Isolation and in vitro characterization of anti-salmonella enteritidis probiotic potential of indigenous lactobacilli from poultry

Abstract

Aim of the present study was to isolate, identify and characterize new indigenous Lactobacillus strains with probiotic potential against Salmonella Enteritidis. From 84 isolated lactobacilli of indigenous poultry origin, 15 isolates were pre-selected for in vitro characterization on the basis of their activity (6.33±0.57-20.33±1.15 mm) against S. Enteritidis by well diffusion assay. All pre-selected isolates had variable tolerance to acidic pH (2, 3 and 4). All isolates also showed growth in MRS broth supplemented with 0.3, 1 and 1.8% bile salts. Isolates had varying degree of auto-aggregation (27.05±0.72 - 65.87±3.12%) and co-aggregation with S. Enteritidis (6.33±0.11 - 55.70±1.32%) within 2 hours. Safety profile of lactobacilli indicated that IKP23, IKP 111 and IKP 333 had no acquired antibiotic resistance. IKP 23, IKP 111 and IKP 333 were selected as potential probiotics on the basis of probiotic prerequisites and identified as L. fermentum, L. fermentum and L. salivarius, respectively by sequencing their partial 16S rRNA gene or 16S-23S intergenic spacer region. IKP 23, IKP 111 and IKP 333 inhibited S. Enteritidis (81, 99.3 and 93%, respectively) in co-culture experiments. This study insinuate that IKP 23, IKP 111 and IKP 333 have favourable probiotic potential and may be used for in vivo studies for the development of probiotics against S. Enteritidis.