Evaluation of antibacterial activity and susceptibility antibiotics of native lactic acid bacteria from tilapia (Oreochromis niloticus) in Ivory Coast

Abstract

Lactic Acid Bacteria probiotics play a crucial role in improving aquaculture productivity however, their use required beforehand a rigorous selection. This study appeared as a preliminary research in LAB potential probiotics selection. The aim of study was to select LAB strains potentially probiotic isolated from gut intestine of tilapia (Oreochromis niloticus) based on antibacterial activity and susceptibility antibiotics tests. The antibacterial activity was carried by agar well diffusion method against five pathogen indicators (E. coli ATCC 25922, K. pneumoniae ATCC 43816, P. aeruginosa ATCC 27853, P. mirabilis JCM1669, and S. aureus ATCC 25913). The susceptibility antibiotic test was performed by disc diffusion method by 12 antibiotics use. Seventy-two (72) from 154 LAB isolates completed the antibacterial activity test. With 79.08% inhibition, S. aureus was the pathogen most inhibited, whereas E. coli had the least inhibition, at 61.44%. In terms of antibiotic susceptibility testing, out of the 72 LAB isolates from earlier studies, only 25 LAB isolates demonstrated resistance to ciprofloxacin, gentamycin, and oxacillin and sensitivity to nine out of the twelve antibiotics employed. The 25 LAB isolates seemed suitable candidates for more probiotic tests.