Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jan 19;23(1):23.
doi: 10.1186/s12866-023-02758-4.

Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii

Maryam Pourhajibagher  1 , Nava Hosseini  2   3   4 , Abbas Bahador  5   6
Affiliations

Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii

Maryam Pourhajibagher et al. BMC Microbiol. .

Abstract

Background: The emergence of multidrug-resistant Acinetobacter baumannii strains is increasing worldwide. To overcome these life-threatening infections, the development of new treatment approaches is critical. For this purpose, this study was conducted to determine the antimicrobial photo-sonodynamic therapy (aPSDT) using hypericin nanoparticles (HypNP) in combination with D-Tryptophan (D-Trp) against A. baumannii.

Materials and methods: HypNP was synthesized and characterized, followed by the determination of the fractional inhibitory concentration (FIC) index of HypNP and D-Trp by checkerboard assay. Next, the antimicrobial and anti-biofilm potential of HypNP@D-Trp-mediated aPSDT against A. baumannii was evaluated. Finally, the anti-virulence activity of aPSDT using HypNP@D-Trp was accessed following the characterization of HypNP@D-Trp interaction with AbaI using in silico virtual screening and molecular docking.

Results: A synergistic activity in the combination of HypNP and D-Trp against A. baumannii was observed with a FIC index value of 0.5. There was a 5.10 log10 CFU/mL reduction in the cell viability of A. baumannii when the bacterial cells were treated with 1/2 × MIC of HypNP@D-Trp and subsequently exposed to ultrasound waves and blue light (P < 0.05). Moreover, a significant biofilm degradation effect on biofilm-associated cells of A. baumannii was observed after treatment with aPSDT using 2 × MIC of HypNP@D-Trp in comparison with the control groups (P < 0.05). According to the molecular docking analysis of the protein-ligand complex, Hyp with a high affinity for AbaI showed a binding affinity of - 9.41 kcal/mol. Also, the expression level of abaI gene was significantly downregulated by 10.32-fold in A. baumannii treated with aPSDT as comprised with the control group (P < 0.05).

Conclusions: It can be concluded that HypNP@D-Trp-mediated aPSDT can be considered a promising strategy to overcome the infections caused by A. baumannii by reducing the growth of bacterial biofilm and decreasing the expression of abaI as a gene involved in A. baumannii biofilm formation.

Keywords: Acinetobacter baumannii; Antimicrobial photodynamic therapy; Antimicrobial sonodynamic therapy; Biofilms; Drug resistance; Nosocomial infection.

PubMed Disclaimer

Conflict of interest statement

There is no competing interest.

Figures

Fig. 1
Fig. 1
Characterization of synthesized hypericin nanoparticle (HypNP): a) Transmission electron microscope (TEM) image (Scale bar = 200 nm), b) The size distribution profile of HypNP
Fig. 2
Fig. 2
Effects of different treatment groups on the cell viability of Acinetobacter baumannii. *Significantly different from the control group (no treatment), P < 0.05
Fig. 3
Fig. 3
Effects of different treatment groups on the biofilm of Acinetobacter baumannii. *Significantly different from the control group (no treatment), P < 0.05
Fig. 4
Fig. 4
Confirmation of quality of AbaI structure by a. The three-dimensional modeling of 3P2F; b. The Ramachandran plot of 3P2F; c. Verify_3D; and d. ERRAT
Fig. 5
Fig. 5
Protein-protein interactions network analysis of AbaI
Fig. 6
Fig. 6
Representation of docked ligand-protein complex; Interaction of Hypericin with amino acid residues of AbaI
Fig. 7
Fig. 7
Effects of different treatment groups on the expression of gene involved in biofilm formation of Acinetobacter baumannii. *Significantly different from the control group (no treatment), P < 0.05
See this image and copyright information in PMC

References

    1. Amraei S, Eslami G, Taherpour A, Hashemi A. Relationship between MOX genes and antibiotic resistance in Klebsiella pneumoniae strains in nosocomial infections. Micro Nano Bio Asp. 2022;1(2):12–17.
    1. Bahador A, Raoofian R, Taheri M, Pourakbari B, Hashemizadeh Z, Hashemi FB. Multidrug resistance among Acinetobacter baumannii isolates from Iran: changes in antimicrobial susceptibility patterns and genotypic profile. Microb Drug Resist. 2014;20(6):632–640. doi: 10.1089/mdr.2013.0146. - DOI - PubMed
    1. Amraei S, Eslami G, Taherpour A, Hashemi A. The role of ACT and FOX genes in Klebsiella pneumoniae strains isolated from hospitalized patients. Micro Nano Bio Asp. 2022;1(2):18–25.
    1. Alavi M, Hamblin MR, Kennedy JF. Antimicrobial applications of lichens: secondary metabolites and green synthesis of silver nanoparticles: a review. Nano Micro Bios. 2022;1(1):15–21.
    1. Alavi M, Martinez F, Delgado DR, Tinjacá DA. Anticancer and antibacterial activities of embelin: micro and nano aspects. Micro Nano Bio Asp. 2022;1(1):30–37.

LinkOut - more resources