OL-073 Evaluation of serum concentration of endothelium nitric oxide synthase in Helicobacter pylori positive people

M. Amani, G.H. Ettehad, F. Afshar
2011 International Journal of Infectious Diseases  
A recent IVI study in Kolkata, India, found that 24% of enteric fever episodes were due to S. paratyphi A. Estimates indicate that the incidence of enteric fever, in India, due to S. paratyphi A is 2.2 million cases per annum. Vi based vaccines only protect against typhoid fever, thus there is a need for a bivalent vaccine that protects against both S. typhi and S. paratyphi A. Methods: IVI transferred its high yield, high recovery technology for Vi and Vi conjugate production to Shantha
more » ... n to Shantha Biotechnics in 2009. A high yielding fed batch fermentation system for Salmonella paratyphi A was first developed. The Lipopolysaccharide was separated from the cells using micro and ultrafiltration then detoxified by acid hydrolysis to release O specific polysaccharide (OSP) from the Lipid A. The OSP was further purified by precipitation of contaminating Lipid A, proteins and nucleic acid, concentrated by ultrafiltration then sterilized by 0.2 mm filtration. The process developed uses equipment that is scalable and cGMP compliant thus it is anticipated that the technology transfer and scale up to a manufacturer will not be overly complicated. Results: OSP from S. paratyphi A has been successfully purified and the final bulk contains less than 1% of contaminating nucleic acid and protein, and very low endotoxin (by LAL) values. The purified OSP has been used to prepare a series of conjugates using Diphtheria Toxoid (DT) as the carrier protein. The conjugates are currently undergoing preclinical evaluation. Conclusion: We have developed a high yielding and efficient technologies for Vi and OSP production and for conjugation to these polysaccharides to DT. Our aim is to develop a cost effective bivalent conjugate vaccine for developing countries. This work was funded by the governments of Korea and Sweden.
doi:10.1016/s1201-9712(11)60138-0 fatcat:bqyxo3su6ja5fchdqrvdeprhe4