Antibacterial Effect of Black Cumin Seed (Nygella sativa) on the Specific Pathogen of Vibrio cholerae Isolated from Dried Fish

Abstract

This study aimed to analyze the antibacterial activity of black cumin seed (Nigella sativa) extracts in inhibiting the growth of Vibrio cholerae bacteria. This specific human pathogenic bacteria was isolated from three types of commercially valuable dried fish Lottya (Harpodon nehereus),Chingri (Penaeus monodon) and Churi (Trichiurus haumela). The extracts were made in ethanol and acetone solvents separately. The antibacterial activities of the extracts were determined by three different method of enumerating the bacterial load before and after extract treatment, disc diffusion method and tube dilution method. The average loads of the bacteria in Lottya and Chingri were 3.1×10⁴ CFU/g and 2.67×10³ CFU/g respectively while no V. cholerae was detected in dried Churi fish. Though both extracts showed strong sensitivity to the isolated bacteria but acetone extract of black cumin was found to be more effective than ethanol extract. The Minimum Inhibitory Concentrations (MIC) value of acetone and ethanol extracts in inhibiting the growth of V. cholerae was 25% and 30% respectively. So, black cumin seed extract can be used as an alternative medicine to prevent the enteric disease of consumers associated with dried fish consumption.