scholarly journals Possible Growth Retrieval Simulation on the Heat-Stressed Pseudomonas aeruginosa (SUBP01) Cells

2016 ◽  
pp. 59-64
Author(s):  
M Sakil Munna ◽  
Kazi Rumana Tanzim ◽  
M Mohibul Hassan Afrad ◽  
Sanjida Humayun ◽  
M Sidiqur Rahman ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylenediaminetetraacetic Acid ◽  
Positive Impact ◽  
Morphological Changes ◽  
Cellular Damage ◽  
Bacillus Species ◽  
Oxygen Species ◽  
Stabilizing Agents ◽  
Spot Tests ◽  
The Given

Earlier observation of cellular damage of Pseudomonas aeruginosa (SUBP01) by the extrinsic oxidative agent (H2O2) and the assumptive accumulation of the reactive oxygen species (ROS) through aeration further led to the growth retrieval assay of the bacterium. Current study investigated the influence of the inorganic growth stabilizers (20 mM MgSO4 plus 5 mM ethylenediaminetetraacetic acid, EDTA) and the organic extracellular fractions of the heat-resistant Bacillus species (SUBB01) and P. fluorescens (SUBP02) on the growth pattern of P. aeruginosa at 45° and 46°C. Bacterial growth (cfu) was measured on the minimal agar plates up to 72 hours, microscopic experiments to monitor the subsequent morphological changes, and finally by the spot tests to examine the cell viability under the given heat stressed conditions. As expected, growth revival was observed at both 45° and 46°C after 48 to 72 hours, upon supplementation with inorganic growth stabilizing agents and the extracellular fractions (secretions) of P. fluorescens compared to that of the control; i.e., untreated with inorganic or organic supplements. Interestingly, compared to that of P. fluorescens extracellular extracts, no positive impact on growth retrieval was noticed by the application of the extracellular fractions of Bacillus species.Bangladesh J Microbiol, Volume 31, Number 1-2,June-Dec 2014, pp 59-64

scholarly journals Prevalence of metallo-β-lactamase genes among Pseudomonas aeruginosa isolated from various clinical samples in China

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wei Wang ◽  
Xiaoya Wang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Ethylenediaminetetraacetic Acid ◽  
Carbapenem Resistance ◽  
Opportunistic Pathogen ◽  
Detection Methods ◽  
Clinical Samples ◽  
Routine Practice ◽  
Carbapenem Resistant ◽  
High Prevalence

AbstractBackgroundPseudomonas aeruginosa is an opportunistic pathogen which is associated with nosocomial infections and causes various diseases including urinary tract infection, pneumonia, soft-tissue infection and sepsis. The emergence of P. aeruginosa-acquired metallo-β-lactamase (MBL) is most worrisome and poses a serious threat during treatment and infection control. The objective of this study was to identify antibiotic susceptibility, phenotypic detection of MBL production and to determine the prevalence of MBL genes in carbapenem-resistant P. aeruginosa isolated from different clinical samples.MethodsA total of 329 non-duplicate P. aeruginosa isolated from various clinical samples from two hospitals in China between September 2017 and March 2019 were included in this study. Phenotypic detection of MBL was performed by the combined detection method using imipenem and imipenem-ethylenediaminetetraacetic acid (EDTA) discs. MBL-encoding genes including blaVIM-1, blaVIM-2, blaIMP-1, blaIMP-2, blaSPM-1, blaSIM, blaNDM-1 and blaGIM were detected by polymerase chain reaction (PCR).ResultsOf the 329 P. aeruginosa, majority of the isolates were resistant to imipenem (77.5%) followed by meropenem (64.7%). Of the 270 P. aeruginosa isolates tested, 149 (55.2%) isolates were found to be positive for MBL detection. Of the different samples, 57.8% (n = 26) of P. aeruginosa isolated from blood were found to be positive for MBL production. Of the various MBL genes, blaIMP-1 (28.2%) was the most predominant gene detected followed by blaVIM-2 (18.8%), blaVIM-1 (16.1%), blaNDM-1 (9.4%), blaIMP-2 (6.7%), blaSIM (6.0%), blaSPM-1 (4.0%) and blaGIM (1.3%) genes.ConclusionsThe high resistance of P. aeruginosa toward imipenem and meropenem and the high prevalence of blaIMP-1 and blaVIM-2 set the alarm on the increasing, perhaps the increased, carbapenem resistance. In addition to routine antibiotic susceptibility testings, our results emphasize the importance of both the phenotypic and genotypic MBL detection methods in routine practice for early detection of carbapenem resistance and to prevent further dissemination of this resistant pathogen.

scholarly journals Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 342
Author(s):  
Vitalij Novickij ◽  
Ramunė Stanevičienė ◽  
Rūta Gruškienė ◽  
Kazimieras Badokas ◽  
Juliana Lukša ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Foodborne Pathogens ◽  
Morphological Changes ◽  
Foodborne Pathogen ◽  
Cellular Damage ◽  
Suitable Model ◽  
Log Reduction ◽  
Invasive Infections ◽  
Alternating Magnetic Fields ◽  
Inactivation Of Bacteria

Foodborne pathogens are frequently associated with risks and outbreaks of many diseases; therefore, food safety and processing remain a priority to control and minimize these risks. In this work, nisin-loaded magnetic nanoparticles were used and activated by alternating 10 and 125 mT (peak to peak) magnetic fields (AMFs) for biocontrol of bacteria Listeria innocua, a suitable model to study the inactivation of common foodborne pathogen L. monocytogenes. It was shown that L. innocua features high resistance to nisin-based bioactive nanoparticles, however, application of AMFs (15 and 30 min exposure) significantly potentiates the treatment resulting in considerable log reduction of viable cells. The morphological changes and the resulting cellular damage, which was induced by the synergistic treatment, was confirmed using scanning electron microscopy. The thermal effects were also estimated in the study. The results are useful for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections. The proposed methodology is a contactless alternative to the currently established pulsed-electric field-based treatment in food processing.

scholarly journals Performance Analysis on the Use of Oscillating Water Column in Barge-Based Floating Offshore Wind Turbines

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 475
Author(s):  
Payam Aboutalebi ◽  
Fares M’zoughi ◽  
Izaskun Garrido ◽  
Aitor J. Garrido
Keyword(s):  
Wind Turbines ◽  
Positive Impact ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Water Columns ◽  
Numerical Tools ◽  
Oscillating Water Columns ◽  
The Given ◽  
The Waves

Undesired motions in Floating Offshore Wind Turbines (FOWT) lead to reduction of system efficiency, the system’s lifespan, wind and wave energy mitigation and increment of stress on the system and maintenance costs. In this article, a new barge platform structure for a FOWT has been proposed with the objective of reducing these undesired platform motions. The newly proposed barge structure aims to reduce the tower displacements and platform’s oscillations, particularly in rotational movements. This is achieved by installing Oscillating Water Columns (OWC) within the barge to oppose the oscillatory motion of the waves. Response Amplitude Operator (RAO) is used to predict the motions of the system exposed to different wave frequencies. From the RAOs analysis, the system’s performance has been evaluated for representative regular wave periods. Simulations using numerical tools show the positive impact of the added OWCs on the system’s stability. The results prove that the proposed platform presents better performance by decreasing the oscillations for the given range of wave frequencies, compared to the traditional barge platform.

scholarly journals Oxidative Stress and Inflammation in Renal and Cardiovascular Complications of Diabetes

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 18
Author(s):  
Amelia Charlton ◽  
Jessica Garzarella ◽  
Karin A. M. Jandeleit-Dahm ◽  
Jay C. Jha
Keyword(s):  
Oxidative Stress ◽  
Cardiovascular Disease ◽  
Tissue Injury ◽  
Cardiovascular Complications ◽  
Therapeutic Strategies ◽  
Cellular Damage ◽  
Antioxidant Defenses ◽  
Pathological State ◽  
Oxygen Species ◽  
Emerging Therapies

Oxidative stress and inflammation are considered major drivers in the pathogenesis of diabetic complications, including renal and cardiovascular disease. A symbiotic relationship also appears to exist between oxidative stress and inflammation. Several emerging therapies target these crucial pathways, to alleviate the burden of the aforementioned diseases. Oxidative stress refers to an imbalance between reactive oxygen species (ROS) and antioxidant defenses, a pathological state which not only leads to direct cellular damage but also an inflammatory cascade that further perpetuates tissue injury. Emerging therapeutic strategies tackle these pathways in a variety of ways, from increasing antioxidant defenses (antioxidants and Nrf2 activators) to reducing ROS production (NADPH oxidase inhibitors and XO inhibitors) or inhibiting the associated inflammatory pathways (NLRP3 inflammasome inhibitors, lipoxins, GLP-1 receptor agonists, and AT-1 receptor antagonists). This review summarizes the mechanisms by which oxidative stress and inflammation contribute to and perpetuate diabetes associated renal and cardiovascular disease along with the therapeutic strategies which target these pathways to provide reno and cardiovascular protection in the setting of diabetes.

scholarly journals Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

2021 ◽  
Vol 9 (1) ◽  
pp. 152
Author(s):  
Carly M. Davis ◽  
Jaclyn G. McCutcheon ◽  
Jonathan J. Dennis
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Morphological Changes ◽  
Burst Size ◽  
Type Iv Pili ◽  
Biofilm Growth ◽  
Promising Alternative ◽  
Type Iv ◽  
Alternative Treatment Option ◽  
One Step ◽  
Step Growth

Pseudomonas aeruginosa is a pernicious bacterial pathogen that is difficult to treat because of high levels of antibiotic resistance. A promising alternative treatment option for such bacteria is the application of bacteriophages; the correct combination of phages plus antibiotics can produce synergistic inhibitory effects. In this study, we describe morphological changes induced by sub-MIC levels of the antibiotic aztreonam lysine (AzLys) on P. aeruginosa PA01, which may in part explain the observed phage–antibiotic synergy (PAS). One-step growth curves for phage E79 showed increased adsorption rates, decreased infection latency, accelerated time to lysis and a minor reduction in burst size. Phage E79 plus AzLys PAS was also able to significantly reduce P. aeruginosa biofilm growth over 3-fold as compared to phage treatment alone. Sub-inhibitory AzLys-induced filamentation of P. aeruginosa cells resulted in loss of twitching motility and a reduction in swimming motility, likely due to a reduction in the number of polar Type IV pili and flagella, respectively, on the filamented cell surfaces. Phage phiKZ, which uses Type IV pili as a receptor, did not exhibit increased activity with AzLys at lower sub-inhibitory levels, but still produced phage–antibiotic synergistic killing with sub-inhibitory AzLys. A one-step growth curve indicates that phiKZ in the presence of AzLys also exhibits a decreased infection latency and moderately undergoes accelerated time to lysis. In contrast to prior PAS studies demonstrating that phages undergo delayed time to lysis with cell filamentation, these PAS results show that phages undergo accelerated time to lysis, which therefore suggests that PAS is dependent upon multiple factors, including the type of phages and antibiotics used, and the bacterial host being tested.

REACTIVE CHANGES OF LIVER AND KIDNEY HISTOLOGICAL ELEMENTS IN MURINE MODELS OF SEPSIS CAUSED BY ADMINISTRATION OF DIFFERENT STRAINS TO MICE

2020 ◽  
pp. 66-71
Author(s):  
Татьяна Геннадьевна Боровая ◽  
Владимир Григорьевич Жуховицкий ◽  
Мария Николаевна Черкасова
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Morphological Changes ◽  
Blood Stasis ◽  
Intraperitoneal Administration ◽  
Liver Parenchyma ◽  
Experimental Models ◽  
Control Group ◽  
Reactive Changes ◽  
Liver And Kidney ◽  
Different Strains

Цель - выявление реактивных изменений гистологических элементов печени и почек у мышей в экспериментальных моделях сепсиса, вызванного штаммами 1840 и 1623 Pseudomonas aeruginosa (PsA1840, 1623). Материал и методы. Сепсис моделировали на двух группах половозрелых самцов мышей линии C57Bl/6 интраперитонеальным введением Pseudomonas aeruginosa. Животным 1-й группы (8 особей) вводили штамм 1840, животным 2-й группы (12 особей) - штамм 1623. Контрольная группа состояла из 3 животных. Перед началом опыта штаммы тестировали на присутствие генов экзотоксинов U, S, T, Y (ExoU, ExoS, ExoT, ExoY) с помощью полимеразной цепной реакции (ПЦР). Для визуализации продуктов ПЦР применяли электрофорез в горизонтальном 1,5 % агарозном геле. Животных вскрывали на терминальной стадии сепсиса. Серийные парафиновые срезы печени и почек толщиной 4 мкм окрашивали гематоксилином - эозином, анализировали особенности гистоструктуры органов и фотографировали в световом микроскопе «AxioPlus» (фирма Zeiss, Германия). Результаты. Штамм PsA 1840, имеющий ген exoU, вызывал выраженные деструктивные изменения пластинок гепатоцитов и замещение участков паренхимы печени гомогенным эозинофильным веществом. Присутствовали признаки стаза крови в синусоидных капиллярах, расширение и тромбоз центральных вен, немногочисленные скопления лейкоцитов. Морфологические изменения нефронов состояли в локальных деструктивных изменениях проксимальных канальцев на периферии коркового вещества почек. При введении PsA1623, имеющего ген exoS, возникали массовая гибель почечных телец и дегенерация канальцев нефронов. В печени дольковая гистоархитектура в основном сохранялась. Выводы. Предполагается связь выявленных различий в реактивных изменениях гистологических элементов печени и почек в подопытных группах с особенностями геномов штаммов PsA, использованных для моделирования сепсиса. Objective - to identify reactive changes of liver and kidney histological elements in experimental models of sepsis in mice caused by 1840 and 1623 Pseudomonas aeruginosa strains (PsA1840, 1623). Material and methods. Sepsis was modeled in two groups of mature male C57Bl/6 mice by intraperitoneal administration of Pseudomonas aeruginosa. Strain 1840 was administered to animals of the first group (n=8), animals of the second group (n=12) were administered strain 1623; the control group consisted of 3 animals. Before the experiment, the strains were tested for the presence of genes of exotoxins U, S, T, Y (ExoU, ExoS, ExoT, ExoY) using polymerase chain reaction (PCR). Electrophoresis in horizontal 1,5 % agarose gel was used to visualize PCR products. The animals were euthanized at the terminal stage of sepsis. The extracted liver and kidneys were fixed according to the generally accepted histological method, and embedded into paraffin blocks. Serial 4 μm thick sections of organs were stained with hematoxylin and eosin, analyzed and photographed using «AxioPlus» light microscope (Zeiss, Germany). Results. Strain PsA 1840, carrying the gene of exotoxin U (ExoU), caused severe destructive changes of hepatocytes plates and the replacement of the liver parenchyma with homogeneous eosinophilic substance. There were signs of blood stasis in sinusoidal capillaries, expansion and thrombosis of central veins, a few accumulations of leukocytes. Morphological changes of nephrons consisted of local destructive changes in the proximal tubules at the periphery of kidney cortical substance. After the introduction of PsA1623, carrying the gene of exotoxin S (ExoS), the massive death of renal corpuscles and degeneration of nephron tubules were registered. However, the lobular histoarchitecture in the liver remained mostly unaltered. Conclusions. It is supposed that there is a possible connection of the observed differences in reactive changes of liver and kidney histological elements in two experimental groups with genome features of PsA strains used for the sepsis modeling.

scholarly journals Factors Determining Income among Real Estate Salespersons: The Impacts of Individual Conditions, Franchises, and Regular Chains

2015 ◽  
Vol 7 (11) ◽  
pp. 94
Author(s):  
Chun-Chang Lee ◽  
Cheng-Huang Tung ◽  
Yu-Heng Lee ◽  
Shu-Man You
Keyword(s):  
Real Estate ◽  
Hierarchical Linear Modeling ◽  
Positive Impact ◽  
Working Hours ◽  
Education Level ◽  
Linear Modeling ◽  
Individual Level ◽  
The Individual ◽  
The Given ◽  
Regular Chains

<p>This study explores the factors that affect the incomes of real estate salespersons by applying hierarchical linear modeling (HLM) to investigate the incomes of real estate salespersons in Kaohsiung. A total of 510 questionnaires were distributed to large chain housing agencies, of which a total of 319 effective samples were retrieved from 54 branch stores, for an effective return rate of 62.55%. The empirical results showed that individual incomes vary significantly from store to store. About 4.8% of the variation in individual incomes was due to differences among different branch stores. The individual income of a real estate salesperson is also significantly affected by individual-level factors such as age, working hours, and working experience. The marginal impact of education level, age, working hours, and working experience on real estate salesperson income is moderated by the type of store at which the given salesperson works. In addition, a branch store’s location has a direct, significant, and positive impact on a real estate salesperson’s income.</p>

scholarly journals Investigation of Metallo-Beta-Lactamases in Carbapenem Resistant Pseudomonas aeruginosa Strains by Phenotypic and Genotypic Methods

2020 ◽  
Vol 25 (3) ◽  
pp. 301-307
Author(s):  
M. Duygu Aksoy ◽  
H. Murat Tuğrul
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylenediaminetetraacetic Acid ◽  
Carbapenem Resistance ◽  
Beta Lactamase ◽  
Bacterial Strains ◽  
Beta Lactamases ◽  
Carbapenem Resistant ◽  
Synergy Test ◽  
Phenotypic Tests ◽  
Positive Controls

Introduction: Carbapenem resistant Pseudomonas aeruginosa strains cause serious problems in treatment. A large number of identified metallo-beta-lactamase (MBL) enzymes produced by P. aeruginosa are one of the most important mechanisms in resistance to carbapenems. MBL genes are located on the chromosome or plasmid, and they can easily spread between different bacterial strains. The activities of these enzymes are zinc-dependent, and they are inhibited by ethylenediaminetetraacetic acid (EDTA). Therefore, this advantage is used in MBL identification tests. In this study, it was aimed to determine MBL among P. aeruginosa strains. Materials and Methods: MBL existence was investigated in 35 P. aeruginosa strains accepted to be mildly susceptible/resistant to any of the carbapenem group of antibiotics through phenotypic and genotypic methods. Phenotypic tests were performed as double disk synergy test (DDST), combined disk diffusion tests (CDDT) by using 0.1 M and 0.5 M EDTA, MBL E-test, and modified Hodge test (MHT). blaIMP, blaVIM, blaGIM, blaSIM, blaSPM genes and blaNDM gene were investigated by multiplex polimerase chain reaction (PCR) and PCR, respectively. Escherichia coli ATCC 25922 and P. aeruginosa ATCC 27853 standard bacteria were used in tests. VIM-1, VIM-2, IMP-13, SPM-1, NDM-1 type MBL-producing P. aeruginosa strains were used as positive controls. Results: Among the carbapenems resistant P. aeruginosa isolates, positivity of MBL was found as 54.2% by MBL E-test, 42.8% by DDST, 94.2% and 37.1% by CDDT method using 0.5 M and 0.1 M EDTA, respectively. Modified Hodge test and genotypic method did not detect MBL. Conclusion: In order to correctly evaluate the results of the phenotypic method, the investigation of resistance genes by molecular methods is also required. The most common metallo-beta-lactamase enzymes responsible for resistance to carbapenem in Pseudomonas were not observed. It was thought that different mechanisms might be responsible for the identified carbapenem resistance.

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