scholarly journals The Mammalian Neuroendocrine Hormone Norepinephrine Supplies Iron for Bacterial Growth in the Presence of Transferrin or Lactoferrin

2000 ◽  
Vol 182 (21) ◽  
pp. 6091-6098 ◽  
Author(s):  
Primrose P. E. Freestone ◽  
Mark Lyte ◽  
Christopher P. Neal ◽  
Anthony F. Maggs ◽  
Richard D. Haigh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Serum Albumin ◽  
Bacterial Growth ◽  
Bacterial Species ◽  
Bacterial Cells ◽  
Excess Iron ◽  
Iron Supply ◽  
Inactive Metabolite ◽  
Serum Components ◽  
Stimulation Of

ABSTRACT Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive metabolite norepinephrine 3-O-sulfate, by contrast, did not result in iron loss from transferrin or lactoferrin and did not stimulate bacterial growth in serum-SAPI medium. Norepinephrine formed stable complexes with transferrin, lactoferrin, and serum albumin. Norepinephrine-transferrin and norepinephrine-lactoferrin complexes, but not norepinephrine-apotransferrin or norepinephrine-albumin complexes, stimulated bacterial growth in serum-SAPI medium in the absence of additional norepinephrine. Norepinephrine-stimulated growth in medium containing 55Fe complexed with transferrin or lactoferrin resulted in uptake of radioactivity by bacterial cells. Moreover, norepinephrine-stimulated growth in medium containing [3H]norepinephrine indicated concomitant uptake of norepinephrine. In each case, addition of excess iron did not affect growth but significantly reduced levels of radioactivity (55Fe or 3H) associated with bacterial cells. A role for catecholamine-mediated iron supply in the pathophysiology of infectious diseases is proposed.

scholarly journals Impact of Different Carbon Sources on the in vitro Growth and Viability of Escherichia coli (SUBE01) and Salmonella spp. (SUBS01) Cells

2016 ◽  
pp. 39-44
Author(s):  
Ifra Tun Nur ◽  
Jannatun Tahera ◽  
Md Sakil Munna ◽  
M Majibur Rahman ◽  
Rashed Noor
Keyword(s):  
Escherichia Coli ◽  
Bacterial Growth ◽  
Culture Media ◽  
Bacterial Species ◽  
Carbon Sources ◽  
Growth Dynamics ◽  
Luria Bertani ◽  
Tween 20 ◽  
Salmonella Spp

With a previous observation of Escherichia coli growth cessation along with temperature variation within three different bacteriological culture media (nutrient agar, Luria-Bertani agar and minimal agar), current investigation further depicted on the possible growth dynamics of Escherichia coli (SUBE01) and Salmonella (SUBS01) growth and viability upon supplementation of different carbon sources (dextrose, sucrose, lactose, glycerol and tween 20) at 37°C under the aeration of 100 rpm. Viability of the tested bacterial species was assessed through the enumeration of the colony forming unit (cfu) appeared upon prescribed incubation for 12-24 hours on different agar plates consisting of the above mentioned carbon sources. Besides, to inspect the cellular phenotypic changes, morphological observations were conducted under the light microscope. Variations in bacterial growth (either growth acceleration or cessation) were further noticed through the spot tests on the agar plates. Considerable shortfalls in the culturable cells of E. coli and Salmonella spp. were noted in the minimal media separately consisting of sucrose, lactose, glycerol or tween 20 while an opposite impact of accelerated growth was noticed in the media supplied with dextrose. The data revealed a hierarchy of consequence of carbon sources as nutrient generators whereby the favourable bacterial growth and survival order of the carbon sources was estimated as dextrose > glycerol > lactose > tween 20 > sucrose.Bangladesh J Microbiol, Volume 32, Number 1-2,June-Dec 2015, pp 39-44

Involvement of the cgtA gene function in stimulation of DNA repair in Escherichia coli and Vibrio harveyi

Microbiology ◽  
2003 ◽  
Vol 149 (7) ◽  
pp. 1763-1770 ◽  
Author(s):  
Ryszard Zielke ◽  
Aleksandra Sikora ◽  
Rafał Dutkiewicz ◽  
Grzegorz Wegrzyn ◽  
Agata Czyż
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Dna Repair ◽  
Gene Product ◽  
Uv Irradiation ◽  
Vibrio Harveyi ◽  
Bacterial Species ◽  
Wild Type ◽  
E Coli ◽  
Stimulation Of

CgtA is a member of the Obg/Gtp1 subfamily of small GTP-binding proteins. CgtA homologues have been found in various prokaryotic and eukaryotic organisms, ranging from bacteria to humans. Nevertheless, despite the fact that cgtA is an essential gene in most bacterial species, its function in the regulation of cellular processes is largely unknown. Here it has been demonstrated that in two bacterial species, Escherichia coli and Vibrio harveyi, the cgtA gene product enhances survival of cells after UV irradiation. Expression of the cgtA gene was found to be enhanced after UV irradiation of both E. coli and V. harveyi. Moderate overexpression of cgtA resulted in higher UV resistance of E. coli wild-type and dnaQ strains, but not in uvrA, uvrB, umuC and recA mutant hosts. Overexpression of the E. coli recA gene in the V. harveyi cgtA mutant, which is very sensitive to UV light, restored the level of survival of UV-irradiated cells to the levels observed for wild-type bacteria. Moreover, the basal level of the RecA protein was lower in a temperature-sensitive cgtA mutant of E. coli than in the cgtA + strain, and contrary to wild-type bacteria, no significant increase in recA gene expression was observed after UV irradiation of this cgtA mutant. Finally, stimulation of uvrB gene transcription under these conditions was impaired in the V. harveyi cgtA mutant. All these results strongly suggest that the cgtA gene product is involved in DNA repair processes, most probably by stimulation of recA gene expression and resultant activation of RecA-dependent DNA repair pathways.

scholarly journals A Stringent Analysis of Polyphosphate Dynamics inEscherichia coli

2019 ◽  
Vol 201 (9) ◽  
Author(s):  
Michael Downey
Keyword(s):  
Escherichia Coli ◽  
Infection Control ◽  
Bacterial Species ◽  
Stringent Response ◽  
Industrial Applications ◽  
Bacterial Cells ◽  
Inescherichia Coli ◽  
Content Type ◽  
Polyphosphate Accumulation ◽  
Inorganic Phosphates

ABSTRACTDuring stress, bacterial cells activate a conserved pathway called the stringent response that promotes survival. Polyphosphates are long chains of inorganic phosphates that modulate this response in diverse bacterial species. In this issue, Michael J. Gray provides an important correction to the model of how polyphosphate accumulation is regulated during the stringent response inEscherichia coli(M. J. Gray, J. Bacteriol, 201:e00664-18, 2019,https://doi.org/10.1128/JB.00664-18). With other recent publications, this study provides a revised framework for understanding how bacterial polyphosphate dynamics might be exploited in infection control and industrial applications.

scholarly journals Bioremediation of Diazinon, Pirimicarb and Atrazine Pesticides Using Bacterial Species

2021 ◽  
pp. 14-20
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Bacterial Species ◽  
Serial Dilution ◽  
Bacterial Cells ◽  
E Coli ◽  
Highly Efficient

Bacterial species such as E.coli, S. aureus and Sa. bongori were isolated from soil by using serial dilution. Bioremediation results showed the S. aureus was highly efficient on Diazinon removal by 62%, 63.2% and 68.6%, Pirimicarb removal was 44%, 52.4% and 53.8%, and Atrazine removal was 61%, 65.6% and 70.6%. and the efficiency of E.coli removal on Diazinon was 59%, 60.8% and 63.8%; on Pirimicarb was 44%, 52.4% and 53.8%; and for Atrazine 57%, 60.8% and 64.4%. Sa. bongori efficiency on Diazinon was 49%, 51.2% and 55.8%; on Pirimicarb removal was 61%, 63.2% and 68.4%; Also, in Atrazine removal 48%, 50.4% and 57.2%. When comparing the growth rate of bacterial cells. The bacterial cells before treatment with S. aureus was 22.01×10^4, Results after treatment showed Diazinon of 35.58×10^4. The Pirimicarb 32.41×10^4 and Atrazine was 38.45 ×10^4. Either E. coli Its bacterial growth was before treatment 17.09×10^4 To show the results of growth on diazinon 30.43×10^4, Pirimicarb 27.71×10^4 and Atrazine 24.34 ×10^4. While the growth was in Sa. bongori Before treatment 10.09×10^4 While recorded a growth rate on Diazinon 18.82×10^4, Pirimicarb 19.98×10^4 and Atrazine 17.08 ×10^4.These bacterial species efficiencies on bioremediation of these three pesticides proved to be promising It can be used safely in the process of removing pesticides, yet more research on safety, mechanisms and kinetics needs to be further investigated.

scholarly journals Accelerated microbial-induced CaCO<sub>3</sub> precipitation in a defined co-culture of ureolytic and non-ureolytic bacteria

2013 ◽  
Vol 10 (11) ◽  
pp. 17249-17273 ◽  
Author(s):  
D. Gat ◽  
M. Tsesarsky ◽  
D. Shamir ◽  
Z. Ronen
Keyword(s):  
Mixed Culture ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Bacterial Species ◽  
Control Treatment ◽  
Bacterial Cells ◽  
Nucleation Sites ◽  
Chemical Conditions ◽  
Ureolytic Bacteria ◽  
Stimulation Of

Abstract. Microbial-induced CaCO3 precipitation (MICP) is an innovative technique that harnesses bacterial activity for the modification of the physical properties of soils. Since stimulation of MICP by urea hydrolysis in natural soils is likely to be affected by interactions between ureolytic and non-ureolytic bacteria, we designed an experiment to examine the interactions between ureolytic and non-ureolytic bacteria and the effect of these interactions on MICP. An artificial groundwater-based rich medium was inoculated with two model species of bacteria, the ureolytic species Sporosarcina pasteurii and the non-ureolytic species Bacillus subtilis. The control treatment was inoculated with a pure culture of S. pasteurii. The following parameters were monitored during the course of the experiment: optical density, pH, and the evolution of ammonium, dissolved calcium, and dissolved inorganic carbon. The results showed that dissolved calcium was precipitated as CaCO3 faster in the mixed culture than in the control, despite less favorable chemical conditions in the mixed culture, i.e., lower pH and lower CO32− concentration. B. subtilis exhibited a considerably higher growth rate than S. pasteurii, resulting in higher density of bacterial cells in the mixed culture. We suggest that the presence of the non-ureolytic bacterial species, B. subtilis, accelerated the MICP process, via the supply of nucleation sites in the form of non-ureolytic bacterial cells.

scholarly journals RNA Polymerases from Bacillus subtilisand Escherichia coli Differ in Recognition of Regulatory Signals In Vitro

2000 ◽  
Vol 182 (21) ◽  
pp. 6027-6035 ◽  
Author(s):  
Irina Artsimovitch ◽  
Vladimir Svetlov ◽  
Larry Anthony ◽  
Richard R. Burgess ◽  
Robert Landick
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
In Vitro Transcription ◽  
Rna Polymerases ◽  
Bacterial Cells ◽  
Signal Recognition ◽  
E Coli ◽  
Promoter Recognition ◽  
Species Specific

ABSTRACT Adaptation of bacterial cells to diverse habitats relies on the ability of RNA polymerase to respond to various regulatory signals. Some of these signals are conserved throughout evolution, whereas others are species specific. In this study we present a comprehensive comparative analysis of RNA polymerases from two distantly related bacterial species, Escherichia coli and Bacillus subtilis, using a panel of in vitro transcription assays. We found substantial species-specific differences in the ability of these enzymes to escape from the promoter and to recognize certain types of elongation signals. Both enzymes responded similarly to other pause and termination signals and to the general E. coli elongation factors NusA and GreA. We also demonstrate that, although promoter recognition depends largely on the ς subunit, promoter discrimination exhibited in species-specific fashion by both RNA polymerases resides in the core enzyme. We hypothesize that differences in signal recognition are due to the changes in contacts made between the β and β′ subunits and the downstream DNA duplex.

scholarly journals Flavonoids from mango leaves with antibacterial activity

2009 ◽  
Vol 74 (12) ◽  
pp. 1389-1399 ◽  
Author(s):  
Qudsia Kanwal ◽  
Ishtiaq Hussain ◽  
Latif Siddiqui ◽  
Arshad Javaid
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Bacterial Growth ◽  
Mangifera Indica ◽  
Bacterial Species ◽  
Bacillus Sp ◽  
Mango Leaves

Five flavonoids, viz. (-)-epicatechin-3-O-?-glucopyranoside (1), 5-hydroxy- 3-(4-hydroxylphenyl)pyrano[3,2-g]chromene-4(8H)-one (2), 6-(p-hydroxybenzyl) taxifolin-7-O-?-D-glucoside (tricuspid) (3), quercetin-3-O-?-glucopyranosyl-(1->2)-?-glucopyranoside (4) and (-)-epicatechin(2-(3,4-dihydroxyphenyl)- 3,4-dihydro-2H-chromene-3,5,7-triol) (5), were isolated from the leaves of mango (Mangifera indica L.). The antibacterial activity of different concentrations of these flavonoids (100, 300, 500, 700, 900 and 1000 ppm) was evaluated against four bacterial species, namely Lactobacillus sp., Escherichia coli, Azospirillium lipoferum and Bacillus sp. All the tested concentrations of the five flavonoids significantly reduced the growth of all the five tested bacterial species. However, differences in the antibacterial activity of the flavonoids were evident. Compound 1 exhibited the lowest antibacterial activity, resulting in a 7-75 % reduction in the growth of the different bacterial species. Compound 5 showed the greatest antibacterial activity and the different concentrations reduced the bacterial growth by 45-99.9%. A. lipoferum and Bacillus sp. showed the highest susceptibility to this compound. Compounds 2-4 also depicted pronounced antibacterial activity. Different concentrations of these compounds decreased bacterial growth by 52-96 %. From the present study, it can be concluded that compound 5 is the most effective of the tested flavonoids against A. lipoferum and Bacillus sp.

scholarly journals The Role of Iron in the Susceptibility of Neonatal Mice to Escherichia coli K1 Sepsis

2019 ◽  
Vol 220 (7) ◽  
pp. 1219-1229
Author(s):  
Kathryn R Michels ◽  
Nathalie J Lambrecht ◽  
William F Carson ◽  
Matthew A Schaller ◽  
Nicholas W Lukacs ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Growth ◽  
Maternal Diet ◽  
Fatal Disease ◽  
E Coli ◽  
Excess Iron ◽  
Neonatal Mice ◽  
Adult Mice ◽  
Escherichia Coli K1

Abstract Sepsis from Escherichia coli expressing the K1 antigen is a leading cause of death in neonates. In a murine model, E. coli K1 grew rapidly in the peritoneal cavity of neonatal mice, causing fatal disease. In contrast, adult mice cleared the infection. Neonatal mice mounted a rapid and equivalent antimicrobial immune response compared to adult mice. Interestingly, peritoneal fluid from neonatal mice contained significantly more total iron than that of adult mice, which was sufficient to support enhanced E. coli growth. Transient iron overload in adult mice infected with E. coli resulted in 100% mortality. Maternal diet–induced mild iron deficiency decreased offspring peritoneal iron, decreased bacterial growth, and conferred protection against sepsis. Taken together, neonatal susceptibility to E. coli K1 sepsis is enhanced by a localized excess of peritoneal iron that allows for unchecked bacterial growth. Targeting this excess iron may provide a new therapeutic target in human patients.

scholarly journals Accelerated microbial-induced CaCO<sub>3</sub> precipitation in a defined coculture of ureolytic and non-ureolytic bacteria

2014 ◽  
Vol 11 (10) ◽  
pp. 2561-2569 ◽  
Author(s):  
D. Gat ◽  
M. Tsesarsky ◽  
D. Shamir ◽  
Z. Ronen
Keyword(s):  
Mixed Culture ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Bacterial Species ◽  
Control Treatment ◽  
Bacterial Cells ◽  
Nucleation Sites ◽  
Chemical Conditions ◽  
Ureolytic Bacteria ◽  
Stimulation Of

Abstract. Microbial-induced CaCO3 precipitation (MICP) is an innovative technique that harnesses bacterial activity for the modification of the physical properties of soils. Since stimulation of MICP by urea hydrolysis in natural soils is likely to be affected by interactions between ureolytic and non-ureolytic bacteria, we designed an experiment to examine the interactions between ureolytic and non-ureolytic bacteria and the effect of these interactions on MICP. An artificial groundwater-based rich medium was inoculated with two model species of bacteria, the ureolytic species Sporosarcina pasteurii and the non-ureolytic species Bacillus subtilis. The control treatment was inoculated with a pure culture of S. pasteurii. The following parameters were monitored during the course of the experiment: optical density, pH, the evolution of ammonium, dissolved calcium and dissolved inorganic carbon. The results showed that dissolved calcium was precipitated as CaCO3 faster in the mixed culture than in the control, despite less favorable chemical conditions in the mixed culture, i.e., lower pH and lower CO32− concentration. B. subtilis exhibited a considerably higher growth rate than S. pasteurii, resulting in higher density of bacterial cells in the mixed culture. We suggest that the presence of the non-ureolytic bacterial species, B. subtilis, accelerated the MICP process, via the supply of nucleation sites in the form of non-ureolytic bacterial cells.

Mechanisms involved in effects of antimicrobial peptides, bactenectins ChBac3.4, ChBac5, and mini-ChBac7.5Nb, on bacterial cells

2017 ◽  
pp. 43-50
Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Innate Immunity ◽  
Infectious Diseases ◽  
Metabolic Activity ◽  
Capra Hircus ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistant Strains

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.

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