Probiotic application reduces Salmonella Enteritidis contamination in layer hatching eggs and embryos

Area of Science:

• Food Science
• Microbiology
• Animal Science

Background:

• Poultry products are a significant source of foodborne salmonellosis in the US.
• Contaminated hatching eggs are a primary route for Salmonella Enteritidis (SE) transmission from hatchery to farm.
• Chemical disinfectants often fail to eliminate internalized pathogens in hatching eggs, risking embryo contamination.

Purpose of the Study:

• To evaluate probiotics as a natural, organic-friendly alternative for sanitizing hatching eggs against SE.
• To compare the efficacy of specific probiotic strains against a chemical disinfectant for reducing SE contamination.

Main Methods:

• 560 Lohman Lite hatching eggs were inoculated with a five-isolate mix of SE.
• Eggs were treated with Lactobacillus rhamnosus NRRL-B-442 (LR), Lactobacillus paracasei DUP 13076 (LP), peracetic acid (PAA), or a control.
• SE and probiotic populations were enumerated on egg surfaces, membranes, and internal contents over 18 days of incubation.

Main Results:

• LR, LP, and PAA treatments significantly reduced SE on egg surfaces compared to controls.
• Probiotic treatments (LR, LP) prevented SE trans-shell migration and contamination of inner shell membranes, unlike PAA.
• SE positivity in embryos was <20% for probiotic-treated eggs versus 60-70% for PAA and control groups.

Conclusions:

• Probiotic application effectively reduces SE surface contamination and minimizes internal contamination and embryo infection.
• Probiotics offer a superior alternative to PAA by preventing SE trans-shell migration.
• Early probiotic intervention in hatching eggs can decrease SE prevalence in hatchlings and limit farm spread.