Monitoring of Polysaccharides-based Vaccine Production for Streptococcus pneumoniae by Fourier-transform Infrared Spectroscopy (FTIR)

TAMARA MENENDEZ; ALEJANDRA BOSCH; YOELIS CRUZ LEAL; MARIA EUGENIA RODRIGUEZ; L CANAAN; GERARDO GUILLEN; OSVALDO YANTORNO

La Habana, Cuba

Congreso; Congreso; 2006

CIGB

The spectrum of disease caused by Streptococcus pneumoniae in infants and children ranges from focal respiratory tract infection to invasive diseases such as meningitis and bacteremia and is the most common cause of bacterial meningitis in adults. Aditionally is one of the top two isolates found in otitis media. At least 90 serotypes based on S. pneumoniae capsular antigens have been identified, and 23 of them account for at least 85% to 90% of the serotypes that cause invasive infections in adults and children [1]. A 23-valent pneumococcal polysaccharide vaccine is available for use in people older than 2 who are at risk of pneumococcal infections, such as elderly people, people who are chronically ill and immunocompromised individuals. The vaccine is not indicated for use in children younger than 2 because the antibody response to polysaccharide antigens does not invoke T cells and thus cannot be sustained [2]. This observation has led to the development of conjugated vaccines to enhance the immunogenicity of the polysaccharides. A 7-valent pneumococcal polysaccharide–protein conjugate vaccine has recently been licensed for use in infants and young children. The vaccine is 97% effective, the protection is good against deep pneumococcal infections, especially septicemia and meningitis, and reduces the number of clinical visits because of acute otitis media by about 9%. [3]. In the process of production of plain or polysaccharides-based vaccines it is necessary the incorporation of simple methodologies able to monitor the bioprocess steps. Conventional biochemical techniques as ELISA and other chemical assays, although accurate, are expensive and time consuming, therefore not appropriate under industrial production conditions Infrared spectroscopy is a nondestructive technique which allows obtaining information of the overall chemical composition of a sample. This technique has been used over the years in chemical analysis and in the characterization of biological samples [4-6] Fourier transform (FT)- infrared (IR) spectroscopy is a methodology fast, easy to perform, and economical [6] that could provide potential alternatives to conventional methods used for the selection of candidate strain for the polysaccharide purification, the monitoring of the bacterial fermentations and polysaccharide purification steps and the characterization of purity of polysaccharides. The objective of the present study was to evaluate the application of the FT-IR spectroscopy in the monitoring of the process of production of plain or conjugated pneumococcal polysaccharide vaccines, including the monitoring of contents of cell-wall polysaccharide, protein, lipopolysaccharide and DNA to asses the purity of polysaccharides after the purification step, the discrimination between pneumoccocal polysaccharides belonging to different serotypes, and the study of the encapsulation levels of pneumococcal strains.