Post-antifungal effect of the combination of anidulafungin with amphotericin B and fluconazole against fluconazole-susceptible and -resistant Candida albicans

Narges Vaseghi; Majid Piramoon; Shaghayegh Khojasteh; Kiana Abbasi; Sahar Mohseni; Javad Javidnia; Behrooz Naghili; Narges Aslani

doi:10.18502/cmm.8.2.10327

Narges Vaseghi Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Majid Piramoon Department of Medicinal Chemistry and Radiopharmacy, School of Pharmacy, Lorestan University of Medical Sciences, Khorramabad, Iran
Shaghayegh Khojasteh Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
Kiana Abbasi Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran
Sahar Mohseni Department of Microbiology, Sari Branch, Islamic Azad University, Sari, Iran
Javad Javidnia Department of Mycology, School of Medicine, Mazandaran University of Medical Science, Mazandaran, Sari, Iran
Behrooz Naghili Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Narges Aslani Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran

DOI: https://doi.org/10.18502/cmm.8.2.10327

Keywords: Anidulafungin, Candida albicans, Combination regimen, Post-antifungal effect

Abstract

Background and Purpose: Invasive candidiasis is a life-threatening condition that kills a large number of immunocompromised patients each year worldwide. We used postantifungal effect studies to analyze the activities of anidulafungin (AFG), as a clinically crucial antifungal drug, amphotericin B (AMB), and fluconazole (alone and in combinations) against FLC-susceptible and -resistant Candida albicans (C. albicans) isolates obtained from the cancer patients.

Materials and Methods: We tested the phenomenon of post antifungal effects of FLC, AMB, AFG, and combinations of FLC+AFG, AFG+AMB, and FLC+AMB against 17 C. albicans isolates obtained from the oral cavity of cancer patients. Isolates that had not been exposed to antifungals, served as a control group. Colony counts were performed at 0, 2, 4, 6, and 24 h after a brief (1 h) exposure to antifungal.

Results: The FLC had no detectable post-antifungal effect independent of antifungal concentration and resembled drug-free FLC (control). Significant variations in the postantifungal effect were observed when all AMB and AFG were compared to FLC. The combination of AFG and AMB with FLC resulted in effective activity compared to FLC alone. Combination regimens were rated as indifferent in general. Interestingly, low dosages of the AFG displayed increasing fungistatic action as it approached a fungistatic endpoint against C. albicans isolates (n=17).

Conclusion: Our findings suggested that brief exposure to AFG, in combination with FLC and AMB, at low concentrations of the medicines utilized, could be effective in the evaluation and optimization of new dosage regimens to manage candidiasis. However, future studies will determine the clinical utility of our findings.