Comparative Study Of The Growth Curves Of B. subtilis, K. pneumoniae, C. xerosis And E. coli Bacteria In Medium Containing Nanometric Silicon Particles

2002 ◽  
Vol 737 ◽  
Author(s):  
Lilyanna Pérez ◽  
Marjorie Flores ◽  
J. Avalos ◽  
L. San Miguel ◽  
O. Resto ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Growth Curve ◽  
Silicon Nanoparticles ◽  
Silicon Film ◽  
Growth Curves ◽  
Bacterial Strains ◽  
E Coli ◽  
Standard Curve ◽  
Nanometric Particles ◽  
Silicon Particles

ABSTRACTIn this research nanometric particles from luminescent (625nm) porous silicon film were synthesized. This particles were later inoculated in bacterial strains of B. subtilis (BSi) and K. pneumoniae (KSi). A comparison of the behavior of their growth curve and the ones reported for C. xerosis (XSi) and E. coli (ESi) in presence of silicon nanoparticles is presented. The growth curve of BSi, as well as the KSi, present changes compared to their standard curves. The BSi growth curve grows below the standard curve after the fifth hour, while in the KSi this happens after the eighth hour. Based on our preliminary findings we can speculate that at this point in time a critical population is present, and this may give rise to the possible incorporation of the silicon particles by the bacteria, or a possible pleomorphism inhibits reproduction. The stationary region, in both cases, takes place sooner than in the standard curve. No significant oscillations are observed in any case, which differs form the XSi curve, were oscillations of intervals of almost 1 hour were reported. In addition, these curves have a different behavior when compared to the ESi growth curve, in which no significant differences between the standard and the particle containing sample were reported.

Effect of Zinc Oxide Nanocrystals in Media Containing E. coli and C. xerosis Bacteria

2005 ◽  
Vol 900 ◽  
Author(s):  
Triana Merced ◽  
Stephanie Santos ◽  
Omayra Rivera ◽  
Nicole Villalba ◽  
Yahira Baez ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Growth Curves ◽  
Adaptation Period ◽  
E Coli ◽  
Standard Curve ◽  
Stable Suspension ◽  
Zno Nanocrystals ◽  
Doped Zno

ABSTRACTThe present investigation is centered on the study of the growth curves of E. coli and C. xerosis bacteria in the presence of nanosize particles of Zinc Oxide. Previous works demonstrated the sensitivity of the bacteria, when these were reproduced in media that contain nanoparticles of luminescent silicon and Cobalt Ferrite. Doped ZnO nanocrystals were synthesized by conventional precipitation in ethanol solutions as reported by Spanhel and Anderson for bare ZnO. In our case, the syntheses were carried out under room-temperature conditions.The experimental results of E. coli bacteria in contact with a stable suspension of nanoparticles of Zinc Oxide, shows a growth curve without adaptation period. Moreover a short and slowly logarithmic stage has been observed, reaching the stationary stage after approximately four hours compared with one in absence of the nanoparticles (standard curve). During the observations, a change in the lifetime of the bacteria (metabolism) with particulate was noticed,as well as the beginning of the mortality stage. However, different results were recorded for silicon and ferrite. For the case of the bacteria C. xerosis, the curve with particles is above its standard curve, for all times with none of the oscillations which occured in the nanometer silicon. For these bacteria the beginning of the mortality stage is observed when they have particles. For both bacteria with Zinc Oxide nanoparticles this occurs approximately after nine hours.

scholarly journals Predicting microbial relative growth in a mixed culture from growth curve data

2015 ◽  
Author(s):  
Yoav Ram ◽  
Eynat Dellus-Gur ◽  
Maayan Bibi ◽  
Uri Obolski ◽  
Judith Berman ◽  
...  
Keyword(s):  
Mixed Culture ◽  
Growth Curve ◽  
Growth Curves ◽  
Relative Fitness ◽  
Model Organisms ◽  
Accurate Estimation ◽  
Relative Growth ◽  
E Coli ◽  
Culture Growth ◽  
Unique Markers

AbstractEstimates of microbial fitness from growth curves are inaccurate. Rather, competition experiments are necessary for accurate estimation. But competition experiments require unique markers and are difficult to perform with isolates derived from a common ancestor or non-model organisms. Here we describe a new approach for predicting relative growth of microbes in a mixed culture utilizing mono- and mixed culture growth curve data. We validated this approach using growth curve and competition experiments withE. coli. Our approach provides an effective way to predict growth in a mixed culture and infer relative fitness. Furthermore, by integrating several growth phases, it provides an ecological interpretation for microbial fitness.

A study of the growth curves of C. xerosis and E. coli Bacteria in Mediums Containing Cobalt Ferrite Nanoparticles

2004 ◽  
Vol 820 ◽  
Author(s):  
Marjorie Flores ◽  
Nanell Colón ◽  
Omayra Rivera ◽  
Nicole Villalba ◽  
Yahira Baez ◽  
...  
Keyword(s):  
Cobalt Ferrite ◽  
Growth Curves ◽  
Precipitation Method ◽  
Adaptation Period ◽  
E Coli ◽  
Standard Curve ◽  
Stable Suspension ◽  
Electric Polarity ◽  
The One ◽  
Co Precipitation

AbstractPrevious publications demonstrated the sensibility of the bacteria, when these were reproduced in mediums that contain nanoparticles of luminescent silicon. The mentioned effect takes place in the development of a bacteriological sensor. The present investigation is centered on the study of the growth curves of E. coli and C. xerosis, but now in the presence of nanosize particles of Cobalt Ferrite (CoFe2O4) which were produced by the co-precipitation method in a watery phase. These nanoparticles present ferromagnetism characteristics (coercivity at room temperature among 600-5000 Oe for a size around 15-40nm). The experiment results evidence that the adaptation period of the bacteria, in contact with a stable suspension of nanoparticles of Ferrite, shows a growth curve of above the one obtained in absence of the nanoparticles (standard curve). The probable interaction of the electric polarity that these possess should be involved with the observed phenomena.

Characterization of Silicon Nanoparticles Prepared from Porous Silicon

1994 ◽  
Vol 351 ◽  
Author(s):  
Richard A. Bley ◽  
Susan M. Kauzlarich ◽  
Howard W. H. Lee ◽  
Jeffrey E. Davis
Keyword(s):  
Porous Silicon ◽  
Silicon Dioxide ◽  
Silicon Nanoparticles ◽  
Size Range ◽  
Amorphous Layer ◽  
Ultrasonic Dispersion ◽  
Thin Sections ◽  
High Resolution Tem ◽  
Silicon Particles

ABSTRACTNanometer sized silicon particles have been produced by ultrasonic dispersion of thin sections of porous silicon in organic solvents. High resolution TEM and FTIR have been used to establish the size range and surface structure/composition of these particles. The larger particles, which range in size from 20 to 50 nm, are made up of a conglomeration of smaller particles with a diameter of a few nanometers. The HRTEM shows an amorphous layer on the surface of many of the clusters. FTIR data suggest this amorphous layer is silicon-dioxide which may also have organic constituents.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

Probiotics Slow the Growth of Pathogenic Bacteria

2019 ◽  
Vol 14 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Rowles H. L.
Keyword(s):  
Growth Rate ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diarrheal Disease ◽  
Growth Curves ◽  
Mortality Rates ◽  
Controlled Delivery ◽  
E Coli ◽  
Multiple Strains ◽  
Commercial Probiotics

Probiotics are live microorganisms, which when ingested in sufficient amounts, confer health benefits to the host by improving the gut microflora balance. The purpose of this research was to determine whether commercial probiotic products containing multitude of commensal bacteria would reduce the growth rate of pathogenic bacteria, specifically Escherichia coli and Salmonella typhimurium. Growth curves were established, and the growth rates were compared for samples of E. coli, S. typhimurium, Nature’s Bounty Controlled Delivery probiotic, Sundown Naturals Probiotic Balance probiotic, and cocultures of the pathogenic bacteria mixed with the probiotics. The findings of this research were that the commercial probiotics significantly reduced the growth rate of E. coli and S. typhimurium when combined in cocultures. Probiotics containing multiple strains may be taken prophylactically to reduce the risk of bacterial infections caused by E. coli and S. typhimurium. Probiotics could be used to reduce the high global morbidity and mortality rates of diarrheal disease.

Fusogenic porous silicon nanoparticles as a broad-spectrum immunotherapy against bacterial infections

2021 ◽  
Author(s):  
Byungji Kim ◽  
Qinglin Yang ◽  
Leslie W. Chan ◽  
Sangeeta N. Bhatia ◽  
Erkki Ruoslahti ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Broad Spectrum ◽  
Therapeutic Efficacy ◽  
Bacterial Infections ◽  
Silicon Nanoparticles ◽  
First Line ◽  
Gram Positive ◽  
Gram Negative ◽  
Porous Silicon Nanoparticles

RNAi-mediated immunotherapy provided by fusogenic porous silicon nanoparticles demonstrates superior therapeutic efficacy against both Gram-positive and Gram-negative bacterial infections compared with first-line antibiotics.

scholarly journals A Hybrid Modeling Technique of Epidemic Outbreaks with Application to COVID-19 Dynamics in West Africa

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 365
Author(s):  
Chénangnon Frédéric Tovissodé ◽  
Jonas Têlé Doumatè ◽  
Romain Glèlè Kakaï
Keyword(s):  
West Africa ◽  
Growth Curve ◽  
Exponential Growth ◽  
Latency Period ◽  
Growth Curves ◽  
Exponential Growth Phase ◽  
Model Framework ◽  
Logistic Regression Models ◽  
Containment Measures ◽  
Reporting Data

The widely used logistic model for epidemic case reporting data may be either restrictive or unrealistic in presence of containment measures when implemented after an epidemic outbreak. For flexibility in epidemic case reporting data modeling, we combined an exponential growth curve for the early epidemic phase with a flexible growth curve to account for the potential change in growth pattern after implementation of containment measures. We also fitted logistic regression models to recoveries and deaths from the confirmed positive cases. In addition, the growth curves were integrated into a SIQR (Susceptible, Infective, Quarantined, Recovered) model framework to provide an overview on the modeled epidemic wave. We focused on the estimation of: (1) the delay between the appearance of the first infectious case in the population and the outbreak (“epidemic latency period”); (2) the duration of the exponential growth phase; (3) the basic and the time-varying reproduction numbers; and (4) the peaks (time and size) in confirmed positive cases, active cases and new infections. The application of this approach to COVID-19 data from West Africa allowed discussion on the effectiveness of some containment measures implemented across the region.

scholarly journals In Vitro Coliform Resistance to Bioactive Compounds in Urinary Infection, Assessed in a Lab Catheterization Model

2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu
Keyword(s):  
Urinary Tract ◽  
Bioactive Compounds ◽  
Urinary Tract Infections ◽  
Antimicrobial Effect ◽  
Biologically Active ◽  
Bacterial Strains ◽  
E Coli ◽  
Functional Product ◽  
Tract Infections

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.

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