Synergistic Effects and Viability of Indigenous Probiotic Bacteria in the Presence of Herbal Extracts and Evaluations of their Minimum Inhibitory Concentrations in invitro Conditions

The aim of the research was to investigate the antibacterial potential of local isolates of probiotic bacteria in the presence of herbal extracts including Chamomile (Matricaria chamomilla), Fennel (Foeniculum vulgare), Peppermint (Mentha piperita) and thyme (thymus vulgaris). Lactobacillus casei(TA0021), L. plantarum(TA0028,TA0026), L.reuteri(TA0034), Enterococcus faecium(TA0033) and Pediococcus acidilactici(TA0049,TA00170) were used as probiotic bacteria, while standard strains of Escherichia coli, Salmonella typhimurium and Salmonella enteriditis were used as indicator organisms. The antibacterial activity of the mentioned probiotic isolates and the herbal extracts against the selected pathogens were examined by agar well diffusion method. The synergistic effect of the mix of probiotic bacteria and different herbal extracts(1:10,1:100 and 1:1000) were also studied. The viability and synergistic inhibitory effect of the selected probiotic bacteria in the presence of different concentrations of herbal extracts were determined after 24, 48 and 72 hours. In order to determine the minimum inhibitory concentrations (MIC), herbal extracts were serially diluted and their effect on fixed concentrations of the indicator organism was measured by microdilution assay. Similarly, the survival percentage of probiotic bacteria in the presence of different concentrations of the herbal extract was determined. MIC values were recorded as the lowest concentration of extract that was able to inhibit the growth of the pathogens. All experiments were performed in triplicate and results analyzed statistically(Using the SAS Software). According to the results the probiotic bacteria in the presence of different concentrations of the extracts was above 70%(P<0/05). Overall, the locally isolated probiotic bacteria with herbal extracts are strong antibacterial agents.