Indian Journal of Medical Research

: 2017  |  Volume : 146  |  Issue : 7  |  Page : 1--8

Staphylococcus aureus biofilm removal by targeting biofilm-associated extracellular proteins

Sudhir K Shukla, T Subba Rao 
 Water & Steam Chemistry Division, BARC Facilities, Kalpakkam; Homi Bhabha National Institute, Mumbai, India

Correspondence Address:
T Subba Rao
Water & Steam Chemistry Division, BARC Facilities, Kalpakkam 603 102, Tamil Nadu

Background & objectives: Among cell surface proteins, biofilm-associated protein (Bap) promotes biofilm development in Staphylococcus aureus strains. The aim of this study was to investigate proteinase-mediated biofilm dispersion in different isolates of S. aureus. Methods: Biofilm assay was done in 96-well microtitre plate to evaluate the effect of proteinase K on biofilms of bovine mastitis S. Aureus isolates. Extracellular polymeric substances were extracted and evaluated for their composition (protein, polysaccharides and extracellular DNA), before and after the proteinase K treatment. Results: Biofilm assay showed that 2 μg/ml proteinase K significantly inhibited biofilm development in bap-positive S. aureus V329 as well as other S. aureus isolates (SA7, SA10, SA33, SA352), but not in bap-mutant M556 and SA392 (a weak biofilm-producing strain). Proteinase K treatment on S. aureus planktonic cells showed that there was no inhibition of planktonic growth up to 32 μg/ml of proteinase K. Proteinase K treatment on 24 h old preformed biofilms showed an enhanced dispersion of bap-positive V329 and SA7, SA10, SA33 and SA352 biofilms; however, proteinase K did not affect the bap-mutant S. aureus M556 and SA392 biofilms. Biofilm compositions study before and after proteinase K treatment indicated that Bap might also be involved in eDNA retention in the biofilm matrix that aids in biofilm stability. When proteinase K was used in combination with antibiotics, a synergistic effect in antibiotic efficacy was observed against all biofilm-forming S. aureus isolates. Interpretation & conclusions: Proteinase K inhibited biofilms growth in S. aureus bovine mastitis isolates but did not affect their planktonic growth. An enhanced dispersion of preformed S. aureus biofilms was observed on proteinase K treatment. Proteinase K treatment with antibiotics showed a synergistic effect against S. aureus biofilms. The study suggests that dispersing S. aureus by protease can be of use while devising strategies againstS. aureus biofilms.

How to cite this article:
Shukla SK, Rao T S. Staphylococcus aureus biofilm removal by targeting biofilm-associated extracellular proteins.Indian J Med Res 2017;146:1-8

How to cite this URL:
Shukla SK, Rao T S. Staphylococcus aureus biofilm removal by targeting biofilm-associated extracellular proteins. Indian J Med Res [serial online] 2017 [cited 2020 Aug 4 ];146:1-8
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