Evaluating the effect of Syzygium aromaticum and Chamaemelum nobile extracts on gram-negative multi-drug resistant bacteria

Abstract

Antibiotic resistance is an important global health issue threatening the healthcare system. International associations have implemented many strategies in order to reduce the emergence of multidrug resistance. However, Multidrug resistant bacteria (MDR) rates have significantly increased. Alternative treatment had become a necessity. Therefore, antimicrobial activity of medicinal plants is becoming of high interest for researchers and physicians. Many studies have shown the benefits, decreased side effects and importance of using plant metabolites as alternatives for antibiotics. Although investigations on antimicrobial activity of herbal medicine are being held in Lebanon, there is not enough evidence on the antimicrobial importance of cloves (Syzygium aromaticum) and indigenous chamomile (Chamaemelum nobile) on different multidrug resistant bacteria isolated from patients. In this study, Chamaemelum nobile flowers and Syzygium aromaticum samples were extracted and fractionated. Then their antimicrobial activity was tested by showing their minimal bactericidal concentration (MBC) and their minimal inhibitory concentration (MIC). Both plants had effective antimicrobial activity against the studied Multidrug resistant organism (MDROs). Chamaemelum nobile MIC and MBC ranged between 80 µg/µl and 160 µg/µl; the crude extract had the lowest MIC 80 µg/µl for all strains. Syzygium aromaticum on the other hand had effect at lower concentrations (93 % to 98 %) at 1.5625 µg/µl. These results were highly prevalent with crude and petroleum ether extracts. The results of this research confirmed that Syzygium aromaticum and Chamaemelum nobile are effective against ESBL and/or CRE bacteria strains such as “E. coli”, “A. baumannii”, “K. pneumonia”, “P. aeruginosa”, “P. mirabilis” and “E. cloacae”.