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Toxicity of antimicrobials assessment

Determination of cytotoxicity induced by anti-infective compounds

Antibiotic resistance is a natural phenomenon in the bacterial world, but the misuse of these drugs in human and veterinary medicine has greatly accelerated the process. Antibiotic resistance is now one of the most serious threats to global health, food safety and the environment. The overall objective is therefore to limit the spread of antimicrobial resistance, in order to allow time for industries to deploy new therapeutic strategies. These solutions are based on the modification of existing antibiotics, the development of new compounds, the use of bacteriophages or other complementary strategies.

The development of new antimicrobial compounds implies an upstream evaluation of their toxicity towards different cell lines.

Our offer

Smaltis accompanies the development of antimicrobial candidates in the in vitro evaluation of cytotoxicity induced by these compounds, whether they are antibiotic candidates, antimicrobial peptides, phages, or any other compound.

Several types of toxicity assessments can be conducted, on different cell lines, depending on the target of the product.

These analyses allow us to obtain a first idea of the toxicity induced by the candidate under development, and of the maximum concentration not to be exceeded.

Evaluation of the induced toxicity on different eukaryotic cell lines

Cytotoxicity can be assessed by measuring the release of lactate dehydrogenase (LDH) into the medium, or by assessing MTT cleavage.
These analyses allow to quantify cell death and to obtain LC50 (Lethal Concentration 50) or EC50 (Median Effective Concentration) values, that is to say information on the concentration of compound able to kill 50% of eukaryotic cells.

Assessment of the hemolytic power

The determination of the ability of a compound to lyse red blood cells is done by the Red Blood Cell Lysis technique. This analysis is based on the measurement by spectrophotometry of the hemoglobin released by the red blood cells, in the presence of the tested molecule.
Red blood cells of different origins can be used (human, sheep, mouse…).
This determination can be done in end-point, i.e. with a measurement at a defined time, or in kinetic, allowing to carry out measurements at various times.

Example of achievement

Determination of cytotoxicity induced by P. aeruginosa strain PAO1 and its mutant SM46 deleted from virulence genes.

Measurement of the amount of LDH released into the medium by macrophages.