Antibacterial and anti-Toxoplasma activities of Aspergillus niger endophytic fungus isolated from Ficus retusa: in vitro and in vivo approach

• Published in: Artificial cells, nanomedicine, and biotechnology Vol. 51; no. 1; pp. 297 - 308
• Main Authors: Moglad, Ehssan, Elekhnawy, Engy, Negm, Walaa A., Eliwa, Duaa, Sami Younis, Salwa, Mohamed Elmansory, Basma, Mahgoub, Sebaey, Ahmed, Eman A., Momtaz Al-Fakhrany, Omnia
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01-12-2023; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Anti-Bacterial Agents - pharmacology; anti-biofilm; Antibacterial activity; Aspergillus niger; Asteraceae; Biofilms; Biological properties; Chemical profiling; Clinical isolates; Electron microscopes; Endophytes; Ficus; Ficus retusa; Flow cytometry; Fungi; Gene sequencing; Klebsiella; Klebsiella pneumoniae; membrane depolarization; Membrane potential; Minimum inhibitory concentration; Plant Extracts; rRNA 18S; Scanning electron microscopy; Tachyzoites; Toxoplasma; Toxoplasma gondii; ultrastructure; Chemical profiling; tachyzoites; anti-biofilm; ultrastructure; Klebsiella pneumoniae; membrane depolarization
• ISSN: 2169-1401; 2169-141X
• DOI: 10.1080/21691401.2023.2215531

Emergent records propose that Aspergillus niger endophytic fungus is a vital source for various bioactive molecules possessing many biological properties. The current study was designed to inspect the antibacterial and anti-Toxoplasma potentials of Ficus retusa-derived endophytic fungi. After isolation and identification (using 18S rRNA gene sequencing) of A. niger endophytic fungus, LC/MS was utilized for identification and authentication of the chemical profile of the A. niger endophyte extract. Then, the fungal extract was assessed for its antibacterial and antibiofilm activities against Klebsiella pneumoniae clinical isolates. Additionally, its efficacy against Toxoplasma gondii was elucidated in vivo. The fungal extract displayed antibacterial activity against K. pneumoniae isolates with minimum inhibitory concentration values of 64-512 µg/mL. It also possessed a membrane potential dissipating effect using flow cytometry. Moreover, it formed distorted cells with rough surfaces and deformed shapes using a scanning electron microscope (SEM). Regarding its antibiofilm activity, it resulted in a dysregulation of the genes encoding biofilm formation (fimH, mrkA and mrkD) using qRT-PCR in nine K. pneumoniae isolates. The in vivo anti-Toxoplasma potential was demonstrated by decreasing the mortality rate of mice and reducing the tachyzoites' count in the peritoneal fluids and liver impression smears of mice. In addition, the deformities of the parasite decreased, as revealed by SEM and the inflammation in tissues diminished. Thus, A. niger endophytic fungi could be a valuable source of antibacterial and anti-Toxoplasma compounds.