St Petersburg University scientists are continuing to work on the study of the new peptide complex FLIP7 fly larvae, which affects the causative agents of human infectious diseases.

Research results published in the journal Infection and Drug Resistance showed that FLIP7 greatly enhances the effects of many other antibiotics.

Since antibiotics appeared in the first half of the 20th century, many bacteria have developed resistance to most of the existing medicines. One of the forms of bacterial protection is the ability of microorganisms to pass into the state of biofilm. A biofilm is a community of dormant cells protected by an extracellular matrix where many antibiotics are not able to penetrate.

Unlike conventional antibiotics, natural peptide complexes can destroy biofilms formed by the majority of pathogenic microorganisms: Staphylococcus aureus, E. Сoli, acinetobacter and others. However, the effectiveness of new drugs does not mean that humanity should abandon the classic drugs.

«Today, there are already complex and proven antibiotic regimens approved by the World Health Organisation. We are not faced with the task of supplanting existing drugs. On the contrary, we want to give them a second life, making them work as well as 50 years ago,» stated Andrey Yakovlev, Researcher in the Department of Entomology at St Petersburg University.

Andrey Yakovlev explained «We consider the peptide complex not only as an independent new antibiotic but also as a synergist, increasing the effectiveness of synthetic substances. This approach will make the new drug affordable and reduce the likelihood of side effects from the use of "classic" antibiotics by reducing their effective concentration».

Antibiotics, whose action can be enhanced with the help of the developed peptide complex, are mainly used systemically, even in the treatment of infections of the skin and soft tissues. The reason for this approach is precisely the inability of the antibiotic to destroy the biofilm formed at the site of infection. The solution to this situation could be the development of a combined treatment regimen combining the advantages of the antibiotic and natural peptide complexes.

The peptide complex was developed in the framework of the project «Antimicrobial and anticancer peptides of insect-saprophages: biosynthesis from renewable raw materials, structural and functional characteristics, prospects for application in medicine», supported by the Russian Science Foundation (RSF).

«The use of the FLIP7 external form, which will be registered as a medical device, will lead to the destruction of the biofilm, and the antibiotic used systematically will destroy free bacterial cells,» explains Andrey Yakovlev.

It should be understood that peptides are complex molecules that are difficult to synthesise in unlimited quantities. The technology is based on obtaining target components directly from insects. It became the winner of the competition of innovative projects in the nomination «The Best Scientific and Innovative Idea». The existing prototype technology allows to obtain a new drug in tens of thousands of packages per year. But this is clearly not enough to help those in need. Currently, researchers at St Petersburg University who study the immune system of meat flies are improving the technology for industrial production of an antimicrobial peptide complex.

The developed product is a carbopol-based hydrogel, which has already established itself at the testing stage in the complex treatment of trophic ulcers and diabetic foot. A promising area of ​​application for a medical device is not only medicine, but also veterinary medicine — scientists are confident that the new drug will be in demand for ear and eye infections in domestic animals.