scholarly journals Assessment of experimental conditions affecting spontaneous mutation level of Salmonella strains used in the Ames test

2021 ◽  
Vol 100 (7) ◽  
pp. 736-743
Author(s):  
Olga V. Egorova ◽  
Yuliya V. Demidova ◽  
Nataliya A. Ilyushina

Introduction. The bacterial reverse gene mutations test (the Ames test) is widely used to assess chemicals’ mutagenic activity. The spontaneous mutation level of test strains is a mandatory characteristic that has to be monitored in a laboratory performing mutagenicity studies using the Ames test. In this regard, it is important to assess the factors affecting the spontaneous mutation level in the experiment and, therefore, on the general conclusion on the test item mutagenicity. Material and methods. A plate incorporation test version was used both in the presence and absence of a metabolic activation system. Results. We summarized the historical control data obtained in the laboratory in 2016-2020, determine the fluctuation limits in the number of revertant colonies for each strain, and identify the factors affecting the negative control variability. No significant differences were found in the spontaneous background of test strains when using DMSO or water as solvents, polypropylene or polystyrene tubes, as well as Petri dishes of different types. In the case of the TA1535, TA102 and TA100 cultures, no influence of the presence of the S9 mixture on the spontaneous reversion range was revealed (p≤0.05). Statistically significant differences in the number of spontaneous revertants (at + S9 or -S9) were found for the strains that allow detecting frameshift mutations, TA97 and TA98. It has been shown that the volume of the selective medium and the brand of gelling agent in its composition are important factors leading to the variability of the historical negative control. Conclusion. To ensure the quality of experiments according to the principles of good laboratory practice and the reliability of the data obtained using the bacterial reverse mutation method, it is necessary to standardize the operations in advance of experiments.

2010 ◽  
Vol 1 (1) ◽  
pp. 55 ◽  
Author(s):  
Akram Hassan ◽  
S.A Omar ◽  
Zaihan Ariffin

Silver amalgam/Silverfil Argentum® is a ‘Malaysian made amalgam’ has already been approved to be free from cytotoxicity, however its genotoxic effect has not been explored yet as biocompatible material. The objective of this study was to identify the genotoxic characteristic of silver amalgam by using Bacterial Reverse Mutation Assay (Ames test). This was a descriptive experimental study involving one strain of mutated Salmonella. The test material was evaluated in one mutated strain of Salmonella typhimurium TA1538 with and without an external metabolic activation system (S9 Mix). The bacteria were incubated for 48 hours at 37±0.5ºC before the colony growth or revertant colonies were counted. Data obtained were analyzed by using non-statistical method. The investigation of the genotoxic reaction on the test material revealed thatthe number of revertant colonies in both strains with and without S9 Mix were less than twice of the negative control even in the presence of high silver amalgam concentrations (5.0μg/ml). This study demonstratedthat the test material did not exhibit any mutagenic activity under the chosen conditions. Thus, silver amalgam could be considered to have no genotoxicity effect.


Caryologia ◽  
2021 ◽  
Author(s):  
Dilek Akyıl

The objective of this study was to explore the mutagenic and cytotoxic effects of Napoleon 4EC pesticide used in Turkey to control insect pest by using two standard assays. The Allium cepa test was used for determined the cytotoxic effects of this pesticide. For this test, onion seeds were exposed to Napoleon 4EC (100, 200, and 400 ppm) for 24, 48, and 72 hours. For each test group root tip cells were stained with Feulgen and five slides were prepared for each concentration and counted microscopically. The concentrations Napoleon 4EC was compared with the value for the negative control using Dunnet-t test, 2 sided. The results indicated that mitotic index was clearly decreased with increasing the concentration of Napoleon 4EC in each treatment group as compared to the controls. The percentage of mitotic phases has been markedly impacted. Five different doses of the pesticide (50, 100, 200, 400, 800 μg/plate) were examined with Ames test using Salmonella typhimurium strains TA98 and TA100 with and without S9 metabolic activation for mutagenic activity. Ames test results showed a dose dependent effect, but not twice the negative control for S. typhimurium TA98 and TA100, with or without S9 mix except 800 μg/plate doses. In 800 μg/plate doses, colony numbers are two-fold increase according to colony number of control group. So, this places the this compound as a weak mutagen according to the parameters.


2019 ◽  
Vol 98 (4) ◽  
pp. 455-460
Author(s):  
Lyudmila V. Akhaltseva ◽  
V. S. Zhurkov ◽  
L. P. Sycheva ◽  
O. N. Savostikova ◽  
A. V. Alekseeva

Introduction. One of the important steps in assessing the nanoparticles (NP) safety is the analysis of mutagenic activity, including the evaluation of gene, chromosomal, and genomic mutations. Material and methods. The purpose of this investigation is to study the ability of different NP aqueus suspensions and the same compounds in microforms to unduce gene mutations in Salmonella/microsome test (Ames test). Anatase titanium dioxide NP coated with simethicone (33.16 ± 16.7 nm, 5-50000 μg/ml), magnetite NP coated with silicate (10 nm, 0.92-575 μg/ml), silver NP coated with аrabian gum (14 ± 0.2 nm, 5-50000 μg/ml), aluminum hydroxide nanofibres (50-70 nm, 24-3000 μg/ml) and multi-walled carbon nanotubes (Taunit MWСNTs, outer diameter 15-40 nm, inner diameter 3-8 nm, length 2 and more microns, 5-50000 μg/ml). In parallel, the mutagenic activity of equivalent microparticles was evaluated in experiments. Ames test (Salmonella/microsomes) registers gene mutations induced by a different mechanism of action, in the variant with preincubation. A set of Salmonella typhimurium indicator strains: TA 100 (base pair substitution mutations), TA 98 and TA 97 (mutations of the frameshift type of the genetic code) were used. Using addition the S9 microsomal activating mixture during the experiment makes it is possible to determine the effect not only of the substances themselves, but also of their metabolites. Conclusion. The investigated nanomaterials as well as their micro analogs in the studied dose range did not induce gene mutations in the Ames test both in presence and absence microsomal activating mixture.


2018 ◽  
Vol 245 ◽  
pp. 18002 ◽  
Author(s):  
Olga Ivanchenko ◽  
Rustem Khabibullin ◽  
Rahat Bhat

Environmental pollution and ecosystem dysfunction are one of the most important problems of the today’s world. Assessment of toxigenic properties of effluents from the meat-processing enterprise was carried out using the short-term microorganisms biotests in vitro. Both native waste water and its ether and water fractions were investigated. The probes’ sterilization was carried out by filtration through the sterile membrane filters Synpor with pores diameter of 0.45 m. Mutagenic activity of wastewaters was determined using the Salmonella/microsomes plate with in vitro metabolic activation and without metabolic activation (Ames test). As a metobolic activation the rat liver microsomes were used. Studying of the DNA-damaging activity was carried out using the suspension method modification on the mutant Escherichia coli strains, in which the functioning of one reparation systems is suppressed: uvrA-, recAand рol A-. Native waste water doesn’t have an influence on the mutant strains recAand рol A-, its survivability degree is in the range 96-100%. However, DNA-damaging action was registered for the strain with the damaged excision repair (uvrA-), survivability of which was 81.31%. Ames test of wastewater and its fractions didn’t reveal any mutagenic activity. The tests used in this work allow one to comprehensively estimate the genetic danger of the enterprise wastewaters within a short time and are recommended as test-systems for monitoring the ecological safety of wastewaters.


2008 ◽  
Vol 6 (4) ◽  
pp. 29-33 ◽  
Author(s):  
Nazira S Karamova ◽  
Alexandra P Denisova ◽  
Zenon Stasevski

The mutagenic activity of five pesticides actara, sencor, mospilan, pencozeb, fastac widely used for treatment of potato plant lands in Tatarstan was tested in the Ames test. The non toxic concentrations of the pesticides determined in preliminary cytotoxicty test were used in the Ames assay. Pesticides actara, mospilan, pencozeb, fastac did not show mutagenic effect in Salmonella typhimurium TA 100 without rat liver S9 fraction. The weak mutagenic effect of herbicide sencor was established at concentration 1 ug/plate. Metabolic activation in vitro using rat liver S9 fraction decreased the mutagenic activity of sencor and did not alter the mutagenicity rate of the pesticides actara, mospilan, pencozeb and fastac.


2000 ◽  
Vol 63 (7) ◽  
pp. 945-952 ◽  
Author(s):  
M. STEVANOVIĆ ◽  
P. ČADEŽ ◽  
B. ŽLENDER ◽  
M. FILIPIČ

The preformed cooked cured meat pigment (CCMP) synthesized directly from bovine red blood cells or through a hemin intermediate was found to be a viable colorant for application to comminuted pork as a nitrite substitute. However the genotoxicity of CCMP and meat emulsion coagulates prepared with CCMP has not been evaluated. Therefore the objectives of this work were to investigate genotoxicity of CCMP and the influence of CCMP addition on genotoxicity and the content of residual nitrite in model meat emulsion coagulates. Meat emulsions were prepared from white (musculus longissimus dorsi) and red (musculus quadriceps femoris) pork muscles with two different amounts of synthesized pigment CCMP. Comparatively, emulsions with fixed addition of nitrite salt and emulsions without any addition for color development were made. Genotoxicity of CCMP and meat emulsion coagulates was tested with the SOS/umu test and the Ames test. Neither CCMP nor meat emulsion coagulates prepared with CCMP or nitrite salt were genotoxic in the SOS/umu test. In the Ames test using Salmonella Typhimurium strains TA98 and TA100 samples of coagulates prepared with CCMP and with nitrite showed weak mutagenic activity in Salmonella Typhimurium strain TA100 but only in the absence of the metabolic activation, while CCMP was not mutagenic. Coagulates prepared with CCMP contained significantly less residual nitrite than coagulates prepared with nitrite salt. These results indicate that from the human health standpoint the substitution of nitrite salt with CCMP would be highly recommendable.


1992 ◽  
Vol 8 (6) ◽  
pp. 369-376 ◽  
Author(s):  
David H. Blakey ◽  
Earle R. Nestmann ◽  
Janet M. Bayley ◽  
K. Laurie Maus ◽  
George R. Douglas

Toluenesulfonhydrazide (TSH) is a high volume production chemical for which there is relatively little toxicological data. In this study, the mutagenic activity of TSH was determined in the Salmonella/mammalian microsome assay and the in vitro chromosomal aberration assay using Chinese hamster ovary cells. TSH induced gene mutations both with and without metabolic activation in the Salmonella/mammalian microsome assay but that it did not induce chromosomal aberrations in Chinese hamster ovary cells. The results of this study indicate that TSH is an in vitro mutagen and should be assessed for in vivo mutagenicity.


2017 ◽  
Vol 9 (13) ◽  
pp. 62
Author(s):  
Ahmad Rohi Ghazali ◽  
Farah Mardhiah Khairuddin ◽  
Tava Shelan Nagapan ◽  
Dayang Fredalina Basri

Canarium odontophyllum or locally known as Dabai in Sarawak is a fruit largely consumed by the locals. Based on previous studies, the plant possessed various biological activities, such as antimicrobial, antioxidant, antifungal and anticancer. Our aim was to investigate the mutagenicity and antimutagenicity of C. odontophyllum acetone leaves extracts by using the Ames test (Salmonella reverse mutagenicity assay).The Ames test also involved the pre-incubation method against Salmonella typhimurium TA98 and TA100 bacterial strains in the absence and presence of metabolic activator S9 system. C. odontophyllum crude acetone extracts were diluted with 10% DMSO to obtain three different concentrations of 3.125, 12.5 and 50 mg/ml. To determine the mutagenicity effects of the extracts, each concentration of the extract was evaluated based on the two-fold value of the number of revertant’s colony in negative control plate as the cut-of point. No mutagenic activity was observed for the frameshift mutation (TA98) and base-pair substitution mutation (TA100) in all concentrations of C. odontophyllum in the presence and absence of metabolic activator S9 system. Antimutagenicity test was carried out to determine the potential of C. odontophyllum extracts to inhibit the mutation induced by specific mutagens. The highest antimutagenic activity was seen in the presence of metabolic activator S9 system with inhibition percentage greater than 50% in both bacteria strains TA98 (62.38%) and TA100 (58.24%). In conclusion, C. odontophyllum acetone leaves extract was not mutagenic and had significant inhibitory effects on mutagenicity in both bacterial strains with and without the metabolic activator S9 system. Our results could contribute to the safe use of C. odontophyllum. In addition, based on the significant antimutagenic activity demonstrated by the C. odontophyllum acetone leaves extracts, the extract could also be developed as a chemopreventive agent.


2019 ◽  
pp. 81-87
Author(s):  
M. Ya. Golovenko ◽  
V. B. Larionov ◽  
S. S. Basok ◽  
A. S. Reder

In recent years, studies in the field of chemical mutagenesis have undergone significant development, due to the introduction of a large number of different chemicals and scientific advances in the creation and use of new test systems, allowing a complete assessment of both mutagens themselves and their metabolites. The aim of the work was to determine possible induction of gene mutations under influence of hydrochloride N-(γ-aminobuturil)-1-aza-4,7,10,13-tetraozacyclopentadecan (TOCPD), which has nootropic, anxiolytic and anticonvulsant activity. The ability of TOCPD to induce gene mutations was evaluated in Ames test on strains Salmonella typhimurium ТА 98 (frame shift mutations) and ТА 100 (substitution point mutations). The compound was used at concentrations of 10, 100, 250, 500 and 1000 μg/ml. Standard mutagens were 2-nitrofluoren for Salmonella typhimurium ТА 98 and sodium azide for Salmonella typhimurium ТА 100 in test without metabolic activation. In an activation variant a microsomal activating mixture was used (S9 mix). In tests with activation for both strains, 2-aminoantracene was used. The µAmes kit, Moltox (USA) and Muta-ChromoPlate kit (Canada) were used in the work. The results were evaluated by the number of wells with mutated cells with medium color changing from purple to yellow. The obtained data showed that in the control and according to the action of corresponding mutagens, the percentage of wells with mutated cells corresponded to the standard parameters determined by protocol of the microplate test. For the action of TOCPD compound, no gene mutations were detected in both S. typhimurium ТА 98 and ТА 100 strains within the concentrations used.


2019 ◽  
Vol 98 (11) ◽  
pp. 1309-1320
Author(s):  
Lyudmila V. Akhaltseva ◽  
V. S. Zhurkov ◽  
F. I. Ingel

Despite the widespread use of nanomaterials in various areas of industry and medicine, the question of assessing their safety, in particular, genotoxicity, remains to be open. The review presents the analysis of the results of a number of nanomaterials mutagenic activity evaluations in the test for induction of reverse mutations in bacteria (the Ames test). The literature search was carried out using PubMed, eLIBRARY.RU, Web of Science, Google Scholar databases up to 2019. The analysis of the literature showed mostly negative results on the induction of gene mutations. Particularly, quantum dots (QD), nanoparticles, and nanofibres of aluminum oxide and hydroxide, multi-walled carbon nanotubes (MWCNTs) and single-wall carbon nanotubes (SWCNTs) did not induce gene mutations. Among the more than 120 different types of nanomaterials (size, coating), for 22 the mutagenic activity as varying severity was found. These few numbers of positive results show that the degree of the mutagenic effect of nanomaterials may depend on the conditions of the experiment as well as coating composition. So, the diversity of nanomaterials and the sharp change in their properties even with a slight shift in the particle size parameters leads to the necessity to study the mutagenic activity of each nanomaterial separately. We conclude that there is the necessity to elaborate special international documents with the reglament of the investigation of nanomaterials’ mutagenic properties in the Ames test using the range of concentrations, with the full set of indicator strains and the description of the exact dimensions and properties of the studied particles.


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