The In vitro Effect of Nanoliposomal Amphotericin B Against Rhizopus arrhizus Isolated From COVID-19-Associated Mucormycosis Patients.

BACKGROUND &

OBJECTIVE

Rhizopus arrhizus, a major contributor to COVID-19-associated mucormycosis (CAM) globally. Nanoliposomal amphotericin B (NLAmB) presents a promising approach due to its enhanced drug delivery and reduced side effects. This study aimed to assess the in vitro antifungal susceptibility of NLAmB against R. arrhizus isolated from CAM patients.

METHODS

Thirty-nine R. arrhizus isolated from CAM patients were identified through phenotypic characterization, MALDI-TOF, and the internal transcribed spacer rDNA region (ITS) sequencing approaches. Antifungal susceptibility testing (AFST) for NLAmB, amphotericin B (AmB), posaconazole (PSC), and isavuconazole (ISC) was conducted through broth microdilution methods according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standard E.DEF 9.4. Results were analyzed for MIC ranges, MIC50, MIC90, and distributions.

RESULTS

NLAmB demonstrated superior in vitro efficacy against R. arrhizus (MIC50/90, 0.063/0.25 μg/ml) compared to AmB, PSC, and ISC. PSC exhibited notable activity (MIC range: ≤0.031 - ≥16 μg/ml).

CONCLUSION

The study emphasized NLAmB's sustained activity, making it a potential alternative to LAmB. Further exploration and clinical correlation are warranted to validate NLAmB in CAM treatment.