Thesis (Ph.D.) - Cairo University - Faculty of Pharmacy - Department of Microbiology and Immunology

Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, due to a number of severe infections, including sepsis, pneumonia, meningitis and otitis media. Approximately 2.6 million children {u02C2} 5 years of age die annually of pneumonia predominantly in the developing world. In this study we aimed to determine the recent antimicrobial susceptibility patterns of S. pneumoniae and the most prevalent serotypes in Egypt, trying to introduce a vaccine including these serotypes. 100 specimens of different sources were collected, in Cairo, Egypt, from 2011 to 2013, representing almost all diseases caused by S. pneumoniae. Both conventional and molecular identification were achieved. The antimicrobial susceptibility patterns of the selected isolates of S. pneumoniae were assessed. High rates of resistance were found to different antibiotic classes. Most prevalent serotypes was determined using PCR assay, where it was found that serotype 6A/B and serotype 19F representing 58 out of 100 isolates (58%). Analyzing the virulence factors including the pneumolysin (ply) gene, the autolysin (lytA) gene and pneumococcal surface antigen A (psaA) gene for the prevalent serotypes, showing that both lytA and psaA are more specific than ply for S. pneumonia identification. Prevention of pneumococcal diseases depends mainly on vaccination, polysaccharide {u2013} BSA (Bovine Serum Albumin) protein conjugated vaccine was prepared from each serotype, equally mixed and in-vivo estimation of antibodies response for each serotype was detected using ELISA assay. Protective activity of the prepared vaccine was assessed by challenging the immunized mice with pathogenic strains of S. pneumoniae. This study imposes the importance and urgency to periodically collect and analyze more data on the current predominant serotypes present in Egypt. This will aid in effective treatment strategies, effective vaccine administration and effective means to synthesize new effective vaccines for the region

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