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Také A, Uojima H, Sakaguchi Y, Gotoh K, Satoh T, Hidaka H, Horio K, Mizokami M, Hayashi S, Kusano C. Impact of liver fibrosis on the relative abundance of a urease-positive Streptococcus salivarius group from saliva in patients with chronic liver disease. Hepatol Res 2023; 53:998-1007. [PMID: 37279155 DOI: 10.1111/hepr.13930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 06/08/2023]
Abstract
AIM We performed genomic analysis to study the relative abundance of a urease-positive Streptococcus salivarius group isolated from the saliva of patients with chronic liver disease. METHODS Male and female patients with chronic liver disease aged over 20 years were included. First, we assessed the frequency and type of the S. salivarius group isolated from oral saliva using molecular biology techniques based on 16S rRNA and dephospho-coenzyme A kinase gene sequencing. Next, we assessed the correlation between the urease positivity rate in the S. salivarius group isolated from oral saliva and liver fibrosis based on chronic liver disease. Urease-positive strains were identified by the urease test using urea broth (Difco, Franklin Lakes, NJ, USA). Liver fibrosis was evaluated by the liver stiffness measurement value based on magnetic resonance elastography. RESULTS A total of 45 patients identified using the multiplex polymerase chain reaction for the 16S rRNA gene were tested using the multiplex polymerase chain reaction for the dephospho-coenzyme A kinase gene. Confirming the strains detected in each of the 45 patients, urease-positive S. salivarius was detected in 28 patients (62%), urease-negative S. salivarius in 25 patients (56%), and urease-positive Streptococcus vestibularis in 12 patients (27%). There was no patient with urease-negative S. vestibularis. The urease-positive rate of the S. salivarius group in the cirrhosis and non-cirrhosis groups were 82.2% and 39.2%, respectively. The liver cirrhosis group had a higher urease positivity rate than the non-cirrhotic group (p < 0.001). CONCLUSIONS Liver fibrosis influences the frequency of a urease-positive S. salivarius group isolated from oral saliva.
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Affiliation(s)
- Akira Také
- Department of Microbiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Haruki Uojima
- Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Genome Medical Sciences Project, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan
| | - Yoshihiko Sakaguchi
- Department of Microbiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, Japan
| | - Kazuyoshi Gotoh
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takashi Satoh
- Division of Hematology, Kitasato University School of Allied Health Sciences, Sagamihara, Kanagawa, Japan
| | - Hisashi Hidaka
- Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Kazue Horio
- Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masashi Mizokami
- Department of Genome Medical Sciences Project, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan
| | - Shunji Hayashi
- Department of Microbiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Chika Kusano
- Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
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Synthesis, Characterization, and Biological Evaluation of 2-(N-((2'-(2H-tetrazole-5-yl)-[1,1'-biphenyl]-4yl)-methyl)-pentanamido)-3-methyl Butanoic Acid Derivatives. Molecules 2023; 28:molecules28041908. [PMID: 36838897 PMCID: PMC9959676 DOI: 10.3390/molecules28041908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
This study aimed to evaluate 2-(N-((2'-(2H-tetrazole-5-yl)-[1,1'-biphenyl]-4yl)-methyl)-pentanamido)-3-methyl butanoic acid-based ester derivatives as a new class of angiotensin-II receptor antagonists. For this purpose, a series of compounds were synthesized using a variety of phenols. Their chemical characterization was established by FTIR, 1HNMR, and 13CNMR techniques. The biological activities including antioxidant potentials using the DPPH assay, the antihypertensive assay, the urease enzyme inhibition assay, and the antibacterial assay using agar well diffusion methods were performed. All the new compounds showed significant free radical scavenging potentials more than the parent drug while retaining antihypertensive potentials along with urease inhibition properties. However, the AV2 test compound was found to be the most potent against hypertension. Most of the synthesized analogs showed urease inhibitory actions. Molecular docking studies were performed for all the active analogs to decode the binding detail of the ligands with receptors of the enzyme's active site.
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3
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Nobori T, Cao Y, Entila F, Dahms E, Tsuda Y, Garrido‐Oter R, Tsuda K. Dissecting the cotranscriptome landscape of plants and their microbiota. EMBO Rep 2022; 23:e55380. [PMID: 36219690 PMCID: PMC9724666 DOI: 10.15252/embr.202255380] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/07/2022] Open
Abstract
Interactions between plants and neighboring microbial species are fundamental elements that collectively determine the structure and function of the plant microbiota. However, the molecular basis of such interactions is poorly characterized. Here, we colonize Arabidopsis leaves with nine plant-associated bacteria from all major phyla of the plant microbiota and profile cotranscriptomes of plants and bacteria six hours after inoculation. We detect both common and distinct cotranscriptome signatures among plant-commensal pairs. In planta responses of commensals are similar to those of a disarmed pathogen characterized by the suppression of genes involved in general metabolism in contrast to a virulent pathogen. We identify genes that are enriched in the genome of plant-associated bacteria and induced in planta, which may be instrumental for bacterial adaptation to the host environment and niche separation. This study provides insights into how plants discriminate among bacterial strains and lays the foundation for in-depth mechanistic dissection of plant-microbiota interactions.
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Affiliation(s)
- Tatsuya Nobori
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
- Salk Institute for Biological StudiesLa JollaCAUSA
| | - Yu Cao
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
| | - Frederickson Entila
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
| | - Eik Dahms
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
| | - Yayoi Tsuda
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Hubei Key Lab of Plant Pathology, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- Shenzhen Institute of Nutrition and HealthHuazhong Agricultural UniversityWuhanChina
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
| | - Ruben Garrido‐Oter
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
- Cluster of Excellence on Plant SciencesDüsseldorfGermany
| | - Kenichi Tsuda
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Hubei Key Lab of Plant Pathology, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- Shenzhen Institute of Nutrition and HealthHuazhong Agricultural UniversityWuhanChina
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina
- Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologneGermany
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4
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Mazzei L, Cianci M, Ciurli S. Inhibition of Urease by Hydroquinones: A Structural and Kinetic Study. Chemistry 2022; 28:e202201770. [PMID: 35994380 PMCID: PMC9826003 DOI: 10.1002/chem.202201770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Indexed: 01/11/2023]
Abstract
Hydroquinones are a class of organic compounds abundant in nature that result from the full reduction of the corresponding quinones. Quinones are known to efficiently inhibit urease, a NiII -containing enzyme that catalyzes the hydrolysis of urea to yield ammonia and carbonate and acts as a virulence factor of several human pathogens, in addition to decreasing the efficiency of soil organic nitrogen fertilization. Here, we report the molecular characterization of the inhibition of urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) by 1,4-hydroquinone (HQ) and its methyl and tert-butyl derivatives. The 1.63-Å resolution X-ray crystal structure of the SPU-HQ complex discloses that HQ covalently binds to the thiol group of αCys322, a key residue located on a mobile protein flap directly involved in the catalytic mechanism. Inhibition kinetic data obtained for the three compounds on JBU reveals the occurrence of an irreversible inactivation process that involves a radical-based autocatalytic mechanism.
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Affiliation(s)
- Luca Mazzei
- Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT)University of BolognaViale Giuseppe Fanin 4040127BolognaItaly
| | - Michele Cianci
- Department of Agricultural, Food and Environmental SciencesPolytechnic University of MarcheVia Brecce Bianche 1060131AnconaItaly
| | - Stefano Ciurli
- Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT)University of BolognaViale Giuseppe Fanin 4040127BolognaItaly
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5
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Ren X, Cao S, Akami M, Mansour A, Yang Y, Jiang N, Wang H, Zhang G, Qi X, Xu P, Guo T, Niu C. Gut symbiotic bacteria are involved in nitrogen recycling in the tephritid fruit fly Bactrocera dorsalis. BMC Biol 2022; 20:201. [PMID: 36104720 PMCID: PMC9476588 DOI: 10.1186/s12915-022-01399-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 09/02/2022] [Indexed: 11/23/2022] Open
Abstract
Background Nitrogen is considered the most limiting nutrient element for herbivorous insects. To alleviate nitrogen limitation, insects have evolved various symbiotically mediated strategies that enable them to colonize nitrogen-poor habitats or exploit nitrogen-poor diets. In frugivorous tephritid larvae developing in fruit pulp under nitrogen stress, it remains largely unknown how nitrogen is obtained and larval development is completed. Results In this study, we used metagenomics and metatranscriptomics sequencing technologies as well as in vitro verification tests to uncover the mechanism underlying the nitrogen exploitation in the larvae of Bactrocera dorsalis. Our results showed that nitrogenous waste recycling (NWR) could be successfully driven by symbiotic bacteria, including Enterobacterales, Lactobacillales, Orbales, Pseudomonadales, Flavobacteriales, and Bacteroidales. In this process, urea hydrolysis in the larval gut was mainly mediated by Morganella morganii and Klebsiella oxytoca. In addition, core bacteria mediated essential amino acid (arginine excluded) biosynthesis by ammonium assimilation and transamination. Conclusions Symbiotic bacteria contribute to nitrogen transformation in the larvae of B. dorsalis in fruit pulp. Our findings suggest that the pattern of NWR is more likely to be applied by B. dorsalis, and M. morganii, K. oxytoca, and other urease-positive strains play vital roles in hydrolysing nitrogenous waste and providing metabolizable nitrogen for B. dorsalis. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01399-9.
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Yukawa-Muto Y, Kamiya T, Fujii H, Mori H, Toyoda A, Sato I, Konishi Y, Hirayama A, Hara E, Fukuda S, Kawada N, Ohtani N. Distinct responsiveness to rifaximin in patients with hepatic encephalopathy depends on functional gut microbial species. Hepatol Commun 2022; 6:2090-2104. [PMID: 35429147 PMCID: PMC9315133 DOI: 10.1002/hep4.1954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/09/2022] [Accepted: 03/19/2022] [Indexed: 12/11/2022] Open
Abstract
Hepatic encephalopathy (HE) is the neuropsychiatric complication of liver cirrhosis (LC). The influence of gut microbiota on HE pathogenesis has been suggested but not precisely elucidated. Here, we investigate how the gut microbial profile changed in patients with HE to clarify the functional gut microbial species associated with HE. We focused on their responses to rifaximin (RFX), a nonabsorbable antibiotic used in HE therapy. Feces samples were collected from patients with decompensated LC (all HE), patients with compensated LC, and healthy controls, and fecal gut microbial profiles were compared using 16S ribosomal RNA gene amplicon and metagenomic sequencing. The linear discriminant analysis effect size was used to identify specific species. Urease-positive Streptococcus salivarius, which can produce ammonia, was identified as the most significantly abundant gut microbiota in the HE group, and its ability to elevate the levels of blood ammonia as well as brain glutamine was experimentally verified in mice. Urease-negative Ruminococcus gnavus was also identified as a significantly abundant species in patients with RFX-nonresponsive HE after RFX administration. Interestingly, R. gnavus enhanced urease activity of recombinant urease itself, implying that R. gnavus could amplify ammonia production of surrounding urease-positive microbiota. Furthermore, the sensitivity of S. salivarius and R. gnavus to RFX depended on conjugated secondary bile acid levels, suggesting a therapeutic potential of the combined use of secondary bile acid levels with RFX for enhancing the efficacy of RFX. This study identified specific gut bacterial species abundant in patients with HE and verified their functions linked to HE pathophysiology. Targeting these bacteria could be a potentially effective strategy to treat HE.
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Affiliation(s)
- Yoshimi Yukawa-Muto
- Department of PathophysiologyGraduate School of MedicineOsaka Metropolitan University (formerly, Osaka City University)OsakaJapan.,Department of HepatologyGraduate School of MedicineOsaka Metropolitan University (formerly, Osaka City University)OsakaJapan
| | - Tomonori Kamiya
- Department of PathophysiologyGraduate School of MedicineOsaka Metropolitan University (formerly, Osaka City University)OsakaJapan
| | - Hideki Fujii
- Department of Premier Preventive MedicineGraduate School of MedicineOsaka City UniversityOsakaJapan
| | - Hiroshi Mori
- 26359Advanced Genomics CenterNational Institute of GeneticsMishimaJapan
| | - Atsushi Toyoda
- 26359Advanced Genomics CenterNational Institute of GeneticsMishimaJapan
| | - Ikuya Sato
- Medical Affairs DepartmentASKA Pharmaceutical Co., Ltd.TokyoJapan
| | - Yusuke Konishi
- Research Institute for Microbial DiseasesOsaka UniversitySuitaJapan
| | | | - Eiji Hara
- Research Institute for Microbial DiseasesOsaka UniversitySuitaJapan.,Immunology Frontier Research CenterOsaka UniversitySuitaJapan.,Center for Infectious Disease Education and ResearchOsaka UniversitySuitaJapan
| | - Shinji Fukuda
- Institute for Advanced BiosciencesKeio UniversityTsuruokaJapan.,Gut Environmental Design GroupKanagawa Institute of Industrial Science and TechnologyKawasakiJapan.,Transborder Medical Research CenterUniversity of TsukubaTsukubaJapan
| | - Norifumi Kawada
- Department of HepatologyGraduate School of MedicineOsaka Metropolitan University (formerly, Osaka City University)OsakaJapan
| | - Naoko Ohtani
- Department of PathophysiologyGraduate School of MedicineOsaka Metropolitan University (formerly, Osaka City University)OsakaJapan.,AMED-CRESTJapan Agency for Medical Research and DevelopmentTokyoJapan
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7
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Sánchez-Andrea I, van der Graaf CM, Hornung B, Bale NJ, Jarzembowska M, Sousa DZ, Rijpstra WIC, Sinninghe Damsté JS, Stams AJM. Acetate Degradation at Low pH by the Moderately Acidophilic Sulfate Reducer Acididesulfobacillus acetoxydans gen. nov. sp. nov. Front Microbiol 2022; 13:816605. [PMID: 35391737 PMCID: PMC8982180 DOI: 10.3389/fmicb.2022.816605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/31/2022] [Indexed: 11/19/2022] Open
Abstract
In acid drainage environments, biosulfidogenesis by sulfate-reducing bacteria (SRB) attenuates the extreme conditions by enabling the precipitation of metals as their sulfides, and the neutralization of acidity through proton consumption. So far, only a handful of moderately acidophilic SRB species have been described, most of which are merely acidotolerant. Here, a novel species within a novel genus of moderately acidophilic SRB is described, Acididesulfobacillus acetoxydans gen. nov. sp. nov. strain INE, able to grow at pH 3.8. Bioreactor studies with strain INE at optimum (5.0) and low (3.9) pH for growth showed that strain INE alkalinized its environment, and that this was more pronounced at lower pH. These studies also showed the capacity of strain INE to completely oxidize organic acids to CO2, which is uncommon among acidophilic SRB. Since organic acids are mainly in their protonated form at low pH, which increases their toxicity, their complete oxidation may be an acid stress resistance mechanism. Comparative proteogenomic and membrane lipid analysis further indicated that the presence of saturated ether-bound lipids in the membrane, and their relative increase at lower pH, was a protection mechanism against acid stress. Interestingly, other canonical acid stress resistance mechanisms, such as a Donnan potential and increased active charge transport, did not appear to be active.
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Affiliation(s)
- Irene Sánchez-Andrea
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
- *Correspondence: Irene Sánchez-Andrea,
| | | | - Bastian Hornung
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen, Netherlands
| | - Nicole J. Bale
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Netherlands
| | - Monika Jarzembowska
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Diana Z. Sousa
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - W. Irene C. Rijpstra
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Netherlands
| | - Jaap S. Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
| | - Alfons J. M. Stams
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
- Centre of Biological Engineering, University of Minho, Braga, Portugal
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Nitrogen Acquisition Strategies Mediated by Insect Symbionts: A Review of Their Mechanisms, Methodologies, and Case Studies. INSECTS 2022; 13:insects13010084. [PMID: 35055927 PMCID: PMC8781418 DOI: 10.3390/insects13010084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 12/10/2022]
Abstract
Simple Summary Nitrogen acquisition strategies mediated by insect symbionts through biological nitrogen fixation (BNF) and nitrogenous waste recycling (NWR) were reviewed and compared in our paper, and a model for nitrogen provisioning in insects was then constructed. In our model, (1) insects acquired nitrogen nutrition from food stuffs directly, and the subprime channels (e.g., BNF or NWR) for nitrogen provisioning were accelerated when the available nitrogen in diets could not fully support the normal growth and development of insects; (2) the NWR strategy was more accessible to more insects due to its energy conservation and mild reaction conditions; (3) ammonia produced by different channels was used for essential nitrogenous metabolites synthesis via the glutamine synthetase and glutamate synthase pathways. Abstract Nitrogen is usually a restrictive nutrient that affects the growth and development of insects, especially of those living in low nitrogen nutrient niches. In response to the low nitrogen stress, insects have gradually developed symbiont-based stress response strategies—biological nitrogen fixation and nitrogenous waste recycling—to optimize dietary nitrogen intake. Based on the above two patterns, atmospheric nitrogen or nitrogenous waste (e.g., uric acid, urea) is converted into ammonia, which in turn is incorporated into the organism via the glutamine synthetase and glutamate synthase pathways. This review summarized the reaction mechanisms, conventional research methods and the various applications of biological nitrogen fixation and nitrogenous waste recycling strategies. Further, we compared the bio-reaction characteristics and conditions of two strategies, then proposed a model for nitrogen provisioning based on different strategies.
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9
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Wimmi S, Balinovic A, Jeckel H, Selinger L, Lampaki D, Eisemann E, Meuskens I, Linke D, Drescher K, Endesfelder U, Diepold A. Dynamic relocalization of cytosolic type III secretion system components prevents premature protein secretion at low external pH. Nat Commun 2021; 12:1625. [PMID: 33712575 PMCID: PMC7954860 DOI: 10.1038/s41467-021-21863-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 02/12/2021] [Indexed: 01/31/2023] Open
Abstract
Many bacterial pathogens use a type III secretion system (T3SS) to manipulate host cells. Protein secretion by the T3SS injectisome is activated upon contact to any host cell, and it has been unclear how premature secretion is prevented during infection. Here we report that in the gastrointestinal pathogens Yersinia enterocolitica and Shigella flexneri, cytosolic injectisome components are temporarily released from the proximal interface of the injectisome at low external pH, preventing protein secretion in acidic environments, such as the stomach. We show that in Yersinia enterocolitica, low external pH is detected in the periplasm and leads to a partial dissociation of the inner membrane injectisome component SctD, which in turn causes the dissociation of the cytosolic T3SS components. This effect is reversed upon restoration of neutral pH, allowing a fast activation of the T3SS at the native target regions within the host. These findings indicate that the cytosolic components form an adaptive regulatory interface, which regulates T3SS activity in response to environmental conditions.
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Affiliation(s)
- Stephan Wimmi
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Alexander Balinovic
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Hannah Jeckel
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, Marburg, Germany
| | - Lisa Selinger
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Dimitrios Lampaki
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Max-Planck-Institut für Immunbiologie und Epigenetik, Freiburg, Germany
| | - Emma Eisemann
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- James Madison University, Harrisonburg, VA, USA
| | - Ina Meuskens
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, Marburg, Germany
| | - Ulrike Endesfelder
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.
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10
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Mazzei L, Contaldo U, Musiani F, Cianci M, Bagnolini G, Roberti M, Ciurli S. Inhibition of Urease, a Ni-Enzyme: The Reactivity of a Key Thiol With Mono- and Di-Substituted Catechols Elucidated by Kinetic, Structural, and Theoretical Studies. Angew Chem Int Ed Engl 2021; 60:6029-6035. [PMID: 33245574 DOI: 10.1002/anie.202014706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Indexed: 12/30/2022]
Abstract
The inhibition of urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) by a class of six aromatic poly-hydroxylated molecules, namely mono- and dimethyl-substituted catechols, was investigated on the basis of the inhibitory efficiency of the catechol scaffold. The aim was to probe the key step of a mechanism proposed for the inhibition of SPU by catechol, namely the sulfanyl radical attack on the aromatic ring, as well as to obtain critical information on the effect of substituents of the catechol aromatic ring on the inhibition efficacy of its derivatives. The crystal structures of all six SPU-inhibitors complexes, determined at high resolution, as well as kinetic data obtained on JBU and theoretical studies of the reaction mechanism using quantum mechanical calculations, revealed the occurrence of an irreversible inactivation of urease by means of a radical-based autocatalytic multistep mechanism, and indicate that, among all tested catechols, the mono-substituted 3-methyl-catechol is the most efficient inhibitor for urease.
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Affiliation(s)
- Luca Mazzei
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy.,Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Giuseppe Fanin 40, 40127, Bologna, Italy
| | - Umberto Contaldo
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy.,Laboratory of Chemistry and Biology of Metals, Université Grenoble Alpes, CEA, CNRS, 17 Avenue des Martyrs, 38000, Grenoble, France
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy.,Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Giuseppe Fanin 40, 40127, Bologna, Italy
| | - Michele Cianci
- Department of Agricultural, Food and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy
| | - Greta Bagnolini
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy
| | - Marinella Roberti
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy
| | - Stefano Ciurli
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy.,Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Giuseppe Fanin 40, 40127, Bologna, Italy
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11
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Mazzei L, Contaldo U, Musiani F, Cianci M, Bagnolini G, Roberti M, Ciurli S. Inhibition of Urease, a Ni‐Enzyme: The Reactivity of a Key Thiol With Mono‐ and Di‐Substituted Catechols Elucidated by Kinetic, Structural, and Theoretical Studies. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Luca Mazzei
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
- Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Giuseppe Fanin 40 40127 Bologna Italy
| | - Umberto Contaldo
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
- Laboratory of Chemistry and Biology of Metals Université Grenoble Alpes, CEA CNRS 17 Avenue des Martyrs 38000 Grenoble France
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
- Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Giuseppe Fanin 40 40127 Bologna Italy
| | - Michele Cianci
- Department of Agricultural, Food and Environmental Sciences Polytechnic University of Marche Via Brecce Bianche 60131 Ancona Italy
| | - Greta Bagnolini
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
| | - Marinella Roberti
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
| | - Stefano Ciurli
- Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Belmeloro 6 40126 Bologna Italy
- Laboratory of Bioinorganic Chemistry Department of Pharmacy and Biotechnology (FaBiT) University of Bologna Via Giuseppe Fanin 40 40127 Bologna Italy
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12
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Righetto RD, Anton L, Adaixo R, Jakob RP, Zivanov J, Mahi MA, Ringler P, Schwede T, Maier T, Stahlberg H. High-resolution cryo-EM structure of urease from the pathogen Yersinia enterocolitica. Nat Commun 2020; 11:5101. [PMID: 33037208 PMCID: PMC7547064 DOI: 10.1038/s41467-020-18870-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/15/2020] [Indexed: 01/09/2023] Open
Abstract
Urease converts urea into ammonia and carbon dioxide and makes urea available as a nitrogen source for all forms of life except animals. In human bacterial pathogens, ureases also aid in the invasion of acidic environments such as the stomach by raising the surrounding pH. Here, we report the structure of urease from the pathogen Yersinia enterocolitica at 2 Å resolution from cryo-electron microscopy. Y. enterocolitica urease is a dodecameric assembly of a trimer of three protein chains, ureA, ureB and ureC. The high data quality enables detailed visualization of the urease bimetal active site and of the impact of radiation damage. The obtained structure is of sufficient quality to support drug development efforts. Urease is a nickel enzyme responsible for catalyzing the conversion of urea into ammonia and carbon dioxide. Here the authors report a high resolution cryo-EM structure of urease from the bacterial pathogen Yersinia enterocolitica, providing a detailed visualization of the urease bimetal active site and a basis for drug development.
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Affiliation(s)
- Ricardo D Righetto
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Leonie Anton
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Ricardo Adaixo
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Roman P Jakob
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Jasenko Zivanov
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Mohamed-Ali Mahi
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Philippe Ringler
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Torsten Schwede
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Timm Maier
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
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13
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The structure-based reaction mechanism of urease, a nickel dependent enzyme: tale of a long debate. J Biol Inorg Chem 2020; 25:829-845. [PMID: 32809087 PMCID: PMC7433671 DOI: 10.1007/s00775-020-01808-w] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 06/29/2020] [Indexed: 01/22/2023]
Abstract
This review is an attempt to retrace the chronicle that starts from the discovery of the role of nickel as the essential metal ion in urease for the enzymatic catalysis of urea, a key step in the biogeochemical cycle of nitrogen on Earth, to the most recent progress in understanding the chemistry of this historical enzyme. Data and facts are presented through the magnifying lenses of the authors, using their best judgment to filter and elaborate on the many facets of the research carried out on this metalloenzyme over the years. The tale is divided in chapters that discuss and describe the results obtained in the subsequent leaps in the knowledge that led from the discovery of a biological role for Ni to the most recent advancements in the comprehension of the relationship between the structure and function of urease. This review is intended not only to focus on the bioinorganic chemistry of this beautiful metal-based catalysis, but also, and maybe primarily, to evoke inspiration and motivation to further explore the realm of bio-based coordination chemistry.
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14
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Nieckarz M, Kaczor P, Jaworska K, Raczkowska A, Brzostek K. Urease Expression in Pathogenic Yersinia enterocolitica Strains of Bio-Serotypes 2/O:9 and 1B/O:8 Is Differentially Regulated by the OmpR Regulator. Front Microbiol 2020; 11:607. [PMID: 32322248 PMCID: PMC7156557 DOI: 10.3389/fmicb.2020.00607] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/19/2020] [Indexed: 12/31/2022] Open
Abstract
Yersinia enterocolitica exhibits a dual lifestyle, existing as both a saprophyte and a pathogen colonizing different niches within a host organism. OmpR has been recognized as a regulator that controls the expression of genes involved in many different cellular processes and the virulence of pathogenic bacteria. Here, we have examined the influence of OmpR and varying temperature (26°C vs. 37°C) on the cytoplasmic proteome of Y. enterocolitica Ye9N (bio-serotype 2/O:9, low pathogenicity). Differential label-free quantitative proteomic analysis indicated that OmpR affects the cellular abundance of a number of proteins including subunits of urease, an enzyme that plays a significant role in acid tolerance and the pathogenicity of Y. enterocolitica. The impact of OmpR on the expression of urease under different growth conditions was studied in more detail by comparing urease activity and the transcription of ure genes in Y. enterocolitica strains Ye9N and Ye8N (highly pathogenic bio-serotype 1B/O:8). Urease expression was higher in strain Ye9N than in Ye8N and in cells grown at 26°C compared to 37°C. However, low pH, high osmolarity and the presence of urea did not have a clear effect on urease expression in either strain. Further analysis showed that OmpR participates in the positive regulation of three transcriptional units encoding the multi-subunit urease (ureABC, ureEF, and ureGD) in strain Ye9N, but this was not the case in strain Ye8N. Binding of OmpR to the ureABC and ureEF promoter regions was confirmed using an electrophoretic mobility shift assay, suggesting that this factor plays a direct role in regulating the transcription of these operons. In addition, we determined that OmpR modulates the expression of a ureR-like gene encoding a putative regulator of the ure gene cluster, but in the opposite manner, i.e., positively in Ye9N and negatively in Ye8N. These findings provide some novel insights into the function of OmpR in adaptation strategies of Y. enterocolitica.
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Affiliation(s)
| | | | | | | | - Katarzyna Brzostek
- Department of Molecular Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
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15
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The Phylogeny and Biological Function of Gastric Juice-Microbiological Consequences of Removing Gastric Acid. Int J Mol Sci 2019; 20:ijms20236031. [PMID: 31795477 PMCID: PMC6928904 DOI: 10.3390/ijms20236031] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 12/15/2022] Open
Abstract
Gastric juice is a unique combination of hydrochloric acid (HCl), lipase, and pepsin. Acidic gastric juice is found in all vertebrates, and its main function is to inactivate microorganisms. The phylogenetic preservation of this energy-consuming and, at times, hazardous function (acid-related diseases) reflects its biological importance. Proton pump inhibitors (PPIs) are one of the most widely used drugs in the world. Due to the reduced prevalence of Helicobacter pylori infection as well as the increased use of inhibitors of gastric acid secretion, the latter has become the most important cause of gastric hypoacidity. In the present manuscript, we review the microbiological consequences of removing gastric acidity. The resulting susceptibility to infections has not been studied extensively, and focus has mainly been restricted to bacterial and parasitic agents only. The strongest evidence concerning the relationship between hypochlorhydria and predisposition to infections relates to bacterial infections affecting the gastrointestinal tract. However, several other clinical settings with increased susceptibility to infections due to inhibited gastric acidity are discussed. We also discuss the impact of hypochlorhydria on the gut microbiome.
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16
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Abstract
Nickel is an essential cofactor for some pathogen virulence factors. Due to its low availability in hosts, pathogens must efficiently transport the metal and then balance its ready intracellular availability for enzyme maturation with metal toxicity concerns. The most notable virulence-associated components are the Ni-enzymes hydrogenase and urease. Both enzymes, along with their associated nickel transporters, storage reservoirs, and maturation enzymes have been best-studied in the gastric pathogen Helicobacter pylori, a bacterium which depends heavily on nickel. Molecular hydrogen utilization is associated with efficient host colonization by the Helicobacters, which include both gastric and liver pathogens. Translocation of a H. pylori carcinogenic toxin into host epithelial cells is powered by H2 use. The multiple [NiFe] hydrogenases of Salmonella enterica Typhimurium are important in host colonization, while ureases play important roles in both prokaryotic (Proteus mirabilis and Staphylococcus spp.) and eukaryotic (Cryptoccoccus genus) pathogens associated with urinary tract infections. Other Ni-requiring enzymes, such as Ni-acireductone dioxygenase (ARD), Ni-superoxide dismutase (SOD), and Ni-glyoxalase I (GloI) play important metabolic or detoxifying roles in other pathogens. Nickel-requiring enzymes are likely important for virulence of at least 40 prokaryotic and nine eukaryotic pathogenic species, as described herein. The potential for pathogenic roles of many new Ni-binding components exists, based on recent experimental data and on the key roles that Ni enzymes play in a diverse array of pathogens.
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Bishai WR, Timmins GS. Potential for breath test diagnosis of urease positive pathogens in lung infections. J Breath Res 2019; 13:032002. [DOI: 10.1088/1752-7163/ab2225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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18
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Kanwal, Khan M, Arshia, Khan KM, Parveen S, Shaikh M, Fatima N, Choudhary MI. Syntheses, in vitro urease inhibitory activities of urea and thiourea derivatives of tryptamine, their molecular docking and cytotoxic studies. Bioorg Chem 2019; 83:595-610. [DOI: 10.1016/j.bioorg.2018.10.070] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/25/2018] [Accepted: 10/31/2018] [Indexed: 11/16/2022]
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19
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Khaleque HN, Shafique R, Kaksonen AH, Boxall NJ, Watkin EL. Quantitative proteomics using SWATH-MS identifies mechanisms of chloride tolerance in the halophilic acidophile Acidihalobacter prosperus DSM 14174. Res Microbiol 2018; 169:638-648. [DOI: 10.1016/j.resmic.2018.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 02/08/2023]
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Dai Q, Xu L, Xiao L, Zhu K, Song Y, Li C, Zhu L, Shen X, Wang Y. RovM and CsrA Negatively Regulate Urease Expression in Yersinia pseudotuberculosis. Front Microbiol 2018; 9:348. [PMID: 29535702 PMCID: PMC5835112 DOI: 10.3389/fmicb.2018.00348] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 02/13/2018] [Indexed: 01/07/2023] Open
Abstract
Urease acts as an important acid resistance system and virulence factor that is widespread among microorganisms. RovM is a global regulator that regulates a series of genes and pathways including acid survival systems in the enteric bacterium Yersinia pseudotuberculosis (Yptb). However, whether RovM regulates the urease activity in Yptb was still unknown. In this study, by using qualitative and quantitative urease assays, we show that the urease expression responds to nutrient conditions and the RovM protein represses urease expression by binding to its promoter. A previously reported positive regulator OmpR activates urease activity but RovM plays a dominant role in different nutrient conditions. In addition, carbon storage regulator system A (CsrA), the upstream regulator of RovM, dramatically down-regulates urease activity possibly by its binding to the Shine-Dalgarno (SD) sequence of the mRNA encoding the urease. In conclusion, this study demonstrates that urease activity is strictly controlled by nutrient conditions and is down-regulated by the CsrA-RovM pathway.
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Affiliation(s)
- Qingyun Dai
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Lei Xu
- College of Life Sciences, Northwest A&F University, Yangling, China
- Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Lu Xiao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Kaixiang Zhu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Yunhong Song
- College of Life Sciences, Northwest A&F University, Yangling, China
| | - Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Lingfang Zhu
- College of Life Sciences, Northwest A&F University, Yangling, China
| | - Xihui Shen
- College of Life Sciences, Northwest A&F University, Yangling, China
- Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
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21
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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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22
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Álvarez A, Toledo H. The histone-like protein HU has a role in gene expression during the acid adaptation response in Helicobacter pylori. Helicobacter 2017; 22. [PMID: 28244177 DOI: 10.1111/hel.12381] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Gastritis, ulcers, and gastric malignancy have been linked to human gastric epithelial colonization by Helicobacter pylori. Characterization of the mechanisms by which H. pylori adapts to the human stomach environment is of crucial importance to understand H. pylori pathogenesis. MATERIAL AND METHODS In an effort to extend our knowledge of these mechanisms, we used proteomic analysis and qRT-PCR to characterize the role of the histone-like protein HU in the response of H. pylori to low pH. RESULTS Proteomic analysis revealed that genes involved in chemotaxis, oxidative stress, or metabolism are under control of the HU protein. Also, expression of the virulence factors Ggt and NapA is affected by the null mutation of hup gene both at neutral and acid pH, as evidenced by qRT-PCR analysis. CONCLUSIONS Those results showed that H. pylori gene expression is altered by shift to low pH, thus confirming that acid exposure leads to profound changes in genomic expression, and suggest that the HU protein is a regulator that may help the bacterium adapt to the acid stress. In accordance with previous reports, we found that the HU protein participates in gene expression regulation when the microorganism is exposed to acid stress. Such transcriptional regulation underlies protein accumulation in the H. pylori cell.
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Affiliation(s)
- Alhejandra Álvarez
- Laboratory of Molecular Microbiology, Department of Molecular and Cellular Biology, Faculty of Medicine, ICBM, University of Chile, Santiago, Chile
| | - Héctor Toledo
- Laboratory of Molecular Microbiology, Department of Molecular and Cellular Biology, Faculty of Medicine, ICBM, University of Chile, Santiago, Chile
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Abstract
BACKGROUND Helicobacter pylori is well adapted to colonize the epithelial surface of the human gastric mucosa and can cause persistent infections. In order to infect the gastric mucosa, it has to survive in the gastric acidic pH. This organism has well developed mechanisms to neutralize the effects of acidic pH. OBJECTIVE This review article was designed to summarize the various functional and molecular aspects by which the bacterium can combat and survive the gastric acidic pH in order to establish the persistent infections. METHODS We used the keywords (acid acclimation, gastric acidic environment, H. pylori and survival) in combination or alone for pubmed search of recent scientific literatures. One hundred and forty one papers published between 1989 and 2016 were sorted out. The articles published with only abstracts, other than in English language, case reports and reviews were excluded. RESULTS Many literatures describing the role of several factors in acid survival were found. Recently, the role of several other factors has been claimed to participate in acid survival. CONCLUSION In conclusion, this organism has well characterized mechanisms for acid survival.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan,Department of Medicine-Gastroenterology, Baylor College of Medicine, Houston, Texas, USA,Corresponding author: Yoshio Yamaoka, MD, PhD, Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu-City, Oita 879-5593, Japan, Tel: +81-97-586-5740; Fax: +81-97-586-5749,
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24
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Mühling M, Poehlein A, Stuhr A, Voitel M, Daniel R, Schlömann M. Reconstruction of the Metabolic Potential of Acidophilic Sideroxydans Strains from the Metagenome of an Microaerophilic Enrichment Culture of Acidophilic Iron-Oxidizing Bacteria from a Pilot Plant for the Treatment of Acid Mine Drainage Reveals Metabolic Versatility and Adaptation to Life at Low pH. Front Microbiol 2016; 7:2082. [PMID: 28066396 PMCID: PMC5178258 DOI: 10.3389/fmicb.2016.02082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/08/2016] [Indexed: 11/13/2022] Open
Abstract
Bacterial community analyses of samples from a pilot plant for the treatment of acid mine drainage (AMD) from the lignite-mining district in Lusatia (East Germany) had previously demonstrated the dominance of two groups of acidophilic iron oxidizers: the novel candidate genus "Ferrovum" and a group comprising Gallionella-like strains. Since pure culture had proven difficult, previous studies have used genome analyses of co-cultures consisting of "Ferrovum" and a strain of the heterotrophic acidophile Acidiphilium in order to obtain insight into the life style of these novel bacteria. Here we report on attempts to undertake a similar study on Gallionella-like acidophiles from AMD. Isolates belonging to the family Gallionellaceae are still restricted to the microaerophilic and neutrophilic iron oxidizers Sideroxydans and Gallionella. Availability of genomic or metagenomic sequence data of acidophilic strains of these genera should, therefore, be relevant for defining adaptive strategies in pH homeostasis. This is particularly the case since complete genome sequences of the neutrophilic strains G. capsiferriformans ES-2 and S. lithotrophicus ES-1 permit the direct comparison of the metabolic capacity of neutrophilic and acidophilic members of the same genus and, thus, the detection of biochemical features that are specific to acidophilic strains to support life under acidic conditions. Isolation attempts undertaken in this study resulted in the microaerophilic enrichment culture ADE-12-1 which, based on 16S rRNA gene sequence analysis, consisted of at least three to four distinct Gallionellaceae strains that appear to be closely related to the neutrophilic iron oxidizer S. lithotrophicus ES-1. Key hypotheses inferred from the metabolic reconstruction of the metagenomic sequence data of these acidophilic Sideroxydans strains include the putative role of urea hydrolysis, formate oxidation and cyanophycin decarboxylation in pH homeostasis.
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Affiliation(s)
- Martin Mühling
- Institute of Biological Sciences, Technische Universität Bergakademie Freiberg Freiberg, Germany
| | - Anja Poehlein
- Georg-August-University Göttingen, Genomic and Applied Microbiology and Göttingen Genomics, Laboratory Göttingen, Germany
| | - Anna Stuhr
- Institute of Biological Sciences, Technische Universität Bergakademie Freiberg Freiberg, Germany
| | - Matthias Voitel
- Institute of Biological Sciences, Technische Universität Bergakademie Freiberg Freiberg, Germany
| | - Rolf Daniel
- Georg-August-University Göttingen, Genomic and Applied Microbiology and Göttingen Genomics, Laboratory Göttingen, Germany
| | - Michael Schlömann
- Institute of Biological Sciences, Technische Universität Bergakademie Freiberg Freiberg, Germany
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Mazzei L, Cianci M, Musiani F, Lente G, Palombo M, Ciurli S. Inactivation of urease by catechol: Kinetics and structure. J Inorg Biochem 2016; 166:182-189. [PMID: 27888701 DOI: 10.1016/j.jinorgbio.2016.11.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/14/2016] [Accepted: 11/08/2016] [Indexed: 10/20/2022]
Abstract
Urease is a Ni(II)-containing enzyme that catalyzes the hydrolysis of urea to yield ammonia and carbamate at a rate 1015 times higher than the uncatalyzed reaction. Urease is a virulence factor of several human pathogens, in addition to decreasing the efficiency of soil organic nitrogen fertilization. Therefore, efficient urease inhibitors are actively sought. In this study, we describe a molecular characterization of the interaction between urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) with catechol, a model polyphenol. In particular, catechol irreversibly inactivates both SPU and JBU with a complex radical-based autocatalytic multistep mechanism. The crystal structure of the SPU-catechol complex, determined at 1.50Å resolution, reveals the structural details of the enzyme inhibition.
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Affiliation(s)
- Luca Mazzei
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Italy
| | - Michele Cianci
- European Molecular Biology Laboratory, DESY, Hamburg, Germany
| | - Francesco Musiani
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Italy
| | - Gábor Lente
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Hungary
| | - Marta Palombo
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Italy
| | - Stefano Ciurli
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Italy.
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26
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Connecting phenome to genome in Pseudomonas stutzeri 5190: an artwork biocleaning bacterium. Res Microbiol 2016; 167:757-765. [DOI: 10.1016/j.resmic.2016.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 08/28/2016] [Accepted: 09/01/2016] [Indexed: 11/21/2022]
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Lotowska WA, Rutkowska IA, Seta E, Szaniawska E, Wadas A, Sek S, Raczkowska A, Brzostek K, Kulesza PJ. Bacterial-biofilm enhanced design for improved electrocatalytic reduction of oxygen in neutral medium. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.07.117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Ullrich SR, Poehlein A, Tischler JS, González C, Ossandon FJ, Daniel R, Holmes DS, Schlömann M, Mühling M. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus "Ferrovum". PLoS One 2016; 11:e0146832. [PMID: 26808278 PMCID: PMC4725956 DOI: 10.1371/journal.pone.0146832] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/22/2015] [Indexed: 02/07/2023] Open
Abstract
Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus ferrivorans (iron oxidase) indicates the existence of a modified pathway in “Ferrovum” strain JA12. Therefore, the results of the present study extend our understanding of the genus “Ferrovum” and provide a comprehensive framework for future comparative genome and metagenome studies.
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Affiliation(s)
- Sophie R. Ullrich
- Institute of Biological Sciences, TU Bergakademie Freiberg, Leipziger Straße 29, Freiberg, Germany
- * E-mail: (SRU); (MM)
| | - Anja Poehlein
- Georg-August-University Göttingen, Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Grisebachstraße 8, Göttingen, Germany
| | - Judith S. Tischler
- Institute of Biological Sciences, TU Bergakademie Freiberg, Leipziger Straße 29, Freiberg, Germany
| | - Carolina González
- Center for System Biotechnology, Bio-Computing Division and Applied Genetics Division, Fraunhofer Chile Research Foundation, Avenida Mariano Sánchez Fontecilla 310, Santiago, Chile, and Center for Bioinformatics and Genome Biology, Fundación Ciencia y Vida, Zañartu 1482, and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avenida Los Leones 745, Santiago, Chile
| | - Francisco J. Ossandon
- Center for Bioinformatics and Genome Biology, Fundación Ciencia y Vida, Zañartu 1482 and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avenida Los Leones 745, Santiago, Chile
| | - Rolf Daniel
- Georg-August-University Göttingen, Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Grisebachstraße 8, Göttingen, Germany
| | - David S. Holmes
- Center for Bioinformatics and Genome Biology, Fundación Ciencia y Vida, Zañartu 1482 and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avenida Los Leones 745, Santiago, Chile
| | - Michael Schlömann
- Institute of Biological Sciences, TU Bergakademie Freiberg, Leipziger Straße 29, Freiberg, Germany
| | - Martin Mühling
- Institute of Biological Sciences, TU Bergakademie Freiberg, Leipziger Straße 29, Freiberg, Germany
- * E-mail: (SRU); (MM)
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Tikhomirova A, Jiang D, Kidd SP. A new insight into the role of intracellular nickel levels for the stress response, surface properties and twitching motility by Haemophilus influenzae. Metallomics 2016; 7:650-61. [PMID: 25350148 DOI: 10.1039/c4mt00245h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nickel acts as a co-factor for a small number of enzymes in bacteria. Urease is one of the two nickel-dependent enzymes that have been identified in Haemophilus influenzae; glyoxalase I is the other. However, nickel has been suggested to have roles in H. influenzae that can not attributed to the function of these enzymes. We have previously shown that in the H. influenzae strain Rd KW20 the inability to acquire nickel led to alterations to the cell-type; an increased biofilm formation and changes in cell surface properties. Here we report the differences in the genome wide gene expression between Rd KW20 and a strain incapable of importing nickel (nikQ); revealing a link between intracellular nickel levels and genes involved in metabolic pathways, stress responses and genes associated with surface factors such as type IV pili. We have then taken a strain previously shown to use type IV pili both in biofilm formation and for twitching motility (86-028NP) and have shown its homologous genes (NTHI1417-1422; annotated as cobalt transporter, cbiKLMOQ) did import nickel and mutations in this locus had pleiotropic effects correlating to stress response and motility. Compared to wild type cells, the nickel depleted cells were more electronegativity charged, they aggregated and formed a biofilm. Correct intracellular nickel levels were also important for resistance to oxidative stress; the nickel depleted cells were more sensitive to oxidative stress. The nickel depleted cells were also non-motile, but the addition specifically of nickel returned these cells to a wild type motility state. We have also analysed the role of nickel uptake in a naturally, urease negative strain (the blood isolate R2866) and depleting intracellular nickel (a nikQ mutant) in this strain effected a similar range of cell functions. These data reveal a role for the capacity to acquire nickel from the environment and for the correct intracellular nickel levels as part of H. influenzae stress response and in signalling for a switch to a sessile bacterial lifestyle.
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Affiliation(s)
- Alexandra Tikhomirova
- Research Centre for Infectious Disease, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, 5005, Australia.
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Kinetic and structural studies reveal a unique binding mode of sulfite to the nickel center in urease. J Inorg Biochem 2016; 154:42-9. [DOI: 10.1016/j.jinorgbio.2015.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/22/2015] [Accepted: 11/01/2015] [Indexed: 11/21/2022]
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Wang W, Chen J, Chen G, Du X, Cui P, Wu J, Zhao J, Wu N, Zhang W, Li M, Zhang Y. Transposon Mutagenesis Identifies Novel Genes Associated with Staphylococcus aureus Persister Formation. Front Microbiol 2015; 6:1437. [PMID: 26779120 PMCID: PMC4689057 DOI: 10.3389/fmicb.2015.01437] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/02/2015] [Indexed: 12/20/2022] Open
Abstract
Pathogenic bacterial persisters are responsible for the recalcitrance of chronic and persistent infections to antimicrobial therapy. Although the mechanisms of persister formation and survival have been widely studied in Escherichia coli, persistence mechanisms in Staphylococcus aureus remain largely unknown. Here, we screened a transposon mutant library of a clinical methicillin-resistant Staphylococcus aureus(MRSA)strain, USA500 (ST8), under antibiotic pressure and identified 13 genes whose insertion mutations resulted in a defect in persistence. These candidate genes were further confirmed by evaluating the survival of the mutants upon exposure to levofloxacin and several other stress conditions. We found 13 insertion mutants with significantly lower persister numbers under several stress conditions, including sdhA, sdhB, ureG, mnhG1, fbaA, ctaB, clpX, parE, HOU_0223, HOU_0587, HOU_2091, HOU_2315, and HOU_2346, which mapped into pathways of oxidative phosphorylation, TCA cycle, glycolysis, cell cycle, and ABC transporters, suggesting that these genes and pathways may play an important role in persister formation and survival. The newly constructed knockout strains of ureG, sdhA and sdhB and their complemented strains were also tested for defect in persisters following exposure to levofloxacin and several other stress conditions. The results from these experiments were consistent with the screening results, which indicated that deletion of these genes in MRSA USA500 leads to persister defect. These findings provide novel insights into the mechanisms of persister formation and survival in S. aureus and offer new targets for the development of persister-directed antibiotics for the improved treatment of chronic and persistent infections.
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Affiliation(s)
- Wenjie Wang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Jiazhen Chen
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Gang Chen
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Xin Du
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Peng Cui
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Jing Wu
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Jing Zhao
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Nan Wu
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Wenhong Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan University Shanghai, China
| | - Min Li
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Ying Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins UniversityBaltimore, MD, USA
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Champagne C, Raymond Y, Guertin N, Martoni C, Jones M, Mainville I, Arcand Y. Impact of a yogurt matrix and cell microencapsulation on the survival of Lactobacillus reuteri in three in vitro gastric digestion procedures. Benef Microbes 2015; 6:753-63. [DOI: 10.3920/bm2014.0162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The goal of this study was to assess the interaction between microencapsulation and a yogurt food matrix on the survival of Lactobacillus reuteri NCIMB 30242 in four different in vitro systems that simulate a gastric environment. The four systems were: United States Pharmacopeia (USP) solutions, a static two-step (STS) procedure which included simulated food ingredients, a constantly dynamic digestion procedure (IViDiS), as well a multi-step dynamic digestion scheme (S’IViDiS). The pH profiles of the various procedures varied between systems with acidity levels being: USP > STS > IViDiS = S’IVIDiS. Addition of a food matrix increased the pH in all systems except for the USP methodology. Microencapsulation in alginate-based gels was effective in protecting the cells in model solutions when no food ingredients were present. The stability of the probiotic culture in the in vitro gastric environments was enhanced when (1) yoghurt or simulated food ingredient were present in the medium in sufficient quantity, (2) pH was higher. The procedure-comparison data of this study will be helpful in interpreting the literature with respect to viable counts of probiotics obtained from different static or dynamic in vitro gastric systems.
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Affiliation(s)
- C.P. Champagne
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant, St-Hyacinthe, QC J2S 8E3, Canada
- Institute for Nutrition and Functional Foods (INAF), Laval University, Suite 1710, 2440 Boulevard Hochelaga, Québec, QC G1V 0A6, Canada
| | - Y. Raymond
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant, St-Hyacinthe, QC J2S 8E3, Canada
| | - N. Guertin
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant, St-Hyacinthe, QC J2S 8E3, Canada
| | - C.J. Martoni
- Micropharma Limited, 4200 Saint-Laurent Boulevard, 4th floor, Unit 409, Montréal, QC H2W 2R2, Canada
| | - M.L. Jones
- Micropharma Limited, 4200 Saint-Laurent Boulevard, 4th floor, Unit 409, Montréal, QC H2W 2R2, Canada
| | - I. Mainville
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant, St-Hyacinthe, QC J2S 8E3, Canada
| | - Y. Arcand
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant, St-Hyacinthe, QC J2S 8E3, Canada
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Song Y, Xiao X, Li C, Wang T, Zhao R, Zhang W, Zhang L, Wang Y, Shen X. The dual transcriptional regulator RovM regulates the expression of AR3- and T6SS4-dependent acid survival systems in response to nutritional status in Yersinia pseudotuberculosis. Environ Microbiol 2015; 17:4631-45. [PMID: 26234561 DOI: 10.1111/1462-2920.12996] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 07/06/2015] [Accepted: 07/21/2015] [Indexed: 12/01/2022]
Abstract
Coordinated regulation of various acid survival systems in response to environmental stimuli is crucial for the adaptation of enteropathogenic bacteria to acidic environments such as the stomach. In this study, we demonstrated that the RovM protein, a central regulator of the CsrABC-RovM-RovA cascade, conversely regulates the expression of two acid survival systems in Yersinia pseudotuberculosis by acting as a dual transcriptional regulator. RovM activated the expression of T6SS4, which is essential for bacterial survival under mild acidic conditions, by binding upstream of the T6SS4 promoter. On the contrary, RovM repressed the expression of a functional arginine-dependent acid resistance system (AR3), which is crucial for bacterial survival under strong acidic conditions, by directly binding to the -35 element in the AR3 promoter. Consistent with previous findings that rovM expression responds to the availability of nutrients, the expression of T6SS4 and AR3 was differentially regulated by nutritional status. Based on these results, a dynamic model whereby RovM coordinately regulates the expression of AR3 and T6SS4 in response to the availability of nutrients in the environment was proposed.
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Affiliation(s)
- Yunhong Song
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiao Xiao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tietao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ruoxi Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Weipeng Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lei Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Genome Sequence of the Moderately Acidophilic Sulfate-Reducing Firmicute Desulfosporosinus acididurans (Strain M1T). GENOME ANNOUNCEMENTS 2015; 3:3/4/e00881-15. [PMID: 26251501 PMCID: PMC4541271 DOI: 10.1128/genomea.00881-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Microbial dissimilatory sulfate reduction is commonplace in many anaerobic environments, though few acidophilic bacteria are known to mediate this process. We report the 4.64-Mb draft genome of the type strain of the moderate acidophile Desulfosporosinus acididurans, which was isolated from acidic sediment in a river draining the Soufrière volcano, Montserrat.
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Lassek C, Burghartz M, Chaves-Moreno D, Otto A, Hentschker C, Fuchs S, Bernhardt J, Jauregui R, Neubauer R, Becher D, Pieper DH, Jahn M, Jahn D, Riedel K. A metaproteomics approach to elucidate host and pathogen protein expression during catheter-associated urinary tract infections (CAUTIs). Mol Cell Proteomics 2015; 14:989-1008. [PMID: 25673765 PMCID: PMC4390275 DOI: 10.1074/mcp.m114.043463] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 01/20/2015] [Indexed: 12/11/2022] Open
Abstract
Long-term catheterization inevitably leads to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (1) to unravel bacterial community structure and function of such a uropathogenic biofilm and (2) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, that is, Pseudomonas aeruginosa, Morganella morganii, and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that these opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Although P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated with neutrophils, macrophages, and the complement system in the patient's urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of catheter-associated urinary tract infections might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system.
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Affiliation(s)
- Christian Lassek
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany; §Institute of Microbiology, Technische Universität Braunschweig, 38106 Braunschweig, Spielmannstrasse 7, Germany
| | - Melanie Burghartz
- §Institute of Microbiology, Technische Universität Braunschweig, 38106 Braunschweig, Spielmannstrasse 7, Germany
| | - Diego Chaves-Moreno
- ¶Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Inhoffenstrasse 7, Germany
| | - Andreas Otto
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany
| | - Christian Hentschker
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany
| | - Stephan Fuchs
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany
| | - Jörg Bernhardt
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany
| | - Ruy Jauregui
- ¶Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Inhoffenstrasse 7, Germany
| | | | - Dörte Becher
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany
| | - Dietmar H Pieper
- ¶Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Inhoffenstrasse 7, Germany
| | - Martina Jahn
- §Institute of Microbiology, Technische Universität Braunschweig, 38106 Braunschweig, Spielmannstrasse 7, Germany
| | - Dieter Jahn
- §Institute of Microbiology, Technische Universität Braunschweig, 38106 Braunschweig, Spielmannstrasse 7, Germany
| | - Katharina Riedel
- From the ‡Institute of Microbiology, University of Greifswald, 17489 Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, Germany; ¶Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Inhoffenstrasse 7, Germany;
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Heroven AK, Dersch P. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae. Front Cell Infect Microbiol 2014; 4:146. [PMID: 25368845 PMCID: PMC4202721 DOI: 10.3389/fcimb.2014.00146] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/30/2014] [Indexed: 01/07/2023] Open
Abstract
Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Yersinia pseudotuberculosis and Yersinia enterocolitica and the causative agent of plague, Yersinia pestis, are able to survive in a large variety of environmental reservoirs (e.g., soil, plants, insects) as well as warm-blooded animals (e.g., rodents, pigs, humans) with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and interbacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp) and the carbon storage regulator (Csr) system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets.
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Affiliation(s)
- Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Institut für Mikrobiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Institut für Mikrobiology, Technische Universität Braunschweig Braunschweig, Germany
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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: 270] [Impact Index Per Article: 27.0] [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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Abstract
Members of the urea transporter (UT) family mediate rapid, selective transport of urea down its concentration gradient. To date, crystal structures of two evolutionarily distant UTs have been solved. These structures reveal a common UT fold involving two structurally homologous domains that encircle a continuous membrane-spanning pore and indicate that UTs transport urea via a channel-like mechanism. Examination of the conserved architecture of the pore, combined with crystal structures of ligand-bound proteins, molecular dynamics simulations, and functional data on permeation and inhibition by a broad range of urea analogs and other small molecules, provides insight into the structural basis of urea permeation and selectivity.
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Affiliation(s)
- Elena J. Levin
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine 1 Baylor Plaza, Houston, TX 77030 USA
| | - Ming Zhou
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine 1 Baylor Plaza, Houston, TX 77030 USA
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40
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Affiliation(s)
- Michael J Maroney
- Department of Chemistry, University of Massachusetts , Amherst, Massachusetts 01003, United States
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41
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Cheng L, Cord-Ruwisch R. Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture. ACTA ACUST UNITED AC 2013; 40:1095-104. [DOI: 10.1007/s10295-013-1310-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
Abstract
In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterility to avoid contaminant microbes overgrowing the production strain. The current paper describes the sustainable, non-sterile production of an industrial enzyme using activated sludge as inoculum. By using selective conditions (high pH, high ammonia concentration, and presence of urea) for the target bacterium, highly active ureolytic bacteria, physiologically resembling Sporosarcina pasteurii were reproducibly enriched and then continuously produced via chemostat operation of the bioreactor. When using a pH of 10 and about 0.2 M urea in a yeast extract-based medium, ureolytic bacteria developed under aerobic chemostat operation at hydraulic retention times of about 10 h with urease levels of about 60 μmol min−1 ml−1 culture. For cost minimization at an industrial scale the costly protein-rich yeast extract medium could be replaced by commercial milk powder or by lysed activated sludge. Glutamate, molasses, or glucose-based media did not result in the enrichment of ureolytic bacteria by the chemostat. The concentration of intracellular urease was sufficiently high such that the produced raw effluent from the reactor could be used directly for biocementation in the field.
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Affiliation(s)
- Liang Cheng
- grid.1025.6 0000000404366763 School of Biological Sciences and Biotechnology Murdoch University 90 South Street 6150 Perth WA Australia
| | - Ralf Cord-Ruwisch
- grid.1025.6 0000000404366763 School of Biological Sciences and Biotechnology Murdoch University 90 South Street 6150 Perth WA Australia
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Structure of the UreD-UreF-UreG-UreE complex in Helicobacter pylori: a model study. J Biol Inorg Chem 2013; 18:571-7. [PMID: 23661161 DOI: 10.1007/s00775-013-1002-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
Abstract
The molecular details of the protein complex formed by UreD, UreF, UreG, and UreE, accessory proteins for urease activation in the carcinogenic bacterium Helicobacter pylori, have been elucidated using computational modeling. The calculated structure of the complex supports the hypothesis of UreF acting as a GTPase activation protein that facilitates GTP hydrolysis by UreG during urease maturation, and provides a rationale for the design of new drugs against infections by ureolytic bacterial pathogens.
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Contribution of urease to colonization by Shiga toxin-producing Escherichia coli. Infect Immun 2012; 80:2589-600. [PMID: 22665380 DOI: 10.1128/iai.00210-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen with a low infectious dose that colonizes the colon in humans and can cause severe clinical manifestations such as hemolytic-uremic syndrome. The urease enzyme, encoded in the STEC chromosome, has been demonstrated to act as a virulence factor in other bacterial pathogens. The NH(3) produced as urease hydrolyzes urea can aid in buffering bacteria in acidic environments as well as provide an easily assimilated source of nitrogen that bacteria can use to gain a metabolic advantage over intact microflora. Here, we explore the role of urease in STEC pathogenicity. The STEC urease enzyme exhibited maximum activity near neutral pH and during the stationary-growth phase. Experiments altering growth conditions performed with three phylogenetically distinct urease-positive strains demonstrated that the STEC ure gene cluster is inducible by neither urea nor pH but does respond to nitrogen availability. Quantitative reverse transcription-PCR (qRT-PCR) data indicate that nitrogen inhibits the transcriptional response. The deletion of the ure gene locus was constructed in STEC strain 88-0643, and the ure mutant was used with the wild-type strain in competition experiments in mouse models to examine the contribution of urease. The wild-type strain was twice as likely to survive passage through the acidic stomach and demonstrated an enhanced ability to colonize the intestinal tract compared to the ure mutant strain. These in vivo experiments reveal that, although the benefit STEC gains from urease expression is modest and not absolutely required for colonization, urease can contribute to the pathogenicity of STEC.
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Urease activity represents an alternative pathway for Mycobacterium tuberculosis nitrogen metabolism. Infect Immun 2012; 80:2771-9. [PMID: 22645285 DOI: 10.1128/iai.06195-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the urease-deficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrient-limited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment.
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Abstract
Helicobacter pylori infects half of the world's population and plays a causal role in ulcer disease and gastric cancer. This pathogenic neutralophile uniquely colonizes the acidic gastric milieu through the process of acid acclimation. Acid acclimation is the ability of the organism to maintain periplasmic pH near neutrality in an acidic environment to prevent a fall in cytoplasmic pH in order to maintain viability and growth in acid. Recently, due to an increase in antibiotic resistance, the rate of H. pylori eradication has fallen below 80% generating renewed interest in novel eradication regimens and targets. In this article, we review the gastric biology of H. pylori and acid acclimation, various detection procedures, antibiotic resistance and the role that gastric acidity plays in the susceptibility of the organism to antibiotics currently in use and propose several novel drug targets that would promote eradication in the absence of antibiotics.
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Abdela W, Graham M, Tsegaye H, Temesgen S, Yehualaeshet T. Effects of orange juice pH on survival, urease activity and DNA profiles of Yersinia enterocolitica and Yersinia pseudotuberculosis stored at 4 degree C. J Food Saf 2011; 31:487-496. [PMID: 22081735 PMCID: PMC3212038 DOI: 10.1111/j.1745-4565.2011.00325.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The objective of this study was to determine the survival, growth rate and possible cellular adaptation mechanisms of Y. pseudotuberculosis and Y. enterocolitica in orange juice under different pH conditions. Yersinia was inoculated in orange juice with adjusted pH levels of 3.9, 4.0, and 7.0 and stored at 4 C for 3, 24, 72 and 168 hours (h). The inter-and intra-species variation is significant to the pH and time of incubation variables (p<0.05). At 3.9 pH the CFU (colony forming units) count decreased significantly.At pH 3.9 and 4.0, Y. enterocolitica and Y. pseudotuberculosis survived for at least 30 days and 15 days, respectively. Yersinia that survived under low pH in orange juice revealed enhanced urease activity within 12 h of incubation. The attachment gene (ail) could not be detected by PCR in Y. enterocolitica from undiluted sample incubated for 24 h or longer. Moreover, the FesI-restriction profile was altered when Y. pseudotuberculosis was stored at pH 4.0 orange juice for 7 days. These results indicate that Yersinia could survive and grow at low pH and the survival mechanisms could also enable the bacteria to survive the stomach pH barrier to cause enteric infection.
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Affiliation(s)
- Woubit Abdela
- Department of Pathobiology, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, AL 36088
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Kidd SP, Djoko KY, Ng J, Argente MP, Jennings MP, McEwan AG. A novel nickel responsive MerR-like regulator, NimR, from Haemophilus influenzae. Metallomics 2011; 3:1009-18. [PMID: 21952667 DOI: 10.1039/c1mt00127b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have identified a novel regulator from the MerR family of transcription factors in the bacterial pathogen Haemophilus influenzae (HI1623; nickel-associated merR-like Regulator--NimR). NimR regulates the expression of a Ni(2+) uptake transporter (NikKLMQO). The promoters for nimR and the nik operon are divergent and overlapping and NimR binds at a site between the promoter elements for nikKLMQO. Expression of this operon requires NimR and depends on Ni(2+). Growth rates of the H. influenzae nimR and nikQ mutants were reduced in chemically defined media compared to the wild type and the mutants were unable to grow in the presence of EDTA. The mutant strains were less tolerant of acidic pH and the wild type Rd KW20 could not tolerate low pH in the presence of fluoramide, a urease specific inhibitor, confirming that both nickel transport and urea hydrolysis are a central process in pH control. H. influenzae nimR and nikQ strains were deficient in urease activity, but this could be specifically restored by the addition of excess Ni(2+). NimR did not directly regulate the expression of urease genes but the activity of urease requires both nimR and nikQ. Purified NimR is a dimer that binds 1 Ni(2+)ion. NimR is the first example of a Ni-dependent regulator from the MerR family and targeting a metal ion uptake system; it is distinct from NikR the Ni-responsive regulators of the ribbon-helix-helix family.
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Affiliation(s)
- Stephen P Kidd
- School of Molecular and Biomedical Science, The University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
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Curreem SO, Teng JL, Tse H, Yuen KY, Lau SK, Woo PC. General metabolism of Laribacter hongkongensis: a genome-wide analysis. Cell Biosci 2011; 1:16. [PMID: 21711917 PMCID: PMC3125206 DOI: 10.1186/2045-3701-1-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 04/19/2011] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Laribacter hongkongensis is associated with community-acquired gastroenteritis and traveler's diarrhea. In this study, we performed an in-depth annotation of the genes and pathways of the general metabolism of L. hongkongensis and correlated them with its phenotypic characteristics. RESULTS The L. hongkongensis genome possesses the pentose phosphate and gluconeogenesis pathways and tricarboxylic acid and glyoxylate cycles, but incomplete Embden-Meyerhof-Parnas and Entner-Doudoroff pathways, in agreement with its asaccharolytic phenotype. It contains enzymes for biosynthesis and β-oxidation of saturated fatty acids, biosynthesis of all 20 universal amino acids and selenocysteine, the latter not observed in Neisseria gonorrhoeae, Neisseria meningitidis and Chromobacterium violaceum. The genome contains a variety of dehydrogenases, enabling it to utilize different substrates as electron donors. It encodes three terminal cytochrome oxidases for respiration using oxygen as the electron acceptor under aerobic and microaerophilic conditions and four reductases for respiration with alternative electron acceptors under anaerobic conditions. The presence of complete tetrathionate reductase operon may confer survival advantage in mammalian host in association with diarrhea. The genome contains CDSs for incorporating sulfur and nitrogen by sulfate assimilation, ammonia assimilation and nitrate reduction. The existence of both glutamate dehydrogenase and glutamine synthetase/glutamate synthase pathways suggests an importance of ammonia metabolism in the living environments that it may encounter. CONCLUSIONS The L. hongkongensis genome possesses a variety of genes and pathways for carbohydrate, amino acid and lipid metabolism, respiratory chain and sulfur and nitrogen metabolism. These allow the bacterium to utilize various substrates for energy production and survive in different environmental niches.
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Affiliation(s)
- Shirly O Curreem
- Department of Microbiology, The University of Hong Kong, Hong Kong.
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Trček J, Oellerich MF, Niedung K, Ebel F, Freund S, Trülzsch K. Gut proteases target Yersinia invasin in vivo. BMC Res Notes 2011; 4:129. [PMID: 21501502 PMCID: PMC3094372 DOI: 10.1186/1756-0500-4-129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/18/2011] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Yersinia enterocolitica is a common cause of food borne gastrointestinal disease. After oral uptake, yersiniae invade Peyer's patches of the distal ileum. This is accomplished by the binding of the Yersinia invasin to β1 integrins on the apical surface of M cells which overlie follicle associated lymphoid tissue. The gut represents a barrier that severely limits yersiniae from reaching deeper tissues such as Peyer's patches. We wondered if gut protease attack on invasion factors could contribute to the low number of yersiniae invading Peyer's patches. FINDINGS Here we show that invasin is rapidly degraded in vivo by gut proteases in the mouse infection model. In vivo proteolytic degradation is due to proteolysis by several gut proteases such as trypsin, α-chymotrypsin, pancreatic elastase, and pepsin. Protease treated yersiniae are shown to be less invasive in a cell culture model. YadA, another surface adhesin is cleaved by similar concentrations of gut proteases but Myf was not cleaved, showing that not all surface proteins are equally susceptible to degradation by gut proteases. CONCLUSIONS We demonstrate that gut proteases target important Yersinia virulence factors such as invasin and YadA in vivo. Since invasin is completely degraded within 2-3 h after reaching the small intestine of mice, it is no longer available to mediate invasion of Peyer's patches.
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Affiliation(s)
- Janja Trček
- Max von Pettenkofer Institut für Hygiene und Medizinische Mikrobiologie, Ludwig Maximilians Universität München, Germany.
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