Evaluation of antibacterial effects of salvia officinalis and calendula officinalis l. hydroalcoholic extracts on streptococcus salivarius (ptcc 1738) and pseudomonas aeruginosa (ptcc 1707)
Mohammad karim Khosropanah
,1,* Sirvan bahrami
,2 Kambiz davari
1. 1. Assistant professor of plant physiology, Department of Biology, Islamic Azad University, Sanandaj branch.
2. 2. M.Sc Student of Microbiology, Department of Biology, Islamic Azad University, Sanandaj branch
3. 3. Assistant professor of Microbiology, Department of Biology, Islamic Azad University, Sanandaj branch
Infectious diseases are one of the great challenges of medical science in the 21st century, and, as a result, the production of new antibiotics is increasing day by day. at the same time, the increasing spread of bacterial resistance to antibiotics has made it difficult and costly to treat infectious diseases. hence, coping with the drug resistance phenomenon in order to reduce its incidence or to limit resistant microbial agents is of great importance. also, unwanted side effects are one of the biggest treatment problems. in order to solve these problems, there is a great incentive to search and provide antimicrobial compounds, especially from plant origin. natural compounds of plants can be used as antimicrobial agents in the treatment of infections or as food preservatives. accordingly, and considering the use of sage and marigold in the treatment of respiratory and skin infections in traditional medicine, respectively, the aim of this study was to investigate the antimicrobial effects of hydroalcoholic extract of these plants on streptococcus salivarius and pseudomonas aeruginosa .
In this study, disk diffusion method was used to determine the antimicrobial ability of extracts. in this step, 40, 60 and 80 μl of extracts were used at 0.1 g / ml concentration. in the next step, the minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) of the extracts were investigated with serial dilution method. at the end, the antimicrobial activity of the extracts was compared with antibiotics specific to each microbial strain.
The results showed that the extract of both plants had an antimicrobial effect on the gram-positive bacterium, s. salivirus. the highest diameter of zone of inhibition was related to the amount of 80 μl of marigold hydroalcoholic extract with a mean diameter of 17.33 ± 0.57 mm . this value for the extract of sage was 12.33 ± 0.87 mm. it was also found that the extract of the sage in the studied amounts did not affect the growth of the gram negative bacterium, p. aeruginosa, while the inhibition zone of the marigold extract on this bacterium was 13.33 mm in diameter. also, the minimum inhibitory concentration and the minimum bactericidal concentration of the marigold extract on s. salivarius were 3.125 and 25 mg/ml, respectively, and these amounts for p. aeruginosa were 25 and 50 mg/ml, respectively. a comparative study on the effect of specific antibiotics on each bacterial group showed that p. aeruginosa had the lowest resistance to ciprofloxacin with a zone of inhibition diameter of 40.66 and the highest resistance to sulfamethoxazole with a diameter of 10.38 mm. it was also found that amoxiclav, ampicillin and clindamycin antibiotics do not have an effect on the growth of p. aeruginosa in disk diffusion method. the effect of gentamicin, nalidixic acid and tobramycin on s. salivarius was not significantly different and the relative diameter of the inhibition zones was at range of 10.66 to 11.34 mm.
Based on the results, although, the extract of the sage did not affect the growth of p. aeruginosa, which could be due to the type of the compounds of this extract and its inability to penetrate the agar, it can be suggested that, the hydroalcoholic extract of marigold and sage have a good potential to be used as natural antibiotics. however, further proof is needed.
Antibacterial effects, sage, marigold, streptococcus salivarius, pseudomonas aeruginosa