Abstract :
Methicillin-resistant Staphylococcus aureus (MRSA) is the common cause of nosocomial infections and capable of evading the biocidal action of several antimicrobial agents. The objective of this study was for isolation and partial purification of capsular polysaccharide (CP5) from clinical MRSA isolates. This MRSA isolate (A.MS. isolate) can be further used to produce as a candidate immunogenic compound against S. aureus infection. The purification of CPs was carried out by suggesting a modified method depending on the combination of two previously described methods with some modifications. In the present study, given the limited output extracted, method was relied upon UV-Visible Spectrophotometer to detect the capsular polysaccharide (CP5) using a wavelength of 206 nm. The final concentration of S. aureus capsular polysaccharide 5 (CP5) was 6 mg/L, which can be detected from A.MS isolate by UV- visible Spectrophotometer at 206 nm. The chemical composition of the crude extract of S. aureus capsular polysaccharide 5 (CP5) was also detected and the results found that the crude extract of S. aureus included nucleic acid and protein content in addition to capsular polysaccharide 5 (CP5) content. This study is the first record of isolation and purification of the S. aureus capsular polysaccharide (CP5) in Iraq. This MRSA isolate (A.MS. isolate) can be further used to produce as a candidate immunogenic compound against S. aureus infection in rats (as an animal model).