Abstract
Objectives: The present study was designed to screen the antibacterial and synergistic effects of Allium sativum, Ecballiumelaterium, Pelargoniumgraveolens, Rosmarinusofficinalis, Phagnalonrupestre and Rutagraveolens plant extracts and essential oils against the followingclinical multidrug-resistant(MDR) Gram negative pathogenic isolates: Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.
 Methods: All extracts and essential oils were screened for their antibacterial activity and synergistic effect in combination with known antibiotics.The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the plant extracts were assessed.
 Results: Our results revealed that, the average diameter of inhibition zones ranged from: 7-14 mm, 7-17 mm, 8-17 mm and 7-13 mm for water, ethanol, methanol and EOs extracts, respectively. The MICs and MBCs were determined for extracts which showed antibacterial activity. The average MICs values ranged from 1.6-100 mg/ml, 1.6-50 mg/ml, 0.39 -50 mg/ml and 3.13-100 μl/ml for water, ethanol, methanol and EOs extracts, respectively. While MBCs values ranged from 25->200 mg/ml, 25- 200 mg/ml and 50->200 μl/ml for water, ethanol, methanol and EOs extracts, respectively. The antibacterial activity of the afore mentioned plant extracts combined with Ciprofloxacin (CIP), Ampicillin (AM), Cefotaxime (CTX), Nalidixic acid (NA), Norofloxacin (NOR), Cefuroxime (CXM), Cefaclor (CF), Ofloxacin (OFX), Cefalexin (CL), Tetracycline (TE), Rifampicin (RIF), Amoxyclav (AMC) and Amikacin (AK) had different degrees of synergism against the selectedbacteria.Essential oils (Eos) of screened plants had the best synergism with antibiotics than the plant extracts against the tested bacteria. The best synergism was noticed in the Eos of A. sativum, P. graveolens and R. officinalis.
 Conclusion: It was concluded that the synergistic effect of antibiotics and plant extracts is promising approach fortreating infectious diseases caused byMDR Gram negative bacteria.
 Bangladesh Journal of Medical Science Vol.19(3) 2020 p.509-519
Highlights
Medicinal plants have been used as sources of medicine in virtually all cultures
The six medicinal plants investigated in this study (A. sativum bulbs, aerial parts of E. elaterium, P. graveolens, R. officinalis, P. rupestre and leaves of R. graveolens)were collected from Gaza
The results of antibacterial susceptibility testing are represented in Tables (1-3)
Summary
Medicinal plants have been used as sources of medicine in virtually all cultures. During the last decade, the use of traditional medicine (TM)has expanded globally and is gaining popularity.People use herbal remedies due to their efficacy, tradition and their low cost[1, 53]. Medicinal plants have been used as sources of medicine in virtually all cultures. Has expanded globally and is gaining popularity. People use herbal remedies due to their efficacy, tradition and their low cost[1, 53]. Medicinal plants are important elements of indigenous medical systems in Palestine as well as in other developing countries. Complementary and alternative medicine utilization in Palestine are common elsewhere, whereas other types were unique to this area[2, 55]. There has been an increasing incidence of multiple antibiotic resistances in human pathogenic
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
