The effect of polyphosphates on streptococci isolated from mastitis cases

Area of Science:

• Veterinary Microbiology
• Food Safety
• Antimicrobial Agents

Background:

• Streptococcus species, including Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis, are significant mastitis pathogens.
• Controlling Streptococcus infections is crucial for animal health and the dairy industry.
• Polyphosphates are inorganic polymers with potential antimicrobial properties.

Purpose of the Study:

• To evaluate the in vitro efficacy of a polyphosphate mixture against key Streptococcus species.
• To determine the inhibitory concentrations of polyphosphate mixture in both blood agar and milk.

Main Methods:

• Testing polyphosphate mixtures at concentrations ranging from 0.01% to 0.9%.
• Assessing bacterial growth inhibition against five strains of Streptococcus agalactiae, two of Streptococcus dysgalactiae, and three of Streptococcus uberis.
• Conducting experiments in both blood agar (in vitro) and raw milk media.

Main Results:

• Complete inhibition of all tested Streptococcus strains was achieved with 0.03% polyphosphate mixture in blood agar.
• Higher concentrations of polyphosphate mixture, ranging from 0.6% to 0.9%, were required for complete inhibition in milk.
• The required concentration in milk varied depending on the specific Streptococcus strain.

Conclusions:

• Polyphosphate mixtures demonstrate significant antimicrobial activity against mastitis-causing Streptococcus species.
• The efficacy of polyphosphate mixtures is dependent on the medium, with milk requiring higher concentrations than blood agar.
• Polyphosphates show potential as agents for controlling Streptococcus contamination in dairy environments.