Public Relations & Press Office
Press Release
Agia Paraskevi, Friday 16 October 2015

Developing new antimicrobial therapies at NCSR “Demokritos”


Staphylococcus aureus (S. aureus) can cause a broad range of detrimental inflammatory complications in patients such as sepsis, endotoxic shock or endocarditis, thus imposing a heavy socioeconomic burden on the healthcare system. Its emerging antibiotic resistance and formidable immune evasion arsenal have emphasized the need for developing novel targeted therapies that might rely on alternative antimicrobial approaches. Complement is a gatekeeper of innate immunity that ‘patrols’ the human body, sensing external danger signals and becoming rapidly activated in the bloodstream in response to bacterial infections. It orchestrates multiple host antimicrobial pathways, thereby serving as an attractive target for subversion of the innate immune response by S. aureus. A research group in NCSR ‘Demokritos’ led by Dr. Georgia Sfyroera and Dr. Dimitris Mastellos have isolated S. aureus-neutralizing antibodies from human donors that specifically target the Extracellular Fibrinogen-binding Protein (Efb), a key complement inhibitory protein secreted by S. aureus. Employing high-throughput combinatorial approaches the ‘Demokritos’ team went on to characterize human mini-antibodies that block the function of Efb, attenuating the growth of S. aureus in models of bacteremia. More importantly, these mini-antibodies displayed a promising therapeutic profile, protecting mice challenged with S. aureus from tissue damage and bacterial inflammation in affected kidneys. Overall, these findings are anticipated to pave the way towards novel antibody-based therapies for S. aureus-related diseases.

This project was implemented through the ongoing collaboration of NCSR ‘Demokritos’ with researchers from the University of Pennsylvania and Kansas State University (USA), and also the Department of Microbiology of ‘Evangelismos’ General Hospital and the Medical School of the University of Athens. The results of this study were recently published in the Journal of Immunology, being also featured by the "In This Issue" section of the journal. "In This Issue" highlights articles considered to be among the top 10% of all articles published in the journal.

For more information please read:
1. Georgoutsou-Spyridonos M, Ricklin D, Pratsinis H, Perivolioti E, Pirmettis I, Garcia BL, Geisbrecht BV, Foukas PG, Lambris JD, Mastellos DC, Sfyroera G. Attenuation of Staphylococcus aureus-Induced Bacteremia by Human Mini-Antibodies Targeting the Complement Inhibitory Protein Efb. J Immunol. 2015 Oct 15; 195(8):3946-58. (

2. ‘Mini-Abs may manage MRSA’, ‘In this issue’, Journal of Immunology, 2015, 195(8).

See attached files: 

Introduction Journal Immunology:
intro journal immunology.pdf

Paper Staphylococcus: 
Paper Staphylococcus.pdf

For more information:

Public Relations,

+30 210 650 3040, +30 210 650 3002

For the NCSR Demokritos

The National Center for Scientific Research (NCSR) "Demokritos" is the largest multidisciplinary research center in the country with substantial scientific research, technological and educational activities in the areas of: Health, Biology and Biotechnology, New Materials Micro & Nanotechnology, Environment - Energy and Sustainable Development, Information Technology & Telecommunications, Nuclear Physics & Elementary Particle Physics, Nuclear Technology & Radiation Protection, Cultural Heritage.