The Utilization of Chitosan in Streptococcus Agalactiae Encapsulation as Mastitis Vaccine Carrier Candidate

Abstract

Mastitis is a disease in dairy cattle that causes economic losses to farmers around the world. Mastitis is caused by microbes with Streptococcus agalactiae being the main cause of subclinical mastitis. The prevention and control of mastitis is through sanitation management, drug administration and vaccination programs. Administration of vaccines is one of the technical challenges posed by vaccination programs. To optimize vaccination, the development of oral vaccines with microparticle carrier systems can be pursued. The development of chitosanbased vaccine carriers for oral administration has garnered interest due to the substance's potential to boost immune response and its pharmaceutical properties. However, research into the development of vaccine carriers containing inactivated pathogenic bacteria to combat mastitis in dairy cattle is limited. In this study, Streptococcus agalactiae was encapsulated using chitosan-alginate microspheres through a simple poly ionic complexation method with high-speed centrifugation. This study aimed to determine the loading efficiency (LE) and capacity (LC) of S. agalactiae incorporated into chitosan microparticles as a mastitis vaccine carrier system. The results showed that bacterial encapsulation using chitosan complex at pH 5 resulted in LE and LC up to 87.1% and 2.4%, respectively. The addition of 0.022% tripolyphosphate (TPP) resulted in microparticles with higher LE and LC values. Fourier transform infrared (FTIR) investigation revealed a possible interaction between the two constituents of the microsphere S. agalactiae and the chitosan complex. These findings indicate that the chitosan complex loaded with inactive S. agalactiae has good potential as a vaccine carrier system for oral administration. Further characterization of microspheres is needed for their potential application in pre-clinical studies.