In vitro evaluation of nutrients that selectively confer a competitive advantage to lactobacilli

2016 ◽  
Vol 7 (2) ◽  
pp. 299-304 ◽  
Author(s):  
R.A. Vongsa ◽  
R.A. Minerath ◽  
M.A. Busch ◽  
J. Tan ◽  
D.W. Koenig
Keyword(s):  
Competitive Advantage ◽  
Mixed Culture ◽  
Lactobacillus Acidophilus ◽  
Screening Tool ◽  
Growth Curves ◽  
In Vitro Screening ◽  
E Coli ◽  
Single Culture ◽  
The Media

An assay was developed that tested the ability of Lactobacillus acidophilus to outcompete a challenge of Escherichia coli in a mixed culture containing different test nutrients. Using this assay, addition of fructo-oligosaccharide to the media allowed L. acidophilus to outcompete a challenge of E. coli, whereas in a mixed culture without the prebiotic the trend was reversed. Growth curves generated for E. coli in a single culture showed that fructo-oligosaccharide did not affect growth, indicating that the carbohydrate was not toxic to E. coli. This indicates that fructo-oligosaccharides may increase the ability of beneficial microbes to outcompete a pathogenic challenge. These results were confirmed using a skin simulant model that incorporates growth of the organisms at an air-surface interface to mimic the vulvar environment. It is possible to use a co-culture assay as an in vitro screening tool to define nutrients that confer a competitive advantage to beneficial flora specific to the female urogenital tract.

Letter To The Editor

PEDIATRICS ◽  
1970 ◽  
Vol 46 (2) ◽  
pp. 316-316
Author(s):  
Ralph A. Franciosi
Keyword(s):  
E Coli ◽  
In Vitro Sensitivity ◽  
Letter To The Editor ◽  
Mueller Hinton ◽  
The Media ◽  
Interesting Development ◽  
Co2 Atmosphere

Thank you very much for your letter regarding my letter to the editor and for the responses from Drs. Eichenwald and Mortimer. One interesting development that could be added as an addendum to show the artificial atmosphere of in vitro sensitivity is the finding that since we stopped incubating our sensitivity plates in a CO2 atmosphere, we have noted that only 11.5% of E. coli are resistant to kanamycin and only 8% resistant to ampicillin. Our sensitivity media is Mueller-Hinton with a pH of approximately 7.4. Apparently incubatioii in a CO2 atmosphere, which decreases the pH of the media, interferes with the sensitivity of E. coli in particular to kanamycin and ampicillin.

Scar-in-a-Jar, an in vitro screening tool for antifibrotics

2018 ◽  
Author(s):  
Jannie Sand ◽  
Natasja Gudmann ◽  
Sarah Rønnow ◽  
Sarah Brockbank ◽  
Simon Cruwys ◽  
...  
Keyword(s):  
Screening Tool ◽  
In Vitro Screening

scholarly journals In vitro fermentation and prebiotic potential of pigeon pea (Cajanus cajan (L.) Millsp.) flour

Food Research ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 174-184
Author(s):  
A.R.T. Cirunay ◽  
L.E. Mopera ◽  
M.J.V. Sumague ◽  
J.A.N. Bautista
Keyword(s):  
Titratable Acidity ◽  
Pigeon Pea ◽  
Activity Score ◽  
In Vitro Fermentation ◽  
E Coli ◽  
Prebiotic Activity ◽  
Pea Flour ◽  
The Media ◽  
Commercially Important

Prebiotics are widely recognized particularly for their role in selectively stimulating the growth and/or activity of beneficial bacteria in the gastrointestinal tract which beneficially affects the host health. Increasing interest has been given to the use of food materials that contain significant amounts of prebiotic components without the necessity of extracting these compounds. In this study, pigeon pea flour was evaluated as a potential prebiotic source. In vitro fermentation of pigeon pea flour by Lactobacillus plantarum (BIOTECH 1223) and Escherichia coli (BIOTECH 1634) was examined based on the changes in cell density, specific growth rate and mean doubling time of the microorganisms, as well as the change in total sugars, resistant starch, dietary fibers (insoluble, soluble and total), pH, titratable acidity of the media. The prebiotic activity score of pigeon pea flour was also determined to measure the extent to which it encourages the selective growth of L. plantarum compared with that of E. coli under the same conditions. Results showed significantly higher growth and metabolic activity of L. plantarum than E. coli in modified medium containing pigeon pea flour. Prebiotic activity score of pigeon pea flour is 0.14 which is not significantly different from the 0.18 prebiotic activity score of commerciallyavailable inulin. Since the prebiotic activity score of pigeon pea flour is comparable to that of inulin, this activity can be extended to other commercially important probiotic organisms and can serve as a rational basis for identifying synbiotics for incorporation into various food products.

scholarly journals Inibição do crescimento de Escherichia coli isolada de Queijo "Minas Frescal" por Lactobacillus acidophilus

2007 ◽  
Vol 37 (2) ◽  
pp. 583-585 ◽  
Author(s):  
Tammy Priscilla Chioda ◽  
Rubén Pablo Schocken-Iturrino ◽  
Gisela Rojas Garcia ◽  
Caroline Peters Pigatto ◽  
César Augusto Martins Ribeiro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Acidophilus ◽  
E Coli

Escherichia coli faz parte da microbiota anaeróbica facultativa normal, sendo também considerada um dos maiores patógenos entéricos predominantes no cólon dos animais e homem. Neste trabalho, realizaram-se ensaios "in vitro" para avaliar o grau de atividade antagonista de cinco cepas de Lactobacillus acidophilus, com capacidade probiótica sobre Escherichia coli BIA 26 (STEC) isolada de queijo "Minas Frescal". Para tanto, foi utilizado o teste de inibição através do método de dupla camada em triplicata para avaliar zonas de inibição de crescimento. Todas as cepas de Lactobacillus mostraram-se capazes de inibir a E. coli, com zonas de inibição variando de 12 a 15mm de diâmetro, sendo que a maioria apresentou 14mm de diâmetro, consideradas como fortes halos de inibição.

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.

Increased in vitro sensitivity of Candida albicans to amphotericin B when grown in mixed culture with Escherichia coli

1978 ◽  
Vol 24 (12) ◽  
pp. 1482-1489 ◽  
Author(s):  
L. G. Mathieu ◽  
D. Dube ◽  
M. Lebrun
Keyword(s):  
Escherichia Coli ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Mixed Culture ◽  
Mixed Cultures ◽  
Polyene Antibiotics ◽  
E Coli ◽  
Pure Cultures

The growth of Candida albicans was inhibited by some Escherichia coli strains both in conventional batch cultures and also in a chemostat under conditions of constant addition of fresh medium. Concentrations of 0.2 μg amphotericin B per millilitre and of 2 μg nystatin per millilitre, which caused a slight inhibition of C. albicans in pure culture, exerted a strong fungicidal effect when the yeast was placed in mixed cultures with certain strains of E. coli. Candida albicans cells, inhibited by either E. coli or in mixed culture with polyene antibiotics, appeared larger and less uniformly stained by acridine orange than control cells from pure cultures. Addition of chloramphenicol to the mixed cultures, in quantities sufficient to kill the E. coli cells, abolished the increased sensitivity of C. albicans to amphotericin B or nystatin. In preliminary in vivo tests, E. coli did not sensitize C. albicans to the polyene antibiotics.

scholarly journals Prolonged Scar-in-a-Jar: an in vitro screening tool for anti-fibrotic therapies using biomarkers of extracellular matrix synthesis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Sarah Rank Rønnow ◽  
Rand Qais Dabbagh ◽  
Federica Genovese ◽  
Carmel B. Nanthakumar ◽  
Vikki J. Barrett ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Screening Tool ◽  
In Vitro Screening ◽  
Matrix Synthesis

Characterization of bacteriophages with a lytic effect on various Salmonella serotypes and Escherichia coli O157:H7

2011 ◽  
Vol 57 (12) ◽  
pp. 1042-1051 ◽  
Author(s):  
Osvaldo López-Cuevas ◽  
Nohelia Castro-del Campo ◽  
Josefina León-Félix ◽  
Arturo González-Robles ◽  
Cristóbal Chaidez
Keyword(s):  
Escherichia Coli ◽  
Burst Size ◽  
Growth Curves ◽  
Escherichia Coli O157 ◽  
Genetic Characteristics ◽  
E Coli ◽  
Lytic Effect ◽  
One Step ◽  
Salmonella Serotypes

Four phages isolated from cattle and poultry feces were analyzed for their ability to lyse Salmonella serotypes and Escherichia coli O157:H7. The phage one-step growth curves, morphology, and genetic characteristics were determined. All phages showed a lytic effect on various Salmonella serotypes and E. coli O157:H7, which lysed at least 70% of the 234 strains tested. The phages had latent periods ranging from 10 to 15 min and generation times of 30 to 45 min, while burst size fluctuated between 154 and 426 PFU/cell. Phages morphology showed isometric and elongated heads and rigid contractile tails, consistent with morphology of the Myoviridae family. Phages’ DNA dendrograms showed a distinctive RFLP when digested by HindIII and EcoRV, and SDS–PAGE profile showed distinctive proteins expression as well. In vitro phage challenge showed a total reduction of E. coli O157:H7, Salmonella Typhimurium and Saintpaul counts at 2 h, whereas for Salmonella Montevideo a reduction and retardation growth, at a multiplicity of infection (MOI) of 100, was observed; however, under a MOI of 10 000, no viable cells were detected after 4 h. The wide host ranges of these phages suggested they could be used for simultaneous biocontrol of some Salmonella serotypes and E. coli O157:H7.

scholarly journals An Efficient Synthesis of Thiophene Conjugated Benzothiazepines: in vitro Screening for their Antimicrobial Activity

2020 ◽  
Vol 32 (10) ◽  
pp. 2601-2605
Author(s):  
K.R. Raghavendra ◽  
P. Sudeep ◽  
K. Ajay Kumar ◽  
H.P. Jayadevappa
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Spectroscopic Studies ◽  
In Vitro Screening ◽  
Efficient Synthesis ◽  
Citrus Juice ◽  
E Coli ◽  
Antimicrobial Evaluation ◽  
New Compounds

A series of novel thiophene conjugated benzothiazepines were synthesized by the reaction of chalcones with 2-aminobenzenethiol in citrus juice medium. The new compounds were characterized by spectroscopic studies. Results of in vitro antimicrobial evaluation of newly synthesized compounds 5a-j shows that the compounds 5a and 5c have excellent antimicrobial inhibition in the range of 12.5-25.0 μg/mL against bacteria S. aureus, E. coli, P. aeruginosa and fungi A. niger, A. flavus organisms comparable to ciprofloxacin and nystatin and therefore these compounds might acts as lead molecules as antimicrobial agents.

Effects of Lactobacillus acidophilus and Lactobacillus helveticus on biofilm formation by ESBL-producing uropathogenic Escherichia coli

2020 ◽  
Vol 29 (3) ◽  
pp. 163-170
Author(s):  
Alaa M. Ibrahim ◽  
Magda I. Ayoub ◽  
Alaa R. Awad
Keyword(s):  
Lactobacillus Acidophilus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Uropathogenic Escherichia Coli ◽  
Lactobacillus Helveticus ◽  
Diffusion Method ◽  
Esbl Production ◽  
E Coli ◽  
Microbiological Methods

Background: Uropathogenic E. coli (UPEC) are important clinical pathogens and are considered as one of the major causes of urinary tract infection. Unfortunately, the treatment of UPEC infections is becoming more difficult because isolates are increasingly resistant to commonly used antimicrobial agents. The potential ability of UPEC to form biofilm might explain its outstanding antibiotic resistance and survival properties. Objectives: We aimed to assess the effect of cell free supernatants (CFS) of Lactobacillus acidophilus La-5 and Lactobacillus helveticus B-734 on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and to eradicate the already formed biofilm of UPEC isolates. Methodology: A total of 50 isolates of ESBLproducing UPEC, were recovered from different private laboratories, then subcultured on MacConkey’s medium and identified by conventional microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and confirmed for ESBL production. The ability of UPEC to produce biofilm was determined using Congo red agar (CRA) method and tissue culture plate (TCP) method. CFS of L.acidophilus La-5 and L. helveticus B-734 were prepared and used to assess its effect on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and the eradicationof the already formed biofilm. Results: Biofilm formation was found in 28% of theisolates. Furthermore, the strong biofilm-forming category was detected in 10% of the isolates, whereas the moderate biofilm-forming category was detected in 18%. CFS of L. acidophilus La-5 was more effective (91.12%) in inhibiting the formation of E. coli biofilm than CFS of L. helveticus B-734 (76.44%), while it was almost the same efficacy (83%) regarding eradication of E. coli biofilm. All ESBL- producing UPEC isolates were sensitive to cefoxitin (100%) followed by nitrofurantoin (98%) and imipenem (94%). Conclusion: L. acidophilus La-5 and L. helveticus B-734 may be a new therapeutic options for UTI caused by UPEC.

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