TITLE:
Modulation of Anti-Microbial Resistant Salmonella heidelberg Using Synbiotics (Probiotics and Prebiotics) in Two In-Vitro Assays (Cross-Streaking and Agar Wells Diffusion)
AUTHORS:
Ahmed Gomaa, Martha Verghese, Josh Herring
KEYWORDS:
Salmonella, Synbiotics, Cross-Streaking, Agar Well Diffusion
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.10 No.9,
September
30,
2020
ABSTRACT: Salmonellosis is the most prevalent bacterial foodborne disease in many
countries worldwide. Utilization of probiotics is one of the most accepted ways
to reduce Salmonella,
especially lactic acid bacteria, as it has proven to reduce the enteric pathogens in monogastric
and ruminant livestock animals through different mechanisms such as
antimicrobials production, competitive adhesion to the gastrointestinal tract,
and immune stimulation. Prebiotics could be utilized solely for health benefits
as an alternative to probiotics or in addition to probiotics for a synergistic
effect known as synbiotics. The aim of this study was to compare effects of
different probiotic strains (Lactobacillus acidophilus (La-14), Lactobacillus paracasei (Lpc-37), Streptococcus
thermophiles (St-21), Bifidobacterium bifidum (Bb-06),
and Aspergillus niger (ATCC�TM) and
without prebiotics (Mannose; Xylose; Galactooligosaccharides GOS; Inulin; and
Dandelion extract) on lowering Salmonella
heidelberg CFU in vitro.
Different inhibition levels probiotic strains were assessed and compared in the
presence and absence of 2.5% prebiotic compounds using cross-streaking and agar
well diffusion assays. Recommendations for the growth of selected
microorganisms such as temperature and oxygen conditions were taken into
consideration. All the analysis was conducted in triplicates. The results showed that
all the probiotics strains except S. thermophiles were
able to significantly (P S. heidelberg in
at least one of the assays. The difference in inhibition percentage confirms that probiotic
strains have multiple inhibition mechanisms, such as production of
antimicrobials, lower pH by producing organic acids (acetic acid, lactic acid,
etc.), and inhibition of pathogen’s virulence factor expression, and production of lipopolysaccharide
solubilizing compounds.