New study to develop antibiotic alternatives against Salmonella

Researchers at the Ohio State University have studied new alternatives to control salmonella in poultry. The research is part of the...

Researchers at the Ohio State University have studied new alternatives to control salmonella in poultry. The research is part of the Association’s comprehensive research program encompassing all poultry and egg production and processing phases and was sponsored by the US Poultry Foundation, the US Poultry and Egg Association, and Simmons Foods.

Some reasons to carry out this project are:

• The need to look for antibiotic alternatives to reduce the Salmonella disease
• Reduction of intestinal Salmonella population since this bacteria colonizes the gut
• Avian defensins are antimicrobial peptides naturally secreted from the intestinal epithelial cells into the lumen.
• These defensins kill bacteria by forming pores and disrupting the bacterial membrane.
• Avian defensins have potent anti-bacterial activity. However, sequencing of the AvBD1 gene found two different variants that might have different antimicrobial activities, an assumption based on prediction modeling of the protein structure of the two variants.

This new research project consisted of three objectives:

1. determine allele frequency of these AvBD1 variants in several major chicken breeds,
2. validate the most potent AvBD1 chicken genotype by challenging chickens (screened according to their AvBD1 genotype) with live Salmonella inoculations, and
3. assess synthetic AvBD1 variants for antimicrobial activity against Salmonella.

Researchers analyzed two batches of hatching eggs (300 broiler eggs and 400 leghorn eggs) for sequencing the AvBD1 gene. There were sequence variations in the AvBD1 gene that caused amino acid changes at the 35th, 45th and 57th positions.