Standardization of the Spot-on-the-Lawn antagonism test in the inhibition of Salmonella Heidelberg by <i>Lactobacillus salivarius</i>

• Main Author: Ribeiro, G. C. [UNESP]
• Publication Date: 2024
• Other Authors: Dias, G. S. [UNESP], Filho, R. L. Andreatti [UNESP], Garcia, H. D. M., Okamoto, A. S. [UNESP]
• Format: Other
• Language: eng
• Source: Repositório Institucional da UNESP
• Download full: https://hdl.handle.net/11449/309476
• topic: poultry; probiotic; antagonism; Salmonella; Lactobacillus

Using extremes concentrations for both bacteria involved in the Spot -on -the -Lawn antagonism test is highly contraindicated, as results may vary mor than expected and thus, not be reliable. The present study recommends a standardization model with similar values for the concentration of both bacteria to avoid high variability, and non-replicability as well as to ensure reliable results. Using a nephelometric scale such as McFarland (0.5 tube; 1.5 x 108 CFU/mL) is highly advised, which is a turbidity standard pattern used to pre -assess the bacterial concentration in liquid culture media. It is also advised to perform bacterial quantification through serial decimal counts, ensuring similar concentrations of both probiotic and pathogen bacteria.