In Vitro Toxicity Testing Using Marine Luminescent Bacteria (Photobacterium phosphoreum): the Biotox™ test

1993 ◽  
Vol 21 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Anne Kahru
Keyword(s):  
Light Output ◽  
Toxicity Testing ◽  
Test System ◽  
Photobacterium Phosphoreum ◽  
In Vitro Toxicity ◽  
Luminescent Bacteria ◽  
Time Period ◽  
Freeze Dried ◽  
Light Loss

Marine luminescent bacteria emit light naturally when they are in an optimal environment. If harmful substances are present, their bioluminescence decreases, and the amount of light loss is proportional to the toxicity. In this paper, a new short-term toxicity test system, Biotox™, based on freeze-dried Photobacterium phosphoreum, is assessed. Concentration-effect curves for 25 laboratory chemicals were measured, and EC50 values (the concentrations of chemical, μg/ml, which reduce the light output of bacteria by 50% after being in contact with bacteria over a certain time period) were calculated. The sensitivity of the Biotox™ test to hydrophilic compounds was approximately two times greater than the sensitivity of the Microtox™ test. However, the sensitivity of the Biotox™ test to hydrophobic compounds was shown to be 2–4 times lower than the sensitivity of the Microtox™ test. The Biotox™ test was especially sensitive to As5+, giving an EC50 value of 0.04μg/ml, compared with 1.5μg/ml in the Microtox™ assay.

Toxicity of 39 MEIC Chemicals to Bioluminescent Photobacteria (The Biotox™ Test): Correlation with Other Test Systems

1994 ◽  
Vol 22 (3) ◽  
pp. 147-160 ◽  
Author(s):  
Anne Kahru ◽  
Barbara Borchardt
Keyword(s):  
Toxic Substance ◽  
Light Output ◽  
Test Organism ◽  
Toxicity Testing ◽  
Correlation Coefficients ◽  
Photobacterium Phosphoreum ◽  
Short Term ◽  
Freeze Dried ◽  
Light Loss ◽  
Test Correlation

Photobacterium phosphoreum are naturally luminescent marine bacteria, which emit light as a result of metabolism. Any damage to the cellular metabolism caused by a toxic substance can therefore be monitored by measuring the change in light output of the bacteria, the light loss being proportional to the degree of toxicity. The Biotox™ test, based on reconstituted freeze-dried (viable) Photobacterium phosphoreum as the test organism, was used for the short-term toxicity testing of 39 chemicals from the MEIC list. Concentration-effect curves for these 39 chemicals were measured and five-minute EC50 values (the concentration of chemical, mM, which reduces the light output of the bacteria by 50% after contact for five minutes) were calculated. The EC50 data from the Biotox test were correlated with data from the literature: octanol/water partition coefficients, EC50 data from the Microtox™ test, minimal inhibitory concentration values for Escherichia coli and Bacillus subtilis and acute toxicity data from animal and human cell lines, rodents and man. The correlation coefficients ranged between 0.63 and 0.93.

Study of toxicity of pesticides using luminescent bacteria Photobacterium phosphoreum

1996 ◽  
Vol 33 (6) ◽  
pp. 147-154 ◽  
Author(s):  
A. Kahru ◽  
K. Tomson ◽  
T. Pall ◽  
I. Külm
Keyword(s):  
Light Output ◽  
Correlation Coefficients ◽  
Toxic Effects ◽  
Photobacterium Phosphoreum ◽  
Dichlorophenoxyacetic Acid ◽  
Data Set ◽  
Lipophilic Compounds ◽  
Luminescent Bacteria ◽  
Freeze Dried ◽  
2,4 Dichlorophenoxyacetic Acid

The relative toxicity (expressed as 5-min EC50 value - the concentration of chemical which reduces the light output of bacteria by 50% after contact for 5 minutes) of 13 pesticides (e.g., 2,4-dichlorophenoxyacetic acid, atrazine, coumarin, glyphosate, paraquat, pentachlorophenol, lindane, malathion) and 14 solvents was evaluated using BiotoxTM test that is based on reconstituted freeze-dried viable Photobacterium phosphoreum. The most toxic of the 13 pesticides analyzed using BiotoxTM was pentachlorophenol (5-min EC50=0.55 mg/L) and the less toxic was paraquat (5-min EC50=14800 mg/L). The 5-min EC50 data for BiotoxTM were compared to the respective data for MicrotoxTM test (also based on freeze-dried P. phosphoreum) and rodent oral LD50 values. For BiotoxTMvs MicrotoxTM the log-log correlation coefficients for the whole data set (pesticides+solvents, pesticides, solvents) were 078, 0.37 and 0.95, respectively. The less toxic solvents to BiotoxTM were ethylene glycol, DMSO, methanol, ethanol, acetone and acetonitrile and, therefore, these solvents could be used for increasing the solubility of lipophilic compounds, e.g., for testing the toxicity of pesticides. In order to analyze toxic effects of pesticides in complex mixtures the EC50 values of pentachlorophenol, coumarin and glyphosate as pure substances and in their mixtures were compared: the toxic effects of the above-mentioned pesticides in their mixtures were not additive.

scholarly journals Testing Strategies of the In Vitro Micronucleus Assay for the Genotoxicity Assessment of Nanomaterials in BEAS-2B Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1929
Author(s):  
Tereza Cervena ◽  
Andrea Rossnerova ◽  
Tana Zavodna ◽  
Jitka Sikorova ◽  
Kristyna Vrbova ◽  
...  
Keyword(s):  
Cytochalasin B ◽  
Culture Media ◽  
Methodological Approach ◽  
Micronucleus Assay ◽  
Toxicity Testing ◽  
In Vitro Toxicity ◽  
Testing Strategies ◽  
Transmission Electron ◽  
The Impact

The evaluation of the frequency of micronuclei (MN) is a broadly utilised approach in in vitro toxicity testing. Nevertheless, the specific properties of nanomaterials (NMs) give rise to concerns regarding the optimal methodological variants of the MN assay. In bronchial epithelial cells (BEAS-2B), we tested the genotoxicity of five types of NMs (TiO2: NM101, NM103; SiO2: NM200; Ag: NM300K, NM302) using four variants of MN protocols, differing in the time of exposure and the application of cytochalasin-B combined with the simultaneous and delayed co-treatment with NMs. Using transmission electron microscopy, we evaluated the impact of cytochalasin-B on the transport of NMs into the cells. To assess the behaviour of NMs in a culture media for individual testing conditions, we used dynamic light scattering measurement. The presence of NMs in the cells, their intracellular aggregation and dispersion properties were comparable when tests with or without cytochalasin-B were performed. The genotoxic potential of various TiO2 and Ag particles differed (NM101 < NM103 and NM302 < NM300K, respectively). The application of cytochalasin-B tended to increase the percentage of aberrant cells. In conclusion, the comparison of the testing strategies revealed that the level of DNA damage induced by NMs is affected by the selected methodological approach. This fact should be considered in the interpretation of the results of genotoxicity tests.

scholarly journals A survey of aerosol exposure systems relative to the analysis of cytotoxicity: A Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) perspective

2021 ◽  
Vol 5 ◽  
pp. 239784732110222
Author(s):  
David Thorne ◽  
Roman Wieczorek ◽  
Toshiro Fukushima ◽  
Han-Jae Shin ◽  
Robert Leverette ◽  
...  
Keyword(s):  
Scientific Research ◽  
Toxicity Testing ◽  
User Preferences ◽  
In Vitro Toxicity ◽  
Aerosol Generation ◽  
Aerosol Exposure ◽  
Comprehensive Survey ◽  
Survey Results ◽  
System Data

During a Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) meeting, the in vitro toxicity testing Sub-Group (IVT SG) met to discuss the evolving field of aerosol exposure research. Given the diversity of exposure parameters and biological endpoints being used, it was considered a high priority to investigate and contextualise the responses obtained. This is particularly driven by the inability to compare between studies on different exposure systems due to user preferences and protocol differences. Twelve global tobacco and contract research companies met to discuss this topic and formulate an aligned approach on how this diverging field of research could be appropriately compared. Something that is becoming increasingly important, especially in the light of more focused regulatory scrutiny. A detailed and comprehensive survey was conducted on over 40 parameters ranging from aerosol generation, dilution and data analysis across eight geographically independent laboratories. The survey results emphasise the diversity of in vitro exposure parameters and methodologies employed across the IVT SG and highlighted pockets of harmonisation. For example, many of the biological protocol parameters are consistent across the Sub-Group. However, variables such as cell type and exposure time remain largely inconsistent. The next steps for this work will be to map parameters and system data against biological findings and investigate whether the observed inconsistencies translate into increased biological variability. The results from the survey provide improved awareness of parameters and nuances, that may be of substantial benefit to scientists in intersecting fields and in the development of harmonised approaches.

Time-lapse Phase-contrast Microphotography of Cell Populations as a Basis for Improvement of In Vitro Toxicity Assessment

1992 ◽  
Vol 20 (2) ◽  
pp. 302-306
Author(s):  
Miroslav Červinka
Keyword(s):  
Cell Proliferation ◽  
Cell Morphology ◽  
Video Recording ◽  
Toxicity Testing ◽  
Time Lapse ◽  
Time Dependent ◽  
In Vitro Toxicity ◽  
Simple Modification ◽  
Pertinent Data

Recent trends in the field of in vitro toxicology have centred around the validation of in vitro methods. The ultimate goal is to obtain pertinent data with the minimum of effort. In our laboratory, we have used toxicological methods based on the evaluation of cell morphology and cell proliferation. A method suitable for this purpose is time-lapse microcinematographic (or video) recording of cellular changes, which we used for many years. For practical in vitro toxicity testing, however, this method is far too complicated. Therefore, we have tried to develop a simple modification for the evaluation of cell morphology and cell proliferation, which would still allow for a basic time-dependent analysis. Comparison of detailed microcinematographic analysis with analysis according to our new proliferation assay is demonstrated with cisplatin as the toxicant. We believe that a time-dependent approach could improve the in vitro assessment of toxicity.

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