Antibiofilm Activity of Dual-Function Tail Tubular Protein B from KP32 Phage on Enterobacter cloacae

Background: Dual function tail tubular proteins (TTP) from lytic bacteriophage are novel interesting group of biologically active enzymes possessing antibiofilm activity. Surprisingly, apart from their structural function, they are also polysaccharide hydrolyzes destroying bacterial extracellular components. One of the representatives of this group is TTPB from KP32 phage. Here, we present its biological activity towards biofilm of E. cloacae ATCC 13047 strain and towards its exopolysaccharide (EPS). Methods: TTPB was overexpressed in E coli system, purified and tested towards the pathogenic bacteria using agar overlay method. Hydrolytic activity of TTPB against bacterial EPS has been performed by reducing sugar (RS) determination in TTPB/EPS mixture regarding the RS amount obtained after acidic hydrolysis. Antibiofilm activity of TTPB has been set down on one-day E. cloacae biofilm using a biochemical method. Finally, the synergistic activity of TTPB with kanamycin has been demonstrated. Results: For the first time the hydrolytic activity of TTPB towards bacterial EPS has been showed. TTPB releases about a half of the whole RS amount of E. cloacae ATCC 13047 EPS and can reduce its biofilm by over 60%. Destroying the bacterial biofilm the phage protein improves the antibiotic action increasing kanamycin effectiveness almost four times.