Razi Journal of Medical Sciences

Background: Excessive use of antibiotics and biocides has led to emergence of resistant Staphylococcal strains.  The aim of this study was to examine resistance of Staphylococcal strains biofilm isolated to biocidal components.

Methods: 100 clinical isolates of Staphylococcus aureus were collected from hospitalized patients with infectious skins from two Shohadaye Tajrish and Valiasr hospitals for one year in Tehran City. Isolated strains were identified by standard biochemical tests and confirmed using polymerase chain reaction.  The pattern of resistance of strains to antibiotics and biocides such as Savlon, Decosept and Deconex (Dermocept) were determined by disc diffusion method and their minimal inhibition and cidal concentrations were estimated using microdilution. The biofilm of MDR strains were formed on polystyrene microplates.

Results: Most of strains were resistant to penicillin, amoxicillin, ampicillin and methicillin and the most sensitivity was seen to clarythromicin. The phenotyping findings of biofilm formation show that 6%, 23.2% and 50.4% of isolates were able to biofilm formation as strong, intermediate and weak, repectively, and only 20.4% were unable to form biofilm. Biofilm had the lower and higher resistant to Savlon and Deconex, respectively.

Conclusion: The prevalence of hospital resistance strains with ability of biofilm formation can be serious danger for health of society in an extended spectrum of patients.