RESUMEN
BACKGROUND: The aim of this study is investigate the antimicrobial effect of plant oils against bacterial strains isolated from neonatal asymptomatic bacteriuria (ABU) and to evaluate the antiseptic effect of the most potent one. METHODS: The antimicrobial effect of 17 plant oils were tested against 15- gram-negative bacterial strains recovered from cases of neonatal ABU (11 Escherichia. coli, 3 Klebsiella pneumonia, and 1 Pseudomonas aeruginosa) using the agar well diffusion method. The micro-dilution method was performed to investigate the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) in concentrations ranging from 1.95 µg/ml to 500 µg/ml. The evaluation of the antiseptic activity of the Eruca sativa (arugula) seed oil was investigated using time-kill assay in concentrations ranging from 50 µg/ml to 0.195 µg/ml. RESULTS: All tested oils showed variable antimicrobial activities against the tested strains. Arugula, wheat germ, cinnamon, parsley, dill, and onion oils were the most active oils. Among them, arugula oil was the most active oil with MIC50 and MIC90 were 3.9 µg/ml and 31.3 µg/ml respectively. MBC50 and MBC90 of arugula oil were 15.6 µg/ml and 125µg/ml respectively. The time-kill assay of arugula oil indicated that a concentration of 100 µg/ml completely killed nine of the tested strains after 10 min and reduced the CFU/ml of the rest of the strains by 3 log10 at the same time interval. CONCLUSION: Arugula seed oil could be a potentially used as an antiseptic especially for neonates.