A Comparative Study of the Antibacterial Activity of Cyndon dactylon ( L ) pers ; its Synergic Effect with Some of the Standard Antimicrobs and Extracts of Some Medicinal Plants

The antibacterial effect of some selected algerian plants like Cyndon dactylon (L) pers were evaluated on several bacterial strains : Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATTC 27853, Staphylococcus Coagulasse (ATTC 5118), Staphylococcus aureus ATCC 25923, Klebcsiella pneumonie and Enterococcus faecalis.The in vitro antibacterial activity was performed by agar disc diffusion method. The combination of Cyndon dactylon (L) pers with each of the standard antimicrobs E (Erythromycine), C (Chloramphenicol), CTX (Cefotaxime), AMX (Amoxicillin), CZN : (Cefazoline), CXN (Cefalexine) were most active and showed significant synergic effects. Moreover, Cyndon dactylon (L)/ other extracts of screened medicinal plants showed also high synergic effects. The results obtained in the present study suggest that Cyndon dactylon (L) pers can be used in treating deseases caused by the tested organisms. Further chemical and pharmacological investigations may be carried out to isolate and identify the chemical constituents in the selected plants responsible for the antimicrobial activity.


INTRODUCTION
Since the 1940's, chemists have developped all sorts of highly effective antibiotics (Sulfa drugs, penicillins, tetracyclines, and others that are effective) against bacterial and viral infections.[3][4][5][6] Today there is an imperative necessity to find out new antibacterial compounds with various chemical structures and new mecanisms of action for new and re-emerging contagious syndoms. 7herefore, researchers are increasingly turning their attention to folk medicine, looking for new leads to develop better drugs that are effective against bacterial infections and viral infections from infuenza and the common cold and even the more serious herbs infections and AIDS (Aquired Immune Defectious Syndrome).The viral infectious account for about 60% ilnesses, contrasted with about 15% for bacterial infections.10] The medicinal plants have been used for ages as remedies for human diseases.Plant derived compounds are getting more and more interest owing to their adaptable applications.[13][14] The aim of of this study was to evaluate the activity of extracts from 9 plants against several Gram-positive and Gram-negative bacterial strains in vitro.

Materials and methods
Fresh plant/plant parts : Cynodon dactylon (L) Pers, Malva parviflora, Mentha viridis Hort, Mentha pulegium L, Artemisia, Rosmarinus Officinalis were collected randomly from the mountain of Batna-Algeria in November 2013.The plants were deposited at Lab. Dynamique, Interaction et Réactivité des Systèmes, Department of Process engeneering, Faculty of Applied Sciences, University of Kasdi Merbah-Ouargla, Algeria.Fresh plant material was washed under running tap water, air dried under dark and then homoggenized to fine powder and stored in closed container away from light and moisture.

Extraction of plant material
The extracts were prepared by soaking 200g of the plant powder in a mixture of EtOH/H 2 O (70/30) evaporated under reduced pressure.The resulting extracts were diluted with distilled water and left overnight.The filtrates were subjected to extraction by various solvents with increasing polarity (petroleum ether, dichloromethane, ethyl acetate , and butanol).The organic phases were separated and evaporated.The rsulting residue was stored at 4°C.

Microorganisms
All bacterial standard strains : Escherichia Preparation of the bacterial culture media 3.7 of muller Hilton agar was mixed with hot distilled water and autoclaved at 121°C and 2 atm for 15 minutes.After autoclavingit was allowed to cool to 45°C in a water bath.Then the medium was poured into sterillized petri dishes with a uniform depth of approximately 5 mm. 20

Preparation of plant extract impregnated discs
Whatman N°1 filter paper was used to prepare discs of 6 mm in diameter.They were sterillized by autoclaving and then dried during the autoclaving cycle.The discs were then impregnated with extract of the plants. 21

Disc diffusion method
Disc diffusion method for antimicrobial susceptibility test was carried out according to the standard method by Kirby-Bauer to assess the presence of antibecterial activities of plant extracts. 22A bacterial suspension adjusted to 0.5 McFarland standard (1.5x10 8 CFU/ml) was used to inoculate Mueller Hinton agar plates evenly using a sterile swab.The discs impregnated with the plant extracts were placed individually on the Mueller Hinton agar surface.The discs were spaced far enough to avoid both reflection waves from the edges of the petri disces and overlapping rings of inhibition.The plate was then incubated at 37°C for 18 hours in inverted position to look for zones of inhibition.Zones of inhibitions produced by the sensitive organisms were demarcated by a circular area of clearing around the plant extract impregnated discs.The diameter of the zone of inhibition through the center of the disc was measured to the nearest millimeter.
The rsulting residue of all extracts stored at 4°C were tested at a concentration of 10 -3 g/ml and were prepared in DMSO.

RESULTS AND DISCUSSION
The antibacterial activity of 9 species extract tested in vitro by agar disc difusion against  As far as the synergic effect is concerned the combination of Cyndon dactylon (L) pers with each of the standard antimicrobics, E, C, CTX, CZN and AMX were most active and showed the synergic effect.The maximum antibacterial activity was recorded against Esherichia coli, Pseudomonas aeruginosa, Staphylococcus coagulasse and Enterococcos faecale with a maximum synergic effect of "R = 02-04 mm, whereas Cyndon dactylon (L)/CXN Showed no synergic effect against Pseudomonas aeruginosa, and Staphylococus coagulasse.Table -3 summarizes the microbial growth inhibition of Cyndon dactylon (L)/standard antimicrobics.
The maximum antibacterial activity was recorded with Cyndon dactylon (L) Pers/ Nigella sativa and Cyndon dactylon (L) Pers/ Juncus maritimus asch against Pseudomonas aeruginosa and Enterococcos faecal with a maximum synergic effect of "R = 6 mm and 5 mm respectively.Table-4 summarizes the microbial growth inhibition of Cyndon dactylon (L)/ other extracts of screened medicinal plants.
In conclusion, Cyndon dactylon (L) pers with each of the standard antimicrobics, E, C, CTX, CZN and AMX were most active and showed the synergic effect against Esherichia coli, Pseudomonas aeruginosa, Staphylococcus coagulasse and Enterococcos faecale.Antibacterial activity of mixture of Cynodon dactylon (L) Pers and other extracts of screened medicinal plants possess a broad spectrum of activity against a panel of bacteria responsible for the moste common bacterial diseases.These promissssory extracts open the possibility of finding new clinically effective antibacterial compounds.Further chemical and pharmacological investigations may be carried out to isolate and identify the chemical constituents in the selected plants responsible for the antimicrobial activity.

Table 1 : 3 :Table 4 :
Antibacterial activity of extracts of screened medicinal ; C : Chloramphenicol ; CTX : Cefotaxime ; AMX : Amoxicillin ; CZN : Cefazoline ; CXN : CefalexineTable Antibacterial activity of of Cyndon dactylon (L) pers with some Antibacterial activity of a mixture of Cynodon dactylon (L) Pers and the other extracts of screened medicinal