Laboratory of Emerging Infectious Diseases, School of Medicine, Department of Health Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Laboratory of Emerging Infectious Diseases, School of Medicine, Department of Health Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Enferm Infecc Microbiol Clin (Engl Ed). 2023 Dec;41(10):596-603. doi: 10.1016/j.eimce.2022.07.009. Epub 2023 Jan 25.
Biofilm formation causes virulence and resistance in Candida albicans. However, little is known about breakthrough candidemia isolates. We evaluated the antifungal activity of fluconazole, anidulafungin, deoxycholate amphotericin B (dAMB), and amphotericin B lipid complex (ABLC) against biofilms of C. albicans isolated from patients with breakthrough candidemia.
The present study used strains of C. albicans isolated from breakthrough and non-breakthrough candidemia patients (control group). The susceptibility of planktonic cells to amphotericin B, anidulafungin, and fluconazole was determined by broth microdilution. Antifungal activity in sessile cells was evaluated using the minimum biofilm eradication concentration (MBEC), metabolic activity was estimated by reducing MTT, and biomass was estimated using crystal violet retention.
The planktonic strains were susceptible to amphotericin B, anidulafungin, and fluconazole, with minimum inhibitory concentrations of 1, ≤0.03, and 2mg/L, respectively. However, fluconazole and anidulafungin did not exert an antifungal effect on biofilms. Additionally, dAMB and ABCL reduced the metabolic activity and biomass. However, eradication was only achieved using 16mg/L dAMB. C. albicans isolates of breakthrough candidemia exhibited strong biofilm production, and the in vitro activity of available therapeutic options was poor.
In the present study, only dAMB and ABCL exhibited antibiofilm effects against sessile breakthrough candidemia isolates.
生物膜的形成会导致白色念珠菌的毒力和耐药性。然而，对于突破性念珠菌血症分离株知之甚少。我们评估了氟康唑、阿尼芬净、去氧胆酸盐两性霉素 B（dAMB）和两性霉素 B 脂质复合物（ABLC）对来自突破性念珠菌血症患者的白色念珠菌生物膜的抗真菌活性。
本研究使用了从突破性和非突破性念珠菌血症患者（对照组）中分离的白色念珠菌菌株。通过肉汤微量稀释法测定浮游细胞对两性霉素 B、阿尼芬净和氟康唑的敏感性。用最低生物膜清除浓度（MBEC）评估固定细胞的抗真菌活性，用 MTT 减少法估计代谢活性，用结晶紫保留法估计生物量。
浮游菌对两性霉素 B、阿尼芬净和氟康唑敏感，最低抑菌浓度分别为 1、≤0.03 和 2mg/L。然而，氟康唑和阿尼芬净对生物膜没有抗真菌作用。此外，dAMB 和 ABCL 降低了代谢活性和生物量。然而，只有 16mg/L 的 dAMB 才能实现清除。突破性念珠菌血症的白色念珠菌分离株表现出强烈的生物膜生成能力，而现有治疗选择的体外活性较差。
在本研究中，只有 dAMB 和 ABCL 对固定的突破性念珠菌血症分离株表现出抗生物膜作用。
