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Sharma V, Kaur P, Aulakh RS, Sharma R, Verma R, Singh BB. Is Brucella excreted in cattle faeces? - Evidence from Punjab, India. Comp Immunol Microbiol Infect Dis 2024; 104:102099. [PMID: 38007989 DOI: 10.1016/j.cimid.2023.102099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/13/2023] [Indexed: 11/28/2023]
Abstract
Brucellosis is a neglected zoonosis that affects animals and people in much of the underdeveloped world. The disease is endemic in cattle in Punjab, India and controlling it is a public health challenge. Dairy farmers and farm labour commonly handle cattle faeces with bare hands and personal protective equipments are not used. No studies have been conducted about the shedding of Brucella species in faeces of sero positive cattle in the state. This study aimed to isolate and identify the Brucella species from faeces of sero positive cattle in Punjab, India. Faecal samples were collected from 350 Brucella sero positive cattle in Ludhiana district of Punjab, India. Isolation was performed using a pre-enriched Brucella selective broth medium as well as Brucella selective medium agar plates containing horse serum and Brucella selective supplements. Isolates were identified using Gram staining technique and rapid slide agglutination test, and then confirmed by using bcsp31 and 16s rRNA genus specific PCR. Isolates were further identified up to species level by using Bruce-Ladder multiplex PCR. Fourteen Brucella species were isolated, all of which showed coccobacilli on gram staining, positive rapid slide agglutination test and amplification of bcsp31 and 16s rRNA genes. Of the 14 isolates, 11 were identified as Brucella abortus and 3 were identified as Brucella melitensis. The study demonstrates that animal faeces could pose a potential risk for animal and human health and faeces of seropositive cattle must be handled with care.
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Affiliation(s)
- V Sharma
- Centre for One Health, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India
| | - P Kaur
- Department of Veterinary Microbiology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India
| | - R S Aulakh
- Centre for One Health, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India
| | - R Sharma
- Centre for One Health, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India
| | - R Verma
- Animal Disease Research Centre, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India
| | - B B Singh
- Centre for One Health, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141004, India.
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2
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Han K, Dong H, Peng X, Sun J, Jiang H, Feng Y, Ding J, Xiao S. Transcriptome and the gut microbiome analysis of the impacts of Brucella abortus oral infection in BALB/c mice. Microb Pathog 2023; 183:106278. [PMID: 37532208 DOI: 10.1016/j.micpath.2023.106278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/22/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023]
Abstract
Brucellosis is a zoonotic infectious disease caused by Brucella spp, which could cause serious economic losses to animal husbandry and threaten human public health. Ingestion of contaminated animal products is a common way to acquire Brucella infection in humans, while research on effect of oral Brucella infection on host gut microbiota and the gene expression in intestinal tissues is limited. In the present study, 16S rRNA sequencing and RNA sequencing were conducted to explore gut microbiota and expression profiles of mRNAs in the colon of BALB/c mice, which were infected by Brucella abortus 2308. The fecal samples were collected at 7 and 28 days post infection to observe changes in the gut microbiota during Brucella infection. In the alpha diversity analysis, significantly increased Chao 1 index was observed at 28 days after Brucella infection. The Bray-Curtis distancebased principal coordinate analysis indicated that the WT group showed a separation from the Brucella infection groups. In addition, analysis of composition of microbes revealed that Prevotellaceae_NK3B31_group were more abundant in 1 week and 4 week infection groups, while Turicibacter was only more abundant in 4 week infection group. Based on the RNA-seq assay, a total of 45 differentially expressed genes were detected between Brucella abortus infection group and control group. Furthermore, KEGG pathway enrichment analysis showed that protein processing in endoplasmic reticulum, Legionellosis, Spliceosome, Hippo signaling pathway and Influenza A were significantly enriched in response to Brucella abortus infection. Our finding will help to improve the knowledge of the mechanisms underlying Brucella infection and may provide novel targets for future treatment of this pathogen infection.
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Affiliation(s)
- Kun Han
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hao Dong
- National Institutes for Food and Drug Control, Beijing, 102600, China
| | - Xiaowei Peng
- China Institute of Veterinary Drug Control, Beijing, 102600, China
| | - Jiali Sun
- China Institute of Veterinary Drug Control, Beijing, 102600, China; College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Hui Jiang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yu Feng
- China Institute of Veterinary Drug Control, Beijing, 102600, China
| | - Jiabo Ding
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Sa Xiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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3
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Lionello FCP, Rotundo S, Bruno G, Marino G, Morrone HL, Fusco P, Costa C, Russo A, Trecarichi EM, Beltrame A, Torti C. Touching Base with Some Mediterranean Diseases of Interest from Paradigmatic Cases at the "Magna Graecia" University Unit of Infectious Diseases: A Didascalic Review. Diagnostics (Basel) 2023; 13:2832. [PMID: 37685370 PMCID: PMC10486464 DOI: 10.3390/diagnostics13172832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/25/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Among infectious diseases, zoonoses are increasing in importance worldwide, especially in the Mediterranean region. We report herein some clinical cases from a third-level hospital in Calabria region (Southern Italy) and provide a narrative review of the most relevant features of these diseases from epidemiological and clinical perspectives. Further, the pathogenic mechanisms involved in zoonotic diseases are reviewed, focusing on the mechanisms used by pathogens to elude the immune system of the host. These topics are of particular concern for individuals with primary or acquired immunodeficiency (e.g., people living with HIV, transplant recipients, patients taking immunosuppressive drugs). From the present review, it appears that diagnostic innovations and the availability of more accurate methods, together with better monitoring of the incidence and prevalence of these infections, are urgently needed to improve interventions for better preparedness and response.
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Affiliation(s)
- Ferdinando Carmelo Pio Lionello
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
| | - Salvatore Rotundo
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
| | - Gabriele Bruno
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
| | - Gabriella Marino
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
| | - Helen Linda Morrone
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
| | - Paolo Fusco
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
- Unit of Infectious and Tropical Diseases, “Mater Domini” Teaching Hospital, 88100 Catanzaro, Italy;
| | - Chiara Costa
- Unit of Infectious and Tropical Diseases, “Mater Domini” Teaching Hospital, 88100 Catanzaro, Italy;
| | - Alessandro Russo
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
- Unit of Infectious and Tropical Diseases, “Mater Domini” Teaching Hospital, 88100 Catanzaro, Italy;
| | - Enrico Maria Trecarichi
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
- Unit of Infectious and Tropical Diseases, “Mater Domini” Teaching Hospital, 88100 Catanzaro, Italy;
| | - Anna Beltrame
- College of Public Health, University of South Florida, Gainesville, FL 33620, USA;
| | - Carlo Torti
- Department of Medical and Surgical Sciences, University “Magna Graecia”, 88100 Catanzaro, Italy; (F.C.P.L.); (S.R.); (G.B.); (G.M.); (H.L.M.); (A.R.); (E.M.T.); (C.T.)
- Unit of Infectious and Tropical Diseases, “Mater Domini” Teaching Hospital, 88100 Catanzaro, Italy;
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de Carvalho TP, da Silva LA, Castanheira TLL, de Souza TD, da Paixão TA, Lazaro-Anton L, Tsolis RM, Santos RL. Cell and Tissue Tropism of Brucella spp. Infect Immun 2023; 91:e0006223. [PMID: 37129522 PMCID: PMC10187126 DOI: 10.1128/iai.00062-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
Brucella spp. are facultatively intracellular bacteria that can infect, survive, and multiply in various host cell types in vivo and/or in vitro. The genus Brucella has markedly expanded in recent years with the identification of novel species and hosts, which has revealed additional information about the cell and tissue tropism of these pathogens. Classically, Brucella spp. are considered to have tropism for organs that contain large populations of phagocytes such as lymph nodes, spleen, and liver, as well as for organs of the genital system, including the uterus, epididymis, testis, and placenta. However, experimental infections of several different cultured cell types indicate that Brucella may actually have a broader cell tropism than previously thought. Indeed, recent studies indicate that certain Brucella species in particular hosts may display a pantropic distribution in vivo. This review discusses the available knowledge on cell and tissue tropism of Brucella spp. in natural infections of various host species, as well as in experimental animal models and cultured cells.
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Affiliation(s)
- Thaynara Parente de Carvalho
- Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Medical Microbiology and Immunology, University of California – Davis, Davis, California, USA
| | - Laice Alves da Silva
- Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Thaís Larissa Lourenço Castanheira
- Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Instituto Federal de Educação Ciência e Tecnologia do Norte de Minas Gerais, Salinas, Brazil
| | - Tayse Domingues de Souza
- Escuela de Medicina Veterinaria, Facultad de Agronomía e Ingeniería Forestal, Facultad de Ciencias Biológicas y Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Tatiane Alves da Paixão
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leticia Lazaro-Anton
- Department of Medical Microbiology and Immunology, University of California – Davis, Davis, California, USA
| | - Renee M. Tsolis
- Department of Medical Microbiology and Immunology, University of California – Davis, Davis, California, USA
| | - Renato Lima Santos
- Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Medical Microbiology and Immunology, University of California – Davis, Davis, California, USA
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5
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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: 5] [Impact Index Per Article: 2.5] [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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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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The regulon of Brucella abortus two-component system BvrR/BvrS reveals the coordination of metabolic pathways required for intracellular life. PLoS One 2022; 17:e0274397. [PMID: 36129877 PMCID: PMC9491525 DOI: 10.1371/journal.pone.0274397] [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: 03/30/2022] [Accepted: 08/26/2022] [Indexed: 11/19/2022] Open
Abstract
Brucella abortus is a facultative intracellular pathogen causing a severe zoonotic disease worldwide. The two-component regulatory system (TCS) BvrR/BvrS of B. abortus is conserved in members of the Alphaproteobacteria class. It is related to the expression of genes required for host interaction and intracellular survival. Here we report that bvrR and bvrS are part of an operon composed of 16 genes encoding functions related to nitrogen metabolism, DNA repair and recombination, cell cycle arrest, and stress response. Synteny of this genomic region within close Alphaproteobacteria members suggests a conserved role in coordinating the expression of carbon and nitrogen metabolic pathways. In addition, we performed a ChIP-Seq analysis after exposure of bacteria to conditions that mimic the intracellular environment. Genes encoding enzymes at metabolic crossroads of the pentose phosphate shunt, gluconeogenesis, cell envelope homeostasis, nucleotide synthesis, cell division, and virulence are BvrR/BvrS direct targets. A 14 bp DNA BvrR binding motif was found and investigated in selected gene targets such as virB1, bvrR, pckA, omp25, and tamA. Understanding gene expression regulation is essential to elucidate how Brucella orchestrates a physiological response leading to a furtive pathogenic strategy.
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8
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Vaughn B, Abu Kwaik Y. Idiosyncratic Biogenesis of Intracellular Pathogens-Containing Vacuoles. Front Cell Infect Microbiol 2021; 11:722433. [PMID: 34858868 PMCID: PMC8632064 DOI: 10.3389/fcimb.2021.722433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
While most bacterial species taken up by macrophages are degraded through processing of the bacteria-containing vacuole through the endosomal-lysosomal degradation pathway, intravacuolar pathogens have evolved to evade degradation through the endosomal-lysosomal pathway. All intra-vacuolar pathogens possess specialized secretion systems (T3SS-T7SS) that inject effector proteins into the host cell cytosol to modulate myriad of host cell processes and remodel their vacuoles into proliferative niches. Although intravacuolar pathogens utilize similar secretion systems to interfere with their vacuole biogenesis, each pathogen has evolved a unique toolbox of protein effectors injected into the host cell to interact with, and modulate, distinct host cell targets. Thus, intravacuolar pathogens have evolved clear idiosyncrasies in their interference with their vacuole biogenesis to generate a unique intravacuolar niche suitable for their own proliferation. While there has been a quantum leap in our knowledge of modulation of phagosome biogenesis by intravacuolar pathogens, the detailed biochemical and cellular processes affected remain to be deciphered. Here we discuss how the intravacuolar bacterial pathogens Salmonella, Chlamydia, Mycobacteria, Legionella, Brucella, Coxiella, and Anaplasma utilize their unique set of effectors injected into the host cell to interfere with endocytic, exocytic, and ER-to-Golgi vesicle traffic. However, Coxiella is the main exception for a bacterial pathogen that proliferates within the hydrolytic lysosomal compartment, but its T4SS is essential for adaptation and proliferation within the lysosomal-like vacuole.
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Affiliation(s)
- Bethany Vaughn
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY, United States
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Leya M, Kim WK, Ochirkhuyag E, Yu EC, Kim YJ, Yeo Y, Yang MS, Han SS, Lee JH, Tark D, Hur J, Kim B. Protective efficacy of attenuated Salmonella Typhimurium strain expressing BLS, Omp19, PrpA, or SOD of Brucella abortus in goats. J Vet Sci 2021; 22:e15. [PMID: 33774931 PMCID: PMC8007450 DOI: 10.4142/jvs.2021.22.e15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/28/2020] [Accepted: 01/04/2021] [Indexed: 12/03/2022] Open
Abstract
Background Attenuated Salmonella strain can be used as a vector to transport immunogens to the host antigen-binding sites. Objectives The study aimed to determine the protective efficacy of attenuated Salmonella strain expressing highly conserved Brucella immunogens in goats. Methods Goats were vaccinated with Salmonella vector expressing individually lipoprotein outer-membrane protein 19 (Omp19), Brucella lumazine synthase (BLS), proline racemase subunit A (PrpA), Cu/Zn superoxide dismutase (SOD) at 5 × 109 CFU/mL and challenge of all groups was done at 6 weeks after vaccination. Results Among these vaccines inoculated at 5 × 109 CFU/mL in 1 mL, Omp19 or SOD showed significantly higher serum immunoglobulin G titers at (2, 4, and 6) weeks post-vaccination, compared to the vector control. Interferon-γ production in response to individual antigens was significantly higher in SOD, Omp19, PrpA, and BLS individual groups, compared to that in the vector control (all p < 0.05). Brucella colonization rate at 8 weeks post-challenge showed that most vaccine-treated groups exhibited significantly increased protection by demonstrating reduced numbers of Brucella in tissues collected from vaccinated groups. Real-time polymerase chain reaction revealed that Brucella antigen expression levels were reduced in the spleen, kidney, and parotid lymph node of vaccinated goats, compared to the non-vaccinated goats. Besides, treatment with vaccine expressing individual antigens ameliorated brucellosis-related histopathological lesions. Conclusions These results delineated that BLS, Omp19, PrpA, and SOD proteins achieved a definite level of protection, indicating that Salmonella Typhimurium successfully delivered Brucella antigens, and that individual vaccines could differentially elicit an antigen-specific immune response.
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Affiliation(s)
- Mwense Leya
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Won Kyong Kim
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | | | - Eun Chae Yu
- Korea Zoonosis Research institute, Jeonbuk National University, Iksan 54531, Korea
| | - Young Jee Kim
- Korea Zoonosis Research institute, Jeonbuk National University, Iksan 54531, Korea
| | - Yoonhwan Yeo
- Korea Zoonosis Research institute, Jeonbuk National University, Iksan 54531, Korea
| | - Myeon Sik Yang
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Sang Seop Han
- Korea Zoonosis Research institute, Jeonbuk National University, Iksan 54531, Korea
| | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Dongseob Tark
- Korea Zoonosis Research institute, Jeonbuk National University, Iksan 54531, Korea
| | - Jin Hur
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Bumseok Kim
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea.
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10
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Bialer MG, Ferrero MC, Delpino MV, Ruiz-Ranwez V, Posadas DM, Baldi PC, Zorreguieta A. Adhesive Functions or Pseudogenization of Type Va Autotransporters in Brucella Species. Front Cell Infect Microbiol 2021; 11:607610. [PMID: 33987105 PMCID: PMC8111173 DOI: 10.3389/fcimb.2021.607610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 04/01/2021] [Indexed: 01/18/2023] Open
Abstract
Adhesion to host cells is a key step for successful infection of many bacterial pathogens and may define tropism to different host tissues. To do so, bacteria display adhesins on their surfaces. Brucella is an intracellular pathogen capable of proliferating in a wide variety of cell types. It has been described that BmaC, a large protein that belongs to the classical (type Va) autotransporter family, is required for efficient adhesion of Brucella suis strain 1330 to epithelial cells and fibronectin. Here we show that B. suis 1330 harbors two other type Va autotransporters (BmaA and BmaB), which, although much smaller, share significant sequence similarities with BmaC and contain the essential domains to mediate proper protein translocation to the bacterial surface. Gain and loss of function studies indicated that BmaA, BmaB, and BmaC contribute, to a greater or lesser degree, to adhesion of B. suis 1330 to different cells such as synovial fibroblasts, osteoblasts, trophoblasts, and polarized epithelial cells as well as to extracellular matrix components. It was previously shown that BmaC localizes to a single bacterial pole. Interestingly, we observed here that, similar to BmaC, the BmaB adhesin is localized mostly at a single cell pole, reinforcing the hypothesis that Brucella displays an adhesive pole. Although Brucella species have strikingly similar genomes, they clearly differ in their host preferences. Mainly, the differences identified between species appear to be at loci encoding surface proteins. A careful in silico analysis of the putative type Va autotransporter orthologues from several Brucella strains showed that the bmaB locus from Brucella abortus and both, the bmaA and bmaC loci from Brucella melitensis are pseudogenes in all strains analyzed. Results reported here evidence that all three autotransporters play a role in the adhesion properties of B. suis 1330. However, Brucella spp. exhibit extensive variations in the repertoire of functional adhesins of the classical autotransporter family that can be displayed on the bacterial surface, making them an interesting target for future studies on host preference and tropism.
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Affiliation(s)
- Magalí G Bialer
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina
| | - Mariana C Ferrero
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Victoria Delpino
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Diana M Posadas
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina
| | - Pablo C Baldi
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Angeles Zorreguieta
- Fundación Instituto Leloir (FIL), IIBBA (CONICET-FIL), Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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11
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Quantification of Brucella abortus population structure in a natural host. Proc Natl Acad Sci U S A 2021; 118:2023500118. [PMID: 33688053 DOI: 10.1073/pnas.2023500118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cattle are natural hosts of the intracellular pathogen Brucella abortus, which inflicts a significant burden on the health and reproduction of these important livestock. The primary routes of infection in field settings have been described, but it is not known how the bovine host shapes the structure of B. abortus populations during infection. We utilized a library of uniquely barcoded B. abortus strains to temporally and spatially quantify population structure during colonization of cattle through a natural route of infection. Introducing 108 bacteria from this barcoded library to the conjunctival mucosa resulted in expected levels of local lymph node colonization at a 1-wk time point. We leveraged variance in strain abundance in the library to demonstrate that only 1 in 10,000 brucellae introduced at the site of infection reached a parotid lymph node. Thus, cattle restrict the overwhelming majority of B. abortus introduced via the ocular conjunctiva at this dose. Individual strains were spatially restricted within the host tissue, and the total B. abortus census was dominated by a small number of distinct strains in each lymph node. These results define a bottleneck that B. abortus must traverse to colonize local lymph nodes from the conjunctival mucosa. The data further support a model in which a small number of spatially isolated granulomas founded by unique strains are present at 1 wk postinfection. These experiments demonstrate the power of barcoded transposon tools to quantify infection bottlenecks and to define pathogen population structure in host tissues.
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Santos RL, Souza TD, Mol JPS, Eckstein C, Paíxão TA. Canine Brucellosis: An Update. Front Vet Sci 2021; 8:594291. [PMID: 33738302 PMCID: PMC7962550 DOI: 10.3389/fvets.2021.594291] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 01/28/2021] [Indexed: 01/18/2023] Open
Abstract
Canine brucellosis is an infectious and zoonotic disease caused by Brucella canis, which has been reported worldwide, and is a major public health concern due to close contact between dogs and humans. In dogs, canine brucellosis manifests with abortion outbreaks, reproductive failure, enlargement of lymph nodes, and occasionally affects the osteoarticular system, although the occurrence of asymptomatic infections in dogs are not uncommon. In humans, the disease is associated with a febrile syndrome, commonly with non-specific symptoms including splenomegaly, fatigue, and weakness. Infection of dogs occurs mostly by the oronasal route when in contact with contaminated tissues such as aborted fetuses, semen, urine, and vaginal secretions. In humans, contact with contaminated fluids from infected dogs is an important source of infection, and it is an occupational risk for veterinarians, breeders, laboratory workers, among other professionals who deal with infected animals or biological samples. The diagnosis in dogs is largely based on serologic methods. However, serologic diagnosis of canine brucellosis remains very challenging due to the low accuracy of available tests. Molecular diagnostic methods have been increasingly used in the past few years. Treatment of infected dogs is associated with a high frequency of relapse, and should be employed only in selected cases. Currently there are no commercially available vaccines for prevention of canine brucellosis. Therefore, development of novel and improved diagnostic methods as well as the development of efficacious and safe vaccination protocols are needed for an effective control of canine brucellosis and its associated zoonotic risk.
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Affiliation(s)
- Renato L Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Tayse D Souza
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juliana P S Mol
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Camila Eckstein
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Tatiane A Paíxão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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NLRP6-associated host microbiota composition impacts in the intestinal barrier to systemic dissemination of Brucella abortus. PLoS Negl Trop Dis 2021; 15:e0009171. [PMID: 33617596 PMCID: PMC7932538 DOI: 10.1371/journal.pntd.0009171] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 03/04/2021] [Accepted: 01/25/2021] [Indexed: 02/07/2023] Open
Abstract
Brucella abortus is a Gram-negative bacterium responsible for a worldwide zoonotic infection—Brucellosis, which has been associated with high morbidity rate in humans and severe economic losses in infected livestock. The natural route of infection is through oral and nasal mucosa but the invasion process through host gut mucosa is yet to be understood. Studies have examined the role of NLRP6 (NOD-like receptor family pyrin domain-containing-6 protein) in gut homeostasis and defense against pathogens. Here, we investigated the impact of gut microbiota and NLRP6 in a murine model of Ba oral infection. Nlrp6-/- and wild-type (WT) mice were infected by oral gavage with Ba and tissues samples were collected at different time points. Our results suggest that Ba oral infection leads to significant alterations in gut microbiota. Moreover, Nlrp6-/- mice were more resistant to infection, with decreased CFU in the liver and reduction in gut permeability when compared to the control group. Fecal microbiota transplantation from WT and Nlrp6-/- into germ-free mice reflected the gut permeability phenotype from the donors. Additionally, depletion of gut microbiota by broad-spectrum-antibiotic treatment prevented Ba replication in WT while favoring bacterial growth in Nlrp6-/-. Finally, we observed higher eosinophils in the gut and leukocytes in the blood of infected Nlrp6-/- compared to WT-infected mice, which might be associated to the Nlrp6-/- resistance phenotype. Altogether, these results indicated that gut microbiota composition is the major factor involved in the initial stages of pathogen host replication and partially also by the resistance phenotype observed in Nlrp6 -/- mice regulating host inflammation against Ba infection. Brucella abortus (Ba) is an intracellular bacterium that causes zoonotic and clinical problems worldwide. Although the common route of infection is through oral and nasal, the mechanisms toward the gastrointestinal mucosa response is still unexplored. It is well known that microbiota promotes and maintains host intestinal homeostasis during bacterial infections. However, mechanisms by which the gut microbiota affects the Ba infection have not yet been demonstrated. Here, we provide significant insights into the relationship between gut microbiota and B. abortus oral infection and demonstrate the gut microbiota contribution to the gut permeability and dissemination of Ba. Furthermore, we investigated the participation of the gut microbiota from Nlrp6 deficient mice, on the gut permeability and Ba infection. Substantial experiments performed, mostly in vivo, showed that gut microbiota alterations promote gut barrier disruption, as indicated by increased gut permeability after Ba oral infection. Thus, our work highlights the role of gut mucosal environment through gut microbiota and Nlrp6 molecule involved in host innate immune responses to Ba infection.
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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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Ma S, Wang X, Wang M, Liu Z, Li Z. A retrospective survey of Brucella melitensis human infection in Hainan Province, China. BIOSAFETY AND HEALTH 2021. [DOI: 10.1016/j.bsheal.2021.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Abstract
Brucellosis is a bacterial disease of domestic animals and humans. The pathogenic ability of Brucella organisms relies on their stealthy strategy and their capacity to replicate within host cells and to induce long-lasting infections. Brucella organisms barely induce neutrophil activation and survive within these leukocytes by resisting microbicidal mechanisms. Very few Brucella-infected neutrophils are found in the target organs, except for the bone marrow, early in infection. Still, Brucella induces a mild reactive oxygen species formation and, through its lipopolysaccharide, promotes the premature death of neutrophils, which release chemokines and express "eat me" signals. This effect drives the phagocytosis of infected neutrophils by mononuclear cells that become thoroughly susceptible to Brucella replication and vehicles for bacterial dispersion. The premature death of the infected neutrophils proceeds without NETosis, necrosis/oncosis, or classical apoptosis morphology. In the absence of neutrophils, the Th1 response exacerbates and promotes bacterial removal, indicating that Brucella-infected neutrophils dampen adaptive immunity. This modulatory effect opens a window for bacterial dispersion in host tissues before adaptive immunity becomes fully activated. However, the hyperactivation of immunity is not without a price, since neutropenic Brucella-infected animals develop cachexia in the early phases of the disease. The delay in the immunological response seems a sine qua non requirement for the development of long-lasting brucellosis. This property may be shared with other pathogenic alphaproteobacteria closely related to Brucella We propose a model in which Brucella-infected polymorphonuclear neutrophils (PMNs) function as "Trojan horse" vehicles for bacterial dispersal and as modulators of the Th1 adaptive immunity in infection.
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The Role of ST2 Receptor in the Regulation of Brucella abortus Oral Infection. Pathogens 2020; 9:pathogens9050328. [PMID: 32353980 PMCID: PMC7281115 DOI: 10.3390/pathogens9050328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/15/2020] [Accepted: 04/25/2020] [Indexed: 01/18/2023] Open
Abstract
The ST2 receptor plays an important role in the gut such as permeability regulation, epithelium regeneration, and promoting intestinal immune modulation. Here, we studied the role of ST2 receptor in a murine model of oral infection with Brucella abortus, its influence on gut homeostasis and control of bacterial replication. Balb/c (wild-type, WT) and ST2 deficient mice (ST2−/−) were infected by oral gavage and the results were obtained at 3 and 14 days post infection (dpi). Our results suggest that ST2−/− are more resistant to B. abortus infection, as a lower bacterial colony-forming unit (CFU) was detected in the livers and spleens of knockout mice, when compared to WT. Additionally, we observed an increase in intestinal permeability in WT-infected mice, compared to ST2−/− animals. Breakage of the intestinal epithelial barrier and bacterial dissemination might be associated with the presence of the ST2 receptor; since, in the knockout mice no change in intestinal permeability was observed after infection. Together with enhanced resistance to infection, ST2−/− produced greater levels of IFN-γ and TNF-α in the small intestine, compared to WT mice. Nevertheless, in the systemic model of infection ST2 plays no role in controlling Brucella replication in vivo. Our results suggest that the ST2 receptor is involved in the invasion process of B. abortus by the mucosa in the oral infection model.
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Eckstein C, Mol JPS, Costa FB, Nunes PP, Lima PA, Melo MM, Carvalho TP, Santos DO, Silva MF, Carvalho TF, Costa LF, Melo Júnior OAO, Giunchette RC, Paixão TA, Santos RL. Brucella ovis mutant in ABC transporter protects against Brucella canis infection in mice and it is safe for dogs. PLoS One 2020; 15:e0231893. [PMID: 32298378 PMCID: PMC7162469 DOI: 10.1371/journal.pone.0231893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 04/02/2020] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND/OBJECTIVES Vaccination is the most important tool for controlling brucellosis, but currently there is no vaccine available for canine brucellosis, which is a zoonotic disease of worldwide distribution caused by Brucella canis. This study aimed to evaluate protection and immune response induced by Brucella ovis ΔabcBA (BoΔabcBA) encapsulated with alginate against the challenge with Brucella canis in mice and to assess the safety of this strain for dogs. METHODS Intracellular growth of the vaccine strain BoΔabcBA was assessed in canine and ovine macrophages. Protection induced by BoΔabcBA against virulent Brucella canis was evaluated in the mouse model. Safety of the vaccine strain BoΔabcBA was assessed in experimentally inoculated dogs. RESULTS Wild type B. ovis and B. canis had similar internalization and intracellular multiplication profiles in both canine and ovine macrophages. The BoΔabcBA strain had an attenuated phenotype in both canine and ovine macrophages. Immunization of BALB/c mice with alginate-encapsulated BoΔabcBA (108 CFU) induced lymphocyte proliferation, production of IL-10 and IFN-γ, and protected against experimental challenge with B. canis. Dogs immunized with alginate-encapsulated BoΔabcBA (109 CFU) seroconverted, and had no hematologic, biochemical or clinical changes. Furthermore, BoΔabcBA was not detected by isolation or PCR performed using blood, semen, urine samples or vaginal swabs at any time point over the course of this study. BoΔabcBA was isolated from lymph nodes near to the site of inoculation in two dogs at 22 weeks post immunization. CONCLUSION Encapsulated BoΔabcBA protected mice against experimental B. canis infection, and it is safe for dogs. Therefore, B. ovis ΔabcBA has potential as a vaccine candidate for canine brucellosis prevention.
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Affiliation(s)
- Camila Eckstein
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana P. S. Mol
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Fabíola B. Costa
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Philipe P. Nunes
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Pâmela A. Lima
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marília M. Melo
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Thaynara P. Carvalho
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Daniel O. Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Monique F. Silva
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tatiane F. Carvalho
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Luciana F. Costa
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Otoni A. O. Melo Júnior
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Rodolfo C. Giunchette
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tatiane A. Paixão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Renato L. Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Osman AY, Kadir AA, Jesse FF, Saharee AA. Modelling the immunopathophysiology of Brucella melitensis and its lipopolysaccharide in mice infected via oral route of exposure. Microb Pathog 2019; 136:103669. [PMID: 31445124 DOI: 10.1016/j.micpath.2019.103669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 07/23/2019] [Accepted: 08/13/2019] [Indexed: 01/18/2023]
Abstract
Brucella melitensis is one of the leading zoonotic pathogens with significant economic implications in animal industry worldwide. Lipopolysaccharide, however, remains by far the major virulence with substantial role in diseases pathogenesis. Nonetheless, the effect of B. melitensis and its lipopolysaccharide on immunopathophysiological aspects largely remains an enigma. This study examines the effect of B.melitensis and its lipopolysaccharide on immunopathophysiological parameters following experimental infection using mouse model. Eighty four (n = 84) mice, BALB/c, both sexes with equal gender distribution and 6-8 weeks-old were randomly assigned into three groups. Group 1-2 (n = 72) were orally inoculated with 0.4 mL containing 109 CFU/mL of B. melitensis and its LPS, respectively. Group 3 (n = 12) was challenged orally with phosphate buffered saline and served as a control group. Animals were observed for clinical signs, haematological and histopathological analysis for a period of 24 days post-infection. We hereby report that B.melitensis infected group demonstrated significant clinical signs and histopathological changes than LPS infected group. However, both infected groups showed elevated levels of interleukins (IL-1β and IL-6) and antibody levels (IgM and IgG) with varying degrees of predominance in LPS infected group than B. melitensis infected group. For hormone analysis, low levels of progesterone, estradiol and testosterone were observed in both B. melitensis and LPS groups throughout the study period. Moreover, in B. melitensis infected group, the organism was re-isolated from the organs and tissues of gastrointestinal, respiratory and reproductive systems thereby confirming the infection and transmission dynamics. This report is the first detailed investigation comparing the infection progression and host responses in relation to the immunopathophysiological aspects in a mouse model after oral inoculation with B. melitensis and its lipopolysaccharide.
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Affiliation(s)
- Abdinasir Yusuf Osman
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, Pengkalan Chepa, 16100, Kota Bharu, Kelantan, Malaysia; Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | - Arifah Abdul Kadir
- Department of Preclinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Faez Firdaus Jesse
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Abdul Aziz Saharee
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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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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Pasquevich KA, Carabajal MV, Guaimas FF, Bruno L, Roset MS, Coria LM, Rey Serrantes DA, Comerci DJ, Cassataro J. Omp19 Enables Brucella abortus to Evade the Antimicrobial Activity From Host's Proteolytic Defense System. Front Immunol 2019; 10:1436. [PMID: 31297115 PMCID: PMC6607954 DOI: 10.3389/fimmu.2019.01436] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/07/2019] [Indexed: 01/18/2023] Open
Abstract
Pathogenic microorganisms confront several proteolytic events in the molecular interplay with their host, highlighting that proteolysis and its regulation play an important role during infection. Microbial inhibitors, along with their target endogenous/exogenous enzymes, may directly affect the host's defense mechanisms and promote infection. Omp19 is a Brucella spp. conserved lipoprotein anchored by the lipid portion in the Brucella outer membrane. Previous work demonstrated that purified unlipidated Omp19 (U-Omp19) has protease inhibitor activity against gastrointestinal and lysosomal proteases. In this work, we found that a Brucella omp19 deletion mutant is highly attenuated in mice when infecting by the oral route. This attenuation can be explained by bacterial increased susceptibility to host proteases met by the bacteria during establishment of infection. Omp19 deletion mutant has a cell division defect when exposed to pancreatic proteases that is linked to cell-cycle arrest in G1-phase, Omp25 degradation on the cell envelope and CtrA accumulation. Moreover, Omp19 deletion mutant is more susceptible to killing by macrophage derived microsomes than wt strain. Preincubation with gastrointestinal proteases led to an increased susceptibility of Omp19 deletion mutant to macrophage intracellular killing. Thus, in this work, we describe for the first time a physiological function of B. abortus Omp19. This activity enables Brucella to better thrive in the harsh gastrointestinal tract, where protection from proteolytic degradation can be a matter of life or death, and afterwards invade the host and bypass intracellular proteases to establish the chronic infection.
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Affiliation(s)
- Karina A Pasquevich
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Marianela V Carabajal
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Francisco F Guaimas
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Laura Bruno
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Mara S Roset
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Lorena M Coria
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Diego A Rey Serrantes
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Diego J Comerci
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Juliana Cassataro
- Consejo Nacional de Investigaciones Científicas y Técnicas (UNSAM-CONICET), Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Universidad Nacional de San Martín, Buenos Aires, Argentina
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Brucella neotomae Recapitulates Attributes of Zoonotic Human Disease in a Murine Infection Model. Infect Immun 2018; 87:IAI.00255-18. [PMID: 30373892 DOI: 10.1128/iai.00255-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 10/23/2018] [Indexed: 01/03/2023] Open
Abstract
Members of the genus Brucella are Gram-negative pathogens that cause chronic systemic infection in farm animals and zoonotic infection in humans. Study of the genus Brucella has been hindered by the need for biosafety level 3 select agent containment. Brucella neotomae, originally isolated from the desert pack rat, presented an opportunity to develop an alternative, non-select agent experimental model. Our prior in vitro work indicated that the cell biology and type IV secretion system (T4SS) dependence of B. neotomae intracellular replication were similar to observations for human-pathogenic select agent Brucella species. Therefore, here, we investigated the pathobiology of B. neotomae infection in the BALB/c mouse. During a sustained infectious course, B. neotomae replicated and persisted in reticuloendothelial organs. Bioluminescent imaging and histopathological and PCR-based analysis demonstrated that the T4SS contributed to efficient early infection of the liver, spleen, and lymph nodes; granuloma formation and hepatosplenomegaly; and early induction of Th1-associated cytokine gene expression. The infectious course and pathologies in the murine model showed similarity to prior observations of primate and native host infection with zoonotic Brucella species. Therefore, the B. neotomae BALB/c infection model offers a promising system to accelerate and complement experimental work in the genus Brucella.
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Goswami G, Panda D, Samanta R, Boro RC, Modi MK, Bujarbaruah KM, Barooah M. Bacillus megaterium adapts to acid stress condition through a network of genes: Insight from a genome-wide transcriptome analysis. Sci Rep 2018; 8:16105. [PMID: 30382109 PMCID: PMC6208408 DOI: 10.1038/s41598-018-34221-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 10/05/2018] [Indexed: 11/18/2022] Open
Abstract
RNA-seq analysis of B. megaterium exposed to pH 7.0 and pH 4.5 showed differential expression of 207 genes related to several processes. Among the 207 genes, 11 genes displayed increased transcription exclusively in pH 4.5. Exposure to pH 4.5 induced the expression of genes related to maintenance of cell integrity, pH homeostasis, alternative energy generation and modification of metabolic processes. Metabolic processes like pentose phosphate pathway, fatty acid biosynthesis, cysteine and methionine metabolism and synthesis of arginine and proline were remodeled during acid stress. Genes associated with oxidative stress and osmotic stress were up-regulated at pH 4.5 indicating a link between acid stress and other stresses. Acid stress also induced expression of genes that encoded general stress-responsive proteins as well as several hypothetical proteins. Our study indicates that a network of genes aid B. megaterium G18 to adapt and survive in acid stress condition.
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Affiliation(s)
- Gunajit Goswami
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India.,Department of Life-Sciences, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Debashis Panda
- Distributed Information Centre, Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India
| | - Ramkrishna Samanta
- Department of Life-Sciences, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Robin Chandra Boro
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India
| | - Mahendra Kumar Modi
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India.,Distributed Information Centre, Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India
| | - Kamal Malla Bujarbaruah
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India
| | - Madhumita Barooah
- Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, 785013, India.
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24
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Tissue distribution and cell tropism of Brucella canis in naturally infected canine foetuses and neonates. Sci Rep 2018; 8:7203. [PMID: 29740101 PMCID: PMC5940860 DOI: 10.1038/s41598-018-25651-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/24/2018] [Indexed: 12/13/2022] Open
Abstract
Brucella canis infection is an underdiagnosed zoonotic disease. Knowledge about perinatal brucellosis in dogs is extremely limited, although foetuses and neonates are under risk of infection due to vertical transmission. In this study, immunohistochemistry was used to determine tissue distribution and cell tropism of B. canis in canine foetuses and neonates. Diagnosis of B. canis in tissues of naturally infected pups was based on PCR and sequencing of amplicons, bacterial isolation, and immunohistochemistry, whose specificity was confirmed by laser capture microdissection. PCR positivity among 200 puppies was 21%, and nine isolates of B. canis were obtained. Tissues from 13 PCR-positive puppies (4 stillborn and 9 neonates) presented widespread immunolabeling. Stomach, intestines, kidney, nervous system, and umbilicus were positive in all animals tested. Other frequently infected organs included the liver (92%), lungs (85%), lymph nodes (69%), and spleen (62%). Immunolabeled coccobacilli occurred mostly in macrophages, but they were also observed in erythrocytes, epithelial cells of gastrointestinal mucosa, renal tubules, epidermis, adipocytes, choroid plexus, ependyma, neuroblasts, blood vessels endothelium, muscle cells, and in the intestinal lumen. These results largely expand our knowledge about perinatal brucellosis in the dog, clearly demonstrating a pantropic distribution of B. canis in naturally infected foetuses and neonates.
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25
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Freddi L, Damiano MA, Chaloin L, Pennacchietti E, Al Dahouk S, Köhler S, De Biase D, Occhialini A. The Glutaminase-Dependent System Confers Extreme Acid Resistance to New Species and Atypical Strains of Brucella. Front Microbiol 2017; 8:2236. [PMID: 29187839 PMCID: PMC5695133 DOI: 10.3389/fmicb.2017.02236] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/31/2017] [Indexed: 11/28/2022] Open
Abstract
Neutralophilic bacteria have developed specific mechanisms to cope with the acid stress encountered in environments such as soil, fermented foods, and host compartments. In Escherichia coli, the glutamate decarboxylase (Gad)-dependent system is extremely efficient: it requires the concerted action of glutamate decarboxylase (GadA/GadB) and of the glutamate (Glu)/γ-aminobutyrate antiporter, GadC. Notably, this system is operative also in new strains/species of Brucella, among which Brucella microti, but not in the “classical” species, with the exception of marine mammals strains. Recently, the glutaminase-dependent system (named AR2_Q), relying on the deamination of glutamine (Gln) into Glu and on GadC activity, was described in E. coli. In Brucella genomes, a putative glutaminase (glsA)-coding gene is located downstream of the gadBC genes. We found that in B. microti these genes are expressed as a polycistronic transcript. Moreover, using a panel of Brucella genus-representative strains, we show that the AR2_Q system protects from extreme acid stress (pH ≤2.5), in the sole presence of Gln, only the Brucella species/strains predicted to have functional glsA and gadC. Indeed, mutagenesis approaches confirmed the involvement of glsA and gadC of B. microti in AR2_Q and that the acid-sensitive phenotype of B. abortus can be ascribed to a Ser248Leu substitution in GlsA, leading to loss of glutaminase activity. Furthermore, we found that the gene BMI_II339, of unknown function and downstream of the gadBC–glsA operon, positively affects Gad- and GlsA-dependent AR. Thus, we identified novel determinants that allow newly discovered and marine mammals Brucella strains to be better adapted to face hostile acidic environments. As for significance, this work may contribute to the understanding of the host preferences of Brucella species and opens the way to alternative diagnostic targets in epidemiological surveillance of brucellosis.
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Affiliation(s)
- Luca Freddi
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Maria A Damiano
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Laurent Chaloin
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Eugenia Pennacchietti
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Laboratory Affiliated to the Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Latina, Italy
| | | | - Stephan Köhler
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Daniela De Biase
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Laboratory Affiliated to the Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Latina, Italy
| | - Alessandra Occhialini
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
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26
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Miller CN, Smith EP, Cundiff JA, Knodler LA, Bailey Blackburn J, Lupashin V, Celli J. A Brucella Type IV Effector Targets the COG Tethering Complex to Remodel Host Secretory Traffic and Promote Intracellular Replication. Cell Host Microbe 2017; 22:317-329.e7. [PMID: 28844886 PMCID: PMC5599354 DOI: 10.1016/j.chom.2017.07.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 06/16/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
Abstract
Many intracellular pathogens exploit host secretory trafficking to support their intracellular cycle, but knowledge of these pathogenic processes is limited. The bacterium Brucella abortus uses a type IV secretion system (VirB T4SS) to generate a replication-permissive Brucella-containing vacuole (rBCV) derived from the host ER, a process that requires host early secretory trafficking. Here we show that the VirB T4SS effector BspB contributes to rBCV biogenesis and Brucella replication by interacting with the conserved oligomeric Golgi (COG) tethering complex, a major coordinator of Golgi vesicular trafficking, thus remodeling Golgi membrane traffic and redirecting Golgi-derived vesicles to the BCV. Altogether, these findings demonstrate that Brucella modulates COG-dependent trafficking via delivery of a T4SS effector to promote rBCV biogenesis and intracellular proliferation, providing mechanistic insight into how bacterial exploitation of host secretory functions promotes pathogenesis.
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Affiliation(s)
- Cheryl N Miller
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Erin P Smith
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Jennifer A Cundiff
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Leigh A Knodler
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Jessica Bailey Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jean Celli
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA.
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27
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Hallmaier-Wacker LK, Munster VJ, Knauf S. Disease reservoirs: from conceptual frameworks to applicable criteria. Emerg Microbes Infect 2017; 6:e79. [PMID: 28874791 PMCID: PMC5625316 DOI: 10.1038/emi.2017.65] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/20/2017] [Accepted: 06/28/2017] [Indexed: 11/25/2022]
Abstract
Central to the One Health approach and any disease eradication program is the question of whether a pathogen has a non-human reservoir. Despite well-established conceptual frameworks that define a reservoir of infection, empirical characterization of reservoirs often remains controversial, challenging and sometimes misleading. What is essentially missing are applicable requirements that standardize the use of the term ‘reservoir of infection’ across multiple disciplines. We propose an empirical framework, considering maintenance and feasible transmission of a pathogen, to standardize the acceptance of a disease reservoir across multiple disciplines. We demonstrate the intended use of these requirements by applying them to different diseases that are known to infect both humans and animals.
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Affiliation(s)
- Luisa K Hallmaier-Wacker
- Work Group Neglected Tropical Diseases, Pathology Unit, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany.,Primate Genetics Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany
| | - Vincent J Munster
- Virus Ecology Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT 59840, USA
| | - Sascha Knauf
- Work Group Neglected Tropical Diseases, Pathology Unit, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany
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28
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Stiers KM, Muenks AG, Beamer LJ. Biology, Mechanism, and Structure of Enzymes in the α-d-Phosphohexomutase Superfamily. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 109:265-304. [PMID: 28683921 PMCID: PMC5802415 DOI: 10.1016/bs.apcsb.2017.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Enzymes in the α-d-phosphohexomutases superfamily catalyze the reversible conversion of phosphosugars, such as glucose 1-phosphate and glucose 6-phosphate. These reactions are fundamental to primary metabolism across the kingdoms of life and are required for a myriad of cellular processes, ranging from exopolysaccharide production to protein glycosylation. The subject of extensive mechanistic characterization during the latter half of the 20th century, these enzymes have recently benefitted from biophysical characterization, including X-ray crystallography, NMR, and hydrogen-deuterium exchange studies. This work has provided new insights into the unique catalytic mechanism of the superfamily, shed light on the molecular determinants of ligand recognition, and revealed the evolutionary conservation of conformational flexibility. Novel associations with inherited metabolic disease and the pathogenesis of bacterial infections have emerged, spurring renewed interest in the long-appreciated functional roles of these enzymes.
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Affiliation(s)
| | | | - Lesa J Beamer
- University of Missouri, Columbia, MO, United States.
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29
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Wang M, Zhu Q, Yang Q, Li W, Wang X, Liu W, Zhou B, Li Z, Yang H. Intestinal brucellosis associated with celiac artery and superior mesenteric artery stenosis and with ileum mucosa and submucosa thickening: A case report. Medicine (Baltimore) 2017; 96:e5893. [PMID: 28079834 PMCID: PMC5266196 DOI: 10.1097/md.0000000000005893] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
RATIONALE Brucellosis is a multisystem infection found worldwide that has a broad range of characteristics, which range from acute fever and hepatomegaly to chronic infections that most commonly affect the central nervous system, cardiovascular system, or skeletal system. Gastrointestinal and splanchnic artery involvements in brucellosis are relatively uncommon. PATIENT CONCERNS We report a case of brucellosis in an adolescent presenting as intermittent abdominal pain, diarrhea, and fever, with intestinal tract involvement. And stenosis of the celiac artery and the superior mesenteric artery was found after exposed to risk factors of Brucella infection. Splanchnic vessels stenosis and an endothelial lesion may exacerbate the prevalent symptom of abdominal pain, as a form of colic pain, occurring after eating. DIAGNOSES The patient was diagnosed as brucellosis. The narrowing of the SMA and CA was suspected to be vasculitis secondary to the brucellosis. INTERVENTIONS The patient was treated with minocycline and rifampicin for 12 weeks totally. OUTCOMES The gastrointestinal manifestations of brucellosis recovered rapidly under intensive treatment. However, follow-up imaging revealed that the superior mesenteric artery and celiac artery stenosis was unimproved. LESSONS In brucellosis, gastrointestinal manifestations may be the only observable features of the disease. Splanchnic arterial stenosis is a rare complication of brucellosis. Sonography and computed tomography may be useful for both diagnosis and follow-up.
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Affiliation(s)
- Miaoqian Wang
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Qingli Zhu
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Qian Yang
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Wenbo Li
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | | | - Wei Liu
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Baotong Zhou
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Zhenghong Li
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
| | - Hong Yang
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
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30
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Costa LF, Mol JPS, Silva APC, Macêdo AA, Silva TMA, Alves GES, Winter S, Winter MG, Velazquez EM, Byndloss MX, Bäumler AJ, Tsolis RM, Paixão TA, Santos RL. Iron acquisition pathways and colonization of the inflamed intestine by Salmonella enterica serovar Typhimurium. Int J Med Microbiol 2016; 306:604-610. [PMID: 27760693 PMCID: PMC5140723 DOI: 10.1016/j.ijmm.2016.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 10/11/2016] [Accepted: 10/12/2016] [Indexed: 12/11/2022] Open
Abstract
Salmonella enterica serotype Typhimurium is able to expand in the lumen of the inflamed intestine through mechanisms that have not been fully resolved. Here we utilized streptomycin-pretreated mice and dextran sodium sulfate (DSS)-treated mice to investigate how pathways for S. Typhimurium iron acquisition contribute to pathogen expansion in the inflamed intestine. Competitive infection with an iron uptake-proficient S. Typhimurium strain and mutant strains lacking tonB feoB, feoB, tonB or iroN in streptomycin pretreated mice demonstrated that ferric iron uptake requiring IroN and TonB conferred a fitness advantage during growth in the inflamed intestine. However, the fitness advantage conferred by ferrous iron uptake mechanisms was independent of inflammation and was only apparent in models where the normal microbiota composition had been disrupted by antibiotic treatment.
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Affiliation(s)
- Luciana F Costa
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Juliana P S Mol
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Patricia C Silva
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Auricélio A Macêdo
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Teane M A Silva
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Geraldo E S Alves
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil
| | - Sebastian Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Maria G Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eric M Velazquez
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Mariana X Byndloss
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA
| | - Renée M Tsolis
- Department of Medical Microbiology and Immunology, University of California at Davis, Davis, CA, USA.
| | - Tatiane A Paixão
- Departamento de Patologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Renato L Santos
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal Minas Gerais, Belo Horizonte, MG, Brazil.
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31
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Banskar S, Bhute SS, Suryavanshi MV, Punekar S, Shouche YS. Microbiome analysis reveals the abundance of bacterial pathogens in Rousettus leschenaultii guano. Sci Rep 2016; 6:36948. [PMID: 27845426 PMCID: PMC5109407 DOI: 10.1038/srep36948] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/24/2016] [Indexed: 12/11/2022] Open
Abstract
Bats are crucial for proper functioning of an ecosystem. They provide various important services to ecosystem and environment. While, bats are well-known carrier of pathogenic viruses, their possible role as a potential carrier of pathogenic bacteria is under-explored. Here, using culture-based approach, employing multiple bacteriological media, over thousand bacteria were cultivated and identified from Rousettus leschenaultii (a frugivorous bat species), the majority of which were from the family Enterobacteriaceae and putative pathogens. Next, pathogenic potential of most frequently cultivated component of microbiome i.e. Escherichia coli was assessed to identify its known pathotypes which revealed the presence of virulent factors in many cultivated E. coli isolates. Applying in-depth bacterial community analysis using high-throughput 16 S rRNA gene sequencing, a high inter-individual variation was observed among the studied guano samples. Interestingly, a higher diversity of bacterial communities was observed in decaying guano representative. The search against human pathogenic bacteria database at 97% identity, a small proportion of sequences were found associated to well-known human pathogens. The present study thus indicates that this bat species may carry potential bacterial pathogens and advice to study the effect of these pathogens on bats itself and the probable mode of transmission to humans and other animals.
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Affiliation(s)
- Sunil Banskar
- Microbial Culture Collection, National Centre for Cell Science, Pune, India
| | - Shrikant S Bhute
- Department of Zoology, Savitribai Phule Pune University, Pune, India
| | | | - Sachin Punekar
- Biosphere, Eshwari, 52/403, Lakshminagar, Parvati, Pune-411009 (Maharashtra), India
| | - Yogesh S Shouche
- Microbial Culture Collection, National Centre for Cell Science, Pune, India
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32
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Maldonado RF, Sá-Correia I, Valvano MA. Lipopolysaccharide modification in Gram-negative bacteria during chronic infection. FEMS Microbiol Rev 2016; 40:480-93. [PMID: 27075488 PMCID: PMC4931227 DOI: 10.1093/femsre/fuw007] [Citation(s) in RCA: 350] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/23/2015] [Accepted: 03/10/2016] [Indexed: 12/16/2022] Open
Abstract
The Gram-negative bacterial lipopolysaccharide (LPS) is a major component of the outer membrane that plays a key role in host-pathogen interactions with the innate immune system. During infection, bacteria are exposed to a host environment that is typically dominated by inflammatory cells and soluble factors, including antibiotics, which provide cues about regulation of gene expression. Bacterial adaptive changes including modulation of LPS synthesis and structure are a conserved theme in infections, irrespective of the type or bacteria or the site of infection. In general, these changes result in immune system evasion, persisting inflammation and increased antimicrobial resistance. Here, we review the modifications of LPS structure and biosynthetic pathways that occur upon adaptation of model opportunistic pathogens (Pseudomonas aeruginosa, Burkholderia cepacia complex bacteria, Helicobacter pylori and Salmonella enterica) to chronic infection in respiratory and gastrointestinal sites. We also discuss the molecular mechanisms of these variations and their role in the host-pathogen interaction.
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Affiliation(s)
- Rita F. Maldonado
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal
| | - Isabel Sá-Correia
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal
| | - Miguel A. Valvano
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
- Centre for Infection and Immunity, Queen's University Belfast, Belfast BT9 7BL, UK
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33
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Wang AH, Li M, Li CQ, Kou GJ, Zuo XL, Li YQ. Human colorectal mucosal microbiota correlates with its host niche physiology revealed by endomicroscopy. Sci Rep 2016; 6:21952. [PMID: 26916597 PMCID: PMC4768150 DOI: 10.1038/srep21952] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/26/2016] [Indexed: 01/05/2023] Open
Abstract
The human gut microbiota plays a pivotal role in the maintenance of health, but how the microbiota interacts with the host at the colorectal mucosa is poorly understood. We proposed that confocal laser endomicroscopy (CLE) might help to untangle this relationship by providing in vivo physiological information of the mucosa. We used CLE to evaluate the in vivo physiology of human colorectal mucosa, and the mucosal microbiota was quantified using 16 s rDNA pyrosequencing. The human mucosal microbiota agglomerated to three major clusters dominated by Prevotella, Bacteroides and Lactococcus. The mucosal microbiota clusters did not significantly correlate with the disease status or biopsy sites but closely correlated with the mucosal niche physiology, which was non-invasively revealed by CLE. Inflammation tilted two subnetworks within the mucosal microbiota. Infiltration of inflammatory cells significantly correlated with multiple components in the predicted metagenome, such as the VirD2 component of the type IV secretory pathway. Our data suggest that a close correlation exists between the mucosal microbiota and the colorectal mucosal physiology, and CLE is a clinically available tool that can be used to facilitate the study of the in vivo correlation between colorectal mucosal physiology and the mucosal microbiota.
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Affiliation(s)
- Ai-Hua Wang
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China.,Department of Gastroenterology, Shandong Rongjun General Hospital, Jinan, 250013, China
| | - Ming Li
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China
| | - Chang-Qing Li
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China
| | - Guan-Jun Kou
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China
| | - Xiu-Li Zuo
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China
| | - Yan-Qing Li
- Department of Gastroenterology, Shandong University, Qilu Hospital, Jinan, 250012, China
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Jacob J, Makou P, Finke A, Mielke M. Inflammatory response of TLR4 deficient spleen macrophages (CRL 2471) to Brucella abortus S19 and an isogenic ΔmglA deletion mutant. Int J Med Microbiol 2016; 306:141-51. [PMID: 26946956 DOI: 10.1016/j.ijmm.2016.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/29/2016] [Accepted: 02/16/2016] [Indexed: 01/21/2023] Open
Abstract
UNLABELLED Brucellosis is a worldwide distributed zoonosis caused by members of the genus Brucella. One of them, Brucella abortus, is the etiological agent of bovine brucellosis. With the attenuated strain B. abortus S19 a vaccine is available. However, both, virulence (safety) and the ability to induce a protective B and T cell response (efficacy) have to be tested in suitable assays before successful use in the field. For this purpose, several macrophage cell lines of various origins have been used while splenic macrophages are the preferred host cells in vivo. We here characterized the in vitro response of the murine splenic macrophage cell line CRL 2471(I-13.35) to B. abortus. This cell line still depends on the presence of colony-stimulating factor 1 (CSF1) and is derived from LPS resistant (TLR4 deficient) C3H/HeJ mice. For infection the vaccine strain B. abortus S19A as well as the formerly described isogenic deletion mutant B. abortus S19A ΔmglA 3.14 were used. While numbers of viable bacteria did not differ significantly between the vaccine strain and the deletion mutant at 6h post infection, a higher bacterial load was measured in case of the mutant at 24h and 48h after infection. This was also true, when IFNγ was used for macrophage activation. A comprehensive gene expression profile of macrophages was analysed 6 and 24h after infection by means of an RT-PCR based gene expression array. The mutant strain B. abortus S19A ΔmglA 3.14 elicited a stronger cellular response of the splenic macrophages as compared to the parental vaccine strain. This was most prominent for the pro-inflammatory cytokines IL-1α, IL-1β, TNF-α and IL6 as well as for the chemokine ligands CXCL1, CXCL2, CXCL10, CCL2, CCL5, CCL7, CCL17 and the co-stimulatory molecules CD40 and ICAM1. While these differences were also present in IFNγ-stimulated macrophages, an addition of IFNγ after infection not only resulted in a dramatic increase of the translation of the afore mentioned genes but also resulted in the translation of IFNß1, IL12ß, MIP1α and β (CCL3, CCL4), NOS2 (and SOD2) and FAS. CONCLUSION The TLR4 deficient murine splenic macrophage cell line CRL 2471 was used for the first time for the characterization of macrophage-Brucella interaction to investigate the pre-immune phase of brucellosis in vitro. Typical pro-inflammatory cytokines and certain surface receptors were differentially induced by B. abortus S19 A and an isogenic ΔmglA deletion mutant in vitro. This model may be useful for further studies to characterize the inflammatory response of splenic macrophages to intracellular gram-negative bacteria avoiding cell responses to soluble LPS.
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Affiliation(s)
- Jens Jacob
- Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany.
| | - Patricia Makou
- Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany
| | - Antje Finke
- Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany
| | - Martin Mielke
- Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany
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Expression of cytokine and apoptosis-related genes in bovine peripheral blood mononuclear cells stimulated with Brucella abortus recombinant proteins. Vet Res 2016; 47:30. [PMID: 26864657 PMCID: PMC4750197 DOI: 10.1186/s13567-016-0311-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 01/12/2016] [Indexed: 01/13/2023] Open
Abstract
Brucellosis is a clinically and economically important disease. Therefore, eradication programs of the disease have been implemented in several countries. One hurdle in these programs is the detection of infected animals at the early stage. Although the protein antigens as diagnostic antigens have recently received attention, the exact mechanisms at the beginning of immune responses are not yet known. Therefore, genes encoding five B. abortus cellular proteins were cloned and the expressed recombinant proteins were purified. The expression of several cytokine genes (IL-1β, IL-4, IL-6, IL-12p40, IFN-γ, TNF-α, and iNOS) was analyzed in bovine peripheral blood mononuclear cells (bPBMC) after stimulation with the recombinant proteins. Three apoptosis-related genes, Bax, Bcl-2, and TLR4, were also included in the analysis to find out the adverse effects of the proteins to the cells. Each protein induced different patterns of cytokine expression depending on the stimulation time and antigen dose. Expression of IL-6, IL-12p40, and IFN-γ was induced with all of the proteins while IL-1β, IL-4, TNF-α, and iNOS gene expression was not. Expression of apoptosis-related genes was not altered except TLR4. These results suggest that the cellular antigens of B. abortus induce both humoral and cellular immunity via the production of IL-6, IL-12p40, and IFN-γ in bPBMC without exerting any adverse effects on the cells.
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Nasal vaccination stimulates CD8(+) T cells for potent protection against mucosal Brucella melitensis challenge. Immunol Cell Biol 2016; 94:496-508. [PMID: 26752510 PMCID: PMC4879022 DOI: 10.1038/icb.2016.5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 12/10/2015] [Accepted: 01/05/2016] [Indexed: 12/31/2022]
Abstract
Brucellosis remains a significant zoonotic threat worldwide. Humans and animals acquire infection via their oropharynx and upper respiratory tract following oral or aerosol exposure. After mucosal infection, brucellosis develops into a systemic disease. Mucosal vaccination could offer a viable alternative to conventional injection practices to deter disease. Using a nasal vaccination approach, the ΔznuA B. melitensis was found to confer potent protection against pulmonary Brucella challenge, and reduce colonization of spleens and lungs by more than 2500-fold, with more than 50% of vaccinated mice showing no detectable brucellae. Furthermore, tenfold more brucellae-specific, IFN-γ-producing CD8+ T cells than CD4+ T cells were induced in the spleen and respiratory lymph nodes. Evaluation of pulmonary and splenic CD8+ T cells from mice vaccinated with ΔznuA B. melitensis revealed that these expressed an activated effector memory (CD44hiCD62LloCCR7lo) T cells producing elevated levels of IFN-γ, TNF-α, perforin, and granzyme B. To assess the relative importance of these increased numbers of CD8+ T cells, CD8−/− mice were challenged with virulent B. melitensis, and they showed markedly increased bacterial loads in organs in contrast to similarly challenged CD4−/− mice. Only ΔznuA B. melitensis- and Rev-1-vaccinated CD4−/− and wild-type mice, not CD8−/− mice, were completely protected against Brucella challenge. Determination of cytokines responsible for conferring protection showed the relative importance of IFN-γ, but not IL-17. Unlike wild-type mice, IL-17 was greatly induced in IFN-γ−/− mice, but IL-17 could not substitute for IFN-γ’s protection, although an increase in brucellae dissemination was observed upon in vivo IL-17 neutralization. These results show that nasal ΔznuA B. melitensis vaccination represents an attractive means to stimulate systemic and mucosal immune protection via CD8+ T cell engagement.
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Abstract
Brucellosis, caused by bacteria of the genus Brucella, is an important zoonotic infection that causes reproductive disease in domestic animals and chronic debilitating disease in humans. An intriguing aspect of Brucella infection is the ability of these bacteria to evade the host immune response, leading to pathogen persistence. Conversely, in the reproductive tract of infected animals, this stealthy pathogen is able to cause an acute severe inflammatory response. In this review, we discuss the different mechanisms used by Brucella to cause disease, with emphasis on its virulence factors and the dichotomy between chronic persistence and reproductive disease.
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Affiliation(s)
| | - Renee M Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, California 95616; ,
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Phospholipase A1 modulates the cell envelope phospholipid content of Brucella melitensis, contributing to polymyxin resistance and pathogenicity. Antimicrob Agents Chemother 2015; 59:6717-24. [PMID: 26282427 DOI: 10.1128/aac.00792-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/31/2015] [Indexed: 12/17/2022] Open
Abstract
A subset of bacterial pathogens, including the zoonotic Brucella species, are highly resistant against polymyxin antibiotics. Bacterial polymyxin resistance has been attributed primarily to the modification of lipopolysaccharide; however, it is unknown what additional mechanisms mediate high-level resistance against this class of drugs. This work identified a role for the Brucella melitensis gene bveA (BMEII0681), encoding a predicted esterase, in the resistance of B. melitensis to polymyxin B. Characterization of the enzymatic activity of BveA demonstrated that it is a phospholipase A1 with specificity for phosphatidylethanolamine (PE). Further, lipidomic analysis of B. melitensis revealed an excess of PE lipids in the bacterial membranes isolated from the bveA mutant. These results suggest that by lowering the PE content of the cell envelope, BveA increases the resistance of B. melitensis to polymyxin B. BveA was required for survival and replication of B. melitensis in macrophages and for persistent infection in mice. BveA family esterases are encoded in the genomes of the alphaproteobacterial species that coexist with the polymyxin-producing bacteria in the rhizosphere, suggesting that maintenance of a low PE content in the bacterial cell envelope may be a shared persistence strategy for association with plant and mammalian hosts.
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Dos Santos LS, da Silva Mol JP, de Macedo AA, Silva APC, Dos Santos Ribeiro DL, Santos RL, da Paixão TA, de Carvalho Neta AV. Transcription of non-classic major histocompatibility complex (MHC) class I in the bovine placenta throughout gestation and after Brucella abortus infection. Vet Immunol Immunopathol 2015; 167:166-70. [PMID: 26188737 DOI: 10.1016/j.vetimm.2015.06.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 06/19/2015] [Accepted: 06/25/2015] [Indexed: 11/29/2022]
Abstract
Transcription of non-classical major histocompatibility complex class I (MHC-I) was assessed in the bovine placenta throughout gestation. Additionally, the effect of Brucella abortus infection on expression of non-classical MHC-I was also evaluated using a chorioallantoic membrane explant model of infection. The non-classical MHC-I genes MICB and NC3 had higher levels of transcription in the intercotyledonary region when compared to the placentome, which had higher levels of transcription at the second trimester of gestation. NC1 and classical MHC-I had very low levels of transcription throughout gestation. Trophoblastic cells of B. abortus-infected chorioallantoic membrane explants had an increase in transcription of non-classical MHC-I at 4h post infection. Therefore, this study provides an analysis of non-classical MHC-I transcription at different stages of gestation and different placental tissues, and during B. abortus infection. These findings provide additional knowledge on immune regulation in placental tissues, a known immune-privileged site.
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Affiliation(s)
| | - Juliana Pinto da Silva Mol
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Auricélio Alves de Macedo
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Patrícia Carvalho Silva
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Renato Lima Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Tatiane Alves da Paixão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Peng Y, Yang Y, Liu Y, Nie Y, Xu P, Xia B, Tian F, Sun Q. Cholesterol gallstones and bile host diverse bacterial communities with potential to promote the formation of gallstones. Microb Pathog 2015; 83-84:57-63. [PMID: 25959528 DOI: 10.1016/j.micpath.2015.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 12/31/2022]
Abstract
The prevalence of cholesterol gallstones has increased in recent years. Bacterial infection correlates with the formation of gallstones. We studied the composition and function of bacterial communities in cholesterol gallstones and bile from 22 cholesterol gallstone patients using culture-dependent and culture-independent methods. Altogether fourteen and eight bacterial genera were detected in cholesterol gallstones and bile, respectively. Pseudomonas spp. were the dominant bacteria in both cholesterol gallstones and bile. As judged by diversity indices, hierarchical clustering and principal component analysis, the bacterial communities in gallstones were different from those in bile. The gallstone microbiome was considered more stable than that of bile. The different microbial communities may be partially explained by differences in their habitats. We found that 30% of the culturable strains from cholesterol gallstones secreted β-glucuronidase and phospholipase A2. Pseudomonas aeruginosa strains showed the highest β-glucuronidase activity and produced the highest concentration of phospholipase A2, indicating that Ps. aeruginosa may be a major agent in the formation of cholesterol gallstones.
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Affiliation(s)
- Yuhong Peng
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China
| | - Yang Yang
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China
| | - Yongkang Liu
- The 452nd Hospital of PLA, Chengdu, Sichuan 610000, PR China
| | - Yuanyang Nie
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China
| | - Peilun Xu
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China
| | - Baixue Xia
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China
| | - Fuzhou Tian
- Chengdu Military General Hospital, Chengdu, Sichuan 610083, PR China
| | - Qun Sun
- Key Laboratory of Bio-resource and Bio-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China.
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41
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von Bargen K, Gagnaire A, Arce-Gorvel V, de Bovis B, Baudimont F, Chasson L, Bosilkovski M, Papadopoulos A, Martirosyan A, Henri S, Mège JL, Malissen B, Gorvel JP. Cervical Lymph Nodes as a Selective Niche for Brucella during Oral Infections. PLoS One 2015; 10:e0121790. [PMID: 25919005 PMCID: PMC4412401 DOI: 10.1371/journal.pone.0121790] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 02/03/2015] [Indexed: 12/23/2022] Open
Abstract
Cervical lymph nodes (CLN) are the first lymph nodes encountered by material taking the oral route. To study their role in orally acquired infections, we analyzed 307 patients of up to 14 years treated in the university clinic of Skopje, Macedonia, for brucellosis, a zoonotic bacterial disease frequently acquired by ingestion of contaminated dairy products. From these children, 36% had lymphadenopathy. Among orally infected children, lymphadenopathy with CLN being the only lymph nodes affected was significantly more frequent as compared to those infected by contact with animals (83% vs. 63%), suggesting a possible involvement of CLN during orally acquired human brucellosis. Using a murine model where bacteria are delivered into the oral cavity, we show that Brucella quickly and selectively colonize the CLN where they proliferate and persist over long periods of time for up to 50 days post-infection. A similar efficient though less specific drainage to CLN was found for Brucella, Salmonella typhimurium and fluorescent microspheres delivered by gavage, a pathway likely representing a mixed infection mode of intragastric and oral infection, suggesting a central pathway of drained material. Microspheres as well as bacteria drained to CLN predominately reside in cells expressing CD68 and no or low levels of CD11c. Even though no systemic response could be detected, Brucella induced a locally restricted inflammatory reaction with increased expression levels of interferon γ, interleukin (IL)-6, IL-12, granzyme B and a delayed induction of Nos2. Inflammation led to pronounced lymphadenopathy, infiltration of macrophages/monocytes expressing high levels of major histocompatibility complex II and to formation of epitheloid granulomas. Together, these results highlight the role of CLN in oral infections as both, an initial and efficient trap for bacterial invaders and as possible reservoir for chronic pathogens. They likewise cast a new light on the significance of oral routes for means of vaccination.
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Affiliation(s)
- Kristine von Bargen
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Aurélie Gagnaire
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Vilma Arce-Gorvel
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Béatrice de Bovis
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Fannie Baudimont
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Lionel Chasson
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Mile Bosilkovski
- University Clinic for Infectious Diseases and Febrile Conditions, Skopje, Republic of Macedonia
| | - Alexia Papadopoulos
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Anna Martirosyan
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Sandrine Henri
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Jean-Louis Mège
- Unité des Rickettsies, Aix-Marseille University, Centre National de la Recherche Scientifique (CNRS), UMR6020, Faculté de Médecine, Marseille, France
| | - Bernard Malissen
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
| | - Jean-Pierre Gorvel
- Centre d'Immunologie de Marseille-Luminy (CIML), Aix-Marseille University, UM2, Marseille, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1104, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), UMR7280, Marseille, France
- * E-mail:
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Gourley CR, Petersen E, Harms J, Splitter G. Decreased in vivo virulence and altered gene expression by a Brucella melitensis light-sensing histidine kinase mutant. Pathog Dis 2015; 73:1-8. [PMID: 25132657 DOI: 10.1111/2049-632x.12209] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Brucella species utilize diverse virulence factors. Previously, Brucella abortus light-sensing histidine kinase was identified as important for cellular infection. Here, we demonstrate that a Brucella melitensis LOV-HK (BM-LOV-HK) mutant strain has strikingly different gene expression than wild type. General stress response genes including the alternative sigma factor rpoE1 and its anti-anti-sigma factor phyR were downregulated, while flagellar, quorum sensing (QS), and type IV secretion system genes were upregulated in the ΔBM-LOV-HK strain vs. wild type. Contextually, expression results agree with other studies of transcriptional regulators involving ΔrpoE1, ΔphyR, ΔvjbR, and ΔblxR (ΔbabR) Brucella strains. Additionally, deletion of BM-LOV-HK decreases virulence in mice. During C57BL/6 mouse infection, the ΔBM-LOV-HK strain had 2 logs less CFUs in the spleen 3 days postinfection, but similar levels 6 days post infection compared to wild type. Infection of IRF-1(-/-) mice more specifically define ΔBM-LOV-HK strain attenuation with fewer bacteria in spleens and significantly increased survival of mutant vs. wild-type infected IRF-1(-/-) mice. Upregulation of flagella, QS, and VirB genes, along with downregulation of rpoE1 and related sigma factor, rpoH2 (BMEI0280) suggest that BM-LOV-HK modulates both QS and general stress response regulatory components to control Brucella gene expression on a global level.
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Affiliation(s)
- Christopher R Gourley
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Erik Petersen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Jerome Harms
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Gary Splitter
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
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Silva TMA, Mol JPS, Winter MG, Atluri V, Xavier MN, Pires SF, Paixão TA, Andrade HM, Santos RL, Tsolis RM. The predicted ABC transporter AbcEDCBA is required for type IV secretion system expression and lysosomal evasion by Brucella ovis. PLoS One 2014; 9:e114532. [PMID: 25474545 PMCID: PMC4256435 DOI: 10.1371/journal.pone.0114532] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/10/2014] [Indexed: 12/23/2022] Open
Abstract
Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi), whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS) proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells.
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Affiliation(s)
- Teane M. A. Silva
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana P. S. Mol
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Vidya Atluri
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Mariana N. Xavier
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Simone F. Pires
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tatiane A. Paixão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Hélida M. Andrade
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Renato L. Santos
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail: (RLS); (RMT)
| | - Renee M. Tsolis
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
- * E-mail: (RLS); (RMT)
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Ronneau S, Moussa S, Barbier T, Conde-Álvarez R, Zuniga-Ripa A, Moriyon I, Letesson JJ. Brucella, nitrogen and virulence. Crit Rev Microbiol 2014; 42:507-25. [PMID: 25471320 DOI: 10.3109/1040841x.2014.962480] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.
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Affiliation(s)
| | - Simon Moussa
- a UNamur, URBM 61 rue de Bruxelles , Namur , Belgium and
| | | | - Raquel Conde-Álvarez
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Amaia Zuniga-Ripa
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
| | - Ignacio Moriyon
- b Departamento de Microbiología , Edificio de Investigación, Universidad de Navarra , Pamplona , Spain
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Glutamate decarboxylase-dependent acid resistance in Brucella spp.: distribution and contribution to fitness under extremely acidic conditions. Appl Environ Microbiol 2014; 81:578-86. [PMID: 25381237 DOI: 10.1128/aem.02928-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Brucella is an expanding genus of major zoonotic pathogens, including at least 10 genetically very close species occupying a wide range of niches from soil to wildlife, livestock, and humans. Recently, we have shown that in the new species Brucella microti, the glutamate decarboxylase (Gad)-dependent system (GAD system) contributes to survival at a pH of 2.5 and also to infection in mice by the oral route. In order to study the functionality of the GAD system in the genus Brucella, 47 isolates, representative of all known species and strains of this genus, and 16 strains of the closest neighbor genus, Ochrobactrum, were studied using microbiological, biochemical, and genetic approaches. In agreement with the genome sequences, the GAD system of classical species was not functional, unlike that of most strains of Brucella ceti, Brucella pinnipedialis, and newly described species (B. microti, Brucella inopinata BO1, B. inopinata-like BO2, and Brucella sp. isolated from bullfrogs). In the presence of glutamate, these species were more acid resistant in vitro than classical terrestrial brucellae. Expression in trans of the gad locus from representative Brucella species in the Escherichia coli MG1655 mutant strain lacking the GAD system restored the acid-resistant phenotype. The highly conserved GAD system of the newly described or atypical Brucella species may play an important role in their adaptation to acidic external and host environments. Furthermore, the GAD phenotype was shown to be a useful diagnostic tool to distinguish these latter Brucella strains from Ochrobactrum and from classical terrestrial pathogenic Brucella species, which are GAD negative.
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Li CH, Wang KC, Hong YH, Chu TH, Chu YJ, Chou IC, Lu DK, Chen CY, Yang WC, Lin YM, Cheng CP. Roles of different forms of lipopolysaccharides in Ralstonia solanacearum pathogenesis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:471-8. [PMID: 24580105 DOI: 10.1094/mpmi-08-13-0248-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Lipopolysaccharides (LPS) are critical components for the fitness of most gram-negative bacteria. Ralstonia solanacearum causes a deadly wilting disease in many crops; however, the pathogenic roles of different forms of LPS and their pathways of biogenesis remain unknown. By screening for phage-resistant mutants of R. solanacearum Pss4, whose genome sequence is unavailable, mutants with various types of structural defects in LPS were isolated. Pathogenesis assays of the mutants revealed that production of rough LPS (R-LPS), which does not contain O-polysaccharides, was sufficient to cause necrosis on Nicotiana benthamiana and induce the hypersensitive response on N. tabacum. However, biosynthesis of smooth LPS (S-LPS), which contains O-polysaccharides, was required for bacterial proliferation at infection sites on N. benthamiana leaves and for proliferation and causing wilt on tomato. Complementation tests confirmed the involvement of the previously unidentified cluster RSc2201 to RSc2204 in the formation of R. solanacearum S-LPS. With these data and the availability of the annotated genomic sequence of strain GMI1000, certain loci involved in key steps of R. solanacearum LPS biosynthesis were identified. The strategy of this work could be useful for similar studies in other bacteria without available genome sequences.
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Xiong L, Teng JLL, Watt RM, Kan B, Lau SKP, Woo PCY. Arginine deiminase pathway is far more important than urease for acid resistance and intracellular survival in Laribacter hongkongensis: a possible result of arc gene cassette duplication. BMC Microbiol 2014; 14:42. [PMID: 24533585 PMCID: PMC3936950 DOI: 10.1186/1471-2180-14-42] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 02/10/2014] [Indexed: 12/27/2022] Open
Abstract
Background Laribacter hongkongensis is a Gram-negative, urease-positive bacillus associated with invasive bacteremic infections in liver cirrhosis patients and fish-borne community-acquired gastroenteritis and traveler’s diarrhea. Its mechanisms of adaptation to various environmental niches and host defense evasion are largely unknown. During the process of analyzing the L. hongkongensis genome, a complete urease cassette and two adjacent arc gene cassettes were found. We hypothesize that the urease cassette and/or the arc gene cassettes are important for L. hongkongensis to survive in acidic environment and macrophages. In this study, we tested this hypothesis by constructing single, double and triple non-polar deletion mutants of the urease and two arc gene cassettes of L. hongkongensis using the conjugation-mediated gene deletion system and examining their effects in acidic environment in vitro, in macrophages and in a mouse model. Results HLHK9∆ureA, HLHK9∆ureC, HLHK9∆ureD and HLHK9∆ureE all exhibited no urease activity. HLHK9∆arcA1 and HLHK9∆arcA2 both exhibited arginine deiminase (ADI) activities, but HLHK9∆arcA1/arcA2 double deletion mutant exhibited no ADI activity. At pH 2 and 3, survival of HLHK9∆arcA1/arcA2 and HLHK9∆ureA/arcA1/arcA2 were markedly decreased (p < 0.001) but that of HLHK9∆ureA was slightly decreased (p < 0.05), compared to wild type L. hongkongensis HLHK9. Survival of HLHK9∆ureA/arcA1/arcA2 and HLHK9∆arcA1/arcA2 in macrophages were also markedly decreased (p < 0.001 and p < 0.01 respectively) but that of HLHK9∆ureA was slightly decreased (p < 0.05), compared to HLHK9, although expression of arcA1, arcA2 and ureA genes were all upregulated. Using a mouse model, HLHK9∆ureA exhibited similar survival compared to HLHK9 after passing through the murine stomach, but survival of HLHK9∆arcA1/arcA2 and HLHK9∆ureA/arcA1/arcA2 were markedly reduced (p < 0.01). Conclusions In contrast to other important gastrointestinal tract pathogens, ADI pathway is far more important than urease for acid resistance and intracellular survival in L. hongkongensis. The gene duplication of the arc gene cassettes could be a result of their functional importance in L. hongkongensis.
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Affiliation(s)
| | | | | | | | - Susanna K P Lau
- Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, University Pathology Building, Hong Kong, China.
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48
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Wang Z, Wang SS, Wang GL, Wu TL, Lv YL, Wu QM. A pregnant mouse model for the vertical transmission of Brucella melitensis. Vet J 2013; 200:116-21. [PMID: 24462801 DOI: 10.1016/j.tvjl.2013.12.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 12/10/2013] [Accepted: 12/19/2013] [Indexed: 11/24/2022]
Abstract
Abortion is the major clinical sign of brucellosis in animals but little is known about the underlying mechanisms. This study was designed to evaluate a pregnant mouse model for the vertical transmission of Brucella melitensis using four infectious doses: 10(3) colony-forming units (CFU), 10(4) CFU, 10(5) CFU, and 10(6) CFU. During the experimental period, no instances of abortion were recorded, but stillbirths were observed in the groups infected with doses of 10(4) CFU and higher. Regardless of whether the fetuses were stillborn or alive, transmission of bacteria to the fetus and bacterial replication in the cytoplasm of placental trophoblast giant cells were detected. A higher degree of bacterial colonization was found in the placenta than in the spleen or fetus. Doses of 10(5) CFU of B. melitensis or higher produced a severe, necrotizing placentitis similar to the pathological damage observed in ruminants. The data suggest that experimental murine brucellosis resembles ruminant brucellosis and represents a potential model for studying the pathogenic mechanisms of B. melitensis.
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Affiliation(s)
- Z Wang
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan Xilu No. 2, Haidian District, Beijing 100193, China
| | - S S Wang
- College of Biological Sciences, Anyang Institute of Technology, Anyang 455000, China
| | - G L Wang
- College of Veterinary Medicine, Qinghai University, Xining 810000, China
| | - T L Wu
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan Xilu No. 2, Haidian District, Beijing 100193, China
| | - Y L Lv
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan Xilu No. 2, Haidian District, Beijing 100193, China
| | - Q M Wu
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan Xilu No. 2, Haidian District, Beijing 100193, China.
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Ruiz-Ranwez V, Posadas DM, Estein SM, Abdian PL, Martin FA, Zorreguieta A. The BtaF trimeric autotransporter of Brucella suis is involved in attachment to various surfaces, resistance to serum and virulence. PLoS One 2013; 8:e79770. [PMID: 24236157 PMCID: PMC3827427 DOI: 10.1371/journal.pone.0079770] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/02/2013] [Indexed: 02/02/2023] Open
Abstract
The adhesion of bacterial pathogens to host cells is an event that determines infection, and ultimately invasion and intracellular multiplication. Several evidences have recently shown that this rule is also truth for the intracellular pathogen Brucella. Brucella suis displays the unipolar BmaC and BtaE adhesins, which belong to the monomeric and trimeric autotransporter (TA) families, respectively. It was previously shown that these adhesins are involved in bacterial adhesion to host cells and components of the extracellular matrix (ECM). In this work we describe the role of a new member of the TA family of B. suis (named BtaF) in the adhesive properties of the bacterial surface. BtaF conferred the bacteria that carried it a promiscuous adhesiveness to various ECM components and the ability to attach to an abiotic surface. Furthermore, BtaF was found to participate in bacterial adhesion to epithelial cells and was required for full virulence in mice. Similar to BmaC and BtaE, the BtaF adhesin was expressed in a small subpopulation of bacteria, and in all cases, it was detected at the new pole generated after cell division. Interestingly, BtaF was also implicated in the resistance of B. suis to porcine serum. Our findings emphasize the impact of TAs in the Brucella lifecycle.
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50
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Monocyte-derived macrophages from Zebu (Bos taurus indicus) are more efficient to control Brucella abortus intracellular survival than macrophages from European cattle (Bos taurus taurus). Vet Immunol Immunopathol 2013; 151:294-302. [DOI: 10.1016/j.vetimm.2012.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 12/01/2012] [Accepted: 12/03/2012] [Indexed: 11/24/2022]
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