Objective: We investigated the effect of removing sialic acid from slime by using neuraminidase on bacterial adherence and antibiotic resistance in coagulase negative staphylococcus strains in our study.

Material and Method: Sixty-three coagulase negative staphylococci strains isolated from various clinical specimens were used in this study. Slime production of the bacteria was investigated by Christensen method (qualitative tube method) and quantitative microdilution plate method. In order to determine neuraminidase effect on slime formation and antibiotic resistance, bacteria were cultured with neuraminidase only and with increasing dilutions of antibiotic-neuraminidase mixtures, and incubated on 96- well polystyrene plates with U bottom. For observation of slime formation, plates were stained with crystal violet and examined spectrophotometrically at 570 nm and for antibiotic resistance directly at 625 nm.

Results: Adherence of slime-forming coagulase negative staphylococci was greater than non-slime forming bacteria. However, neuraminidase did not affect bacterial adherence and growth in both of the groups. Considering the effect of neuraminidase on slime formation, it was observed that neuraminidase reduced slime formation significantly on slime positive strains. Treatment of bacteria with neuraminidase and increasing doses of ciprofloxacin decreased the slime formation more than ciprofloxacin alone in coagulase negative staphylococci.

Conclusion: We believe that our study is important in that it emphasized the role of neuraminidase in increasing the effectiveness of antibiotics on biofilm formation.