Antibacterial activities of polyunsaturated fatty acid extracts from <i>Sardinella longiceps</i> and <i>Sardinella fimbriata</i>

Abstract

Polyunsaturated fatty acids (PUFA) content of two species of fishes - <i style="">Sardinella fimbriata </i>and <i style="">Sardinella longiceps</i> - was examined and their antibacterial activities were compared. PUFA isolated from the tissue extracts were used to conduct Antibacterial Sensitivity Tests on pathogenic bacterial strains like <i style="">Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pnuemoniae, Enterobacter aerogenes, Proteus vulgaris, Salmonella enterica and Pseudomonas aeruginosa</i>. These extracts were subjected to Gas Chromatography for the quantitative analysis of PUFA. Extracts from both species showed inhibitory effects on the strains of <i style="">S. aureus</i>, <i style="">E. faecalis</i>, <i style="">E. coli</i> and <i style="">P. aeruginosa</i>. No inhibitory activities were observed on the strains of <i style="">K. pnuemoniae</i>, <i style="">E. aerogenes</i>, <i style="">P. vulgaris</i> and <i style="">S. enterica</i>.<i style=""> S. fimbriata </i>extract showed a higher inhibitory effect on all the inhibited bacterial strains. Gas Chromatography analysis revealed higher concentrations of docosahexaenoic acid (DHA) in the extracts from <i style="">S. fimbriata</i> as compared to <i style="">S. longiceps</i>. The differences between the antibacterial activities of the two extracts could be attributed to the disparity in DHA content.