Detection of Intracellular Adhesion (ica) and Biofilm Formation Genes in Staphylococcus aureus Isolates from Clinical Samples

• Main Authors: Khadije Rezaie Keikhaie, Aliyeh Sargazi, Mehdi Hassansnhahian, Zahra Shahi
• Format: Article
• Language: English
• Published: Mazandaran University of Medical Sciences and Health Services 2017-02-01
• Series: Research in Molecular Medicine
• Subjects: Biofilm; Staphylococcus aureus; Gene; Pathogenic
• Online Access: http://rmm.mazums.ac.ir/browse.php?a_code=A-10-812-2&slc_lang=en&sid=1

Introduction: Nosocomial infections that result in the formation of biofilms on the surfaces of biomedical implants are a leading cause of sepsis and are often associated with colonization of the implants by Staphylococcus epidermidis. Biofilm formation is thought to require two sequential steps: adhesion of cells to a solid substrate followed by cell-cell adhesion, creating multiple layers of cells. Intercellular adhesion requires the polysaccharide intercellular adhesion (PIA), which is composed of linear β-1, 6-linked glucosaminylglycans and can be synthesized in vitro from UDP-N-acetylglucosamine by products of the intercellular adhesion (ica) locus. We have investigated a variety of Staphylococcus aureus strains and find that all strains tested contain the ica locus and that several can form biofilms in vitro. Material and Method: A total of 31 clinical S. aureus isolates were collected from Zabol, Iran. In vitro biofilm formation ability was determined by microliter tissue culture plates. All clinical isolates were examined for determination the ica locus by using PCR method. Result: The results of this study showed that 40 strains of Staphylococcus aureus, 12 strains carrying the gene Cocos icaA (30%) and 8 strains carrying the gene icaD (20%) and the number of five strains (12.5%) containing both genes ica A and has been ica D. Conclusions:  S. aureus clinical isolates have different ability to form biofilm. This may be caused by the differences in the expression of biofilm related genes, genetic make-up and physiological conditions.