METHOD FOR ASSESSING THE EFFECT OF AGENTS USED TO PREVENT CATHETER-ASSOCIATED INFECTIONS ON BACTERIAL COLONIZATION OF THE CATHETER SURFACE Russian patent published in 2022 - IPC G01N33/52 C12N1/11 C12Q1/00 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely clinical microbiology, surgery, urology, and is intended to evaluate the effect of agents used to prevent catheter-associated infections on bacterial colonization of the catheter surface. Biofilms of luminescent bacteria are formed on a 0.5 cm catheter fragment in 4-well polystyrene culture plates in vitro for 6 and 24 hours in the presence and absence of the agent, washed in 0.89% NaCl solution, after which bioluminescence is assessed (I, arb. units), stained with 0.1% gentian violet, determine the massiveness of the biofilm (OD₅₈₀, units) and compared with the control. The conclusion about the effectiveness of the agent on bacterial colonization of the catheter surface is made as follows: with a decrease from the control of the bioluminescence index by 99% and the biofilm massiveness index by 70% and above, the high efficiency of the agent is judged; a decrease from control in the bioluminescence index from 98% to 70% and the biofilm massiveness index from 69% to 30% indicates the average effectiveness of the agent; a decrease from the control of the bioluminescence index of less than 70% and the index of biofilm massiveness of less than 30% indicates a low effectiveness of the agent or its absence; with a different combination of indicators of bioluminescence and biofilm massiveness, the effectiveness of the agent is evaluated by the indicator that has the least effect on microbial colonization.

EFFECT: method allows to increase the accuracy and objectivity of the method by bringing the conditions of the experiment in vitro to the situation in vivo; increasing the information content of the method by assessing the viability of adherent cells in the composition of the biofilm by bioluminescence; accessibility of the method; with frequent measurements of bioluminescence, the method allows monitoring all processes associated with the persistence of bacteria in the presence of various agents, namely cell adhesion (acceleration/inhibition), the rate of colonization and biofilm formation (deceleration/intensification).

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