Evaluation of antibacterial efficacy and phytochemical analysis of Echinacea purpurea towards MDR strains with clinical origins

Abstract

Microbes that are resistant to antibiotics are becoming a severe threat to global healthcare system. The well possible alternative to the possibility of medication resistance is the incorporation of natural remedies with considerable antimicrobial property in the therapeutic approaches of bacterial illnesses. Methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa (P. aeruginosa), Acinetobacter baumannii (A. baumannii), Proteus mirabilis (P. mirabilis), Stenotrophomonas maltophilia (S. maltophilia) were isolated from 50 clinical specimens taken from patients admitted to Al-Zahraa University Hospital and Cairo Specialized Hospital from January 2016 to June 2016. Antimicrobial impacts of various solvents including (hexane, ethyl acetate, chloroform, and aqueous) were screened against multi-drug resistant (MDR) strains isolated from clinical samples. Echinacea Purpurea ethyl acetate fraction showed the most promising antibacterial activity versus bacterial clinical isolates with inhibition zone range 16.8-22.7 mm, and MIC range of 15.63-250 µg/mL, whereas other fractions were found to exhibit lower inhibition zones and higher minimal inhibitory concentration (MIC) values than ethyl acetate fraction against MDR strains. None of fractions have antibacterial action versus S. maltophilia. Electron microscopic investigation of MRSA treated by E. purpurea ethyl acetate reveled its role in lysis of pathogenic bacterial cells. The ethyl acetate fraction of the E. purpurea was analyzed using LC–MS to screen various molecules present in the fraction of E. Purpurea ethyl acetate fraction showed promising antioxidant activity with IC50 = 14.24 ± 0.58 µg/m. E. Purpurea ethyl acetate fraction had CC50 value of 1145.97 μg/ml upon testing on Vero cells highlighted its minimal toxicity. The study's findings will be used to further in vivo elucidate the E. purpurea ethyl acetate fraction for potential medicinal purposes.