Prażyńska Małgorzata, Bogiel Tomasz, Gospodarek-Komkowska Eugenia
Department of Microbiology, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, 9 Marii Curie-Skłodowskiej Street, 85-094, Bydgoszcz, Poland.
Folia Microbiol (Praha). 2018 Mar;63(2):209-216. doi: 10.1007/s12223-017-0555-2. Epub 2017 Oct 5.
Candida spp. is able to form a biofilm, which is considered resistant to the majority of antifungals used in medicine. The aim of this study was to evaluate the in vitro activity of micafungin against Candida spp. biofilms at different stages of their maturation (2, 6, and 24 h). We assessed the inhibitory effect of micafungin against 78 clinical isolates of Candida spp., growing as planktonic or sessile cells, by widely recommended broth microdilution method. The in vitro effect on sessile cells viability was evaluated by colorimetric reduction assay. All examined strains were susceptible or intermediate to micafungin when growing as planktonic cells. At the early stages of biofilm maturation, from 11 (39.3%) to 20 (100%), tested strains, depending on the species, exhibited sessile minimal inhibitory concentrations (SMICs) of micafungin at ≤ 2 mg/L. For 24-h-old Candida spp. biofilms, from 3 (10.7%) to 20 (100%) of the tested strains displayed SMICs of micafungin at ≤ 2 mg/L. Our findings confirm that micafungin exhibits high potential anti-Candida-biofilm activity. However, this effect does not comprise all Candida species and strains. All strains were susceptible or intermediate to micafungin when growing as planktonic cells, but for biofilms, micafungin displays species- and strain-specific activity. Paradoxical growth of C. albicans and C. parapsilosis was observed. Antifungal susceptibility testing of Candida spp. biofilms would be the best solution, but to date, no reference method is available. The strongest antibiofilm activity of micafungin is observed at early stages of biofilm formation. Possibly, micafungin could be considered as an effective agent for prevention of biofilm-associated candidiasis, especially catheter-related candidaemia.
念珠菌属能够形成生物膜，这种生物膜被认为对医学上使用的大多数抗真菌药物具有抗性。本研究的目的是评估米卡芬净在念珠菌属生物膜成熟的不同阶段（2、6和24小时）的体外活性。我们通过广泛推荐的肉汤微量稀释法，评估了米卡芬净对78株念珠菌属临床分离株（以浮游或固着细胞形式生长）的抑制作用。通过比色还原试验评估对固着细胞活力的体外影响。所有检测菌株在以浮游细胞形式生长时对米卡芬净敏感或为中介敏感。在生物膜成熟的早期阶段，根据菌种不同，11株（39.3%）至20株（100%）受试菌株的米卡芬净固着最小抑菌浓度（SMIC）≤2mg/L。对于24小时龄的念珠菌属生物膜，3株（10.7%）至20株（100%）受试菌株的米卡芬净SMIC≤2mg/L。我们的研究结果证实，米卡芬净具有很高的抗念珠菌生物膜活性。然而，这种作用并不涵盖所有念珠菌菌种和菌株。所有菌株在以浮游细胞形式生长时对米卡芬净敏感或为中介敏感，但对于生物膜，米卡芬净表现出菌种和菌株特异性活性。观察到白色念珠菌和近平滑念珠菌的反常生长。念珠菌属生物膜的抗真菌药敏试验将是最佳解决方案，但迄今为止，尚无参考方法可用。在生物膜形成的早期阶段观察到米卡芬净最强的抗生物膜活性。可能，米卡芬净可被视为预防生物膜相关念珠菌病，尤其是导管相关念珠菌血症的有效药物。
