Modulating Effect of 4,6,6-trimethylbicyclo [3.1.1] hept-3-ene on Antimicrobials Used to Combat <em>Escherichia coli</em>

Abstract

The growing number of resistant bacteria is considered a worldwide public health problem. In this context, several control initiatives have been proposed, such as the elaboration of medicines from vegetable raw material as an alternative to fight against microorganisms such as Escherichia coli, which is related to approximately 50% of hospital infections. α-Pinene is found in the oils of many coniferous tree species and has antimicrobial activity against some microorganisms. The positive enantiomer of this compound (+)-α-pinene (+ AP), also called 4,6,6trimethylbicyclo [3.1.1] hept-3-ene, obtained from the company Sigma-Aldrich do Brasil Ltda. The solutions were dissolved in 1% Tween 80 and 5% DMSO and sterile distilled water was used to achieve desired concentrations. The tests were performed on the Escherichia coli strain ATTC 25922. To perform the modulation and adaptation tests, discs containing commercial antibiotics (ATM) were used. The modulating action of monoterpene was determined by the disc diffusion method. The antimicrobials Ceftazidime, Amoxicillin, Cefepime and Cefoxitin demonstrated synergism through association with phytoconstituent. For the remaining ATM, there was no statistically significant difference, and the effect of the association was classified as indifferent. It is concluded that