PENGEMBANGAN VAKSIN SEPTICAEMIA EPIZOOTICA BERBASIS MATRIKS PROTEIN A Staphylococcus aureus

Abstract

Septicaemia epizootica (SE) is an acute bacterial disease caused by Pasteurella multocida serotype B:2, with high morbidity and mortality rates, approximately 42.7% and 63.6%, respectively. During the period 2006–2010, around 1,156 SE cases were reported in Aceh Province and in the past five years, SE cases have continued to be reported in Riau, Bengkulu, and South Sumatra. The presence of SE in Indonesia has caused significant economic losses in the livestock sector. Vaccination remains the primary strategy in controlling this disease. As an endemic disease in Indonesia, SE causes significant economic losses in the livestock sector. Vaccination is the main strategy for controlling this disease. The currently available commercial vaccine uses the Katha strain from Burma; therefore, developing an SE vaccine based on local isolates is highly necessary. Local isolates of P. multocida from the East Nusa Tenggara (NTT) region have demonstrated high immunogenic potential and are suitable for development as vaccine candidates. This study aims to develop an innovative SE vaccine based on a protein A (SpA) matrix derived from Staphylococcus aureus, with the expectation of enhancing vaccination effectiveness. Protein A is known to have a high affinity for the Fc (constant) region of mammalian immunoglobulin G (IgG), thereby potentially strengthening antigen presentation by dendritic cells as antigen presenting cells (APCs). The research methodology included genomic characterization of P. multocida isolates from East Nusa Tenggara and Lampung using whole genome sequencing via the MinION sequencing platform (Oxford Nanopore Technologies). Antimicrobial resistance was analysed both genotypically and phenotypically to identify resistance potential in each isolate. The vaccine formulation was developed using a Staphylococcus aureus Protein A matrix in two different compositions. The vaccine’s effectiveness was then tested using rabbits as the animal model. The results showed that the P. multocida genomes had BUSCO scores above 99 percent, reflecting complete, accurate genome structures with minimal sequencing errors. The reliability of this genomic data is crucial for predicting protein structures, identifying immunogenic epitopes, and discovering genes and proteins involved in bacterial invasiveness and virulence. Comprehensive antimicrobial resistance analysis revealed more than 22 resistance genes in each isolate studied. The vaccine formulation based on the S. aureus Protein A matrix was successfully developed in two compositions and tested in rabbits. The formulation consisting of five parts S. aureus Protein A suspension and one-part anti-P. multocida IgG serum, previously complexed with P. multocida antigen, showed the highest effectiveness in stimulating antibody responses. This study produced an innovative SE vaccine candidate based on S. aureus Protein A matrix, utilizing the immunogenic potential of local P. multocida isolates from East Nusa Tenggara. The vaccine demonstrated promising performance and opens up opportunities for developing more effective SE vaccines tailored to the local epidemiological characteristics of Indonesia.