scholarly journals Structural and proteomic changes in viable but non-culturableVibrio cholerae

2018 ◽  
Author(s):  
Susanne Brenzinger ◽  
Lizah T. van der Aart ◽  
Gilles P. van Wezel ◽  
Jean-Marie Lacroix ◽  
Timo Glatter ◽  
...  
Keyword(s):  
Natural Waters ◽  
Diarrheal Disease ◽  
Cell Envelope ◽  
Iron Acquisition ◽  
Central Carbon Metabolism ◽  
Vbnc State ◽  
First Time ◽  
And Storage ◽  
Infectious Potential ◽  
Overnight Culture

AbstractAquatic environments are reservoirs of the human pathogenVibrio choleraeO1, which causes the acute diarrheal disease cholera. Upon low temperature or limited nutrient availability, the cells enter a viable but non-culturable (VBNC) state. Characteristic of this state are an altered morphology, low metabolic activity and lack of growth under standard laboratory conditions. Here, for the first time, the cellular ultrastructure ofV. choleraeVBNC cells raised in natural waters was investigated using electron cryo-tomography complemented by comparison of the proteomes and the peptidoglycan composition of LB overnight culture and VBNC cells. The extensive remodeling of the VBNC cells was most obvious in the passive dehiscence of the cell envelope, resulting in improper embedment of flagella and pili. Only minor changes of the peptidoglycan and osmoregulated periplasmic glucans were observed. Active changes in VBNC cells included the production of cluster I chemosensory arrays and change of abundance of cluster II array proteins. Components involved in iron acquisition and storage, peptide import and arginine biosynthesis were overrepresented in VBNC cells, while enzymes of the central carbon metabolism were found at lower levels. Finally, several pathogenicity factors ofV. choleraewere less abundant in the VBNC state, potentially limiting their infectious potential.

scholarly journals The degree analysis of hydrobionts response to the content of chemicals in the water of the upper and middle reaches of the Belaya River (Republic of Bashkortostan)

2018 ◽  
Vol 7 (4) ◽  
pp. 144-152
Author(s):  
Boris Yuryevich Chaus
Keyword(s):  
Natural Waters ◽  
Anthropogenic Pollution ◽  
Hydrochemical Parameters ◽  
Republic Of Bashkortostan ◽  
Invertebrate Animals ◽  
State Water ◽  
The Republic ◽  
First Time ◽  
Reliable Correlation ◽  
Water Vegetation

The paper deals with the analysis of bioindicator opportunities of hydrobionts of various systematic categories that helps to assess and forecast anthropogenic pollution of the Belaya River (the top and average currents) during environmental monitoring of natural waters of the Republic of Bashkortostan. Hydrobionts were collected and the occurrence analysis (in unit shares) of 30 species of invertebrate animals from groups Pyramidelloida, Littorinimorpha, Pulmonata, Plecoptera, Ephemeroptera, Trichoptera and 12 species of the highest water vegetation was carried out from 2005 to 2017 in regions of 10 state water posts on the Belaya River. The data from annual State reports on the average annual content of compounds of manganese, nickel and iron, oil products, phenols, nitrogen ammoniyny, copper and zincum were used as hydrochemical parameters during the research. The reliable correlation between some water organisms with chemicals and their connections was defined in the water of the Belaya River. The author also constructs for the first time an indicator range of hydrobionts on decrease extent in their response to the chemicals content in the studied water. Similar approach can be used for recommendations development about the use of biological analyses while identifying the chemicals influencing water fauna and flora.

scholarly journals Molecular architecture of theLegionellaDot/Icm type IV secretion system

2018 ◽  
Author(s):  
Debnath Ghosal ◽  
Yi-Wei Chang ◽  
Kwang Cheol Jeong ◽  
Joseph P. Vogel ◽  
Grant J. Jensen
Keyword(s):  
Legionella Pneumophila ◽  
Cell Envelope ◽  
Secretion System ◽  
Host Cells ◽  
Molecular Architecture ◽  
Intact Cells ◽  
Type Iv ◽  
Type Ivb Secretion ◽  
Electron Cryotomography ◽  
First Time

AbstractLegionella pneumophilasurvives and replicates inside host cells by secreting ~300 effectors through the Dot/Icm type IVB secretion system (T4BSS). Understanding this machine’s structure is challenging because of its large number of components (27) and integration into all layers of the cell envelope. Previously we overcame this obstacle by imaging the Dot/Icm T4BSS in its native state within intact cells through electron cryotomography. Here we extend our observations by imaging a stabilized mutant that yielded a higher resolution map. We describe for the first time the presence of a well-ordered central channel that opens up into a windowed large (~32 nm wide) secretion chamber with an unusual 13-fold symmetry. We then dissect the complex by matching proteins to densities for many components, including all those with periplasmic domains. The placement of known and predicted structures of individual proteins into the map reveals the architecture of the T4BSS and provides a roadmap for further investigation of this amazing specialized secretion system.

scholarly journals Investigation of Iron uptake and virulence gene factors (fur, tonB, exbD, exbB, hgbA, hgbB1, hgbB2 and tbpA) among isolates of Pasteurella multocida from Iran

2019 ◽  
Author(s):  
Motahare Feizabadi Farahani ◽  
Majid Esmaelizad ◽  
Ahmad Reza Jabbari
Keyword(s):  
Virulence Factors ◽  
Iron Uptake ◽  
Pasteurella Multocida ◽  
Iron Acquisition ◽  
Virulence Gene ◽  
Basic Information ◽  
Iron Supply ◽  
Wide Range ◽  
Pcr Method ◽  
First Time

Background and Objectives: Iron is an essential compound in metabolic pathway of wide range of organisms. Because of limited free iron supply in mammalian and avian hosts, bacteria have applied various ways to acquire iron. Materials and Methods: In this study, the frequency of 8 iron acquisition factors was examined among 63 avian and ovine Pasteurella multocida field isolates and their vaccine strains using PCR method. Results: Five candidate genes (fur, tonB, exbD, exbB and hgbA) were identified among all isolates. For the first time, 2 loci (hgbB1 and hgbB2) of the hgbB gene were identified, which were previously reported as 1 gene. Also, it was found that 5 ovine and 1 avian isolates possessed all the virulence factors, which could also be considered for evaluating the frequency of other virulence factors. Conclusion: More studies need to be conducted on the frequency of all other virulence factors among these isolates, which can provide basic information for improvement or substitution of current vaccinal strains. Overall, as the new designed sets of primers showed more potential in detecting the corresponded genes, researchers can consider them in further studies.

Iron Oxides: An Example of Structural Versatility

2019 ◽  
Author(s):  
Jean-Pierre Jolivet
Keyword(s):  
Iron Oxides ◽  
Natural Waters ◽  
Active Centers ◽  
Large Variability ◽  
Oxygenated Compounds ◽  
Crystal Structural ◽  
Living Organisms ◽  
Inorganic Ligands ◽  
And Storage ◽  
Microbial Mediation

Iron is Earth’s fourth most widespread element (6.2% in mass), behind oxygen, silicon, and aluminum. It exists mostly as ferric oxide and oxyhydroxide (Fig. 7.1a) and to a lesser extent as sulfide (pyrite), carbonate (siderite), and silicate (fayalite). Iron oxides are largely used in technological areas such as metallurgy, colored pigments, magnetic materials, and catalysts. They also play an important role in the environment because the dissolution of ferric oxides in natural waters, promoted by acid–base, redox, photochemical phenomena, and also microbial mediation, allows iron to be involved in many biogeochemical processes. Iron is present in many living organisms such as plants, bacteria, mollusks, animals, and humans in various forms: . . . Porphyrinic complexes of iron, which are active centers of hemoglobin and several ferredoxins involved in biological functions, especially respiration mechanism and photosynthesis. Nanoparticles of amorphous ferric oxyhydroxides in animal and human organisms as ferritin, which allows regulation and storage of iron and in various nanophases present in plants as phytoferritin. Crystalline iron oxy(hydroxi)des produced by biomineralization processes. Goethite, lepidocrocite, and magnetite are the main constituents of radulas and the teeth of mollusks (limpets, chitons). Magnetite nanoparticles produced by magnetotactic bacteria (Fig. 7.1b), as well as by bees and pigeons, are used for purposes of orientation and guiding along the lines of force of the Earth’s magnetic field. Green rusts are also ferric- ferrous compounds belonging to the biogeochemical cycle of iron. . . . The crystal chemistry of iron oxy(hydroxi)des is very rich. The ferric, ferrous, and mixed ferric- ferrous oxygenated compounds correspond to around a dozen crystal structural types (Fig. 7.2). Most of these crystal phases can be synthesized from solutions in the laboratory, giving rise to a most diversified chemistry. They are also formed in nature because of the large variability of physicochemical conditions: an acidity range from around pH 0 to 13; redox conditions from oxic to totally anoxic media; bacterial activity that can be extremely intense; salinity largely varying from almost pure waters to real brines; presence of many organic and inorganic ligands; and various photochemical processes.

Bacterial Contamination of Sago Starch in Papua New Guinea

2007 ◽  
Vol 70 (12) ◽  
pp. 2868-2872 ◽  
Author(s):  
A. R. GREENHILL ◽  
W. A. SHIPTON ◽  
A. D. OMOLOSO ◽  
B. AMOA ◽  
J. M. WARNER
Keyword(s):  
Papua New Guinea ◽  
Diarrheal Disease ◽  
Fecal Contamination ◽  
New Guinea ◽  
Sago Starch ◽  
Indicator Organisms ◽  
High Starch ◽  
Storage Methods ◽  
And Storage ◽  
Coagulase Positive Staphylococci

Sago starch is an important food in lowland Papua New Guinea. Extraction of the starch from the palm and storage were performed by way of traditional methods that have been used for thousands of years. Currently, very little is known about the microbiology of sago starch. Sago samples were collected from areas of high starch utilization and analyzed for the presence of bacterial pathogens and indicator organisms. Storage methods and duration were recorded at the time of collection, and pH and water activity on arrival at the laboratory. Sago starch was found to harbor high levels of fecal contamination, as well as various food pathogens including Salmonella, Bacillus cereus, and coagulase-positive staphylococci. Clostridium perfringens was only present infrequently in samples and in very low numbers, while Listeria monocytogenes was not isolated from sago starch. The presence of high levels of fecal contamination in sago starch is of particular concern, and may contribute to diarrheal disease in rural Papua New Guinea.

Determination of Glyphosate Herbicide and (Aminomethyl)phosphonic Acid in Natural Waters by Liquid Chromatography Using Pre-Column Fluorogenic Labeling with 9-Fluorenylmethyl Chloroformate

1986 ◽  
Vol 69 (3) ◽  
pp. 458-461 ◽  
Author(s):  
Carl J Miles ◽  
Louis R Wallace ◽  
H Anson Moye
Keyword(s):  
Liquid Chromatography ◽  
Phosphonic Acid ◽  
Natural Waters ◽  
Sample Pretreatment ◽  
Fluorescence Detector ◽  
Rotary Evaporation ◽  
Glyphosate Herbicide ◽  
And Storage ◽  
Aminomethyl Phosphonic Acid

Abstract An analytical method has been developed for determination of glyphosate herbicide and its major metabolite, (aminomethyl)phosphonic acid (AMFA), in natural waters. Sample pretreatment consisted of filtration, addition of phosphate buffer, concentration by rotary evaporation, and a final filtration before derivatization with 9-fluorenylmethyl chloroformate. The derivatives were separated by anion exchange liquid chromatography and measured with a fluorescence detector. Standard curves were linear over 3 orders of magnitude and minimal detectable quantities were 10 ng/mL for glyphosate and 5 ng/mL for AMPA. The 20-fold concentration factor realized in sample preparation corresponds to ppb method detection limits for glyphosate and AMPA in natural waters. Recovery and storage studies were performed and are discussed.

scholarly journals Iron Deprivation Affects Drug Susceptibilities of Mycobacteria Targeting Membrane Integrity

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Rahul Pal ◽  
Saif Hameed ◽  
Zeeshan Fatima
Keyword(s):  
Mycobacterium Smegmatis ◽  
Cell Envelope ◽  
Membrane Integrity ◽  
Genotoxic Stress ◽  
Drug Susceptibility ◽  
First Line ◽  
Antitubercular Drugs ◽  
Iron Deprivation ◽  
Cellular Iron ◽  
First Time

Multidrug resistance (MDR) acquired byMycobacterium tuberculosis(MTB) through continuous deployment of antitubercular drugs warrants immediate search for novel targets and mechanisms. The ability of MTB to sense and become accustomed to changes in the host is essential for survival and confers the basis of infection. A crucial condition that MTB must surmount is iron limitation, during the establishment of infection, since iron is required by both bacteria and humans. This study focuses on how iron deprivation affects drug susceptibilities of known anti-TB drugs inMycobacterium smegmatis, a “surrogate of MTB.” We showed that iron deprivation leads to enhanced potency of most commonly used first line anti-TB drugs that could be reverted upon iron supplementation. We explored that membrane homeostasis is disrupted upon iron deprivation as revealed by enhanced membrane permeability and hypersensitivity to membrane perturbing agent leading to increased passive diffusion of drug and TEM images showing detectable differences in cell envelope thickness. Furthermore, iron seems to be indispensable to sustain genotoxic stress suggesting its possible role in DNA repair machinery. Taken together, we for the first time established a link between cellular iron and drug susceptibility of mycobacteria suggesting iron as novel determinant to combat MDR.

scholarly journals Purification and Characterization of the Bacterial UDP-GlcNAc:Undecaprenyl-Phosphate GlcNAc-1-Phosphate Transferase WecA

2008 ◽  
Vol 190 (21) ◽  
pp. 7141-7146 ◽  
Author(s):  
Bayan Al-Dabbagh ◽  
Dominique Mengin-Lecreulx ◽  
Ahmed Bouhss
Keyword(s):  
Cell Envelope ◽  
Functional Characterization ◽  
Integral Membrane Protein ◽  
Minimal Length ◽  
Purification And Characterization ◽  
Effects Of Ph ◽  
Undecaprenyl Phosphate ◽  
First Time ◽  
Lipid Substrate

ABSTRACT To date, the structural and functional characterization of proteins belonging to the polyprenyl-phosphate N-acetylhexosamine-1-phosphate transferase superfamily has been relentlessly held back by problems encountered with their overexpression and purification. In the present work and for the first time, the integral membrane protein WecA that catalyzes the transfer of the GlcNAc-1-phosphate moiety from UDP-GlcNAc onto the carrier lipid undecaprenyl phosphate, yielding undecaprenyl-pyrophosphoryl-GlcNAc, the lipid intermediate involved in the synthesis of various bacterial cell envelope components, was overproduced and purified to near homogeneity in milligram quantities. An enzymatic assay was developed, and the kinetic parameters of WecA as well as the effects of pH, salts, cations, detergents, and temperature on the enzyme activity were determined. A minimal length of 35 carbons was required for the lipid substrate, and tunicamycin was shown to inhibit the enzyme at submicromolar concentrations.

scholarly journals The Dynamic Transition of Persistence toward the Viable but Nonculturable State during Stationary Phase Is Driven by Protein Aggregation

mBio ◽  
2021 ◽  
Author(s):  
Liselot Dewachter ◽  
Celien Bollen ◽  
Dorien Wilmaerts ◽  
Elen Louwagie ◽  
Pauline Herpels ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Protein Aggregation ◽  
Conceptual Framework ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Dynamic Transition ◽  
Nonculturable State ◽  
First Time ◽  
Further Development ◽  
Viable But Nonculturable State

While persistence and the viable but nonculturable (VBNC) state are currently investigated in isolation, our results strongly indicate that these phenotypes represent different stages of the same dormancy program and that they should therefore be studied within the same conceptual framework. Moreover, we show here for the first time that the dynamics of protein aggregation perfectly match the onset and further development of bacterial dormancy and that different dormant phenotypes are linked to different stages of protein aggregation.

scholarly journals Spatial Distribution Patterns of the Hydro-Ecosystems’ Quality Indicators in the Ukrainian Carpathians

2021 ◽  
Vol 4 (1) ◽  
pp. 80-93
Author(s):  
Liudmyla Mykolayivna Arkhypova ◽  
Marta Vasylivna Korchemlyuk ◽  
Oleh Mуkolayovych Mandryk ◽  
Valery Grygorovych Omelchenko ◽  
Yuliya Stanislavivna Stakhmych
Keyword(s):  
Quality Indicators ◽  
Natural Waters ◽  
Statistical Processing ◽  
Distribution Patterns ◽  
Quality Parameters ◽  
Anthropogenic Pressure ◽  
Carpathian Region ◽  
Standard Values ◽  
First Time ◽  
Ecological Standard

This study is devoted to the two major hydro-ecosystems of the Carpathian region in Ukraine, the Dniester and Danube Rivers. For the first time, the patterns of changes in the ecosystems’ quality parameters were established by means of developing functional dependences among the ecological standard values of the composite quality indicators of natural waters and the river length and terrain altitude. Using the statistical processing of the data, the quality monitoring of the upper reaches of Dniester and Danube ecosystems in the Ukrainian Carpathians was conducted for the period from 2001 to 2019. The data on the Composite Potential Quality Indicators standard values was gathered for the heights of the Carpathian region: at 50 m interval for the altitude up to 1,000 m, and at 100 m interval for more than 1,000 m altitude. The acquired dependencies can be used as the territorial background standard values of the ecological indicators of basin ecosystems. It will help to scientifically substantiate the ecologically safe values of the anthropogenic pressure.

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