toxic xenobiotic substances, thus, contributing to the development of antimicrobial resistance. We also show that ABC transporters display considerable potential for therapeutic application through immunisation and resistance reversal. In conclusion, bacterial ABC transporters play an immense role in virulence and pathogenesis and display desirable traits for clinical use, therefore, potentially aiding in the battle against MDR.
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Affiliation(s)
- Armaan A Akhtar
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
| | - David Pj Turner
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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9
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He CY, Zhang YZ, Liu MZ, Zhao HL, Ren LS, Liu BS, He S, Chen ZL. Combined immunization with inactivated vaccine reduces the dose of live B. abortus A19 vaccine. BMC Vet Res 2022; 18:128. [PMID: 35366881 PMCID: PMC8976406 DOI: 10.1186/s12917-022-03229-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/23/2022] [Indexed: 11/18/2022] Open
Abstract
Background Brucella spp. is an important zoonotic pathogen responsible for brucellosis in humans and animals. Brucella abortus A19 strain is a widespread vaccine in China. However, it has a drawback of residual virulence in animals and humans. Methods In this study, the BALB/c mice were inoculated with either 100 μL PBS(control group, C group), 109 CFU/mL inactivated B. abortus A19 strain (I group), 105 CFU/mL (low-dose group, L group) 106 CFU/mL live B. abortus A19 strain (high-dose group, H group), or 105 CFU/mL live B. abortus A19 strain combined with 109 CFU/mL inactivated B. abortus A19 strain (LI group). Mice were challenged with B. abortus strain 2308 at 7 week post vaccination. Subsequently, the immune and protective efficacy of the vaccines were evaluated by measuring splenic bacterial burden, spleen weight, serum IgG, interferon-gamma (IFN-γ), interleukin-4 (IL-4) percentage of CD4 + and CD8 + T cells of mice via bacterial isolation, weighing, ELISA and flow cytometry, respectively. Results The splenic bacterial burden and spleen weight of the mice in group LI were mostly equivalent to the mice of group H. Moreover, Brucella-specific serum IgG, IFN-γ, IL-4, and the percentage of CD4+ and CD8+ T cells of the LI group mice were similar to those of the H group. In the subsequent challenge test, both vaccines conferred protective immunity to wild-type (WT) 2308 strain. In addition, the levels of IL-4 and IFN-γ, CD4+ and CD8+ T cells in these mice were similar to those of the mice in the H group. Conclusions Combined immunization with low dose live vaccine and inactivated vaccine allowed to reduce the live B. abortus A19 vaccine, dose with an equivalent protection of the high-dose live vaccine. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-022-03229-0.
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Yekwa EL, Serrano FA, Yukl E. Conformational flexibility in the zinc solute-binding protein ZnuA. Acta Crystallogr F Struct Biol Commun 2022; 78:128-134. [PMID: 35234138 PMCID: PMC8900738 DOI: 10.1107/s2053230x22001662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
Zinc is an essential metal for all kingdoms of life, making its transport across the cell membrane a critical function. In bacteria, high-affinity zinc import is accomplished by ATP-binding cassette (ABC) transporters, which rely on extracellular solute-binding proteins (SBPs) of cluster A-I to acquire the metal and deliver it to the membrane permease. These systems are important for survival and virulence, making them attractive targets for the development of novel antibiotics. Citrobacter koseri is an emerging pathogen with extensive antibiotic resistance. High-affinity zinc binding to the C. koseri cluster A-I SBP ZnuA has been characterized and the structure of the zinc-bound (holo) form has been determined by X-ray crystallography. Remarkably, despite 95% sequence identity to the ZnuA homologue from Salmonella enterica, C. koseri ZnuA exhibits a different zinc-coordination environment and a closed rather than an open conformation. Comparison with structures of another close ZnuA homologue from Escherichia coli suggests a surprisingly flexible conformational landscape that may be important for efficient zinc binding and/or delivery to the membrane permease.
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Bahr G, González LJ, Vila AJ. Metallo-β-lactamases in the Age of Multidrug Resistance: From Structure and Mechanism to Evolution, Dissemination, and Inhibitor Design. Chem Rev 2021; 121:7957-8094. [PMID: 34129337 PMCID: PMC9062786 DOI: 10.1021/acs.chemrev.1c00138] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Antimicrobial resistance is one of the major problems in current practical medicine. The spread of genes coding for resistance determinants among bacteria challenges the use of approved antibiotics, narrowing the options for treatment. Resistance to carbapenems, last resort antibiotics, is a major concern. Metallo-β-lactamases (MBLs) hydrolyze carbapenems, penicillins, and cephalosporins, becoming central to this problem. These enzymes diverge with respect to serine-β-lactamases by exhibiting a different fold, active site, and catalytic features. Elucidating their catalytic mechanism has been a big challenge in the field that has limited the development of useful inhibitors. This review covers exhaustively the details of the active-site chemistries, the diversity of MBL alleles, the catalytic mechanism against different substrates, and how this information has helped developing inhibitors. We also discuss here different aspects critical to understand the success of MBLs in conferring resistance: the molecular determinants of their dissemination, their cell physiology, from the biogenesis to the processing involved in the transit to the periplasm, and the uptake of the Zn(II) ions upon metal starvation conditions, such as those encountered during an infection. In this regard, the chemical, biochemical and microbiological aspects provide an integrative view of the current knowledge of MBLs.
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Affiliation(s)
- Guillermo Bahr
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Lisandro J. González
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Alejandro J. Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
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12
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Jacob JM, Curtiss R. Characterization of Brucella abortus S19 as a challenge strain for use in a mouse model of brucellosis. Microbes Infect 2021; 23:104809. [PMID: 33753207 DOI: 10.1016/j.micinf.2021.104809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 02/27/2021] [Accepted: 03/05/2021] [Indexed: 11/15/2022]
Abstract
The objective of this project was to conduct a feasibility study to determine whether the Brucella abortus S19 vaccine infects and persists in mice and determine whether S19 can be used as a challenge strain for vaccine trial studies. Groups of BALB/c mice were inoculated (intraperitoneally, subcutaneously, intranasally) and euthanized to determine colonization titers in the spleens and lungs. This study showed that S19 does infect and persist in the tissues of mice for 8 weeks and demonstrates that S19 can be used, safely and economically under BSL2 containment, as the challenge strain for future trials to evaluate vaccine efficacy.
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Affiliation(s)
- Jessica M Jacob
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL, 32608, USA.
| | - Roy Curtiss
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL, 32608, USA.
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13
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Zur: Zinc-Sensing Transcriptional Regulator in a Diverse Set of Bacterial Species. Pathogens 2021; 10:pathogens10030344. [PMID: 33804265 PMCID: PMC8000910 DOI: 10.3390/pathogens10030344] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/02/2021] [Accepted: 03/07/2021] [Indexed: 12/18/2022] Open
Abstract
Zinc (Zn) is the quintessential d block metal, needed for survival in all living organisms. While Zn is an essential element, its excess is deleterious, therefore, maintenance of its intracellular concentrations is needed for survival. The living organisms, during the course of evolution, developed proteins that can track the limitation or excess of necessary metal ions, thus providing survival benefits under variable environmental conditions. Zinc uptake regulator (Zur) is a regulatory transcriptional factor of the FUR superfamily of proteins, abundant among the bacterial species and known for its intracellular Zn sensing ability. In this study, we highlight the roles played by Zur in maintaining the Zn levels in various bacterial species as well as the fact that in recent years Zur has emerged not only as a Zn homeostatic regulator but also as a protein involved directly or indirectly in virulence of some pathogens. This functional aspect of Zur could be exploited in the ventures for the identification of newer antimicrobial targets. Despite extensive research on Zur, the insights into its overall regulon and its moonlighting functions in various pathogens yet remain to be explored. Here in this review, we aim to summarise the disparate functional aspects of Zur proteins present in various bacterial species.
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14
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Xia P, Lian S, Wu Y, Yan L, Quan G, Zhu G. Zinc is an important inter-kingdom signal between the host and microbe. Vet Res 2021; 52:39. [PMID: 33663613 PMCID: PMC7931793 DOI: 10.1186/s13567-021-00913-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/08/2021] [Indexed: 12/15/2022] Open
Abstract
Zinc (Zn) is an essential trace element in living organisms and plays a vital role in the regulation of both microbial virulence and host immune responses. A growing number of studies have shown that zinc deficiency or the internal Zn concentration does not meet the needs of animals and microbes, leading to an imbalance in zinc homeostasis and intracellular signalling pathway dysregulation. Competition for zinc ions (Zn2+) between microbes and the host exists in the use of Zn2+ to maintain cell structure and physiological functions. It also affects the interplay between microbial virulence factors and their specific receptors in the host. This review will focus on the role of Zn in the crosstalk between the host and microbe, especially for changes in microbial pathogenesis and nociceptive neuron-immune interactions, as it may lead to new ways to prevent or treat microbial infections.
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Affiliation(s)
- Pengpeng Xia
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China. .,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
| | - Siqi Lian
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Yunping Wu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Li Yan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guomei Quan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou, 225009, China. .,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
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15
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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: 45] [Impact Index Per Article: 15.0] [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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16
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Quan G, Xia P, Lian S, Wu Y, Zhu G. Zinc uptake system ZnuACB is essential for maintaining pathogenic phenotype of F4ac + enterotoxigenic E. coli (ETEC) under a zinc restricted environment. Vet Res 2020; 51:127. [PMID: 33028391 PMCID: PMC7539401 DOI: 10.1186/s13567-020-00854-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/22/2020] [Indexed: 01/19/2023] Open
Abstract
Zinc is the second trace element of living organisms after iron. Given its crucial importance, mammalian hosts restrict the bioavailability of Zinc ions (Zn2+) to bacterial pathogens. As a countermeasure, pathogens utilize high affinity Zn2+ transporters, such as ZnuACB to compete with the host for zinc. It is essential for bacteria to maintain zinc homeostasis and thus maintain their physiology and pathogenesis. In an attempt to uncover the zinc transporter in F4+ enterotoxigenic E. coli (ETEC) C83902, we analyzed two RNA-seq data sets of bacteria samples when different zinc treatments (restriction or abundance) were applied. Considering data revealing that the high affinity zinc uptake system ZnuACB acts as the main transporter in ETEC C83902 to resist zinc deficiency, we deleted znuACB genes to study the role of them in ETEC C83902. The deletion of znuACB genes results in growth perturbation and a sharp decrease in the ability of biofilm formation and adhesion of bacteria in vitro. Taking the data together, this study demonstrates that the ZnuACB system is required for ETEC C83902 to acquire zinc, which highly contributes to ETEC pathogenicity as well.
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Affiliation(s)
- Guomei Quan
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Pengpeng Xia
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
| | - Siqi Lian
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Yunping Wu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. .,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
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17
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Pandeya A, Ojo I, Alegun O, Wei Y. Periplasmic Targets for the Development of Effective Antimicrobials against Gram-Negative Bacteria. ACS Infect Dis 2020; 6:2337-2354. [PMID: 32786281 PMCID: PMC8187054 DOI: 10.1021/acsinfecdis.0c00384] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Antibiotic resistance has emerged as a serious threat to global public health in recent years. Lack of novel antimicrobials, especially new classes of compounds, further aggravates the situation. For Gram-negative bacteria, their double layered cell envelope and an array of efflux pumps act as formidable barriers for antimicrobials to penetrate. While cytoplasmic targets are hard to reach, proteins in the periplasm are clearly more accessible, as the drug only needs to breach the outer membrane. In this review, we summarized recent efforts on the validation and testing of periplasmic proteins as potential antimicrobial targets and the development of related inhibitors that either inhibit the growth of a bacterial pathogen or reduce its virulence during interaction with host cells. We conclude that the periplasm contains a promising pool of novel antimicrobial targets that should be scrutinized more closely for the development of effective treatment against multidrug-resistant Gram-negative bacteria.
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Affiliation(s)
- Ankit Pandeya
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Isoiza Ojo
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Olaniyi Alegun
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Yinan Wei
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
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18
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Lonergan ZR, Skaar EP. Nutrient Zinc at the Host-Pathogen Interface. Trends Biochem Sci 2019; 44:1041-1056. [PMID: 31326221 PMCID: PMC6864270 DOI: 10.1016/j.tibs.2019.06.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/13/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022]
Abstract
Zinc is an essential cofactor required for life and, as such, mechanisms exist for its homeostatic maintenance in biological systems. Despite the evolutionary distance between vertebrates and microbial life, there are parallel mechanisms to balance the essentiality of zinc with its inherent toxicity. Vertebrates regulate zinc homeostasis through a complex network of metal transporters and buffering systems that respond to changes in nutritional zinc availability or inflammation. Fine-tuning of this network becomes crucial during infections, where host nutritional immunity attempts to limit zinc availability to pathogens. However, accumulating evidence demonstrates that pathogens have evolved mechanisms to subvert host-mediated zinc withholding, and these metal homeostasis systems are important for survival within the host. We discuss here the mechanisms of vertebrate and bacterial zinc homeostasis and mobilization, as well as recent developments in our understanding of microbial zinc acquisition.
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Affiliation(s)
- Zachery R Lonergan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Microbe-Host Interactions Training Program, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
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19
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López-Santiago R, Sánchez-Argáez AB, De Alba-Núñez LG, Baltierra-Uribe SL, Moreno-Lafont MC. Immune Response to Mucosal Brucella Infection. Front Immunol 2019; 10:1759. [PMID: 31481953 PMCID: PMC6710357 DOI: 10.3389/fimmu.2019.01759] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/11/2019] [Indexed: 01/18/2023] Open
Abstract
Brucellosis is one of the most prevalent bacterial zoonosis of worldwide distribution. The disease is caused by Brucella spp., facultative intracellular pathogens. Brucellosis in animals results in abortion of fetuses, while in humans, it frequently manifests flu-like symptoms and a typical undulant fever, being osteoarthritis a common complication of the chronic infection. The two most common ways to acquire the infection in humans are through the ingestion of contaminated dairy products or by inhalation of contaminated aerosols. Brucella spp. enter the body mainly through the gastrointestinal and respiratory mucosa; however, most studies of immune response to Brucella spp. are performed analyzing models of systemic immunity. It is necessary to better understand the mucosal immune response induced by Brucella infection since this is the main entry site for the bacterium. In this review, some virulence factors and the mechanisms needed for pathogen invasion and persistence are discussed. Furthermore, some aspects of local immune responses induced during Brucella infection will be reviewed. With this knowledge, better vaccines can be designed focused on inducing protective mucosal immune response.
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Affiliation(s)
- Rubén López-Santiago
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Ana Beatriz Sánchez-Argáez
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Liliana Gabriela De Alba-Núñez
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | | | - Martha Cecilia Moreno-Lafont
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
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20
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Kandari D, Gopalani M, Gupta M, Joshi H, Bhatnagar S, Bhatnagar R. Identification, Functional Characterization, and Regulon Prediction of the Zinc Uptake Regulator ( zur) of Bacillus anthracis - An Insight Into the Zinc Homeostasis of the Pathogen. Front Microbiol 2019; 9:3314. [PMID: 30687290 PMCID: PMC6336718 DOI: 10.3389/fmicb.2018.03314] [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: 08/01/2018] [Accepted: 12/19/2018] [Indexed: 11/29/2022] Open
Abstract
Zinc has an abounding occurrence in the prokaryotes and plays paramount roles including catalytic, structural, and regulatory. Zinc uptake regulator (Zur), a Fur family transcriptional regulator, is connoted in maintaining zinc homeostasis in the pathogenic bacteria by binding to zinc and regulating the genes involved in zinc uptake and mobilization. Zinc homeostasis has been marginally scrutinized in Bacillus anthracis, the top-rated bio-terror agent, with no decipherment of the role of Zur. Of the three Fur family regulators in B. anthracis, BAS4181 is annotated as a zinc-specific transcriptional regulator. This annotation was further substantiated by our stringent computational and experimental analyses. The residues critical for zinc and DNA binding were delineated by homology modeling and sequence/structure analysis. ba zur existed as a part of a three-gene operon. Purified BaZur prodigiously existed in the dimeric form, indicated by size exclusion chromatography and blue native-polyacrylamide gel electrophoresis (PAGE). Computational and manual strategies were employed to decipher the putative regulon of ba zur, comprising of 11 genes, controlled by six promoters, each harboring at least one Zur box. The DNA binding capability of the purified BaZur to the upstream regions of the ba zur operon, yciC, rpmG, znuA, and genes encoding a GTPase cobalamine synthesis protein and a permease was ascertained by electrophoretic mobility shift assays. The regulon genes, implicated in zinc uptake and mobilization, were mostly negatively regulated by BaZur. The ba zur expression was downregulated upon exposure of cells to an excess of zinc. Conversely, it exhibited a marked upregulation under N, N, N', N'-Tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) mediated zinc-depleted environment, adding credence to its negative autoregulation. Moreover, an increase in the transcript levels of the regulon genes znuA, rpmG, and yciC upon exposure of cells to TPEN connoted their role in combating hypo-zincemic conditions by bringing about zinc uptake and mobilization. Thus, this study functionally characterizes Zur of B. anthracis and elucidates its role in maintaining zinc homeostasis.
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Affiliation(s)
- Divya Kandari
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Monisha Gopalani
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Manish Gupta
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Hemant Joshi
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Sonika Bhatnagar
- Computational and Structural Biology Laboratory, Division of Biotechnology, Netaji Subhas Institute of Technology, University of Delhi, New Delhi, India
| | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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21
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Bobrov AG, Kirillina O, Fosso MY, Fetherston JD, Miller MC, VanCleave TT, Burlison JA, Arnold WK, Lawrenz MB, Garneau-Tsodikova S, Perry RD. Zinc transporters YbtX and ZnuABC are required for the virulence of Yersinia pestis in bubonic and pneumonic plague in mice. Metallomics 2018; 9:757-772. [PMID: 28540946 DOI: 10.1039/c7mt00126f] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A number of bacterial pathogens require the ZnuABC Zinc (Zn2+) transporter and/or a second Zn2+ transport system to overcome Zn2+ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn2+ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn2+ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic plague while a ybtX mutant retains high virulence in both plague models. While sequestration of host Zn is a key nutritional immunity factor, excess Zn appears to have a significant antimicrobial role in controlling intracellular bacterial survival. Here, we demonstrate that ZntA, a Zn2+ exporter, plays a role in resistance to Zn toxicity in vitro, but that a zntA zur double mutant retains high virulence in both pneumonic and bubonic plague models and survival in macrophages. We also confirm that Ybt does not directly bind Zn2+in vitro under the conditions tested. However, we detect a significant increase in Zn2+-binding ability of filtered supernatants from a Ybt+ strain compared to those from a strain unable to produce the siderophore, supporting our previously published data that Ybt biosynthetic genes are involved in the production of a secreted Zn-binding molecule (zincophore). Our data suggest that Ybt or a modified Ybt participate in or promote Zn-binding activity in culture supernatants and is involved in Zn acquisition in Y. pestis.
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Affiliation(s)
- Alexander G Bobrov
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA.
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22
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Tanaka KJ, Song S, Mason K, Pinkett HW. Selective substrate uptake: The role of ATP-binding cassette (ABC) importers in pathogenesis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:868-877. [PMID: 28847505 PMCID: PMC5807212 DOI: 10.1016/j.bbamem.2017.08.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/11/2017] [Accepted: 08/16/2017] [Indexed: 01/14/2023]
Abstract
The uptake of nutrients, including metals, amino acids and peptides are required for many biological processes. Pathogenic bacteria scavenge these essential nutrients from microenvironments to survive within the host. Pathogens must utilize a myriad of mechanisms to acquire these essential nutrients from the host while mediating the effects of toxicity. Bacteria utilize several transport proteins, including ATP-binding cassette (ABC) transporters to import and expel substrates. ABC transporters, conserved across all organisms, are powered by the energy from ATP to move substrates across cellular membranes. In this review, we will focus on nutrient uptake, the role of ABC importers at the host-pathogen interface, and explore emerging therapies to combat pathogenesis. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain.
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Affiliation(s)
- Kari J Tanaka
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Saemee Song
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Kevin Mason
- The Research Institute at Nationwide Children's Hospital and The Ohio State University, College of Medicine, Department of Pediatrics, Center for Microbial Pathogenesis, Columbus, OH, USA
| | - Heather W Pinkett
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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23
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Gonzalez MR, Ducret V, Leoni S, Perron K. Pseudomonas aeruginosa zinc homeostasis: Key issues for an opportunistic pathogen. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1862:722-733. [PMID: 29410128 DOI: 10.1016/j.bbagrm.2018.01.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 01/26/2018] [Indexed: 12/13/2022]
Abstract
Zinc is an essential trace element for almost all living organisms. In the opportunistic bacterial pathogen Pseudomonas aeruginosa, zinc has been shown to play an important role in virulence, in colonization of the host organism and has also been shown to be involved in antibiotic resistance. P. aeruginosa possesses numerous systems enabling it to thrive in zinc-depleted conditions as well as high-zinc situations, two environments that are encountered during human infection. These capabilities account for its pathogenic strength. The main aim of this review is to focus on zinc homeostasis in P. aeruginosa and the genetic regulation of the systems involved. The interconnection with virulence, as well as the mechanism of co-regulation between metal and antibiotic resistance, are of prime interest for understanding the molecular mechanisms allowing P. aeruginosa to switch from its existence as a common environmental bacterium to a severe opportunistic pathogen. This article is part of a Special Issue entitled: Dynamic gene expression, edited by Prof. Patrick Viollier.
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Affiliation(s)
- Manuel R Gonzalez
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Verena Ducret
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Sara Leoni
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Karl Perron
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland; School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva, Switzerland.
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Zinc Acquisition Mechanisms Differ between Environmental and Virulent Francisella Species. J Bacteriol 2018; 200:JB.00587-17. [PMID: 29109188 PMCID: PMC5786701 DOI: 10.1128/jb.00587-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 10/27/2017] [Indexed: 12/29/2022] Open
Abstract
Zinc is an essential nutrient for bacterial growth. Because host cells can restrict pathogen access to zinc as an antimicrobial defense mechanism, intracellular pathogens such as Francisella must sense their environment and acquire zinc in response. In many bacteria, the conserved transcription factor Zur is a key regulator of zinc acquisition. To identify mechanisms of zinc uptake in Francisella novicida U112, transcriptome sequencing of wild-type and putative zur mutant bacteria was performed. Only three genes were confirmed as directly regulated by Zur and zinc limitation by quantitative reverse transcription-PCR. One of these genes, FTN_0879, is predicted to encode a protein with similarity to the zupT family of zinc transporters, which are not typically regulated by Zur. While a putative znuACB operon encoding a high-affinity zinc transporter was identified in U112, expression of this operon was not controlled by Zur or zinc concentration. Disruption of zupT but not znuA in U112 impaired growth under zinc limitation, suggesting that ZupT is the primary mechanism of zinc acquisition under these conditions. In the virulent Francisella tularensis subsp. tularensis Schu S4 strain, zupT is a pseudogene, and attempts to delete znuA were unsuccessful, suggesting that it is essential in this strain. A reverse TetR repression system was used to knock down the expression of znuA in Schu S4, revealing that znuA is required for growth under zinc limitation and contributes to intracellular growth within macrophages. Overall, this work identifies genes necessary for adaptation to zinc limitation and highlights nutritional differences between environmental and virulent Francisella strains. IMPORTANCEFrancisella tularensis is a tier 1 select agent with a high potential for lethality and no approved vaccine. A better understanding of Francisella virulence factors is required for the development of therapeutics. While acquisition of zinc has been shown to be required for the virulence of numerous intracellular pathogens, zinc uptake has not been characterized in Francisella. This work characterizes the Zur regulon in F. novicida and identifies two transporters that contribute to bacterial growth under zinc limitation. In addition, these data identify differences in mechanisms of zinc uptake and tolerance to zinc limitation between F. tularensis and F. novicida, highlighting the role of znuA in the growth of Schu S4 under zinc limitation.
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Mandal SK, Chandravanshi M, Gogoi P, Kanaujia SP. In silico characterization of TTHA0596: A potential Zn 2+ binding protein of ATP-binding cassette transporter. GENE REPORTS 2017. [DOI: 10.1016/j.genrep.2017.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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26
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Goodwin ZI, Pascual DW. Brucellosis vaccines for livestock. Vet Immunol Immunopathol 2016; 181:51-58. [DOI: 10.1016/j.vetimm.2016.03.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 01/18/2023]
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Suárez-Esquivel M, Ruiz-Villalobos N, Castillo-Zeledón A, Jiménez-Rojas C, Roop Ii RM, Comerci DJ, Barquero-Calvo E, Chacón-Díaz C, Caswell CC, Baker KS, Chaves-Olarte E, Thomson NR, Moreno E, Letesson JJ, De Bolle X, Guzmán-Verri C. Brucella abortus Strain 2308 Wisconsin Genome: Importance of the Definition of Reference Strains. Front Microbiol 2016; 7:1557. [PMID: 27746773 PMCID: PMC5041503 DOI: 10.3389/fmicb.2016.01557] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 09/16/2016] [Indexed: 12/25/2022] Open
Abstract
Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference strain B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised.
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Affiliation(s)
- Marcela Suárez-Esquivel
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica Heredia, Costa Rica
| | - Nazareth Ruiz-Villalobos
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica Heredia, Costa Rica
| | - Amanda Castillo-Zeledón
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica Heredia, Costa Rica
| | - César Jiménez-Rojas
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica Heredia, Costa Rica
| | - R Martin Roop Ii
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - Diego J Comerci
- Instituto de Investigaciones Biotecnológicas "Dr. Rodolfo A. Ugalde", Instituto Tecnológico de Chascomús, Universidad Nacional de San Martín, Consejo Nacional de Investigaciones Científicas y Técnicas, Comisión Nacional de Energía Atómica, Grupo Pecuario, Centro Atómico Ezeiza Buenos Aires, Argentina
| | - Elías Barquero-Calvo
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica San José, Costa Rica
| | - Carlos Chacón-Díaz
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa RicaHeredia, Costa Rica; Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa RicaSan José, Costa Rica
| | - Clayton C Caswell
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech Blacksburg, VA, USA
| | - Kate S Baker
- Wellcome Trust Sanger InstituteHinxton, UK; Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of LiverpoolLiverpool, UK
| | - Esteban Chaves-Olarte
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica San José, Costa Rica
| | - Nicholas R Thomson
- Wellcome Trust Sanger InstituteHinxton, UK; The London School of Hygiene and Tropical MedicineLondon, UK
| | - Edgardo Moreno
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa RicaHeredia, Costa Rica; Instituto Clodomiro Picado, Universidad de Costa RicaSan José, Costa Rica
| | - Jean J Letesson
- Unité de Recherche en Biologie des Microorganismes, Université de Namur Namur Belgium
| | - Xavier De Bolle
- Unité de Recherche en Biologie des Microorganismes, Université de Namur Namur Belgium
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa RicaHeredia, Costa Rica; Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa RicaSan José, Costa Rica
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Vaccination with a ΔnorD ΔznuA Brucella abortus mutant confers potent protection against virulent challenge. Vaccine 2016; 34:5290-5297. [PMID: 27639282 DOI: 10.1016/j.vaccine.2016.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 12/17/2022]
Abstract
There remains a need for an improved livestock vaccine for brucellosis since conventional vaccines are only ∼70% efficacious, making some vaccinated animals susceptible to Brucella infections. To address this void, a vaccine capable of evoking protective immunity, while still being sufficiently attenuated to produce minimal disease, is sought. In this pursuit, the ΔnorD ΔznuA B. abortus-lacZ (termed as znBAZ) was developed to be devoid of functional norD and znuA B. abortus genes, and to contain the lacZ as a marker gene. The results show that znBAZ is highly attenuated in mouse and human macrophages, and completely cleared from mouse spleens within eight weeks post-vaccination. Producing less splenic inflammation, znBAZ is significantly more protective than the conventional RB51 vaccine by more than four orders of magnitude. Vaccination with znBAZ elicits elevated numbers of IFN-γ+, TNF-α+, and polyfunctional IFN-γ+ TNF-α+ CD4+ and CD8+ T cells in contrast to RB51-vaccinated mice, which show reduced numbers of proinflammatory cytokine-producing T cells. These results demonstrate that znBAZ is a highly efficacious vaccine candidate capable of eliciting diverse T cell subsets that confer protection against parenteral challenge with virulent, wild-type B. abortus.
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29
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Wątły J, Potocki S, Rowińska-Żyrek M. Zinc Homeostasis at the Bacteria/Host Interface-From Coordination Chemistry to Nutritional Immunity. Chemistry 2016; 22:15992-16010. [DOI: 10.1002/chem.201602376] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Joanna Wątły
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
| | - Sławomir Potocki
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
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30
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Pandey A, Cabello A, Akoolo L, Rice-Ficht A, Arenas-Gamboa A, McMurray D, Ficht TA, de Figueiredo P. The Case for Live Attenuated Vaccines against the Neglected Zoonotic Diseases Brucellosis and Bovine Tuberculosis. PLoS Negl Trop Dis 2016; 10:e0004572. [PMID: 27537413 PMCID: PMC4990199 DOI: 10.1371/journal.pntd.0004572] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Vaccination of humans and animals with live attenuated organisms has proven to be an effective means of combatting some important infectious diseases. In fact, the 20th century witnessed tremendous improvements in human and animal health worldwide as a consequence of large-scale vaccination programs with live attenuated vaccines (LAVs). Here, we use the neglected zoonotic diseases brucellosis and bovine tuberculosis (BTb) caused by Brucella spp. and Mycobacterium bovis (M. bovis), respectively, as comparative models to outline the merits of LAV platforms with emphasis on molecular strategies that have been pursued to generate LAVs with enhanced vaccine safety and efficacy profiles. Finally, we discuss the prospects of LAV platforms in the fight against brucellosis and BTb and outline new avenues for future research towards developing effective vaccines using LAV platforms.
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Affiliation(s)
- Aseem Pandey
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, United States of America
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
- Norman Borlaug Center, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (AP); (PdF)
| | - Ana Cabello
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Lavoisier Akoolo
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Allison Rice-Ficht
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, Bryan, Texas, United States of America
| | - Angela Arenas-Gamboa
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - David McMurray
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, United States of America
| | - Thomas A. Ficht
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Paul de Figueiredo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, United States of America
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
- Norman Borlaug Center, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (AP); (PdF)
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31
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D'Orazio M, Mastropasqua MC, Cerasi M, Pacello F, Consalvo A, Chirullo B, Mortensen B, Skaar EP, Ciavardelli D, Pasquali P, Battistoni A. The capability of Pseudomonas aeruginosa to recruit zinc under conditions of limited metal availability is affected by inactivation of the ZnuABC transporter. Metallomics 2016; 7:1023-35. [PMID: 25751674 DOI: 10.1039/c5mt00017c] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ability of a large number of bacterial pathogens to multiply in the infected host and cause disease is dependent on their ability to express high affinity zinc importers. In many bacteria, ZnuABC, a transporter of the ABC family, plays a central role in the process of zinc uptake in zinc poor environments, including the tissues of the infected host. To initiate an investigation into the relevance of the zinc uptake apparatus for Pseudomonas aeruginosa pathogenicity, we have generated a znuA mutant in the PA14 strain. We have found that this mutant strain displays a limited growth defect in zinc depleted media. The znuA mutant strain is more sensitive than the wild type strain to calprotectin-mediated growth inhibition, but both the strains are highly resistant to this zinc sequestering antimicrobial protein. Moreover, intracellular zinc content is not evidently affected by inactivation of the ZnuABC transporter. These findings suggest that P. aeruginosa is equipped with redundant mechanisms for the acquisition of zinc that might favor P. aeruginosa colonization of environments containing low levels of this metal. Nonetheless, deletion of znuA affects alginate production, reduces the activity of extracellular zinc-containing proteases, including LasA, LasB and protease IV, and decreases the ability of P. aeruginosa to disseminate during systemic infections. These results indicate that efficient zinc acquisition is critical for the expression of various virulence features typical of P. aeruginosa and that ZnuABC also plays an important role in zinc homeostasis in this microorganism.
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Affiliation(s)
- Melania D'Orazio
- Department of Biology, University of Rome Tor Vergata, 00133 Roma, Italy.
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32
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Zinc acquisition via ZnuABC in Yersinia pseudotuberculosis facilitates resistance to oxidative stress. ANN MICROBIOL 2016. [DOI: 10.1007/s13213-016-1205-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Abstract
Ancient bacteria originated from metal-rich environments. Billions of years of evolution directed these tiny single cell creatures to exploit the versatile properties of metals in catalyzing chemical reactions and biological responses. The result is an entire metallome of proteins that use metal co-factors to facilitate key cellular process that range from the production of energy to the replication of DNA. Two key metals in this regard are iron and zinc, both abundant on Earth but not readily accessible in a human host. Instead, pathogenic bacteria must employ clever ways to acquire these metals. In this review we describe the many elegant ways these bacteria mine, regulate, and craft the use of two key metals (iron and zinc) to build a virulence arsenal that challenges even the most sophisticated immune response.
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Affiliation(s)
- Li Ma
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77459, USA.
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34
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Luo Z, Morey JR, McDevitt CA, Kobe B. Heterogeneous nucleation is required for crystallization of the ZnuA domain of pneumococcal AdcA. Acta Crystallogr F Struct Biol Commun 2015; 71:1459-64. [PMID: 26625286 PMCID: PMC4666472 DOI: 10.1107/s2053230x15021330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/10/2015] [Indexed: 01/17/2023] Open
Abstract
Zn(2+) is an essential nutrient for all known forms of life. In the major human pathogen Streptococcus pneumoniae, the acquisition of Zn(2+) is facilitated by two Zn(2+)-specific solute-binding proteins: AdcA and AdcAII. To date, there has been a paucity of structural information on AdcA, which has hindered a deeper understanding of the mechanism underlying pneumococcal Zn(2+) acquisition. Native AdcA consists of two domains: an N-terminal ZnuA domain and a C-terminal ZinT domain. In this study, the ZnuA domain of AdcA was crystallized. The initial crystals of the ZnuA-domain protein were obtained using dried seaweed as a heterogeneous nucleating agent. No crystals were obtained in the absence of the heterogeneous nucleating agent. These initial crystals were subsequently used as seeds to produce diffraction-quality crystals. The crystals diffracted to 2.03 Å resolution and had the symmetry of space group P1. This study demonstrates the utility of heterogeneous nucleation. The solution of the crystal structures will lead to further understanding of Zn(2+) acquisition by S. pneumoniae.
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Affiliation(s)
- Zhenyao Luo
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Jacqueline R. Morey
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Christopher A. McDevitt
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Boštjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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Dorneles EMS, Sriranganathan N, Lage AP. Recent advances in Brucella abortus vaccines. Vet Res 2015; 46:76. [PMID: 26155935 PMCID: PMC4495609 DOI: 10.1186/s13567-015-0199-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 05/05/2015] [Indexed: 01/18/2023] Open
Abstract
Brucella abortus vaccines play a central role in bovine brucellosis control/eradication programs and have been successfully used worldwide for decades. Strain 19 and RB51 are the approved B. abortus vaccines strains most commonly used to protect cattle against infection and abortion. However, due to some drawbacks shown by these vaccines much effort has been undertaken for the development of new vaccines, safer and more effective, that could also be used in other susceptible species of animals. In this paper, we present a review of the main aspects of the vaccines that have been used in the brucellosis control over the years and the current research advances in the development of new B. abortus vaccines.
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Affiliation(s)
- Elaine M S Dorneles
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Laboratório de Bacteriologia Aplicada, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Nammalwar Sriranganathan
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Andrey P Lage
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Laboratório de Bacteriologia Aplicada, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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36
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Afley P, Dohre SK, Prasad GBKS, Kumar S. Prediction of T cell epitopes of Brucella abortus and evaluation of their protective role in mice. Appl Microbiol Biotechnol 2015; 99:7625-37. [PMID: 26150246 DOI: 10.1007/s00253-015-6787-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 06/17/2015] [Accepted: 06/19/2015] [Indexed: 01/18/2023]
Abstract
Brucellae are Gram-negative intracellular bacteria that cause an important zoonotic disease called brucellosis. The animal vaccines are available but have disadvantage of causing abortions in a proportion of pregnant animals. The animal vaccines are also pathogenic to humans. Recent trend in vaccine design has shifted to epitope-based vaccines that are safe and specific. In this study, efforts were made to identify MHC-I- and MHC-II-restricted T cell epitopes of Brucella abortus and evaluate their vaccine potential in mice. The peptides were designed using online available immunoinformatics tools, and five MHC-I- and one MHC-II-restricted T cell peptides were selected on the basis of their ability to produce interferon gamma (IFN-γ) in in vivo studies. The selected peptides were co-administered with poly DL-lactide-co-glycolide (PLG) microparticles and evaluated for immunogenicity and protection in BALB/c mice. Mice immunized with peptides either entrapped in PLG microparticles (EPLG-Pep) or adsorbed on PLG particles (APLG-Pep) showed significantly higher splenocyte proliferation and IFN-γ generation to all selected peptides than the mice immunized with corresponding irrelevant peptides formulated PLG microparticles or phosphate-buffered saline (PBS). A significant protection compared to PBS control was also observed in EPLG-Pep and APLG-Pep groups. A plasmid DNA vaccine construct (pVaxPep) for peptides encoding DNA sequences was generated and injected to mice by in vivo electroporation. Significant protection was observed (1.66 protection units) when compared with PBS and empty vector control group animals. Overall, the MHC-I and MHC-II peptides identified in this study are immunogenic and protective in mouse model and support the feasibility of peptide-based vaccine for brucellosis.
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Affiliation(s)
- Prachiti Afley
- Defence Research & Development Establishment, Jhansi Road, Gwalior, Madhya Pradesh, 474002, India
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37
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Wang T, Si M, Song Y, Zhu W, Gao F, Wang Y, Zhang L, Zhang W, Wei G, Luo ZQ, Shen X. Type VI Secretion System Transports Zn2+ to Combat Multiple Stresses and Host Immunity. PLoS Pathog 2015; 11:e1005020. [PMID: 26134274 PMCID: PMC4489752 DOI: 10.1371/journal.ppat.1005020] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 06/09/2015] [Indexed: 12/21/2022] Open
Abstract
Type VI secretion systems (T6SSs) are widespread multi-component machineries that translocate effectors into either eukaryotic or prokaryotic cells, for virulence or for interbacterial competition. Herein, we report that the T6SS-4 from Yersinia pseudotuberculosis displays an unexpected function in the transportation of Zn2+ to combat diverse stresses and host immunity. Environmental insults such as oxidative stress induce the expression of T6SS-4 via OxyR, the transcriptional factor that also regulates many oxidative response genes. Zinc transportation is achieved by T6SS-4-mediated translocation of a novel Zn2+-binding protein substrate YezP (YPK_3549), which has the capacity to rescue the sensitivity to oxidative stress exhibited by T6SS-4 mutants when added to extracellular milieu. Disruption of the classic zinc transporter ZnuABC together with T6SS-4 or yezP results in mutants that almost completely lost virulence against mice, further highlighting the importance of T6SS-4 in resistance to host immunity. These results assigned an unconventional role to T6SSs, which will lay the foundation for studying novel mechanisms of metal ion uptake by bacteria and the role of this process in their resistance to host immunity and survival in harmful environments. One unique feature of type VI secretion system is the presence of multiple distinct systems in certain bacterial species. It is well established that some of these systems function to compete for their living niches among diverse bacterial species, whilst the activity of many such transporters remains unknown. Because metal ions are essential components to virtually all forms of life including bacteria, eukaryotic hosts have evolved complicated strategies to sequester metal ions, which constitute a major branch of their nutritional immunity. Therefore the ability to acquire metal ions is critical for bacterial virulence. This study reveals that the T6SS-4 of Yersinia pseudotuberculosis (Yptb) functions to import Zn2+ from the environment to mitigate the detrimental effects such as hydroxyl radicals induced by diverse stresses. Expression of the transporter is activated by multiple regulatory proteins, including OxyR and OmpR that sense diverse environmental cues. Zinc ion acquisition is achieved by translocating a Zn2+-binding substrate YezP, which is co-regulated with T6SS-4 by OxyR. Our results reveal a novel role for type VI secretion system, which is important in the study of the mechanism of metal ion acquisition by bacteria and the role of this process in bacterial pathogenesis and survival in detrimental environments.
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Affiliation(s)
- Tietao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Meiru Si
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yunhong Song
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Wenhan Zhu
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Fen Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Lei Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Weipeng Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- * E-mail:
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Coordinated zinc homeostasis is essential for the wild-type virulence of Brucella abortus. J Bacteriol 2015; 197:1582-91. [PMID: 25691532 DOI: 10.1128/jb.02543-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/11/2015] [Indexed: 01/19/2023] Open
Abstract
UNLABELLED Metal homeostasis in bacterial cells is a highly regulated process requiring intricately coordinated import and export, as well as precise sensing of intracellular metal concentrations. The uptake of zinc (Zn) has been linked to the virulence of Brucella abortus; however, the capacity of Brucella strains to sense Zn levels and subsequently coordinate Zn homeostasis has not been described. Here, we show that expression of the genes encoding the zinc uptake system ZnuABC is negatively regulated by the Zn-sensing Fur family transcriptional regulator, Zur, by direct interactions between Zur and the promoter region of znuABC. Moreover, the MerR-type regulator, ZntR, controls the expression of the gene encoding the Zn exporter ZntA by binding directly to its promoter. Deletion of zur or zntR alone did not result in increased zinc toxicity in the corresponding mutants; however, deletion of zntA led to increased sensitivity to Zn but not to other metals, such as Cu and Ni, suggesting that ZntA is a Zn-specific exporter. Strikingly, deletion of zntR resulted in significant attenuation of B. abortus in a mouse model of chronic infection, and subsequent experiments revealed that overexpression of zntA in the zntR mutant is the molecular basis for its decreased virulence. IMPORTANCE The importance of zinc uptake for Brucella pathogenesis has been demonstrated previously, but to date, there has been no description of how overall zinc homeostasis is maintained and genetically controlled in the brucellae. The present work defines the predominant zinc export system, as well as the key genetic regulators of both zinc uptake and export in Brucella abortus. Moreover, the data show the importance of precise coordination of the zinc homeostasis systems as disregulation of some elements of these systems leads to the attenuation of Brucella virulence in a mouse model. Overall, this study advances our understanding of the essential role of zinc in the pathogenesis of intracellular bacteria.
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González-González E, García-Hernández AL, Flores-Mejía R, López-Santiago R, Moreno-Fierros L. The protoxin Cry1Ac of Bacillus thuringiensis improves the protection conferred by intranasal immunization with Brucella abortus RB51 in a mouse model. Vet Microbiol 2015; 175:382-8. [DOI: 10.1016/j.vetmic.2014.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 11/20/2014] [Accepted: 11/24/2014] [Indexed: 11/25/2022]
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Miranda KL, Dorneles EMS, Pauletti RB, Poester FP, Lage AP. Brucella abortus S19 and RB51 vaccine immunogenicity test: Evaluation of three mice (BALB/c, Swiss and CD-1®) and two challenge strains (544 and 2308). Vaccine 2015; 33:507-11. [DOI: 10.1016/j.vaccine.2014.11.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 11/26/2014] [Accepted: 11/28/2014] [Indexed: 12/22/2022]
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Cerasi M, Liu JZ, Ammendola S, Poe AJ, Petrarca P, Pesciaroli M, Pasquali P, Raffatellu M, Battistoni A. The ZupT transporter plays an important role in zinc homeostasis and contributes to Salmonella enterica virulence. Metallomics 2014; 6:845-53. [PMID: 24430377 DOI: 10.1039/c3mt00352c] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Zinc is an essential metal for cellular homeostasis and function in both eukaryotes and prokaryotes. To acquire this essential nutrient, bacteria employ transporters characterized by different affinity for the metal. Several studies have investigated the role of the high affinity transporter ZnuABC in the bacterial response to zinc shortage, showing that this transporter has a key role in adapting bacteria to zinc starvation. In contrast, the role of the low affinity zinc importer ZupT has been the subject of limited investigations. Here we show that a Salmonella strain lacking ZupT is impaired in its ability to grow in metal devoid environments and that a znuABC zupT strain exhibits a severe growth defect in zinc devoid media, is hypersensitive to oxidative stress and contains reduced levels of intracellular free zinc. Moreover, we show that ZupT also plays a role in the ability of S. Typhimurium to colonize the host tissues. During systemic infections, the single zupT mutant strain was attenuated only in Nramp1(+/+) mice, but competition experiments between znuABC and znuABC zupT mutants revealed that ZupT contributes to metal uptake in vivo independently of the presence of a functional Nramp1 transporter. Altogether, the here reported results show that ZupT plays an important role in Salmonella zinc homeostasis, being involved in metal import both in vitro and in infected animals.
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Affiliation(s)
- Mauro Cerasi
- Dipartimento di Biologia, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy.
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Yuan F, Liao Y, You W, Liu Z, Tan Y, Zheng C, BinWang, Zhou D, Tian Y, Bei W. Deletion of the znuA virulence factor attenuates Actinobacillus pleuropneumoniae and confers protection against homologous or heterologous strain challenge. Vet Microbiol 2014; 174:531-539. [PMID: 25465668 DOI: 10.1016/j.vetmic.2014.10.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 01/10/2023]
Abstract
The znuA gene is known to be important for growth and survival in Escherichia coli, Haemophilus spp., Neisseria gonorrhoeae, and Pasteurella multocida under low Zn(2+) conditions. This gene is also present in Actinobacillus pleuropneumoniae serotype 1; therefore, the aim of this study was to investigate the existence of a similar role for the znuA gene in the growth and virulence of this organism. A precisely defined ΔznuA deletion mutant of A. pleuropneumoniae was constructed based on the sequence of the wild-type SLW01 using transconjugation and counterselection. This mutation was found to be lethal in low-Zn(2+) medium. Furthermore, the ΔznuA mutant strain exhibited attenuated virulence (≥22-fold) as well as reduced mortality and morbidity in a murine (Balb/C) model of infection. The majority of the bacteria were cleared from the lungs within 2 weeks. The ΔznuA mutant strain caused no adverse effects in pigs at doses of up to 1.0×10(9) CFU/mL. The ΔznuA mutant strain induced a significant immune response and conferred 80% and 100% protection on immunised pigs against challenge with A. pleuropneumoniae strains belonging to homologous or heterologous serovars, respectively, compared to the blank controls. The data obtained in this study indicate the potential of the mutant ΔznuA strain for development as a live vaccine capable of inducing reliable cross-serovar protection following intratracheal immunisation.
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Affiliation(s)
- Fangyan Yuan
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yonghong Liao
- National Research Center for Veterinary Medicine, Luoyang Pulike Bio-engineering Co. Ltd., Luoyang 471003, Henan, China
| | - Wujin You
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Zewen Liu
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yongqiang Tan
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Chengkun Zheng
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - BinWang
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Danna Zhou
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China
| | - Yongxiang Tian
- Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China.
| | - Weicheng Bei
- Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
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Bhubhanil S, Sittipo P, Chaoprasid P, Nookabkaew S, Sukchawalit R, Mongkolsuk S. Control of zinc homeostasis in Agrobacterium tumefaciens via zur and the zinc uptake genes znuABC and zinT. MICROBIOLOGY-SGM 2014; 160:2452-2463. [PMID: 25227896 DOI: 10.1099/mic.0.082446-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Agrobacterium tumefaciens zinc uptake regulator (Zur) was shown to negatively regulate the zinc uptake genes znuABC, encoding a zinc transport system belonging to the ATP-binding cassette (ABC) transporter family, and zinT, which encodes a periplasmic zinc-binding protein. The expression of znuABC and zinT was inducible when cells were grown in medium containing a metal chelator (EDTA), and this induction was shown to be specific for zinc depletion. The expression of znuABC was reduced in response to increased zinc in a dose-dependent manner, and zinT had a less pronounced but similar pattern of zinc-regulated expression. The inactivation of zur led to constitutively high expression of znuABC and zinT. In addition, a zur mutant had an increased total zinc content compared to the WT NTL4 strain, whereas the inactivation of zinT caused a reduction in the total zinc content. The zinT gene is shown to play a dominant role and to be more important than znuA and znuB for A. tumefaciens survival under zinc deprivation. ZinT can function even when ZnuABC is inactivated. However, mutations in zur, znuA, znuB or zinT did not affect the virulence of A. tumefaciens.
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Affiliation(s)
- Sakkarin Bhubhanil
- Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.,Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Panida Sittipo
- Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Environmental Toxicology, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand
| | - Paweena Chaoprasid
- Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Environmental Toxicology, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand
| | - Sumontha Nookabkaew
- Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand
| | - Rojana Sukchawalit
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.,Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.,Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand
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44
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Mazzon RR, Braz VS, da Silva Neto JF, do Valle Marques M. Analysis of the Caulobacter crescentus Zur regulon reveals novel insights in zinc acquisition by TonB-dependent outer membrane proteins. BMC Genomics 2014; 15:734. [PMID: 25168179 PMCID: PMC4176598 DOI: 10.1186/1471-2164-15-734] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 08/21/2014] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Intracellular zinc concentration needs to be maintained within strict limits due to its toxicity at high levels, and this is achieved by a finely regulated balance between uptake and efflux. Many bacteria use the Zinc Uptake Regulator Zur to orchestrate zinc homeostasis, but little is known regarding the transport of this metal across the bacterial outer membrane. RESULTS In this work we determined the Caulobacter crescentus Zur regulon by global transcriptional and in silico analyses. Among the genes directly repressed by Zur in response to zinc availability are those encoding a putative high affinity ABC uptake system (znuGHI), three TonB-dependent receptors (znuK, znuL and znuM) and one new putative transporter of a family not yet characterized (zrpW). Zur is also directly involved in the activation of a RND and a P-type ATPase efflux systems, as revealed by β-galactosidase and site-directed mutagenesis assays. Several genes belonging to the Fur regulon were also downregulated in the zur mutant, suggesting a putative cross-talk between Zur and Fur regulatory networks. Interestingly, a phenotypic analysis of the znuK and znuL mutants has shown that these genes are essential for growth under zinc starvation, suggesting that C. crescentus uses these TonB-dependent outer membrane transporters as key zinc scavenging systems. CONCLUSIONS The characterization of the C. crescentus Zur regulon showed that this regulator coordinates not only uptake, but also the extrusion of zinc. The uptake of zinc by C. crescentus in conditions of scarcity of this metal is highly dependent on TonB-dependent receptors, and the extrusion is mediated by an RND and P-type ATPase transport systems. The absence of Zur causes a disturbance in the dynamic equilibrium of zinc intracellular concentration, which in turn can interfere with other regulatory networks as seen for the Fur regulon.
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Affiliation(s)
| | | | | | - Marilis do Valle Marques
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av, Prof, Lineu Prestes 1374, 05508-900 São Paulo, Brazil.
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Bobrov AG, Kirillina O, Fetherston JD, Miller MC, Burlison JA, Perry RD. The Yersinia pestis siderophore, yersiniabactin, and the ZnuABC system both contribute to zinc acquisition and the development of lethal septicaemic plague in mice. Mol Microbiol 2014; 93:759-75. [PMID: 24979062 DOI: 10.1111/mmi.12693] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2014] [Indexed: 01/06/2023]
Abstract
Bacterial pathogens must overcome host sequestration of zinc (Zn(2+) ), an essential micronutrient, during the infectious disease process. While the mechanisms to acquire chelated Zn(2+) by bacteria are largely undefined, many pathogens rely upon the ZnuABC family of ABC transporters. Here we show that in Yersinia pestis, irp2, a gene encoding the synthetase (HMWP2) for the siderophore yersiniabactin (Ybt) is required for growth under Zn(2+) -deficient conditions in a strain lacking ZnuABC. Moreover, growth stimulation with exogenous, purified apo-Ybt provides evidence that Ybt may serve as a zincophore for Zn(2+) acquisition. Studies with the Zn(2+) -dependent transcriptional reporter znuA::lacZ indicate that the ability to synthesize Ybt affects the levels of intracellular Zn(2+) . However, the outer membrane receptor Psn and TonB as well as the inner membrane (IM) ABC transporter YbtPQ, which are required for Fe(3+) acquisition by Ybt, are not needed for Ybt-dependent Zn(2+) uptake. In contrast, the predicted IM protein YbtX, a member of the Major Facilitator Superfamily, was essential for Ybt-dependent Zn(2+) uptake. Finally, we show that the ZnuABC system and the Ybt synthetase HMWP2, presumably by Ybt synthesis, both contribute to the development of a lethal infection in a septicaemic plague mouse model.
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Affiliation(s)
- Alexander G Bobrov
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
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46
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Cerasi M, Ammendola S, Battistoni A. Competition for zinc binding in the host-pathogen interaction. Front Cell Infect Microbiol 2013; 3:108. [PMID: 24400228 PMCID: PMC3872050 DOI: 10.3389/fcimb.2013.00108] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/11/2013] [Indexed: 11/13/2022] Open
Abstract
Due to its favorable chemical properties, zinc is used as a structural or catalytic cofactor in a very large number of proteins. Despite the apparent abundance of this metal in all cell types, the intracellular pool of loosely bound zinc ions available for biological exchanges is in the picomolar range and nearly all zinc is tightly bound to proteins. In addition, to limit bacterial growth, some zinc-sequestering proteins are produced by eukaryotic hosts in response to infections. Therefore, to grow and multiply in the infected host, bacterial pathogens must produce high affinity zinc importers, such as the ZnuABC transporter which is present in most Gram-negative bacteria. Studies carried in different bacterial species have established that disruption of ZnuABC is usually associated with a remarkable loss of pathogenicity. The critical involvement of zinc in a plethora of metabolic and virulence pathways and the presence of very low number of zinc importers in most bacterial species mark zinc homeostasis as a very promising target for the development of novel antimicrobial strategies.
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Affiliation(s)
- Mauro Cerasi
- Dipartimento di Biologia, Università di Roma Tor Vergata Rome, Italy
| | - Serena Ammendola
- Dipartimento di Biologia, Università di Roma Tor Vergata Rome, Italy
| | - Andrea Battistoni
- Dipartimento di Biologia, Università di Roma Tor Vergata Rome, Italy ; Istituto Nazionale Biostrutture e Biosistemi, Consorzio Interuniversitario Rome, Italy
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47
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Liu M, Yan M, Liu L, Chen S. Characterization of a novel zinc transporter ZnuA acquired by Vibrio parahaemolyticus through horizontal gene transfer. Front Cell Infect Microbiol 2013; 3:61. [PMID: 24133656 PMCID: PMC3794297 DOI: 10.3389/fcimb.2013.00061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/21/2013] [Indexed: 01/15/2023] Open
Abstract
Vibrio parahaemolyticus is a clinically important foodborne pathogen that causes acute gastroenteritis worldwide. It has been shown that horizontal gene transfer (HGT) contributes significantly to virulence development of V. parahaemolyticus. In this study, we identified a novel znuA homolog (vpa1307) that belongs to a novel subfamily of ZnuA, a bacterial zinc transporter. The vpa1307 gene is located upstream of the V. parahaemolyticus pathogenicity island (Vp-PAIs) in both tdh-positive and trh-positive V. parahaemolyticus strains. Phylogenetic analysis revealed the exogenous origin of vpa1307 with 40% of V. parahaemolyticus clinical isolates possessing this gene. The expression of vpa1307 gene in V. parahaemolyticus clinical strain VP3218 is induced under zinc limitation condition. Gene deletion and complementation assays confirmed that vpa1307 contributes to the growth of VP3218 under zinc depletion condition and that conserved histidine residues of Vpa1307 contribute to its activity. Importantly, vpa1307 contributes to the cytotoxicity of VP3218 in HeLa cells and a certain degree of virulence in murine model. These results suggest that the horizontally acquired znuA subfamily gene, vpa1307, contributes to the fitness and virulence of Vibrio species.
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Affiliation(s)
- Ming Liu
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hong Kong, China ; Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen Research Institute Shenzhen, China
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Role of the zinc uptake ABC transporter of Moraxella catarrhalis in persistence in the respiratory tract. Infect Immun 2013; 81:3406-13. [PMID: 23817618 DOI: 10.1128/iai.00589-13] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Moraxella catarrhalis is a human respiratory tract pathogen that causes otitis media in children and lower respiratory tract infections in adults with chronic obstructive pulmonary disease. We have identified and characterized a zinc uptake ABC transporter that is present in all strains of M. catarrhalis tested. A mutant in which the znu gene cluster is knocked out shows markedly impaired growth compared to the wild type in medium that contains trace zinc; growth is restored to wild-type levels by supplementing medium with zinc but not with other divalent cations. Thermal-shift assays showed that the purified recombinant substrate binding protein ZnuA binds zinc but does not bind other divalent cations. Invasion assays with human respiratory epithelial cells demonstrated that the zinc ABC transporter of M. catarrhalis is critical for invasion of respiratory epithelial cells, an observation that is especially relevant because an intracellular reservoir of M. catarrhalis is present in the human respiratory tract and this reservoir is important for persistence. The znu knockout mutant showed marked impairment in its capacity to persist in the respiratory tract compared to the wild type in a mouse pulmonary clearance model. We conclude that the zinc uptake ABC transporter mediates uptake of zinc in environments with very low zinc concentrations and is critical for full virulence of M. catarrhalis in the respiratory tract in facilitating intracellular invasion of epithelial cells and persistence in the respiratory tract.
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49
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Pascual DW, Suo Z, Cao L, Avci R, Yang X. Attenuating gene expression (AGE) for vaccine development. Virulence 2013; 4:384-90. [PMID: 23652809 PMCID: PMC3714130 DOI: 10.4161/viru.24886] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Live attenuated vaccines are adept in stimulating protective immunity. Methods for generating such vaccines have largely adopted strategies used with Salmonella enterica. Yet, when similar strategies were tested in other gram-negative bacteria, the virulence factors or genes responsible to incapacitate Salmonella often failed in providing the desired outcome. Consequently, conventional live vaccines rely on prior knowledge of the pathogen's virulence factors to successfully attenuate them. This can be problematic since such bacterial pathogens normally harbor thousands of genes. To circumvent this problem, we found that overexpression of bacterial appendages, e.g., fimbriae, capsule, and flagella, could successfully attenuate wild-type (wt) Salmonella enterica serovar Typhimurium. Further analysis revealed these attenuated Salmonella strains conferred protection against wt S. Typhimurium challenge as effectively as genetically defined Salmonella vaccines. We refer to this strategy as attenuating gene expression (AGE), a simple efficient approach in attenuating bacterial pathogens, greatly facilitating the construction of live vaccines.
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Affiliation(s)
- David W Pascual
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL USA.
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50
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YANG X, SKYBERG JA, CAO L, CLAPP B, THORNBURG T, PASCUAL DW. Progress in Brucella vaccine development. FRONTIERS IN BIOLOGY 2013; 8:60-77. [PMID: 23730309 PMCID: PMC3666581 DOI: 10.1007/s11515-012-1196-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 01/16/2012] [Indexed: 01/18/2023]
Abstract
Brucella spp. are zoonotic, facultative intracellular pathogens, which cause animal and human disease. Animal disease results in abortion of fetuses; in humans, it manifests flu-like symptoms with an undulant fever, with osteoarthritis as a common complication of infection. Antibiotic regimens for human brucellosis patients may last several months and are not always completely effective. While there are no vaccines for humans, several licensed live Brucella vaccines are available for use in livestock. The performance of these animal vaccines is dependent upon the host species, dose, and route of immunization. Newly engineered live vaccines, lacking well-defined virulence factors, retain low residual virulence, are highly protective, and may someday replace currently used animal vaccines. These also have possible human applications. Moreover, due to their enhanced safety and efficacy in animal models, subunit vaccines for brucellosis show great promise for their application in livestock and humans. This review summarizes the progress of brucellosis vaccine development and presents an overview of candidate vaccines.
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Affiliation(s)
- Xinghong YANG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Jerod A. SKYBERG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Ling CAO
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Beata CLAPP
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Theresa THORNBURG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - David W. PASCUAL
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
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