Detection of Intercellular Adhesion Genes (Ica) in Staphylococcus Aureus Causing Implant Associated Infections

Abstract

Objective: The complications related to implant associated infections in post-angioplasty patients were considered to increase due to biofilm formation. Methods:Genes responsible for the biofilm formation in the target organisms was investigated in the present study. The presence of the intercellular adhesion biofilm genes (icaA, icaB and icaD) was determined by the Polymerase Chain Reaction method. As preliminary investigations, standard tests, exit-site challenge test and microtitre plate method were used to study the biofilm efficiency of five different test organisms.Results: Exit-site challenge test, was used to identify the ability of test organisms to grow on a bio-materials used in the study. Among the five selected test organisms, Staphylococcus aureus showed the highest ability to colonize the stent materials with in 24h to 48h. In microtitre plate method, Staphylococcus aureus and Staphylococcus epidermidis showed high biofilm forming index values of 0.29 and 0.27 respectively. Biofilm gene studies using PCR revealed the presence of all the three ica genes (Ica A, Ica D and, Ica B) in Staphylococcus aureus. The present research finding has great significance in the treatment to implant associated infections. Conclusions:The results suggest that the virulence factors contributing to the development of infections can be revealed by understanding the presence of biofilm expression genes in the target organisms. This would also prevent dissemination of virulent bacteria in the health care centre; method also considered significant to detect healthy carriers of slime-producing staphylococci.