METHOD FOR ASSESSING ANTIMICROBIAL ACTIVITY OF SUBSTANCES Russian patent published in 2025 - IPC C12N1/20 G01N21/76 C12Q1/02 C12Q1/04 

FIELD: biotechnology.

SUBSTANCE: disclosed is a method for assessing antimicrobial activity of substances, comprising preparing a bacterial suspension by diluting a night culture of the Photobacterium leiognathi Sh1 test strain with 3% sodium chloride until it contains microbial cells of 10³ cells/ml, then, first, antimicrobial activity of working standard samples of antibiotics is assessed by inhibition of bioluminescence of luminous bacteria depending on concentrations of antibiotics and a bioluminescence index of Photobacterium leiognathi Sh1 is calculated using the following formula: BLI = I_i/i₀ × 100%, where I_i is the luminescence intensity of the bacteria in the test sample, I₀ is the luminescence intensity of the bacteria in the control. When recording luminescence, working standard samples of antibiotics are used, standard curves are obtained, EC₈₀ is calculated for reference samples; bioluminescence inhibition of luminous bacteria is assessed by samples of the analysed substances; the bioluminescence index of Photobacterium leiognathi Sh1 – BLI and EC₈₀ is calculated, compared with reference samples and antimicrobial activity of the substances is assessed.

EFFECT: invention widens the range of methods for determining antimicrobial activity of antibiotics and pharmaceutical substances.

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