Antimicrobial Activity of Lactic Acid Bacteria (Lab) Isolated from Yoghurt and Fish against Pathogenic Bacteria Isolated from Fish in Ethiopia

Abstract

Pathogenic bacteria are causative agent of infectious diseases in fish. Antimicrobials are widely applied in fish products for prevention of fish-borne diseases. The global concern of antimicrobial resistance of bacteria raises attentiveness of the different ways of using antimicrobial peptides (AMPs). The aim of the present study was to detect the antimicrobial activity of the AMPs from Lactic acid bacteria (LAB) against the growth of pathogenic bacteria isolated from fish in Ethiopia. Cell Free Supernatants (CFSs) from 4 strains of LAB consisting of lactobacillus paracasei sub.paracasei, lactobacillus casei LC2W, Pediococcus acidilactici and lactobacillus plantarum were tested against pathogenic bacteria of Aeromonas hydrophila, Aeromonas veronii, Edwardsiella tarda, Escherichia coli, Proteus mirabilis, Pseudomonas fluorescens and Shigella flexneri via using agar well diffusion assay. All tested CFSs revealed antimicrobial activity against the tested fish pathogenic isolates at different extents. CFSs of lactobacillus plantarum, Lb. casei LC2W and lactobacillus paracasei sub.paracasei showed strong antibacterial activity against Edwardsiella tarda (19 mm), Aeromonas hydrophila (18 mm) and Pseudomonas fluorescens (18 mm) respectively, with the well diffusion assay. The study shows the antimicrobial activity of the 4 strains of LAB CFSs against the bacterial fish pathogens and indicates the application opportunities as fish product bio preservative.