The antibacterial capabilities of alginate encapsulated lemon essential oil nanocapsules against multi-drug-resistant Acinetobacter baumannii

Abstract

Controlling microbial pollutants is a significant public health concern as they cause several chronic microbial infections and illnesses. In recent years, essential oils (EOs) have become intriguing alternatives for synthetic antimicrobials due to their biodegradability, natural source extraction, and strong antibacterial properties. The bactericidal properties of alginate containing lemon essential oil were examined in this investigation. Following the screening of the MDR strains, the morphological properties of the produced nanoparticles were examined using SEM, DLS, and FTIR. Additionally, the durability, effectiveness, and drug dispersion of encapsulation were assessed. Bacterial virulence factor gene amounts were measured using Q-real-time PCR. Concurrently, the cytotoxic effect of the nanomaterials was evaluated using MTT techniques. Nanoparticles of lemon essential oil encapsulated in alginate, measuring 500 ± 19.32 nm in size, with entrapment efficiency of 77.73 ± 1.78% and were stable for 60 days at 4 °C. Alginate encapsulated with lemon essential oil nanoparticles (ALN) exhibited potent antibacterial qualities, according to the biological investigation. Their ability to decrease the transcription of bacterial virulence genes at least statistically significantly (P ≤ 0.05) served as evidence for this. Between 1.56 and 100 µg/mL (P ≤ 0.01), ALN exhibited lower cytotoxicity against CCD841CoN than free lemon essential oil. The findings show that ALN nanoparticles have the potential to be a breakthrough in the fight against highly resistant illnesses. ALN nanoparticles' potent antibacterial efficacy against MDR strains of Acinetobacter baumannii may inspire new directions in antibacterial research.

Keywords: Acinetobacter baumannii; Multi drug resistant; Nanotechnology; Phytomedicine.

Fig. 1

(A) Synthesized ALN nanocapsules examined by field emission scanning electron microscopy (FE-SEM). (B) The dispersion of particles with diameters ranging from 550 to 950 nm for ALN nanocapsules is shown by the DLS experiment. (C) The zeta potential for ALN nanocapsules was − 1.74 ± 0.32. (D) Fourier Transform Infrared (FTIR) Spectra of ALN nanocapsule.

Fig. 2

(A) The quantity of controlled medication release in ALN nanocapsules and alginate as opposed to free lemon essential oil. (B) the impact of temperature on alginate and ALN nanocapsule average size. (C) Temperature’s impact on ALN nanocapsule’s EE (%).

Fig. 3

(A) MIC and (B) MBC value of Free lemon essential oil, and ALN nanocapsule in pathogenic strains (n = 3).

Fig. 4

(A) PCR confirmation of the cnf1 gene and (B) iutA virulence gene existence in Acinetobacter baumannii. NTC: Negative control, S1: Strain 1, S2: Strain 2, S3: Strain 3, S4: A. baumannii ATCC 17978 and M: 100 bp Ladder. (C) The impact of lemon essential oil, and ALN nanocapsule on the transcription of cnf1 gene and (D) iutA virulence genes. Data are mean ± SD of three independent experiments. The significance level was determined as *** p < 0.001, ** p < 0.01, * p < 0.0.5.

Fig. 5

Cell survival proportion of CCD841CON cells administered an ALN nanocapsule and free lemon essential oil during a 24-hour period compared to PBS. Data are mean ± SD of three independent experiments. The significance level was determined as *** p < 0.001, ** p < 0.01, * p < 0.0.5.