Composição química do óleo essencial de Lippia origanoides Kunth e atividade antimicrobiana frente a diferentes sorotipos de Haemophilus parasuis

Abstract

Pig farming has become increasingly important in recent years in Brazil, because of this, studies for the treatment of diseases that cause the loss of mass of meat animals has increased significantly, such as the Glasser's disease caused by Haemophilus parasuis. Some initial studies have shown human resistance to antibiotics due to the consumption of meat produced with high levels of these substances, and alternatively treatments have been developed from natural products. Lippia origanoides Kunth is presented as a natural source of antimicrobial substances due to the composition of the essential oil obtained, mainly, from the leaves of this plant. In this study the antimicrobial activity of the essential oil from Lippia origanoides Kunth, by determining the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) against Haemophilus parasuis serotypes 1,2,4,5,9,10,12,13,14 and one untypable was studied. Essential oils were obtained by hydrodistillation of the dried leaves and the chemical composition analysis revealed the presence of carvacrol as the predominant component, which characterizes the chemotype B. The results of the antimicrobial activity demonstrated the inhibitory effect of essential oil samples for all tested bacteria. The best result was 0.005% against the sample MV12315 (serotype 10) while the least satisfactory was 0.078% against the sample MV12196 (serotype 12). Results demonstrate the bactericidal action of the oil against the different serotypes of Haemophilus parasuis.