Chemical composition of Lippia Linn. (Verbenaceae) essential oils and their antibacterial potential against Aeromonas spp. isolates from Colossoma macropomum

ABSTRACT

The aim of this study was to determine the chemical composition of Lippia alba and two genotypes of L. origanoides, L. origanoides A and L. origanoides B (syn. Lippia sidoides) essential oils(EOs) and to investigate the antibacterial activity against 27 Aeromonas spp. isolated from tambaqui (Colossoma macropomum). The activity of the antibiotics Florfenicol and Oxytetracycline was also compared. The EOs were obtained by hydrodistillation and their composition determined by CG-MS. Antibacterial activity was assessed based in the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using microdilution method. The main compounds identified were carvone (55.9%) and limonene (21.9%) in L. alba EO, carvacrol (35.6%) and p‐cymene (15.7%) in L. origanoides A EO and thymol (53.5%) and p‐cymene (15.5%) in L. origanoides B EO. The Lippia species showed bacteriostatic and bactericidal action against Aeromonas isolates with MICs and MBCs ranging from 104.17 to 16,666.67 μg.mL⁻¹. Among the tested EOs, the best performance was obtained by that of the L. origanoides B genotype, followed by L. origanoides A and L. alba respectively. Among antibiotics, the best performance was of oxytetracycline (MICs and MBCs ranging from 0.195 to 0.78 μg.mL⁻¹) compared to florfenicol (MICs and MBCs ranging from 0.195 to 3.12 μg.mL⁻¹).

KEYWORDS:

• Lippia alba
• Lippia origanoides
• Lippia sidoides
• florfenicol
• oxytetracycline
• tambaqui

Acknowledgments

The authors thank the Amazonas Research Foundation (Process: 062.01097/2017/ Edital N ° 016/2014 - PPP-CNPq) and the Sectorial Infrastructure Fund (CT-INFRA) through the MCT/CNPq for financial support and Brazilian Agricultural Research Corporation (EMBRAPA), in special to Embrapa Western Amazon for infrastructure.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Etical statement

The Ethics Committee for the Use of Animals (CEUA) of Embrapa Western Amazon approved the activities relevant to this work under protocol No. 04/2018, issued on 10/1/2018. Access to the genetic heritage was authorized by the Genetic Heritage Management Council (CGen) with No. AF34DA8.

Additional information

Funding

This research was funded by Fundação de Amparo à Pesquisa do Estado do Amazonas [Process: 062.01097/2017/ Edital N ° 016/2014 - PPP-CNPq] and the Sectorial Infrastructure Fund (CT-INFRA) through the MCT/CNPq