1 Scientific RepoRts | 7:46068 | DOI: 10.1038/srep46068 www.nature.com/scientificreports Targeting microbial bioilms using Ficin, a nonspeciic plant protease Diana R. Baidamshina 1,* , elena Y. trizna 1,* , Marina G. Holyavka 2 , Mikhail I. Bogachev 3 , Valeriy G. Artyukhov 2 , Farida s. Akhatova 1 , elvira V. Rozhina 1 , Rawil F. Fakhrullin 1 & Airat R. Kayumov 1 Bioilms, the communities of surface-attached bacteria embedded into extracellular matrix, are ubiquitous microbial consortia securing the efective resistance of constituent cells to environmental impacts and host immune responses. Bioilm-embedded bacteria are generally inaccessible for antimicrobials, therefore the disruption of bioilm matrix is the potent approach to eradicate microbial bioilms. We demonstrate here the destruction of Staphylococcus aureus and Staphylococcus epidermidis bioilms with Ficin, a nonspeciic plant protease. The bioilm thickness decreased two-fold after 24 hours treatment with Ficin at 10 μg/ml and six-fold at 1000 μg/ml concentration. We conirmed the successful destruction of bioilm structures and the signiicant decrease of non-speciic bacterial adhesion to the surfaces after Ficin treatment using confocal laser scanning and atomic force microscopy. Importantly, Ficin treatment enhanced the efects of antibiotics on bioilms-embedded cells via disruption of bioilm matrices. Pre-treatment with Ficin (1000 μg/ml) considerably reduced the concentrations of ciproloxacin and bezalkonium chloride required to suppress the viable Staphylococci by 3 orders of magnitude. We also demonstrated that Ficin is not cytotoxic towards human breast adenocarcinoma cells (MCF7) and dog adipose derived stem cells. Overall, Ficin is a potent tool for staphylococcal bioilm treatment and fabrication of novel antimicrobial therapeutics for medical and veterinary applications. Bioilms are formed by the surface-attached bacterial cells arranged into complex communal tertiary structures and embedded into an extracellular matrix 1,2 . he bulk of the matrix is formed by extracellular polymeric sub- stances (EPS) that typically constitute up to 95% of the bioilm and consist of biopolymers (i.e polysaccharides, proteins, lipids and nucleic acids) produced and secreted by the constituent bacteria. he matrix supports the three-dimensional structure of the bioilm and protects the cells from various environmental impacts. Bacterial cells in bioilms are extremely resistant to medicinal treatment and immune system attacks, that leads to chronic reinfections 1,3,4 . Many opportunistic bacteria (i.e. Staphylococcus, Micrococcus, Klebsiella, Pseudomonas, etc.) form bioilms on chronic and acute dermal wounds impeding their healing, causing reinfec- tion and sepsis 1,3,4 . Accordingly, the colonization with S. epidermidis and/or S. aureus is a common cause of intra- and extravascular catheter-associated infection, implants, wound surfaces and mucous membranes 5 . As a result, bacterial bioilms appear a signiicant clinical challenge leading to increased patient morbidity and mortality from infectious diseases 6,7 . herefore, the prevention of bioilm formation and disruption of already established bioilms is crucially important for clinical treatment of infectious diseases 8–10 . Destroying the bioilm matrix backbone, for example via enzymatic lysis, is an advantageous approach for bioilms eradication 6 . Numerous bacterial enzymes, such as glycosidases, proteases, and DNases degrade various components of bioilms stimulating cells detachment and increasing cellular susceptibility to antimicrobials 11 . In particular, the glycoside hydrolase dispersin B produced by Aggregatibacter actinomycetemcomitans has been shown to sensitize S. epidermidis bioilm-embedded cells to antimicrobials action 12,13 . Dispersin B injection in combination with triclosan reduced the catheter colonization density by S. aureus in rabbits in vivo 14 . Another glycoside hydrolase, alginate lyase, successfully enhanced the activity of aminoglycosides against P. aeruginosa bioilms both in vitro 15,16 and in vivo 17 . DNase (NucB) from Bacillus licheniformis induced rapid dispersal of bioilm formed by B. subtilis, E. coli and M. luteus 18 . Recombinant human DNase I (rhDNase) has been shown to disperse preformed S. aureus bioilms and increase the susceptibility of S. aureus bioilm cells to antiseptics 6 . In 1 Kazan federal University, institute of fundamental Medicine and Biology, Kazan, Republic of tatarstan, Russian federation. 2 Voronezh State University, Medicine and Biology faculty, Voronezh, Russian federation. 3 St Petersburg electrotechnical University, Biomedical engineering Research centre, St. Petersburg, Russian federation. * these authors contributed equally to this work. correspondence and requests for materials should be addressed to A.R.K. (email: kairatr@yandex.ru) Received: 26 September 2016 Accepted: 08 March 2017 Published: 07 April 2017 OPEN