The analysis of rotating magnetic field as a trigger of Gram-positive and Gram-negative bacteria growth

Konopacki, Maciej; Rakoczy, Rafał

doi:10.1016/j.bej.2018.10.026

Cited by 32 publications

(16 citation statements)

References 52 publications

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“…Indeed, we observed a spectrum of answers to the same antimicrobial (coupled with the RMF), depending on which staphylococcal strain it was applied against. This phenomenon, of pivotal significance in the studies on MF impact on micro-organisms, is often neglected, i.e., only one reference strain as an example of a given species is analyzed [ 61 , 62 , 63 ]. This specific methodological approach requires a separate line of investigation if proper conclusions on the observed effects are to be drawn.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics

Woroszyło

Ciecholewska-Juśko

Junka

et al. 2021

IJMS

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Methicillin-resistant strains of Staphylococcus aureus (MRSA) have become a global issue for healthcare systems due to their resistance to most β-lactam antibiotics, frequently accompanied by resistance to other classes of antibiotics. In this work, we analyzed the impact of combined use of rotating magnetic field (RMF) with various classes of antibiotics (β-lactams, glycopeptides, macrolides, lincosamides, aminoglycosides, tetracyclines, and fluoroquinolones) against nine S. aureus strains (eight methicillin-resistant and one methicillin-sensitive). The results indicated that the application of RMF combined with antibiotics interfering with cell walls (particularly with the β-lactam antibiotics) translate into favorable changes in staphylococcal growth inhibition zones or in minimal inhibitory concentration values compared to the control settings, which were unexposed to RMF. As an example, the MIC value of cefoxitin was reduced in all MRSA strains by up to 42 times. Apart from the β-lactams, the reduced MIC values were also found for erythromycin, clindamycin, and tetracycline (three strains), ciprofloxacin (one strain), gentamicin (six strains), and teicoplanin (seven strains). The results obtained with the use of in vitro biofilm model confirm that the disturbances caused by RMF in the bacterial cell walls increase the effectiveness of the antibiotics towards MRSA. Because the clinical demand for new therapeutic options effective against MRSA is undisputable, the outcomes and conclusions drawn from the present study may be considered an important road into the application of magnetic fields to fight infections caused by methicillin-resistant staphylococci.

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Section: Discussionmentioning

confidence: 99%

The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics

Woroszyło

Ciecholewska-Juśko

Junka

et al. 2021

IJMS

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“…The growth curve is often plotted as optical density (or CFU/mL) versus time. Based on the previous results [17], an example growth curve is presented in Figure 2. The experimental data can be described mathematically by the means of a logistic curve.…”

Section: Evaluation Of Growth Curvesmentioning

confidence: 99%

“…The optimization procedure is crucial to obtain a higher biomass production and should precede the implementation of every bioprocess. For example, many bacteria are cultivated at 37 • C [17], because this value usually sustains the growth of human and animal pathogens such as Klebsiella pneumoniae in the diagnostic process [18]. However, this does not mean that the production of microbial biomass would be optimal at this temperature.…”

Section: Introductionmentioning

confidence: 99%

Single Mathematical Parameter for Evaluation of the Microorganisms’ Growth as the Objective Function in the Optimization by the DOE Techniques

et al. 2020

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The cultivation of bacteria sets a ground for studying biological processes in many scientific disciplines. The development of the bacterial population is commonly described with three factors that can be used to evaluate culture conditions. However, selecting only one of them for the optimization protocol is rather problematic and may lead to unintended errors. Therefore, we proposed a novel mathematical approach to obtain a single factor that could be used as the objective function to evaluate the whole growth dynamic and support the optimization of the biomass production process. The sigmoidal-shape curve, which is the commonly used function to plot the amount of biomass versus time, was the base for the mathematical analysis. The key process parameters, such as maximal specific growth rate and lag-phase duration were established with the use of mathematical coefficients of the model curve and combined to create the single growth parameter. Moreover, this parameter was used for the exemplary optimization of the cultivation conditions of Klebsiella pneumoniae that was cultured to be further used in the production of lytic bacteriophages. The proposed growth parameter was successfully validated and used to calculate the optimal process temperature of the selected bacterial strain. The obtained results indicated that the proposed mathematical approach could be effortlessly adapted for a precise evaluation of growth curves.

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“…Cell contact time with 1.28 T could be estimated by dividing rotor height with flow velocity which gives 55 mm / 40 mm/s =1.4 s. Studies of magnetic field effects on cells are limited [3], [4], [5] and conclusions vary among researchers.…”

Section: Bušs Et Al Visualization Approaches For Stirred Tank Bioreactorsmentioning

confidence: 99%

Visualization Approaches for Stirred Tank Bioreactors

Buss

Jēkabsons

Šuleiko

et al. 2019

ETR

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Computational Fluid Dynamics (CFD) is the analysis of fluid behaviour employing numerical solution methods. Using CFD it is possible to analyse simple and complex fluid-gas, fluid-fluid or fluid-solid interactions. Fluid dynamics is described with laws of physics in the form of partial differential equations also known as Navier-Stokes equations. Sophisticated CFD solvers transform these laws into algebraic equations which are solved by numerical methods. In this paper Ansys CFX and Fluent analysis systems as research methods are used to visualize flow patterns in a stirred tank bioreactor. The results obtained are informative and can be used to improve the yield of biomass. CFD analysis can save time and aid fluid system designing process. This approach is cheaper and faster compared to conventional build-and-test process. However, it should be noted that CFD analysis results are as accurate as the level of skill possessed by a CFD engineer therefore there are still place for hands-on testing. Authors have developed a stirred tank model and visualized flow patterns. The research presents experimental computation methods and the model setup key parameters. The developed model allows to predict flow patterns inside stirred systems and evaluate efficiency of the mixing process by analysing parameters such as velocity field, turbulence eddy frequency, shear strain rate and power input.

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The analysis of rotating magnetic field as a trigger of Gram-positive and Gram-negative bacteria growth

Cited by 32 publications

References 52 publications

The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics

The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics

Single Mathematical Parameter for Evaluation of the Microorganisms’ Growth as the Objective Function in the Optimization by the DOE Techniques

Visualization Approaches for Stirred Tank Bioreactors

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