Antibacterial activities of the crude extract from free-living amoeba

Abstract

The effects of the extracts from free-living amoebae were studied on two types of pathogenic bacteria; Staphylococcus aureus and Streptococcus agalactiae. The amoebae extract used in this study were Acanthamoeba sp. (strain AK); a clinical isolate, and Acanthamoeba sp. (strain Pl), isolated from marine environment. Antibacterial activities of the amoeba extracts were tested against these bacteria by disc diffusion following Kirby-Bauer method. The concentrations of extracts used in this study were 2.0, 4.0 and 8.0 mg/ml. Both of amoeba extracts; AK and Pl were observed to inhibit the growth of S. aureus, but not on S. agalactiae although its inhibiton is small compare to Chloramphenicol (as a positive control). The minimal inhibitory concentration (MIC) value on S. aureus was 4.0 mg/ml protein of AK and 2.0 mg/ml protein of P 1 extract. Extract from P 1 was found to be more potent as antibacterial agent than AK extract.