Assessment of Potential Probiotic LAB strains to control non-typhoidal Salmonella enterica from poultry

Abstract

Globally multidrug resistant Salmonella enterica is alarming for public health and is major economic concern for animal farming. It is mainly associated with gastroenteritis infection both in humans and animals specially poultry. The irrational use of an antibiotics as a growth promotor in a poultry feed develops potential antimicrobial resistance in non-typhoidal Salmonella enterica. This demands an efficient alternative strategy among which probiotics has been explored as safe substitute. The aim of the study was to isolate potential probiotic LAB strains from poultry gut. Total 17 strains were isolated, all strains were tested for their survival rate including pH 2, 0.3% bile, 10 µg/mL lysozyme and 0.4% phenol concentration that are associated with GIT. All isolates were found resistant to gastric stress conditions. Safety assessment of LAB strains was confirmed by absence of DNase, non- hemolytic assay and antibiotic susceptibility assay. Four selected LAB strains showed remarkable inhibition of non typhoidal Salmonella enterica including S. enteritidis and S. typhimurium after 18hours of co-incubation. L. reuteri PFS4, L. reuteri PFS9, Enterococcus faecium PFS 13 and Enterococcus faecium PFS14 exhibited high co-aggregation, time kill assay, mucin competitive adhesion assay and cell surface hydrophobicity individually as well as in combination. In our study selected indigenous strains shows effective results against S. enteritidis and S. typhimurium isolated from poultry sources. These four strains can be further used as feed additives for poultry to control non typhoidal Salmonella enterica and confirm by in vivo poultry trial.