Assessment of the influence of synthetic peptide of the active center of granulocyte-macrophagal colony-stimulating factor – ZP2 on the growth properties of Corynebacterium spp.

The goal is to study the effect of the synthetic peptide of the active center of the granulocyte-macrophage coline-stimulating factor ZP2 on the growth properties and biofilm formation of microorganisms of the genus Corynebacterium spp. In vitro experiments were carried out on 13 isolates of Corynebacterium spp., including C. amycolatum (n = 7), C. propinquum (n = 2) and C. pseudodiphtheriticum (n = 4)), previously isolated from healthy individuals and are part of the Network Collection of Symbiotic Microorganisms and Their Consortia of the Institute for Cellular and Intracellular Symbiosis UrB RAS (Orenburg, Russia). The effect of different concentrations of the ZP2 peptide on the growth properties (planktonic culture growth and biofilm formation) of test strains was assessed in 96-well polystyrene plates. The inhibitory effect of the ZP2 peptide on the growth of planktonic culture was assessed by the Inhibition Index (%), on biofilm formation – by the Degree of Inhibition of Biofilm Formation (%). It was experimentally established that after 2, 4, 6 and 24 hours, a dose-dependent inhibition of the growth of planktonic cultures of all studied bacterial strains was observed under the influence of various concentrations of ZP2 (0.5-2.0 μg/ml). In this case, the inhibitory effect of the ZP2 peptide depended both on its concentration in the cultivation medium and on the growth phase of the test strain of bacteria. The maximum inhibition of the growth of planktonic culture of all studied bacterial strains under the influence of various concentrations of the ZP2 peptide was observed after 24 hours and ranged from 89.3±1.9 to 94.1±1.8% in C. amycolatum, and in C. propinquum from 90.0±0.6 to 96.7±0.3%, in C. pseudodiphtheriticum from 92.2±2.1 to 95.1±1.3. The ZP2 peptide also had a significant effect on biofilm formation in all test cultures studied. The reduction in biofilm formation depended on the concentration of the peptide and ranged from 62.4 to 78.4% in C. amycolatum, from 70.9 to 79.6% in C. propinquum, and from 76 to 82.7% in C. pseudodiphtheriticum.

Thus, the antibacterial effect of the ZP2 peptide was revealed against the studied strains of corynebacteria species C. amycolatum, C. propinquum and C. pseudodiphtheriticum. According to available data, the ZP2 peptide is a drug with a wide spectrum of action that has an inhibitory effect not only on the studied actinobacteria, but also, according to literature data, on staphylococci and enterobacteria. An important prospect of the study is to reveal the mechanism of the antibacterial action of the ZP2 peptide with the characteristics of the effective concentration of the substance against pathogens and representatives of normal flora.