Hyperexpression of Biofilm-breaking Enzymes and Disturbance of Biofilm from Staphylococcus Aureus and Staphylococcus Epidermidis

Abstract

The formation of biofilm by bacteria poses serious challenges in the treatment of many infectious diseases. To address this issue, an assay of biofilm from Staphylococcus aureus and Staphylococcus epidermidis were used with dispersin B (DspB) and lysostaphin (LSS), enzymes that are known to play a role in impeding biofilm and peptidoglycan formation. Dsp B catalyzes the hydrolysis of linear polymers of N-acetyl-D-glucosamines, which are part of the biofilm matrices. LSS is capable of cleaving the crosslinking pentaglycine bridges found in the cell wall peptidoglycan of certain Staphylococci. We successfully cloned and purified the two enzymes. We added various concentrations of glucose to bacterial media to determine the optimal growing conditions for the bacteria before adding the two enzymes. We found that each enzyme, Dsp B and LSS manifested, statistically, no significant impedance of biofilm formation in either bacteria, and yet the combination of Dsp B and LSS was shown to be much effective in cleaving the biofilm in S. aureus. These observations may support the notion that there is a synergistic effect to impede the formation of biofilm in certain strains of bacteria. The purified Dsp B, in fact, showed the hydrolysis of a polymer of N-acetyl-D-glucosamines present in the biofilm matrix, suggesting that the polymer is a major factor for breaking biofilms and may be useful for further research concerning medical conditions related to antibiotic resistance.