Evaluation of Antimicrobial Activity of a Pyrimidine Derivative Against <i>Staphylococcus Aureus</i>

Abstract

The aim of this study was to evaluate the in vitro and in vivo antimicrobial activity of a new pyrimidine derivative against Staphylococcus aureus . The assessment of the antimicrobial activity of pyrimidine compound 3 3-(2-Phenyl-2- oxoethyl)quinazoline-4(3H)-one was performed in vitro using a test culture of the S. aureus strain isolated from patients’ sputum by serial dilutions in meat-peptone broth, followed by the formation of sequences with a concentration of pyrimidine derivative 128 mcg/ml; 64 mcg/ml; 32 mcg/ml; 16 mcg/ml; 8 mcg/ml; 4 mcg/ml; 2 mcg/ml; 1 mcg/ml. During the study, the minimum inhibitory concentration of 3-(2-Phenyl-2-oxoethyl)quinazoline-4(3H)-one against S. aureus was determined. The antimicrobial activity of the compound under examination was studied in vivo using a model of generalized staphylococcal infection. The infectious process was modeled via intraperitoneal administration of S. aureus at a dose of ×10 8 microbial bodies to 7-week-old mice. All laboratory mice were divided into 4 groups: control I — animals receiving an equivalent volume of water for injection; control II — animals infected with S. aureus ; comparison group — a group of animals treated with the comparison drug ceftriaxone at a dose of 50 mg/kg; experimental group – animals treated with the studied compound at a dose of 1/10 of the molecular weight of 26 mg/ kg, for 7 days starting from the day of infection. The survival rate of mice during the experiment was evaluated. At the end of the experiment, blood, spleen, liver, and lung contamination indices were calculated. The study established the antibacterial activity of the pyrimidine derivative 3-(2-Phenyl-2-oxoethyl)quinazoline-4(3H)-one under in vitro conditions against S. aureus : the compound showed bacteriostatic activity in the dilution of 16 mcg/kg and bactericidal activity in dilution of 64 mcg/kg. The results of the assessment of antimicrobial activity in vivo showed that the studied compound contributes to the survival of laboratory animals, as well as to a decrease in the index of bacterial contamination of internal organs and blood in conditions of generalized staphylococcal infection, which indicates the ability to form antimicrobial immunity.