ANTIBACTERIAL ACTIVITY OF CONIFEROUS EXTRACT

Traditionally, preservatives have been used in cosmetic products to prevent bacterial contamination. Some opportunistic microor- ganisms of the genus Corynebacterium living on human skin have become drug resistance because of what new alternatives are needed. A potential candidate is a coniferous extract (СЕ) with antibacterial activity. Methods. The susceptibility of C. xerosis and C. flavescens was evaluated using the serial dilution method in plain broth and beef-extract agar-agar. The lowest concentration of СЕ, which completely suppressed growth, was rated as the minimum inhibitory concentration (MIC). The antibacterial effect of СЕ was evaluated after exposure to bacteria for 30 minutes, 1, 3, and 24 hours at concentrations of 0; 3,5; 7; 15; 30; 125 and 500 μg / ml. Results. MIC, which inhibited the growth of C. xerosis in plain broth ranged between 15 and 60 μg / ml, and for C. flavescens 60 μg / ml. MIC, which inhibited the growth of C. xerosis, ranged from 60 to 125 μg / ml, and for C. flavescens it was 125 μg / ml. The growth of all C. xerosis strains was inhibited after a 30-minute exposure to 500 μg / ml СЕ. Bacterial growth was not inhibited at 125, 30, 7, and 3.5 μg / ml, but a decrease in the number of colonies was observed compared with the control. C. flavescens growth was not inhibited at any concentration, but a decrease in the number of colonies was observed compared with the control. The growth of all C. xerosis strains was inhibited after a 1-hour exposure to 500 and 125 μg / ml of СЕ. Compared to the control, a decrease in the number of colonies was observed at СЕ concentrations of 30, 7, and 3,5 μg / ml. C. flavescens growth was inhibited after a 1-hour exposure to 500 μg / ml СЕ. Compared with the control, a significant decrease in the number of colonies was observed at a concentration of СЕ of 125 μg / ml. The growth of all strains of C. xerosis and C. flavescens was completely inhibit- ed at 500 and 125 μg / ml after 3 hours of exposure to СЕ. One strain of C. xerosis was also inhibited at an СЕ concentration of 30 μg / ml and a decrease in the number of colonies was observed at a concentration of 7 and 3,5 μg / ml compared to the control. C. flavescens growth was not inhibited at an СЕ concentration of 30, 7, and 3,5 μg / ml, although a decrease in the number of colonies was observed compared with the control. Strains of C. xerosis and C. flavescens did not grow after 24-hour exposure to СЕ concentrations of 500, 125, 30, 7, and 3,5 μg / ml. Conclusion. СЕ can be used as an alternative antibacterial agent in the manufacture of cosmetic products.

Corynebacterium spp, coniferous extract, Corynebacterium spp, antibacterial activity, the minimum inhibitory concentration