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Ojha R, Krug S, Jones P, Koestler BJ. Intact and mutated Shigella diguanylate cyclases increase c-di-GMP. J Biol Chem 2024; 300:107525. [PMID: 38960033 PMCID: PMC11327459 DOI: 10.1016/j.jbc.2024.107525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/31/2024] [Accepted: 06/21/2024] [Indexed: 07/05/2024] Open
Abstract
The intracellular human pathogen Shigella invades the colonic epithelium to cause disease. Prior to invasion, this bacterium navigates through different environments within the human body, including the stomach and the small intestine. To adapt to changing environments, Shigella uses the bacterial second messenger cyclic di-GMP (c di-GMP) signaling system, synthesized by diguanylate cyclases (DGCs) encoding GGDEF domains. Shigella flexneri encodes a total of 9 GGDEF or GGDEF-EAL domain enzymes in its genome, but five of these genes have acquired mutations that presumably inactivated the c-di-GMP synthesis activity of these enzymes. In this study, we examined individual S. flexneri DGCs for their role in c-di-GMP synthesis and pathogenesis. We individually expressed each of the four intact DGCs in a S. flexneri strain, where these four DGCs had been deleted (Δ4DGC). We found that the 4 S. flexneri intact DGCs synthesize c-di-GMP at different levels in vitro and during infection of tissue-cultured cells. We also found that dgcF and dgcI expression significantly reduces invasion and plaque formation, and dgcF expression increases acid sensitivity, and that these phenotypes did not correspond with measured c-di-GMP levels. However, deletion of these four DGCs did not eliminate S. flexneri c-di-GMP, and we found that dgcE, dgcQ, and dgcN, which all have nonsense mutations prior to the GGDEF domain, still produce c-di-GMP. These S. flexneri degenerate DGC pseudogenes are expressed as multiple proteins, consistent with multiple start codons within the gene. We propose that both intact and degenerate DGCs contribute to S. flexneri c-di-GMP signaling.
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Affiliation(s)
- Ruchi Ojha
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA
| | - Stefanie Krug
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Prentiss Jones
- Department of Pathology, Western Michigan University Homer Stryker, M.D. School of Medicine, Kalamazoo, Michigan, USA
| | - Benjamin J Koestler
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA.
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2
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Bain W, Ahn B, Peñaloza HF, McElheny CL, Tolman N, van der Geest R, Gonzalez-Ferrer S, Chen N, An X, Hosuru R, Tabary M, Papke E, Kohli N, Farooq N, Bachman W, Olonisakin TF, Xiong Z, Griffith MP, Sullivan M, Franks J, Mustapha MM, Iovleva A, Suber T, Shanks RQ, Ferreira VP, Stolz DB, Van Tyne D, Doi Y, Lee JS. In Vivo Evolution of a Klebsiella pneumoniae Capsule Defect With wcaJ Mutation Promotes Complement-Mediated Opsonophagocytosis During Recurrent Infection. J Infect Dis 2024; 230:209-220. [PMID: 39052750 PMCID: PMC11272070 DOI: 10.1093/infdis/jiae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/17/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Klebsiella pneumoniae carbapenemase-producing K pneumoniae (KPC-Kp) bloodstream infections are associated with high mortality. We studied clinical bloodstream KPC-Kp isolates to investigate mechanisms of resistance to complement, a key host defense against bloodstream infection. METHODS We tested growth of KPC-Kp isolates in human serum. In serial isolates from a single patient, we performed whole genome sequencing and tested for complement resistance and binding by mixing study, direct enzyme-linked immunosorbent assay, flow cytometry, and electron microscopy. We utilized an isogenic deletion mutant in phagocytosis assays and an acute lung infection model. RESULTS We found serum resistance in 16 of 59 (27%) KPC-Kp clinical bloodstream isolates. In 5 genetically related bloodstream isolates from a single patient, we noted a loss-of-function mutation in the capsule biosynthesis gene, wcaJ. Disruption of wcaJ was associated with decreased polysaccharide capsule, resistance to complement-mediated killing, and surprisingly, increased binding of complement proteins. Furthermore, an isogenic wcaJ deletion mutant exhibited increased opsonophagocytosis in vitro and impaired in vivo control in the lung after airspace macrophage depletion in mice. CONCLUSIONS Loss of function in wcaJ led to increased complement resistance, complement binding, and opsonophagocytosis, which may promote KPC-Kp persistence by enabling coexistence of increased bloodstream fitness and reduced tissue virulence.
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Affiliation(s)
- William Bain
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
- Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
| | - Brian Ahn
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus School of Medicine, Denver
| | - Hernán F Peñaloza
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | | | - Nathanial Tolman
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Rick van der Geest
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Shekina Gonzalez-Ferrer
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Nathalie Chen
- Division of Infectious Diseases, Department of Medicine
| | - Xiaojing An
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Ria Hosuru
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Mohammadreza Tabary
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Erin Papke
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Naina Kohli
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | | | | | - Tolani F Olonisakin
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Zeyu Xiong
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | | | - Mara Sullivan
- Center for Biologic Imaging, Department of Cell Biology
| | | | | | - Alina Iovleva
- Division of Infectious Diseases, Department of Medicine
| | - Tomeka Suber
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
| | - Robert Q Shanks
- Department of Ophthalmology, University of Pittsburgh, Pennsylvania
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Ohio
| | - Donna B Stolz
- Center for Biologic Imaging, Department of Cell Biology
| | | | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine
| | - Janet S Lee
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh
- Division of Pulmonary and Critical Care Medicine, Washington University in St Louis, Missouri
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3
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Ojha R, Krug S, Jones P, Koestler BJ. Intact and Degenerate Diguanylate Cyclases regulate Shigella Cyclic di-GMP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.08.588579. [PMID: 38645013 PMCID: PMC11030455 DOI: 10.1101/2024.04.08.588579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The intracellular human pathogen Shigella invades the colonic epithelium to cause disease. Prior to invasion, this bacterium navigates through different environments within the human body, including the stomach and the small intestine. To adapt to changing environments, Shigella uses the bacterial second messenger c-di-GMP signaling system, synthesized by diguanylate cyclases (DGCs) encoding GGDEF domains. Shigella flexneri encodes a total of 9 GGDEF or GGDEF-EAL domain enzymes in its genome, but 5 of these genes have acquired mutations that presumably inactivated the c-di-GMP synthesis activity of these enzymes. In this study, we examined individual S. flexneri DGCs for their role in c-di-GMP synthesis and pathogenesis. We individually expressed each of the 4 intact DGCs in an S. flexneri strain where these 4 DGCs had been deleted (Δ4DGC). We found that the 4 S. flexneri intact DGCs synthesize c-di-GMP at different levels in vitro and during infection of tissue-cultured cells. We also found that dgcF and dgcI expression significantly reduces invasion and plaque formation, and dgcF expression increases acid sensitivity, and that these phenotypes did not correspond with measured c-di-GMP levels. However, deletion of these 4 DGCs did not eliminate S. flexneri c-di-GMP, and we found that dgcE, dgcQ, and dgcN , which all have nonsense mutations prior to the GGDEF domain, still produce c-di-GMP. These S. flexneri degenerate DGC genes are expressed as multiple proteins, consistent with multiple start codons within the gene. We propose that both intact and degenerate DGCs contribute to S. flexneri c-di-GMP signaling.
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4
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Demey LM, Gumerov VM, Xing J, Zhulin IB, DiRita VJ. Transmembrane Transcription Regulators Are Widespread in Bacteria and Archaea. Microbiol Spectr 2023; 11:e0026623. [PMID: 37154724 PMCID: PMC10269533 DOI: 10.1128/spectrum.00266-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/11/2023] [Indexed: 05/10/2023] Open
Abstract
To adapt and proliferate, bacteria must sense and respond to the ever-changing environment. Transmembrane transcription regulators (TTRs) are a family of one-component transcription regulators that respond to extracellular information and influence gene expression from the cytoplasmic membrane. How TTRs function to modulate expression of their target genes while localized to the cytoplasmic membrane remains poorly understood. In part, this is due to a lack of knowledge regarding the prevalence of TTRs among prokaryotes. Here, we show that TTRs are highly diverse and prevalent throughout bacteria and archaea. Our work demonstrates that TTRs are more common than previously appreciated and are enriched within specific bacterial and archaeal phyla and that many TTRs have unique transmembrane region properties that can facilitate association with detergent-resistant membranes. IMPORTANCE One-component signal transduction systems are the major class of signal transduction systems among bacteria and are commonly cytoplasmic. TTRs are a group of unique one-component signal transduction systems that influence transcription from the cytoplasmic membrane. TTRs have been implicated in a wide array of biological pathways critical for both pathogens and human commensal organisms but were considered to be rare. Here, we demonstrate that TTRs are in fact highly diverse and broadly distributed in bacteria and archaea. Our findings suggest that transcription factors can access the chromosome and influence transcription from the membrane in both archaea and bacteria. This study challenges thus the commonly held notion that signal transduction systems require a cytoplasmic transcription factor and highlights the importance of the cytoplasmic membrane in directly influencing signal transduction.
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Affiliation(s)
- Lucas M. Demey
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Vadim M. Gumerov
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA
| | - Jiawei Xing
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA
| | - Igor B. Zhulin
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA
| | - Victor J. DiRita
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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5
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Abstract
Shigella flexneri is an intracellular human pathogen that invades colonic cells and causes bloody diarrhea. S. flexneri evolved from commensal Escherichia coli, and genome comparisons reveal that S. flexneri has lost approximately 20% of its genes through the process of pathoadaptation, including a disproportionate number of genes associated with the turnover of the nucleotide-based second messenger cyclic di-GMP (c-di-GMP); however, the remaining c-di-GMP turnover enzymes are highly conserved. c-di-GMP regulates many behavioral changes in other bacteria in response to changing environmental conditions, including biofilm formation, but this signaling system has not been examined in S. flexneri. In this study, we expressed VCA0956, a constitutively active c-di-GMP synthesizing diguanylate cyclase (DGC) from Vibrio cholerae, in S. flexneri to determine if virulence phenotypes were regulated by c-di-GMP. We found that expressing VCA0956 in S. flexneri increased c-di-GMP levels, and this corresponds with increased biofilm formation and reduced acid resistance, host cell invasion, and plaque size. We examined the impact of VCA0956 expression on the S. flexneri transcriptome and found that genes related to acid resistance were repressed, and this corresponded with decreased survival to acid shock. We also found that individual S. flexneri DGC mutants exhibit reduced biofilm formation and reduced host cell invasion and plaque size, as well as increased resistance to acid shock. This study highlights the importance of c-di-GMP signaling in regulating S. flexneri virulence phenotypes. IMPORTANCE The intracellular human pathogen Shigella causes dysentery, resulting in as many as one million deaths per year. Currently, there is no approved vaccine for the prevention of shigellosis, and the incidence of antimicrobial resistance among Shigella species is on the rise. Here, we explored how the widely conserved c-di-GMP bacterial signaling system alters Shigella behaviors associated with pathogenesis. We found that expressing or removing enzymes associated with c-di-GMP synthesis results in changes in Shigella's ability to form biofilms, invade host cells, form lesions in host cell monolayers, and resist acid stress.
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6
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Pasqua M, Michelacci V, Di Martino ML, Tozzoli R, Grossi M, Colonna B, Morabito S, Prosseda G. The Intriguing Evolutionary Journey of Enteroinvasive E. coli (EIEC) toward Pathogenicity. Front Microbiol 2017; 8:2390. [PMID: 29259590 PMCID: PMC5723341 DOI: 10.3389/fmicb.2017.02390] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/20/2017] [Indexed: 01/01/2023] Open
Abstract
Among the intestinal pathogenic Escherichia coli, enteroinvasive E. coli (EIEC) are a group of intracellular pathogens able to enter epithelial cells of colon, multiplicate within them, and move between adjacent cells with a mechanism similar to Shigella, the ethiological agent of bacillary dysentery. Despite EIEC belong to the same pathotype of Shigella, they neither have the full set of traits that define Shigella nor have undergone the extensive gene decay observed in Shigella. Molecular analysis confirms that EIEC are widely distributed among E. coli phylogenetic groups and correspond to bioserotypes found in many E. coli serogroups. Like Shigella, also in EIEC the critical event toward a pathogenic life-style consisted in the acquisition by horizontal gene transfer of a large F-type plasmid (pINV) containing the genes required for invasion, intracellular survival, and spreading through the intestinal mucosa. In Shigella, the ample gain in virulence determinants has been counteracted by a substantial loss of functions that, although important for the survival in the environment, are redundant or deleterious for the life inside the host. The pathoadaptation process that has led Shigella to modify its metabolic profile and increase its pathogenic potential is still in infancy in EIEC, although maintenance of some features typical of E. coli might favor their emerging relevance as intestinal pathogens worldwide, as documented by recent outbreaks in industrialized countries. In this review, we will discuss the evolution of EIEC toward Shigella-like invasive forms going through the epidemiology, including the emergence of new virulent strains, their genome organization, and the complex interactions they establish with the host.
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Affiliation(s)
- Martina Pasqua
- Istituto Pasteur Italia, Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
| | - Valeria Michelacci
- European Union Reference Laboratory for Escherichia coli, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Maria Letizia Di Martino
- Istituto Pasteur Italia, Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
| | - Rosangela Tozzoli
- European Union Reference Laboratory for Escherichia coli, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Milena Grossi
- Istituto Pasteur Italia, Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
| | - Bianca Colonna
- Istituto Pasteur Italia, Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
| | - Stefano Morabito
- European Union Reference Laboratory for Escherichia coli, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Gianni Prosseda
- Istituto Pasteur Italia, Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
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7
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Tobias NJ, Mishra B, Gupta DK, Sharma R, Thines M, Stinear TP, Bode HB. Genome comparisons provide insights into the role of secondary metabolites in the pathogenic phase of the Photorhabdus life cycle. BMC Genomics 2016; 17:537. [PMID: 27488257 PMCID: PMC4971723 DOI: 10.1186/s12864-016-2862-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 06/29/2016] [Indexed: 01/28/2023] Open
Abstract
Background Bacteria within the genus Photorhabdus maintain mutualistic symbioses with nematodes in complicated lifecycles that also involves insect pathogenic phases. Intriguingly, these bacteria are rich in biosynthetic gene clusters that produce compounds with diverse biological activities. As a basis to better understand the life cycles of Photorhabdus we sequenced the genomes of two recently discovered representative species and performed detailed genomic comparisons with five publically available genomes. Results Here we report the genomic details of two new reference Photorhabdus species. By then conducting genomic comparisons across the genus, we show that there are several highly conserved biosynthetic gene clusters. These clusters produce a range of bioactive small molecules that support the pathogenic phase of the integral relationship that Photorhabdus maintain with nematodes. Conclusions Photorhabdus contain several genetic loci that allow them to become specialist insect pathogens by efficiently evading insect immune responses and killing the insect host. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2862-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicholas J Tobias
- Fachbereich Biowissenschaften, Merck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität Frankfurt, Frankfurt am Main, Germany
| | - Bagdevi Mishra
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany.,Fachbereich Biowissenschaften, Institut für Ökologie, Evolution und Diversität, Goethe Universität Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt am Main, Germany
| | - Deepak K Gupta
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany.,Fachbereich Biowissenschaften, Institut für Ökologie, Evolution und Diversität, Goethe Universität Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt am Main, Germany
| | - Rahul Sharma
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Marco Thines
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany.,Fachbereich Biowissenschaften, Institut für Ökologie, Evolution und Diversität, Goethe Universität Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt am Main, Germany
| | - Timothy P Stinear
- Department of Microbiology and Immunology, University of Melbourne, at the Doherty Institute for Infection and Immunity, Parkville, VIC, 3010, Australia
| | - Helge B Bode
- Fachbereich Biowissenschaften, Merck Stiftungsprofessur für Molekulare Biotechnologie, Goethe Universität Frankfurt, Frankfurt am Main, Germany. .,Buchmann Institute for Molecular Life Sciences (BMLS), Goethe Universität Frankfurt, Frankfurt am Main, Germany.
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8
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De Biase D, Lund PA. The Escherichia coli Acid Stress Response and Its Significance for Pathogenesis. ADVANCES IN APPLIED MICROBIOLOGY 2015; 92:49-88. [PMID: 26003933 DOI: 10.1016/bs.aambs.2015.03.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Escherichia coli has a remarkable ability to survive low pH and possesses a number of different genetic systems that enable it to do this. These may be expressed constitutively, typically in stationary phase, or induced by growth under a variety of conditions. The activities of these systems have been implicated in the ability of E. coli to pass the acidic barrier of the stomach and to become established in the gastrointestinal tract, something causing serious infections. However, much of the work characterizing these systems has been done on standard laboratory strains of E. coli and under conditions which do not closely resemble those found in the human gut. Here we review what is known about acid resistance in E. coli as a model laboratory organism and in the context of its lifestyle as an inhabitant-sometimes an unwelcome one-of the human gut.
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9
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Campilongo R, Di Martino ML, Marcocci L, Pietrangeli P, Leuzzi A, Grossi M, Casalino M, Nicoletti M, Micheli G, Colonna B, Prosseda G. Molecular and functional profiling of the polyamine content in enteroinvasive E. coli : looking into the gap between commensal E. coli and harmful Shigella. PLoS One 2014; 9:e106589. [PMID: 25192335 PMCID: PMC4156367 DOI: 10.1371/journal.pone.0106589] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/31/2014] [Indexed: 11/19/2022] Open
Abstract
Polyamines are small molecules associated with a wide variety of physiological functions. Bacterial pathogens have developed subtle strategies to exploit polyamines or manipulate polyamine-related processes to optimize fitness within the host. During the transition from its innocuous E. coli ancestor, Shigella, the aetiological agent of bacillary dysentery, has undergone drastic genomic rearrangements affecting the polyamine profile. A pathoadaptation process involving the speG gene and the cad operon has led to spermidine accumulation and loss of cadaverine. While a higher spermidine content promotes the survival of Shigella within infected macrophages, the lack of cadaverine boosts the pathogenic potential of the bacterium in host tissues. Enteroinvasive E. coli (EIEC) display the same pathogenicity process as Shigella, but have a higher infectious dose and a higher metabolic activity. Pathoadaption events affecting the cad locus have occurred also in EIEC, silencing cadaverine production. Since EIEC are commonly regarded as evolutionary intermediates between E. coli and Shigella, we investigated on their polyamine profile in order to better understand which changes have occurred along the path to pathogenicity. By functional and molecular analyses carried out in EIEC strains belonging to different serotypes, we show that speG has been silenced in one strain only, favouring resistance to oxidative stress conditions and survival within macrophages. At the same time, we observe that the content of spermidine and putrescine, a relevant intermediate in the synthesis of spermidine, is higher in all strains as compared to E. coli. This may represent an evolutionary response to the lack of cadaverine. Indeed, restoring cadaverine synthesis decreases the expression of the speC gene, whose product affects putrescine production. In the light of these results, we discuss the possible impact of pathoadaptation events on the evolutionary emergence of a polyamine profile favouring to the pathogenic lifestyle of Shigella and EIEC.
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Affiliation(s)
- Rosaria Campilongo
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
| | - Maria Letizia Di Martino
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
- Dipartimento di Scienze, Università Roma Tre, Roma, Italy
| | - Lucia Marcocci
- Dipartimento di Biochimica, Sapienza Università di Roma, Roma, Italy
| | - Paola Pietrangeli
- Dipartimento di Biochimica, Sapienza Università di Roma, Roma, Italy
| | - Adriano Leuzzi
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
| | - Milena Grossi
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
| | | | - Mauro Nicoletti
- Dipartimento di Scienze Sperimentali e Cliniche, Università G. D'Annunzio, Chieti, Italy
| | - Gioacchino Micheli
- Istituto di Biologia, Medicina Molecolare e NanoBiotecnologie, Consiglio Nazionale delle Ricerche, Roma, Italy
| | - Bianca Colonna
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
| | - Gianni Prosseda
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Roma, Italy
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10
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Lund P, Tramonti A, De Biase D. Coping with low pH: molecular strategies in neutralophilic bacteria. FEMS Microbiol Rev 2014; 38:1091-125. [PMID: 24898062 DOI: 10.1111/1574-6976.12076] [Citation(s) in RCA: 282] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 02/26/2014] [Accepted: 03/14/2014] [Indexed: 12/31/2022] Open
Abstract
As part of their life cycle, neutralophilic bacteria are often exposed to varying environmental stresses, among which fluctuations in pH are the most frequent. In particular, acid environments can be encountered in many situations from fermented food to the gastric compartment of the animal host. Herein, we review the current knowledge of the molecular mechanisms adopted by a range of Gram-positive and Gram-negative bacteria, mostly those affecting human health, for coping with acid stress. Because organic and inorganic acids have deleterious effects on the activity of the biological macromolecules to the point of significantly reducing growth and even threatening their viability, it is not unexpected that neutralophilic bacteria have evolved a number of different protective mechanisms, which provide them with an advantage in otherwise life-threatening conditions. The overall logic of these is to protect the cell from the deleterious effects of a harmful level of protons. Among the most favoured mechanisms are the pumping out of protons, production of ammonia and proton-consuming decarboxylation reactions, as well as modifications of the lipid content in the membrane. Several examples are provided to describe mechanisms adopted to sense the external acidic pH. Particular attention is paid to Escherichia coli extreme acid resistance mechanisms, the activity of which ensure survival and may be directly linked to virulence.
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Affiliation(s)
- Peter Lund
- School of Biosciences, University of Birmingham, Birmingham, UK
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11
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Vergara-Irigaray M, Fookes MC, Thomson NR, Tang CM. RNA-seq analysis of the influence of anaerobiosis and FNR on Shigella flexneri. BMC Genomics 2014; 15:438. [PMID: 24907032 PMCID: PMC4229854 DOI: 10.1186/1471-2164-15-438] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 05/23/2014] [Indexed: 01/03/2023] Open
Abstract
Background Shigella flexneri is an important human pathogen that has to adapt to the anaerobic environment in the gastrointestinal tract to cause dysentery. To define the influence of anaerobiosis on the virulence of Shigella, we performed deep RNA sequencing to identify transcriptomic differences that are induced by anaerobiosis and modulated by the anaerobic Fumarate and Nitrate Reduction regulator, FNR. Results We found that 528 chromosomal genes were differentially expressed in response to anaerobic conditions; of these, 228 genes were also influenced by FNR. Genes that were up-regulated in anaerobic conditions are involved in carbon transport and metabolism (e.g. ptsG, manX, murQ, cysP, cra), DNA topology and regulation (e.g. ygiP, stpA, hns), host interactions (e.g. yciD, nmpC, slyB, gapA, shf, msbB) and survival within the gastrointestinal tract (e.g. shiA, ospI, adiY, cysP). Interestingly, there was a marked effect of available oxygen on genes involved in Type III secretion system (T3SS), which is required for host cell invasion and pathogenesis. These genes, located on the large Shigella virulence plasmid, were down regulated in anaerobiosis in an FNR-dependent manner. We also confirmed anaerobic induction of csrB and csrC small RNAs in an FNR-independent manner. Conclusions Anaerobiosis promotes survival and adaption strategies of Shigella, while modulating virulence plasmid genes involved in T3SS-mediated host cell invasion. The influence of FNR on this process is more extensive than previously appreciated, although aside from the virulence plasmid, this transcriptional regulator does not govern expression of genes on other horizontally acquired sequences on the chromosome such as pathogenicity islands. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-438) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | - Christoph M Tang
- Sir William Dunn School of Pathology, Oxford University, Oxford, United Kingdom.
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A low gastric pH mouse model to evaluate live attenuated bacterial vaccines. PLoS One 2014; 9:e87411. [PMID: 24489912 PMCID: PMC3906194 DOI: 10.1371/journal.pone.0087411] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/27/2013] [Indexed: 12/19/2022] Open
Abstract
The low pH of the stomach serves as a barrier to ingested microbes and must be overcome or bypassed when delivering live bacteria for vaccine or probiotic applications. Typically, the impact of stomach acidity on bacterial survival is evaluated in vitro, as there are no small animal models to evaluate these effects in vivo. To better understand the effect of this low pH barrier to live attenuated Salmonella vaccines, which are often very sensitive to low pH, we investigated the value of the histamine mouse model for this application. A low pH gastric compartment was transiently induced in mice by the injection of histamine. This resulted in a gastric compartment of approximately pH 1.5 that was capable of distinguishing between acid-sensitive and acid-resistant microbes. Survival of enteric microbes during gastric transit in this model directly correlated with their in vitro acid resistance. Because many Salmonella enterica serotype Typhi vaccine strains are sensitive to acid, we have been investigating systems to enhance the acid resistance of these bacteria. Using the histamine mouse model, we demonstrate that the in vivo survival of S. Typhi vaccine strains increased approximately 10-fold when they carried a sugar-inducible arginine decarboxylase system. We conclude that this model will be a useful for evaluating live bacterial preparations prior to clinical trials.
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Di Martino ML, Fioravanti R, Barbabella G, Prosseda G, Colonna B, Casalino M. Molecular evolution of the nicotinic acid requirement within the Shigella/EIEC pathotype. Int J Med Microbiol 2013; 303:651-61. [DOI: 10.1016/j.ijmm.2013.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/05/2013] [Accepted: 09/08/2013] [Indexed: 11/27/2022] Open
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Di Martino ML, Campilongo R, Casalino M, Micheli G, Colonna B, Prosseda G. Polyamines: emerging players in bacteria-host interactions. Int J Med Microbiol 2013; 303:484-91. [PMID: 23871215 DOI: 10.1016/j.ijmm.2013.06.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/13/2013] [Accepted: 06/16/2013] [Indexed: 12/17/2022] Open
Abstract
Polyamines are small polycationic molecules found in almost all cells and associated with a wide variety of physiological processes. In recent years it has become increasingly clear that, in addition to core physiological functions, polyamines play a crucial role in bacterial pathogenesis. Considerable evidence has built up that bacteria have evolved mechanisms to turn these molecules to their own advantage and a novel standpoint to look at host-bacterium interactions emerges from the interplay among polyamines, host cells and infecting bacteria. In this review, we highlight how human bacterial pathogens have developed their own resourceful strategies to exploit polyamines or manipulate polyamine-related processes to optimize their fitness within the host. Besides contributing to a better understanding of the complex relationship between a pathogen and its host, acquisitions in this field have a significant potential towards the development of novel antibacterial therapeutic approaches.
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Affiliation(s)
- Maria Letizia Di Martino
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Roma, Italy; Dipartimento di Biologia, Università Roma Tre, Viale G. Marconi 446, 00146 Roma, Italy
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Prosseda G, Di Martino ML, Campilongo R, Fioravanti R, Micheli G, Casalino M, Colonna B. Shedding of genes that interfere with the pathogenic lifestyle: the Shigella model. Res Microbiol 2012; 163:399-406. [DOI: 10.1016/j.resmic.2012.07.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 07/08/2012] [Indexed: 12/31/2022]
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Peng S, Tasara T, Hummerjohann J, Stephan R. An overview of molecular stress response mechanisms in Escherichia coli contributing to survival of Shiga toxin-producing Escherichia coli during raw milk cheese production. J Food Prot 2011; 74:849-64. [PMID: 21549061 DOI: 10.4315/0362-028x.jfp-10-469] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ability of foodborne pathogens to survive in certain foods mainly depends on stress response mechanisms. Insight into molecular properties enabling pathogenic bacteria to survive in food is valuable for improvement of the control of pathogens during food processing. Raw milk cheeses are a potential source for human infections with Shiga toxin-producing Escherichia coli (STEC). In this review, we focused on the stress response mechanisms important for allowing STEC to survive raw milk cheese production processes. The major components and regulation pathways for general, acid, osmotic, and heat shock stress responses in E. coli and the implications of these responses for the survival of STEC in raw milk cheeses are discussed.
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Affiliation(s)
- Silvio Peng
- Institute for Food Safety and Hygiene, University of Zurich, Winterthurerstrasse 272, 8057 Zürich, Switzerland
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Ruiz JC, D'Afonseca V, Silva A, Ali A, Pinto AC, Santos AR, Rocha AAMC, Lopes DO, Dorella FA, Pacheco LGC, Costa MP, Turk MZ, Seyffert N, Moraes PMRO, Soares SC, Almeida SS, Castro TLP, Abreu VAC, Trost E, Baumbach J, Tauch A, Schneider MPC, McCulloch J, Cerdeira LT, Ramos RTJ, Zerlotini A, Dominitini A, Resende DM, Coser EM, Oliveira LM, Pedrosa AL, Vieira CU, Guimarães CT, Bartholomeu DC, Oliveira DM, Santos FR, Rabelo ÉM, Lobo FP, Franco GR, Costa AF, Castro IM, Dias SRC, Ferro JA, Ortega JM, Paiva LV, Goulart LR, Almeida JF, Ferro MIT, Carneiro NP, Falcão PRK, Grynberg P, Teixeira SMR, Brommonschenkel S, Oliveira SC, Meyer R, Moore RJ, Miyoshi A, Oliveira GC, Azevedo V. Evidence for reductive genome evolution and lateral acquisition of virulence functions in two Corynebacterium pseudotuberculosis strains. PLoS One 2011; 6:e18551. [PMID: 21533164 PMCID: PMC3078919 DOI: 10.1371/journal.pone.0018551] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 03/11/2011] [Indexed: 02/02/2023] Open
Abstract
Background Corynebacterium pseudotuberculosis, a Gram-positive, facultative intracellular pathogen, is the etiologic agent of the disease known as caseous lymphadenitis (CL). CL mainly affects small ruminants, such as goats and sheep; it also causes infections in humans, though rarely. This species is distributed worldwide, but it has the most serious economic impact in Oceania, Africa and South America. Although C. pseudotuberculosis causes major health and productivity problems for livestock, little is known about the molecular basis of its pathogenicity. Methodology and Findings We characterized two C. pseudotuberculosis genomes (Cp1002, isolated from goats; and CpC231, isolated from sheep). Analysis of the predicted genomes showed high similarity in genomic architecture, gene content and genetic order. When C. pseudotuberculosis was compared with other Corynebacterium species, it became evident that this pathogenic species has lost numerous genes, resulting in one of the smallest genomes in the genus. Other differences that could be part of the adaptation to pathogenicity include a lower GC content, of about 52%, and a reduced gene repertoire. The C. pseudotuberculosis genome also includes seven putative pathogenicity islands, which contain several classical virulence factors, including genes for fimbrial subunits, adhesion factors, iron uptake and secreted toxins. Additionally, all of the virulence factors in the islands have characteristics that indicate horizontal transfer. Conclusions These particular genome characteristics of C. pseudotuberculosis, as well as its acquired virulence factors in pathogenicity islands, provide evidence of its lifestyle and of the pathogenicity pathways used by this pathogen in the infection process. All genomes cited in this study are available in the NCBI Genbank database (http://www.ncbi.nlm.nih.gov/genbank/) under accession numbers CP001809 and CP001829.
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Affiliation(s)
- Jerônimo C. Ruiz
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Vívian D'Afonseca
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Artur Silva
- Department of Genetics, Federal University of Pará, Belém, Pará, Brazil
| | - Amjad Ali
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Anne C. Pinto
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Anderson R. Santos
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Aryanne A. M. C. Rocha
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Débora O. Lopes
- Health Sciences Center, Federal University of São João Del Rei, Divinópilis, Minas Gerais, Brazil
| | - Fernanda A. Dorella
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Luis G. C. Pacheco
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Department of Biointeraction Sciences, Federal University of Bahia, Salvador, Bahia, Brazil
| | - Marcília P. Costa
- Department of Veterinary Medicine, State University of Ceará, Fortaleza, Ceará, Brazil
| | - Meritxell Z. Turk
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Núbia Seyffert
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Pablo M. R. O. Moraes
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Siomar C. Soares
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sintia S. Almeida
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Thiago L. P. Castro
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Vinicius A. C. Abreu
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Eva Trost
- Department of Genetics, University of Bielefeld, CeBiTech, Bielefeld, Nordrhein-Westfale, Germany
| | - Jan Baumbach
- Department of Computer Science, Max-Planck-Institut für Informatik, Saarbrücken, Saarlan, Germany
| | - Andreas Tauch
- Department of Genetics, University of Bielefeld, CeBiTech, Bielefeld, Nordrhein-Westfale, Germany
| | | | - John McCulloch
- Department of Genetics, Federal University of Pará, Belém, Pará, Brazil
| | | | | | - Adhemar Zerlotini
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Anderson Dominitini
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Daniela M. Resende
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
- Department of Pharmaceutical Sciences, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Elisângela M. Coser
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Luciana M. Oliveira
- Department of Phisics, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - André L. Pedrosa
- Department of Pharmaceutical Sciences, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
- Department of Biological Sciences, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Carlos U. Vieira
- Department of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Cláudia T. Guimarães
- Brazilian Agricultural Research Corporation (EMBRAPA), Sete Lagoas, Minas Gerais, Brazil
| | - Daniela C. Bartholomeu
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Diana M. Oliveira
- Department of Veterinary Medicine, State University of Ceará, Fortaleza, Ceará, Brazil
| | - Fabrício R. Santos
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Élida Mara Rabelo
- Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Francisco P. Lobo
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Glória R. Franco
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ana Flávia Costa
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ieso M. Castro
- Department of Pharmacy, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Sílvia Regina Costa Dias
- Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Jesus A. Ferro
- Department of Technology, State University of São Paulo, Jaboticabal, São Paulo, Brazil
| | - José Miguel Ortega
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Luciano V. Paiva
- Department of Chemistry, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Luiz R. Goulart
- Department of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Juliana Franco Almeida
- Department of Genetics and Biochemistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Maria Inês T. Ferro
- Department of Technology, State University of São Paulo, Jaboticabal, São Paulo, Brazil
| | - Newton P. Carneiro
- Brazilian Agricultural Research Corporation (EMBRAPA), Sete Lagoas, Minas Gerais, Brazil
| | - Paula R. K. Falcão
- Brazilian Agricultural Research Corporation (EMBRAPA), Campinas, São Paulo, Brazil
| | - Priscila Grynberg
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Santuza M. R. Teixeira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sérgio Brommonschenkel
- Department of Plant Pathology, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil
| | - Sérgio C. Oliveira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Roberto Meyer
- Department of Biointeraction Sciences, Federal University of Bahia, Salvador, Bahia, Brazil
| | | | - Anderson Miyoshi
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Guilherme C. Oliveira
- Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
- Center of Excellence in Bioinformatics, National Institute of Science and Technology, Research Center René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Vasco Azevedo
- Department of General Biology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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Bekhit A, Fukamachi T, Saito H, Kobayashi H. The Role of OmpC and OmpF in Acidic Resistance in Escherichia coli. Biol Pharm Bull 2011; 34:330-4. [DOI: 10.1248/bpb.34.330] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Amany Bekhit
- Graduate School of Pharmaceutical Sciences, Chiba University
| | | | - Hiromi Saito
- Graduate School of Pharmaceutical Sciences, Chiba University
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