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1.
Front Microbiol ; 14: 1279720, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033599

RESUMO

Scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) were applied in many laboratories to visualize and image viruses and virus-like particles (VLPs). Two bacteriophages, P1 and Φ6, were chosen as model microorganisms known for their distinct structure, and viruses obtained from biofilms associated with modern travertines (Terme di Saturnia, Italy; Karahayit "Kizilsu" and Pamukkale, Turkey) were also investigated. Three protocols, (1) full, (2) simplified, and (3) all at once were developed and tested for sample preparation and imaging. The full procedure enabled the observation of P1 bacteriophages, whereas the simplified protocol, successful in visualizing Φ6, did not yield satisfactory results for P1. The preservation state of the latter appeared to be compromised and led to less informative images in SEM and STEM. Viruses in biofilms exhibited various levels of mineralization and aggregation, complicating their characterization. In the all at once procedure, although effective in preserving bacteriophage tails, excessive coating and thickening of samples with heavy chemical reagents led to a reduction in overall image quality. Despite a final washing step, some residues of chemical reagents (OsO4 and uranyl acetate) remained, impacting the clarity of the images. Finally, the results obtained emphasize the critical role of sample preparation and imaging techniques in effectively visualizing and characterizing viruses and VLPs. The choice of analytical procedure significantly influences the resolution and preservation state of the observed bacteriophages and VLPs. It is suggested that the appropriate imaging technique is carefully selected based on the specific objectives of the project and the nature of the samples being investigated to obtain the best images of the viruses.

2.
Physiol Plant ; 175(5): e14034, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37882306

RESUMO

Despite the interest in different temperature acclimatisations of higher plants, few studies have considered the mechanisms that allow psychrotolerant microalgae to live in a cold environment. Although the analysis of the genomes of some algae revealed the presence of specific genes that encode enzymes that can be involved in the response to stress, this area has not been explored deeply. This work aims to clarify the acclimatisation mechanisms that enable the psychrotolerant green alga Coccomyxa subellipsoidea C-169 to grow in a broad temperature spectrum. The contents of various biochemical compounds in cells, the lipid composition of the biological membranes of entire cells, and the thylakoid fraction as well as the electron transport rate and PSII efficiency were investigated. The results demonstrate an acclimatisation mechanism that is specific for C. subellipsoidea and that allows the maintenance of appropriate membrane fluidity, for example, in thylakoid membranes. It is achieved almost exclusively by changes within the unsaturated fatty acid pool, like changes from C18:2 into C18:3 and C16:2 into C16:3 or vice versa. This ensures, for example, an effective transport rate through PSII and in consequence a maximum quantum yield of it in cells growing at different temperatures. Furthermore, reactions characteristic for both psychrotolerant and mesophilic microalgae, involving the accumulation of lipids and soluble sugars in cells at temperatures other than optimal, were observed. These findings add substantially to our understanding of the acclimatisation of psychrotolerant organisms to a wide range of temperatures and prove that this process could be accomplished in a species-specific manner.


Assuntos
Clorófitas , Temperatura , Clorófitas/genética , Membrana Celular
3.
Sci Rep ; 13(1): 11663, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468551

RESUMO

Travertines, which precipitate from high temperature water saturated with calcium carbonate, are generally considered to be dominated by physico-chemical and microbial precipitates. Here, as an additional influence on organomineral formation, metagenomic data and microscopic analyses clearly demonstrate that highly diverse viral, bacterial and archaeal communities occur in the biofilms associated with several modern classic travertine sites in Europe and Asia, along with virus-like particles. Metagenomic analysis reveals that bacteriophages (bacterial viruses) containing icosahedral capsids and belonging to the Siphoviridae, Myoviridae and Podoviridae families are the most abundant of all viral strains, although the bacteriophage distribution does vary across the sampling sites. Icosahedral shapes of capsids are also the most frequently observed under the microscope, occurring as non-mineralized through to mineralized viruses and virus-like particles. Viruses are initially mineralized by Ca-Si amorphous precipitates with subordinate Mg and Al contents; these then alter to nanospheroids composed of Ca carbonate with minor silicate 80-300 nm in diameter. Understanding the roles of bacteriophages in modern carbonate-saturated settings and related organomineralization processes is critical for their broader inclusion in the geological record and ecosystem models.


Assuntos
Bacteriófagos , Podoviridae , Siphoviridae , Vírus , Humanos , Ecossistema , Bacteriófagos/genética , Podoviridae/ultraestrutura , Siphoviridae/genética , Siphoviridae/ultraestrutura
4.
RSC Adv ; 13(2): 926-936, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36686914

RESUMO

Magnetic nanoparticles (MNPs) have recently been a point of interest for many researchers due to their properties. However, the studies on the influence of bacteriophages on the synthesis of MNPs seem to be lacking. Furthermore, bacteriophage-modified MNPs have not been combined with n-alkyl quaternary ammonium ionic liquid precursors (QAS). In this study, the aim was to assess the influence of two distinctly different bacteriophages (Escherichia phage P1 and Pseudomonas phage Φ6) on MNPs synthesis in the presence or absence of QAS. Synthesized MNPs have been characterized with X-ray diffraction (XRD) and Mössbauer spectroscopy in terms of changes in the crystallographic structure; scanning electron microscopy (SEM) for changes in the morphology; and ζ-potential. Moreover, the sorption parameters and the loss of viability of bacteria that interacted with MNPs have been determined. The sorption of bacteria differs significantly among the tested samples. Furthermore, the viability of the bacteria adsorbed on MNPs varies in the presence of QAS, depending on the length of the n-alkyl chain. The study has revealed that MNPs can be bound with bacteriophages. Mössbauer spectroscopy has also revealed the probable influence of bacteriophages on the formation of crystals. However, these phenomena require further studies.

5.
Sci Rep ; 12(1): 20369, 2022 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-36437259

RESUMO

Limited mobility and restrictions in social life caused by the COVID-19 pandemic changed people's recreational behavior and made them seek more contact with nature. As a result, the provision of new recreational spaces in the vicinity of cities gained importance. In conditions of social distancing, rural and suburban areas can be an attractive alternative to individual short-term tourism, satisfying the need for recreation and mental and physical health restoration of urban residents. In the study a methodology for assessing the tourist and recreational potential of the area (METPRET) concerning the recreational behaviors identified in the pandemic was proposed. It includes the Recreational Potential Index (RPI), which comprises four criteria: landscape values and socio-economic conditions; environmental protection; air quality; transportation accessibility. The application of the methodology is exemplified in the Mazovia Voivodeship, Poland. The research allows the determination of characteristics that potential recreation areas should have under pandemic conditions. The RPI makes it possible to select new rural and suburban areas attractive for short-term tourism. Designating additional recreational areas may contribute to the dispersion of users in existing green areas in cities, which is particularly important during a pandemic.


Assuntos
COVID-19 , Turismo , Humanos , Recreação , Pandemias , COVID-19/epidemiologia , Conservação dos Recursos Naturais
6.
Insects ; 13(11)2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36421974

RESUMO

The fully non-invasive method presented here can be used to evaluate Tomicus piniperda L. population sizes in areas subject to strict protection. Data were collected in 2021−2022 in forests containing P. sylvestris, with different stand structures, in the Suchedniowsko-Oblegorski Landscape Park, Poland. Entomological analyses were carried out on natural traps made from live uncolonised trees. Stepwise regression was used to describe the size of T. piniperda populations. From a set of features representing stem colonisation parameters, stem traits and habitat, the following had a significant effect (p < 0.05) on the total number of galleries of T. piniperda on stems: (1) the number of T. piniperda maternal tunnels in the sixth stem section covering 2.5% of the total length, (2) the length of the stem section with bark thickness greater than 7 mm, and (3) stand structure (homogeneous Scots pine stands). The model can explain 93% (Radj2=0.9333) of the variability in the total number of T. piniperda galleries on trap trees. The mean relative error of estimation is 20.1%. The proposed method is particularly valuable in a climate context. The data obtained enable the prediction of the direct effects of climate change on the population dynamics of T. piniperda in natural forests.

7.
Materials (Basel) ; 14(22)2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34832450

RESUMO

Orthodontic appliances discolour over treatment time, and a yellowish plaque builds up on the contact area of the brackets, adhesive and teeth. Brilliant Blue-based plaque-staining agents (BBPSAs), which increase tooth brushing efficiency, have the potential to support the maintenance of proper oral hygiene during orthodontic treatment. However, they exhibit strong colouring properties, and their impact on the aesthetics of braces remains unclear. Therefore, the aim of this study was to investigate the influence of commercially available BBPSAs on the colour of aesthetic orthodontic materials. A light-cured, colour-changing orthodontic adhesive and new-generation, monocrystalline, sapphire brackets were chosen for the experiments. The effect of the staining agent on the tested materials was investigated in terms of the reaction temperature and time, as well as the presence of black tea-induced impurities on the materials. The CIELAB (Commission Internationale de L'éclairage L* a* b*) colour system parameters were measured, and the colour differences (ΔE*ab and ΔE00-the Commission Internationale de L'éclairage 2000 colour-difference) were determined for the materials under several experimental conditions. The braces' green-red colour expression was positively affected by the BBPSA. Under in vitro conditions, the regular use of the BBPSA for 90 days visibly improved the unfavourable colour change caused by the black tea.

8.
Materials (Basel) ; 13(17)2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32825752

RESUMO

Carbon-based (nano)materials doped with transition metals, nitrogen and other heteroatoms are considered active heterogeneous catalysts in a wide range of chemical processes. Recently they have been scrutinized as artificial enzymes since they can catalyze proton-coupled electron transfer reactions vital for living organisms. Herein, interactions between Gram-positive and Gram-negative bacteria and either metal-free N and/or S doped or metal containing Fe-N-S co-doped porous carbons are studied. The Fe- and N-co-doped porous carbons (Fe-N-C) exhibit enhanced affinity toward bacteria as they show the highest adsorption capacity. Fe-N-C materials also show the strongest influence on the bacteria viability with visible toxic effect. Both types of bacteria studied reacted to the presence of Fe-doped carbons in a similar manner, showing a decrease in dehydrogenases activity in comparison to controls. The N-coordinated iron-doped carbons (Fe-N-C) may exhibit oxidase/peroxidase-like activity and activate O2 dissolved in the solution and/or oxygen-containing species released by the bacteria (e.g., H2O2) to yield highly bactericidal reactive oxygen species. As Fe/N/ and/or S-doped carbon materials efficiently adsorb bacteria exhibiting simultaneously antibacterial properties, they can be applied, inter alia, as microbiological filters with enhanced biofouling resistance.

9.
Wideochir Inne Tech Maloinwazyjne ; 14(3): 427-432, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31534574

RESUMO

INTRODUCTION: Open adenomectomy of the prostate, although performed less frequently, is still indicated in patients with prostate adenoma > 100 ml. AIM: This study assessed the frequency of isolated bladder neck stenosis after surgery and the effectiveness of internal optical urethrotomy as monotherapy and in combination with transurethral resection in the treatment of this complication. MATERIAL AND METHODS: One thousand five hundred thirty-eight Millin's operations and 381 trans-vesical adenomectomies were performed in patients with prostate adenoma. In 50 patients, the circular hemostatic suture was applied using the de la Peña technique because of bleeding after surgery. The retrospective analysis compared the incidence of isolated bladder neck stenosis depending on the type of surgery. RESULTS: Isolated bladder neck stenosis or narrowing of the neck combined with partial stenosis of the site after adenomectomy occurred in 0.52% (8/1539) of patients after Millin's operation and in 1.05% of patients (4/381) after trans-vesical adenomectomy. All strictures of the bladder after trans-vesical surgery occurred within 12 month after the procedure, and 25% of stenoses after Millin's operation occurred many years after the surgery. Internal optical urethrotomy as monotherapy or in combination with scar resection resulted in recovery after one treatment in 16 out of 17 patients. CONCLUSIONS: Internal optical urethrotomy as monotherapy or in combination with scar resection was effective in nearly all patients with bladder neck stenosis.

10.
Ecotoxicol Environ Saf ; 181: 172-179, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185431

RESUMO

The present study was focused on the application of an electrochemical oxidation process combined with biodegradation for the removal of novel Herbicidal Ionic Liquids (HILs) -promising protection plant products which incorporate herbicidal anions and ammonium cations. The influence of carbon chain length (n = 8, 10, 12, 14, 16, 18) in the dialkyldimethylammonium cations on electrochemical oxidation kinetics, degradation efficiency and biodegradation by activated sludge was investigated. It was established that the applied cation influenced the heterogeneous rate constant and diffusion coefficient of electrochemical oxidation. The oxidation efficiency ranged from 17% in case of HILs with C8 alkyl chain to approx. 60% in case of HILs comprising C14 and C16 alkyl chains after 3 h of electrochemical treatment. Subsequent biodegradation studies revealed that electrochemical oxidation improved the mineralization efficiency of the studied HILs. The mineralization efficiency of electrochemically-treated HILs ranged from 28% in case of HILs comprising the C8 alkyl chain to 57% in case of HILs with C14 and C16 alkyl chains after 28 days. In case of untreated HILs, the corresponding mineralization efficiency ranged from 0 to 8%, respectively. This confirms the feasibility of a hybrid electrochemical-biological approach for treatment of herbicidal ionic liquids based on MCPA.


Assuntos
Ácido 2-Metil-4-clorofenoxiacético/metabolismo , Herbicidas/metabolismo , Líquidos Iônicos/metabolismo , Ácido 2-Metil-4-clorofenoxiacético/química , Ânions , Biodegradação Ambiental , Cátions , Técnicas Eletroquímicas , Herbicidas/química , Líquidos Iônicos/química , Oxirredução , Esgotos
11.
Biofouling ; 35(1): 59-74, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30727772

RESUMO

Pseudomonas aeruginosa biofilm-associated infections are a serious medical problem, and new compounds and therapies acting through novel mechanisms are much needed. Herein, the authors report a ruthenium(IV) complex that reduces P. aeruginosa PAO1 biofilm formation by 84%, and alters biofilm morphology and the living-to-dead cell ratio at 1 mM concentration. Including the compound in the culture medium altered the pigments secreted by PAO1, and fluorescence spectra revealed a decrease in pyoverdine. Scanning electron microscopy showed that the ruthenium complex did not penetrate the bacterial cell wall, but accumulated on external cell structures. Fluorescence quenching experiments indicated strong binding of the ruthenium complex to both plasmid DNA and bovine serum albumin. Formamidopyrimidine DNA N-glycosylase (Fpg) protein digestion of plasmid DNA isolated after ruthenium(IV) complex treatment revealed the generation of oxidative stress, which was further proved by the observed upregulation of catalase and superoxide dismutase gene expression.


Assuntos
Benzimidazóis/farmacologia , Biofilmes/efeitos dos fármacos , Estresse Oxidativo , Pseudomonas aeruginosa/efeitos dos fármacos , Rutênio/farmacologia , Sideróforos/química , Animais , Sítios de Ligação , Bovinos , Parede Celular/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Modelos Teóricos , Oligopeptídeos , Plasmídeos/metabolismo , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/fisiologia , Soroalbumina Bovina/química
12.
RSC Adv ; 9(49): 28724-28734, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-35529654

RESUMO

Quaternary ammonium theophylline-based ionic liquids and imidazolium-based ionic liquids, magnesium oxide and silica nanoparticles were used in order to investigate the interaction with Gram negative Escherichia coli and Gram positive Bacillus cereus. The changes of bacterial sensitivity to both nanoparticles (NPs) and ionic liquids (ILs) were examined. In order to assess the impact of ILs on the interaction of nanoparticles with bacteria, respirometric analysis, activity of dehydrogenases, peroxidase analyses as well as scanning and fluorescence microscopy examinations were conducted. The interactions of ILs with nanoparticles based on adsorption and sedimentation tests were also investigated in order to assess how the ILs affect the agglomeration of NPs. It was assumed, as the main hypothesis of the present studies, that the differences in sensitivity of bacteria to combined ILs and NPs can be observed, even if the concentration of both compounds are below the minimum inhibitory concentration (MIC). The results indicated that ILs strongly affected the sensitivity of bacteria to nanoparticles however, the changes of sensitivity depended on the surface characteristics of the nanoparticles. The presence of ILs at non-lethal concentrations caused an increase of bacterial sensitivity to MgO nanoparticles. Notably, the sensitivity of Gram positive bacteria increased significantly when ILs were present. This was an important observation because the toxicity of nanoparticles toward Gram positive bacteria is usually lower than their toxicity toward Gram negative bacteria. Using silica nanoparticles, the presence of ionic liquids caused the adsorption of bacteria onto the surface of nanoparticle agglomerates. In conclusion, two opposing effects have been observed. On the one hand, the toxicity of MgO NPs in the presence of ILs has increased. On the other hand, the presence of silica nanoparticles caused a decreased sensitivity of both types of bacteria toward ILs. Our studies indicate potentially useful processes in many environmantal protection technologies like water treatment where flocculation and disinfection are extremely needed.

13.
Chempluschem ; 84(3): 268-276, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31950757

RESUMO

This study presents a new group of herbicidal ionic liquids (HILs) based on a cation occurs commonly in nature-acetylcholine. The HILs were obtained with a high yield through ion exchange between acetylcholine chloride and potassium or sodium salts of selected acids with herbicidal activity. The results of the herbicidal activity measurement against common oilseed rape (Brassica napus L.) exceeded those of the commercial products. Spray solutions of the synthesized HILs revealed high surface activity and wetting properties which further manifested as higher herbicidal activity. The reduction of surface tension and low contact angles together with the specific action of acetylcholine allowed for better penetration of synthesized HILs into plant tissues. In addition, OECD 301F tests confirmed high mineralization of the HILs. The simple transformation of commercial herbicides into acetylcholine HILs proved to be a very effective method of increasing their activity, and constitutes an interesting solution to the problem of weed infestation with the use of a substance commonly found in nature.


Assuntos
Acetilcolina/análogos & derivados , Acetilcolina/toxicidade , Herbicidas/toxicidade , Líquidos Iônicos/toxicidade , Acetilcolina/síntese química , Brassica napus/efeitos dos fármacos , Herbicidas/síntese química , Herbicidas/química , Líquidos Iônicos/síntese química , Líquidos Iônicos/química , Solubilidade , Tensão Superficial , Viscosidade , Molhabilidade
14.
PLoS One ; 13(9): e0202799, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30192784

RESUMO

The effect of dietary level of two types of inulin on amine concentration, redox status and DNA glycosylase activity in the colon of piglets was investigated. Seven groups of piglets were fed diets without inulin addition (control) or with 1%, 2% or 3% inulin with an average degree of polymerisation of 10 (IN10) or 23 (IN23) for 40 days. The 2% and 3% IN10 diets increased tryptamine concentration in the proximal colon, while methylamine concentration in the distal colon was increased by the 1% and 3% IN10 diets. The 1% and 2% IN23 diets increased phenylethylamine and methylamine concentration in the proximal colon, respectively, while 1,7-diaminoheptane content was increased by both diets. Its concentration in the middle and distal colon was increased by the 1% and 2% IN23 diet, respectively. There was no improvement in the oxidant-antioxidant balance in colonic digesta of piglets fed IN10 and IN23 diets. Piglets fed IN10 diets had lower 1,N6-etheno-2'-deoxyadenosine excision activity in each colon segment, as compared with the control group. It was also reduced by the 2% and 3% IN23 diets in the proximal colon, while in the middle and distal colon by all IN23 diets. Feeding all IN10 and IN23 diets reduced 3,N4-etheno-2'-deoxycytidine and 8-oxo-deoxyguanosine excision activities in each colon segment. Feeding IN10 and IN23 diets neither decreased amine concentrations nor improved the oxidant-antioxidant balance in colonic digesta of piglets. However, both types of inulin efficiently reduced the activity of DNA repair enzymes.


Assuntos
Antioxidantes/metabolismo , Aminas Biogênicas/metabolismo , Colo/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Dieta , Inulina/farmacologia , Oxidantes/metabolismo , Animais , Colo/citologia , Colo/metabolismo , Inulina/química , Masculino , Relação Estrutura-Atividade , Suínos
15.
Ecotoxicol Environ Saf ; 164: 370-378, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30138820

RESUMO

This paper presents the adaptation of Escherichia coli Gram-negative bacteria to increased concentrations of ionic liquids. Theophylline-based quaternary ammonium salts were used as an example of an ionic liquid that on the one hand includes an anion of natural origin and on the other hand is characterized by amphiphilic properties due to aliphatic chains in its structure. Theophylline-based ionic liquids can be synthesized relatively cheaply and easily and can exhibit strong antibacterial properties depending on the alkyl chain length. These compounds can also strongly affect bacterial membrane properties, including changes in electrokinetic potential as well as net surface charge. The experiments performed in this study succeeded in obtaining bacterial cultures growing at a tetradecyltrimethylammonium theophyllinate concentration three times higher than the minimum inhibition and bactericidal concentration. The adapted bacteria were characterized by intriguing changes in morphology and grew in the form of almost one-millimeter spheres in a liquid medium. It was shown that cultivation of adapted bacteria with tetradecyltrimethylammonium theophyllinate resulted in changes in the lipid membrane composition and protein patterns of the bacterial lysates, depending on the ionic liquid concentration. This study also revealed that such bacterial adaptation can increase sensitivity to antibiotics by affecting membrane properties like ionophores. These results can be potentially important with regard to synergistic or antagonistic action with other bactericidal compounds like antibiotics and nanoparticles.


Assuntos
Adaptação Fisiológica , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Compostos de Amônio Quaternário/farmacologia , Eletroforese em Gel de Poliacrilamida , Escherichia coli/metabolismo , Ácidos Graxos/análise , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura
16.
Sensors (Basel) ; 17(7)2017 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-28672795

RESUMO

Terrestrial laser scanning is an efficient technique in providing highly accurate point clouds for various geoscience applications. The point clouds have to be transformed to a well-defined reference frame, such as the global Geodetic Reference System 1980. The transformation to the geocentric coordinate frame is based on estimating seven Helmert parameters using several GNSS (Global Navigation Satellite System) referencing points. This paper proposes a method for direct point cloud georeferencing that provides coordinates in the geocentric frame. The proposed method employs the vertical deflection from an external global Earth gravity model and thus demands a minimum number of GNSS measurements. The proposed method can be helpful when the number of georeferencing GNSS points is limited, for instance in city corridors. It needs only two georeferencing points. The validation of the method in a field test reveals that the differences between the classical georefencing and the proposed method amount at maximum to 7 mm with the standard deviation of 8 mm for all of three coordinate components. The proposed method may serve as an alternative for the laser scanning data georeferencing, especially when the number of GNSS points is insufficient for classical methods.

17.
Pol J Microbiol ; 66(3): 375-381, 2017 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-29319506

RESUMO

Investigations of bacterial communities and characterization of mineralogy of the environment in the Zloty Stok As-Au deposit were carried out. PXRD analysis revealed the presence of picropharmacolite as the most common secondary arsenic mineral in the mine. Total DNA was extracted from slime streams or slime biofilms samples to investigate the bacterial communities. PCR amplification of 16S rDNA was performed followed by subcloning of its products. Over 170 clones were analyzed by means of RFLP method. Eight group of clones representing different restriction patterns were identified. The nucleotide sequences of their inserts suggest that bacteria present in the mine environment belong to: Flavobacteria, Sphingobacteriia, Bacteroides, Proteobacteria, Mollicutes and Firmicutes. The metagenomic approach allows to demonstrate a higher diversity of microbiota than classical microbiological studies of cultivable isolates.


Assuntos
Arsênio , Bactérias/classificação , Bactérias/genética , Sedimentos Geológicos/microbiologia , Microbiota/genética , Mineração , Bactérias/isolamento & purificação , DNA Bacteriano/genética , Polônia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética
18.
Ginekol Pol ; 87(10): 690-696, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27958620

RESUMO

OBJECTIVES: To analyzed the therapeutic results for patients with overlooked iatrogenic ureteral injuries after gynecological surgery, treated at the department since 1990. Before the era of endourology, ureteral injuries were operated on immediately after making a diagnosis. This approach was changed after the popularization of percutaneous nephrostomy (PN) and ureteral stenting using a JJ stent. MATERIAL AND METHODS: 27 patients who were diagnosed with a ureteral injury between the first and sixty-fourth day after injury were included. Only PN was performed in 21 patients (group A). In 6 patients, a JJ stent was introduced either immediately after making a diagnosis or after PN (group B). RESULTS: In group A, a good therapeutic result was obtained in only 6 patients (28.6%). Of the 12 patients subjected to PN up to two weeks after injury, 5 had a good result without a need for repair surgery. Of the 9 patients with an injury diagnosed after 3 weeks, only one had a good therapeutic outcome. In Group B, a good result was achieved in 5 out of 6 patients. In 2 patients, a JJ stent was introduced immediately after making the diagnosis, and, in 3 patients, after PN. A successful attempt to "tunnelize" a complete and long obstruction in the sixth patient failed. CONCLUSIONS: Attempting to introduce a JJ stent should be the treatment of choice in patients with an overlooked iatrogenic ureteral injury. If an attempt to introduce the JJ stent fails, PN should be performed as a first step to manage the injury.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Nefrostomia Percutânea , Stents , Ureter/lesões , Ureter/cirurgia , Obstrução Ureteral/cirurgia , Feminino , Humanos , Nefrostomia Percutânea/métodos , Estudos Retrospectivos , Resultado do Tratamento , Obstrução Ureteral/diagnóstico , Obstrução Ureteral/etiologia
19.
Ecotoxicol Environ Saf ; 130: 54-64, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27082812

RESUMO

The aim of this study was to investigate novel theophylline-based ionic liquids and their cytotoxic effects towards model Gram-positive and Gram-negative bacteria (Bacillus cereus and Escherichia coli, respectively). Growth kinetics, respiratory rates and dehydrogenase activities were studied in the presence of ionic liquids at concentrations ranging from 10 to 1000mg/L. Additionally, the influence of ionic liquids on bacterial cells associated with specific interactions based on the structure of cell wall was evaluated. This effect was assessed by viability tests and scanning electron microscope observations. The obtained results confirmed that ionic liquids exhibit different levels of toxicity in relation to Gram-positive and Gram-negative bacteria. Those effects are associated with the chemical structure of the cationic species of the ionic liquids and their critical micelle concentration value. It was established that the presence of an alkyl or allyl group increased the toxicity, whereas the presence of an aryl group in the cation decreased the toxic effect of ILs. Results presented in this study also revealed unexpected effects of self-aggregation of E. coli cells. Overall, it was established that the studied ILs exhibited higher toxicity towards Gram-positive bacteria due to different interactions between the ILs and the cell membranes. These findings may be of importance for the design of ILs with targeted antimicrobial properties.


Assuntos
Antibacterianos/farmacologia , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/fisiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Teofilina/farmacologia , Antibacterianos/química , Cátions/química , Cátions/farmacologia , Líquidos Iônicos/química , Líquidos Iônicos/farmacologia , Micelas , Testes de Sensibilidade Microbiana , Oxirredutases/efeitos dos fármacos , Oxirredutases/metabolismo , Teofilina/química
20.
Pol J Microbiol ; 65(2): 161-170, 2016 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-30015439

RESUMO

This paper presents the interactions of Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas putida) bacteria with ceramic materials obtained by combustion synthesis. These studies were conducted based on an analysis of the adsorption of bacteria onto aggregates of ceramic materials in an aqueous suspension. The materials used in the studies were of a nanostructured nature and consisted mainly of carbides: silicon carbide (SiC) in the form of nanofibers (NFs) and nanorods (NRs), titanium carbide, and graphite, which can also be formed by combustion synthesis. Micrometric SiC was used as a reference material. Gram-positive bacteria adsorbed more strongly to these materials. It seems that both the point of zero charge value and the texture of the ceramic material affected the bacterial adsorption process. Additionally, the viability of bacteria adsorbed onto aggregates of the materials decreased. Generally, P. putida cells were more sensitive to the nanomaterials than S. aureus cells. The maximum loss of viability was noted in the case of bacteria adsorbed onto NRSiC and NFSiC aggregates.

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