التأثير المشترك للمضادات الحياتية و بعض المستخلصات النباتية في حيوية بعض انواع البكتيريا

Abstract

This study aimed to confirm the benefit utilization of plant extracts, widely used for the treatment of bacterial diseases, to increase bacterial sensitivity against some antibiotics. Three types of plant extracts were examined (Eucalyptus spp, Allium sativum and Punica granatum ) on the viability of Staphylococcus aureus bacteria, another type of gram negative bacteria Pseudomonas aerogenosa were used to compare the effect of plant extract alone or along with antibiotics on the viability of both types of bacteria. First of all, minimum inhibitory concentration for the plant extracts on each type of bacteria were determined, large variation in bacterial sensitivity to every type of plant extract were observed, this result was due to the difference in cell wall composition between the two types of bacteria used in the test. After that, number of sub inhibitory concentrations used to determine the synergism with antibiotics. We choose three types of antibiotics; differ in their mode of action, and in bacterial sensitivity toward it, and then antibiotic sensitivity for each antibiotic was performed in the presence of different concentrations of plant extract by using agar diffusion method. The results shows good evidence on the capability of the utilization of plant extracts to increase bacterial sensitivity toward antibiotics appears as increasing of inhibition zones in the presence of plant extract comparing with its size without the extracts. Moreover, some antibiotics which have no effects on bacteria show clear inhibition zones. From this study, we conclude that the problem of bacterial resistance to antibiotics could be overcome by a simple and inexpensive method by using plant compounds which need more study to determine their types and concentrations in the plant parts and their mechanism of action accurately.