Antimicrobial Activity of Medicinal Plants against the Freshwater Fish Pathogen Aeromonas Sp. and Pseudomonas Sp.

Indian forest ecosystem is endowed with medicinal plants. Antibacterial activity of some of these medicinal plant resources was tested in the laboratory. Experiment was conducted in the aquarium and rearing tank using feed containing medicinal plant extracts to evaluate the efficacy on the artificially infected fish with bacterial pathogens. When the fish were exposed to high bacterial pathogens Aeromona hydrophila and Pseudomonas fluorescens, recovery of the infected fish varied with the pathogens challenged and feed treatments. Fish feed containing extract of Coleus aromaticus (4% feeding) showed significantly (p<0.01) high therapeutic effect recovering the infected fish, Magur (Clarias batrachus) with A. hydrophila (95 ± 0.86% recovery) and P. fluorescens (85±1.20% recovery). A similar result was observed in the case of Magur fish feed containing extract of Mentha piperita (3% feeding) and Ocimum bascilicum (3% feeding) where 100 ± 0. 88 % A. hydrophila infected Magur (Clarias batrachus) were found to be cured. In rearing tank, the herbal feed containing extract of Coleus aromaticus was applied experimentally to A. hydrophila infected different fish species maintained in different individual ponds where, 90.40 ± 1.4% Magur (Clarias batrachus) and 80.2 ± 1.2 % Common carp (Cyprinus carpio) were found to be recovered. The other medicinal plants used in this study showed medium to weak effect recovering the bacterial infected fish.