Validación de la técnica de dilución en agar modificada por Katherine A. Hammer, Christine F. Carson, Thomas V. Riley; para la estimación “in vitro” de la actividad antimicrobiana frente a una cepa ATCC de Escherichia coli 25922; y su aplicación a tres aceites esenciales

Abstract

The antibacterial activity of essential oils (EO) has been the subject of great interest since its beginnings, due to the existence of diverse health problems of bacterial etiology that affect the world population, such as the Escherichia coli (E. coli) pathogen which is one of the most prominent microorganisms in terms of its resistance, developed in response to the need to adapt to new adverse environments and in addition by an indiscriminate use of antibiotics. The objective of this study was to validate the dilution technique in agar modified by Katherine A. Hammer, Christine F. Carson, Thomas v. Riley, with an American Type Culture Collection (ATCC) strain of E. coli 25922, and to determine the possible bioactivity of three EO chosen through bibliographic reviews. This was accomplished by using two EO as controls. The first control EO reacts when introduced to the microorganism, while the second does not. For the development of the study, an experimental design was followed based on a, quantitative/ qualitative approach, in which the following EO were tested: Oregano, Ginger, Rue, Lavender and Lemongrass, using the dilution in agar technique modified by Katherine A. Hammer, Christine F. Carson and Thomas V. Riley. Dilution in agar is a method that has been validated and approved by the Clinical Laboratory Standards Institute (CLSI) and that allows one to prove whether or not an EO reacts when introduced to microorganisms such as Gram (+) or Gram (-). This is possible thanks to small modifications such as the addition of Tween 20, which allows one to overcome surface tension, facilitating the formation of an emulsion between the environment and the EO. Finally, it was possible to validate the technique of dilution in agar modified by Katherine A. Hammer, Christine F. Carson, Thomas V. Riley. The results were: Oregano and Ginger in 0.12% v/v Essential Oil (EO) / Agar Mueller Hinton (MHA), Lavendar 0.48% v/v (EO/MHA), Rue ˃0.48% v/v (EO/MHA) and Lemongrass 0.06% v/v (EO/MHA). The preliminary result can serve as the basis of future studies, due to the enormous potential of EO and the great biodiversity of our region, in order to use them as natural products.