DETERMINATION OF THE BIOFILM PRODUCTION CAPABILITIES OF STAPHYLOCOCCUS SPP. AND THE EFFECTS OF SOME ANTIBIOTICS ON THESE ISOLATES

Abstract

Staphylococci are pathogenic microorganisms that have various virulence factors. One of the most important of these virulence factors is biofilm production. Biofilm is a community formed by microorganisms living in a polymeric structured gelatinous layer that they produce by attaching to a surface. Some staphylococci become resistant to antibiotics by producing biofilms and treatment of infections becomes more difficult. The aim of this study is to investigate the biofilm formation capacity of staphylococci isolates which were previously isolated from mastitis cow's milk and to determine the effects of various antibiotics (tetracycline, amoxicillin+clavulanic acid, gentamicin, ampicillin) on these isolates. Biofilm formation of staphylococci is determined by congo red agar and microtitration plate method. As a result of investigated that 70,3% staphylococci were found biofilm formation positive. MIC, BMIC and BMEC values of different antibiotics for staphylococci isolates were compared. The highest MIC value was determined as 64 mu g\ml for amoxicillin+clavulanic acid and the lowest MIC was determined 1 mu g\ml for tetracycline. Staphylococci were found to be resistant to antibiotics by biofilm formation. BMIC and MBEC values were found to be 40-80 times and 80-160 times higher than MIC values, respectively.