Preliminary screening of antibacterial activity on medicinal plant extractions against isolated bacteria from aquaculture

The research is conducted with two purposes which are to identify antibacterial activity from medicinal plant extraction towards isolated bacteria from aquaculture and to identify effectiveness of medicinal plant extractions towards different isolated bacteria from aquaculture. There are still limited number of study that identify antibacterial properties in medicinal plants as an alternative to commercial antibiotics which currently had developed antibiotics resistant in bacteria. Four bacteria isolated from aquaculture species; Pseudomonas spp., Salmonella spp., Vibrio spp. and Escherichia coli were used in the study. Eleven selected medicinal plant were used to test their antibacterial activity towards those four bacteria. They were extracted by using 70% methanolic aqueous solution. The antibacterial activity was determined by using well-diffusion method. All eleven selected medicinal plant showed antibacterial activity. Mulberry (Morus alba) extracts showed the highest inhibition zone on Vibrio spp. While Salmonella spp. showed highest sensitivity towards Arabian Jasmines (Jasminum sambac), Key Lime (Citrus aurantifolia) and Cuban Oregano (Plectranthus amboinicus). Pseudomonas spp. only showed highest sensitivity towards Kesidang leaves (Vallaris glabra) and Escherichia coli showed highest sensitivity towards Soursop leaves (Annona squamosa) and Ipil-ipil (Leucaena leucocephala). However there were also medicinal plants that able to inhibit all four bacteria although they did not showed highest inhibition like Annona squamosa and Vallaris glabra. Therefore, these medicinal plants had antibacterial activity against all four bacteria isolated from aquaculture species. However, further research is required to justify the findings. The results obtained can be used as a guideline for further research in this field in the future.