Characterization of capsule expression of both MSSA/MRSA strains isolated from various body sites of colonization and infections in Amman and Gaza

Abstract

Abstract Background: Staphylococcus aureus is a major cause of nosocomial and community-acquired infections. Despite the predominance of two capsular polysaccharides, types 5 and 8, on the surface of clinical isolates, molecular and epidemiological variations have been reported among various geographical areas in addition to various clinical outcomes of S. aureus increasing the challenge for preventive and control measurements against staphylococcal infections and diseases. Materials and Methods: A total of 315 S. aureus isolates of various clinical conditions comprised both hospital and community-acquired infections between 2009 and 2011 in Amman and Gaza were studied. All S. aureus clinical isolates included in the present study have been investigated by PCR method to determine the distribution and diversity of capsule polysaccharide expression. Results: Collectively, most of the clinical isolates (90%) expressed either capsular polysaccharide CP5 (37%) or CP8 (53%), whereas 10% were nontypeable by PCR. Interestingly, significant predominance of CP8 genotype was reported in clinical strains of S. aureus isolated from infections in comparison to those which are commonly colonising various normal body sites. Conclusion:  Correlation between capsule genotypes and pathogenic behaviour of S. aureus could be established. Further studies on the molecular levels are required to determine the role and mechanisms of capsular expression in the variability of pathogenic potential of S. aureus