Studies Of Vitro Antibacterial Action Of Chinese Herbs Against Aeromonas Spp And Vibrio Spp

It is an effective way to search new antibacterial activity substance from Chinese herbs to control baeteriosis of fishes. There are abundant resources from herbs in our country, and it is easy to gain. In the reaserch, 101 sorts of common herbs are tested, and the bioassayed bacteria are Aeromonas hydrophila ST-3-3, Aeromonas caviae CSS-4-2, Vibrio anguillarum E3-J-1, Vibrio carchariae PHK and PUS. We deeply studied Gulla chinensis and Fructus Chebulae which have strong antimicrobial activity. The results as the following:We determined antibacterial activity of 101 sorts of herbs. It was found that 68 sorts of Chinese herbs have antibacterial action to at least one strain, and there are 48 Chinese herbs have strong antibacterial activity, such as Gulla chinensis, Fructus Chebulae, Bulbus Allii and so on. The widest antimicrobial spectrum is Gulla chinensis, Fructus Chebulae and Bulbus Allii. All tested bacteria are inhibited by them. The max bacteriostatic circle diameter of inhibiting to bacteria of Gulla chinensis is 32.84mm, and the MIC is 0.0488mg/ml; The max bacteriostatic circle diameter of inhibiting to bacteria of Fructus Chebulae is 28.72mm, and the MIC is 1.18725mg/ml; The max bacteriostatic circle diameter of inhibiting to bacteria of Bulbus Allii is 28.80mm, and the MIC is 0.78125mg/ml.Gulla chinensis and Fructus Chebulae or their vary proportion mixture have strong microbiostatic action to fish pathogenic bacteria. The MIC and MBC of Gulla chinensis is between 0.048828mg/ml and 0.78125mg/ml, and between 0.097656mg/ml and 0.78125mg/ml respectively. The MIC and MBC of Fructus Chebulae is between 0.097656mg/ml and 6.25mg/ml, and between 0.195313mg/ml and 25 mg/ml. The antibacterial activity of Gulla chinensis or Fructus Chebulae to 5 , strains is: PHK>PHS>CSS-4-2>ST-3-3>E3-l-l.The joint effect that Gulla chinensis incorporated with Fructus Chebulae to different bacteria indicated that mixture showed strong antimicrobial activity to all strains. The more percent of Gulla chinensis, the more antimicrobial activity will be.When the proportionment of Gulla chinensis is more than Fructus Chebulae, the joint effect exhibit synergy or additivism. To Aeromonas spp, the most effective antibacterial activity of mixture is 2 times Gulla chinensis with 1 time Fructus Chebulae. To Vibrio spp, the most effective antibacterial activity of mixture is 3 : 1 or 4: 1.The extract efficiency of supersonic method was superior to the other methods by the same solvent. Used same method, the extract efficiency of 95% ethanol is the best. The extract efficiency of supersonic method is 1.1~1.2 times to the efficiency of solvent circumfluence method. By 95% ethanol, the extract rate of Gulla chinensis is over 73.39%. The extract rate ofFructus Chebulae is over 13%. As far as antibacterial activity was concerned, the extracts of Gulla chinensis by every method was similar to Aeromonas spp. The result is also similar to the extracts by different solvent to Aeromonas spp. To Vibrio spp, the best method to extract Fructus Chebulae is by 95% ethanol and Supersonic method. Both the antibacterial activity of Gulla chinensis and Fructus Chebulae is best by ethyl acetate method and supersonic method.