Biofilm production by staphylococcus aureus and staphylococcus epidermidis: an evaluation of three different screening methods

The purpose of this study was to determine the rate of biofilm production by S.aureus and S.epidermidis isolated from different clinical specimens.

Quantitation of biofilm formation by staphylococci was carried out using three in vitro methods namely tissue culture plate (TCP), tube method (TM), and congo red agar (CRA) method.

Out of 237 (94.8%) S.aureus isolates tested, 25 strains were found to form biofilm, out of these one (0.42%) was strong biofilm producer and 24 (10.12%) were moderate biofilm producers. In TM and CRA method 20 (8.43%) and 10 (4.2%) strains were moderate biofilm producers, rest were considered as weak or non-biofilm producers. All the 25 biofilm positive strains were S.aureus.

The TCP method is more sensitive to detect biofilm formation by S.aureus when compare to tube method (TM), and congo red agar (CRA) method.