Jafri Huma, Banerjee Gopa, Khan Mohd Sajjad Ahmad, Ahmad Iqbal, Abulreesh Hussein Hasan, Althubiani Abdullah Safar
Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, 202002, India.
Department of Microbiology, King George Medical University, Lucknow, 226020, India.
AMB Express. 2020 Oct 19;10(1):185. doi: 10.1186/s13568-020-01123-2.
In vitro eradication of the C. albicans and S. mutans mixed biofilms by eugenol alone and in combination with the antimicrobial drugs. Previously characterized strains of C. albicans (CAJ-01 and CAJ-12) and S. mutans MTCC497 were used to evaluate the eradication of biofilms using XTT reduction assay, viability assay, time dependent killing assay and scanning electron microscopy (SEM). Synergistic interaction was assessed by checkerboard method. Sessile MIC (SMIC) of eugenol was equivalent to the planktonic MIC (PMIC) against C. albicans and S. mutans mixed biofilms. SMIC of fluconazole and azithromycin was increased upto 1000-folds over PMIC. Eradication of single or mixed biofilms was evident from the viability assay and SEM. At 1 × MIC of eugenol, logCFU count of C. albicans cells were decreased from 6.3 to 4.2 and 3.8 (p < 0.05) in single and mixed biofilms, respectively. SEM studies revealed the eradication of C. albicans and S. mutans cells from glass surface at 800 µg/mL concentration of eugenol. Time dependent killing assay showed dose dependent effect of eugenol on pre-formed CAJ-01, CAJ-12 and S. mutans biofilm cells. Eugenol was highly synergistic with fluconazole (FICI = 0.156) against CAJ-12 single biofilms. However, the combination of eugenol and azithromycin showed maximum synergy (FICI = 0.140) against pre-formed C. albicans and S. mutans mixed biofilms. These findings highlighted the promising efficacy of eugenol in the eradication of biofilms of two oral pathogens (C. albicans and S. mutans) in vitro and could also be exploited in synergy with fluconazole and azithromycin in controlling oral infections.
丁香酚单独及与抗菌药物联合对白色念珠菌和变形链球菌混合生物膜的体外清除作用。使用先前鉴定的白色念珠菌菌株（CAJ - 01和CAJ - 12）和变形链球菌MTCC497，通过XTT还原试验、活力试验、时间依赖性杀菌试验和扫描电子显微镜（SEM）评估生物膜的清除情况。采用棋盘法评估协同相互作用。丁香酚对白色念珠菌和变形链球菌混合生物膜的静态最低抑菌浓度（SMIC）与浮游最低抑菌浓度（PMIC）相当。氟康唑和阿奇霉素的SMIC比PMIC增加了高达1000倍。从活力试验和SEM可以明显看出单一或混合生物膜的清除情况。在丁香酚的1×MIC浓度下，白色念珠菌细胞在单一生物膜和混合生物膜中的对数CFU计数分别从6.3降至4.2和3.8（p < 0.05）。SEM研究表明，在800 μg/mL丁香酚浓度下，白色念珠菌和变形链球菌细胞从玻璃表面被清除。时间依赖性杀菌试验显示丁香酚对预先形成的CAJ - 01、CAJ - 12和变形链球菌生物膜细胞具有剂量依赖性作用。丁香酚与氟康唑对CAJ - 12单一生物膜具有高度协同作用（FICI = 0.156）。然而，丁香酚和阿奇霉素的组合对预先形成的白色念珠菌和变形链球菌混合生物膜显示出最大协同作用（FICI = 0.140）。这些发现突出了丁香酚在体外清除两种口腔病原体（白色念珠菌和变形链球菌）生物膜方面的有前景的疗效，并且在与氟康唑和阿奇霉素协同控制口腔感染方面也可加以利用。
