Influence of a synthetic analogue of the active center of GM-CSF – peptide ZP2 on the growth and biofilm formation of gram-negative bacteria – causes of surgical infections

The aim is to analyze the nature of the effect of the synthetic analogue of the active center of GM- CSF – peptide ZP2 on the growth and biofilm formation (BPO) of gram–negative bacteria – pathogens of surgical infections. The study used 18 clinical isolates of gram-negative bacteria of different species (Klebsiella pneumoniae, Citrobacter freundii, Stenotrophamonas maltophilia) isolated from purulent wounds in patients with surgical pathology and showing pronounced resistance to many antibiotics used in clinical practice. The isolation of pure cultures of microorganisms was carried out by conventional methods; species were assessed by direct protein profiling using a MALDI TOF mass spectrometer. To study the effect of ZP2 peptide on bacterial growth and BPO, isolates were co-cultured with a solution of ZP2 peptide in meat-peptone broth (MPB) at a concentration of 5 micrograms/ml at 37°C for 24-48 hours. The effect of the ZP2 peptide was studied both on emerging biofilms and on those formed, according to the degree of binding of crystalline violet in sterile 96-well polystyrene plates. Next, Growth inhibition indices and coefficients of BPO of microorganisms were determined. It was found that the synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2 inhibited the growth of the studied bacterial strains, reducing the biomass of experimental cultures during the development of bacterial populations. At the same time, the species-specific effect of the ZP2 peptide on the ability of surgical strains of the studied bacteria to form biofilms has been shown. It was experimentally established that all the studied surgical strains of microorganisms were capable of biofilm formation, and the maximum severity of the trait was characteristic of S. maltophilia isolates. The synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2 caused a decrease in the ability to form biofilms in isolates S. maltophilia and destroyed already formed biofilms in all studied species of microorganisms. The experimental data obtained expand the range of potential clinical applications of the synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2, and its use in new medicines can be effective in combating antibiotic-resistant pathogens of surgical infections.