<i>In Vitro</i>Efficacy of Clove Oil and Eugenol against <i>Staphylococcus</i>spp and <i>Streptococcus mutans</i>on Hydrophobicity, Hemolysin Production and Biofilms and their Synergy with Antibiotics

• 作者: Huma Jafri Iqbal Ahmad
• 来源期刊: 微生物学(英文)
• 学科: 经济
• 关键词: Syzygium aromaticum Staphylococcus spp Streptococcus mutans EUGENOL Biofilm Inhibition Hydrobhobicity SMIC SYNERGY
• 年，卷（期）: 2021,（2）
• 页码范围: 117-143
• 页数: 27页
• 分类号: F42

摘要

The present study aimed to evaluate <i>Syzygium aromaticum</i> (clove) plant extract, clove oil and eugenol for their antibacterial activity and their potential to eradicate bacterial biofilms alone and in combination with antibiotics. Anti-bacterial efficacy of <i>S. aromaticum</i> extract, clove oil and eugenol was evaluated as minimum inhibitory concentration (MIC) and subsequently sub-MICs was selected for inhibition of virulence factors against test bacterial strains. Biofilm cultivation and eradication was assayed using XTT reduction in 96-well microtiter plate. Checkerboard method was used to study the interaction between essential oils and antibiotics. <i>Staphylococcus aureus</i> MTCC3160, <i>Staphylococcus epidermidis</i> MTCC435, <i>Staphylococcus sciuri</i> (SC-01), <i>Staphylococcus auricularis</i> (SU-01) <i>and</i> <i>Streptococcus mutans</i> MTCC497 were found strong biofilm former among all the test bacterial strains. The potency of test agents was found in the order of eugenol > clove oil > <i>S. aromaticum</i> methanolic extract. Sub-MIC (0.5 × MIC) of clove oil and eugenol showed a significant reduction in cell surface hydrophobicity (<i>p </i>< 0.05) and hemolysin production in the test bacterial strains. Eugenol showed no increase in sessile MIC (SMIC) against <i>S. auricularis</i> (SU-01), <i>S. epidermidis</i> MTCC435 and <i>S. mutans</i> MTCC497 compared to planktonic MIC (PMIC). Antibiotics (vancomycin and azithromycin) exhibited upto 1000-folds increased in SMIC compared to PMIC against all the test bacterial strains. Synergy was observed between eugenol and antibiotics (vancomycin/azithromycin) against all the test bacterial strains in both planktonic and sessile mode. Highest synergy was exhibited between eugenol and azithromycin in planktonic mode (FICI value 0.141). Further, microscopy also confirmed the spectacular effect of combination treatment on pre-formed <i>S. aureus</i> MTCC3160 and <i>S. mutans</i> MTCC497 biofilms. These findings highlighted the promising role of clove oi