Resistance against commonly used antibacterial agents has become a globally recognized threat to human health. Therefore, the development of new and effective antibacterial agents is necessary to treat infections caused by resistant bacterial strains; plants are a promising source of new agents to be tested.The minimum inhibitory concentrations (MIC) of ethanolic extracts of Erodium gruinum, Euphorbia hierosolymitana, Logoecia cuminoides, and Tamarix tetragyna against 10 Gram-negative and 5 Gram-positive bacteria were determined using agar well diffusion and microtiter plate dilution methods, respectively. The phytochemical composition of the crude extracts of the plants was determined using HPLC.Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae, Proteus mirabilis, and Acinetobacter baumannii were sensitive to E. gruinum and E. hierosolymitana extracts. P. aeruginosa ATCC 27853 and M. catarrhalis were sensitive to L. cuminoides extract. P. aeruginosa ATCC 27853, P. mirabilis, and K. pneumoniae were sensitive to T. tetragyna extracts. For Gram-positive bacteria, Staphylococcus aureus ATCC 33591 and ATCC 43300 were sensitive to E. gruinum and E. hierosolymitana extracts. S. aureus ATCC 43300 and ATCC 33591 and Group D Streptococcus were sensitive to T. tetragyna extract. All Gram-positive bacteria were completely resistant to the extract of L. cuminoides. The major phytochemical components of the plant extracts belonged to flavonoids, tannins, terpenes, quinones, phytosterols, phytoestrogens, carbohydrates, fatty acids, and coumarin.The study showed the potential of the development of antibacterial agents from these plants. Phytochemical analysis revealed compounds that are candidates for new antibacterial drugs.
