ScienceRise: Biological Science

Bacterial plasmids: the role in the development of resistance to antimicrobial compounds

Olena Koshova — 2024-10-09

The rapid increase in the prevalence of multiple drug resistance of pathogenic microorganisms poses a critical threat to public health worldwide, which significantly contributes to the increase in patient mortality and morbidity. Classical agents, used in the past for treatment, are losing their effectiveness, moreover, many of the newer available drugs have already become targets for bacterial resistance mechanisms. As a result, the treatment of infections becomes more complicated, and the total costs of treatment increase.

Purpouse. In this work, we aimed to evaluate the role of plasmids in the development of antibiotic resistance and discuss various mechanisms of bacterial resistance to antibiotics, such as enzymatic inactivation of the antibiotic, reduction of the permeability of the outer cell membrane for the antibiotic, modification of the target mainly due to mutation, active efflux of the drug from the bacterial cell through with the help of enzymatic pumps.

Materials and methods: the search for sources of information was carried out in the databases PubMed, Medline, Web of Science, Google Scholar, as well as electronic repositories of higher education institutions and scientific institutions of Ukraine. Materials related to the research technology of genetic variability and modification of bacteria and mechanisms of resistance of microorganisms to antibiotics were selected.

Results. As a result of evolutionary development, bacteria have acquired two separate genetic systems - chromosomal DNA and extrachromosomal, self-replicating genetic elements called plasmids.

It is bacterial plasmids that play a key role in the diffusion of specific resistance genes, in particular to antibiotics. Plasmids are non-essential parts of bacteria and are double-stranded, circular, or linear DNA molecules capable of autonomous replication, allowing bacteria to adapt to a hostile environment. Today, scientists are most interested in two properties of bacteria, caused by plasmids, - antibiotic resistance and bioremediation. The latter determines the survival and development of bacteria in various adverse conditions, including resistance to pollutants, the ability to decompose different chemical compounds, or adaptation to new ecological niches.

Conclusions. Plasmids carry genes for xenobiotic degradation and heavy metal resistance, making them useful for bioremediation of toxic chemicals in an environmentally safe manner. However, properties, such as antibiotic resistance, result from the excessive and uncontrolled use of these drugs in medicine, veterinary medicine, agriculture, and other fields. Under such conditions, there is a natural selection of those strains of pathogenic bacteria that are carriers of R-plasmids

Analysis of the modern forest fund

Myron Lutskiv — 2024-10-09

The article is dedicated to the study of the forests in the southern part of Kyiv. The article presents data on the projective cover, distribution, vitality, frequency of occurrence, and other data, obtained from 10 geobotanical descriptions in the Holosiivskyi district of Kyiv. The further actions were made with the data observed, and as a result, the graph of similarity was created. Nowadays the territories of cities expand, causing the enhanced tempo of urbanization and this study checks whether the forest is hugely affected or not. Some evaluations could set the pattern and help to estimate the influence on forestry in the very near future.

The aim of the study is to inventory the modern forest fund in Kyiv and observe data to determine the influence of the urbanization on forest in the future.

Materials and methods. Among of the methods for the observation were used geobotanical descriptions, monitoring and various computing methods, including the sorting, creating plots to make evaluations, GPS fixation, and the programme to create a map for the more thorough description of quadrants.

Results. The vegetation in the analyzed areas is very diverse, with 68 species identified. Among the dominant species, Quercus robur was found in the tree layer, and Molinia caerulea along with Convallaria majalis in the herbaceous layer. The Betula pendula and Quercus robur formations have the highest species diversity, with 24 species each. The vegetation classes Querco-Fagetea and Vacinio-Piceateae were analyzed.

Conclusions. The forest, in which the research was conducted, is mildly affected by urbanization. This inference may be made by the common species on this latitude, based on the previous researches

Antimicrobial activity of a new compound of 1,2,4-triazole derivatives against pathogens of poultry bacterial diseases

Yevheniia Vashchyk — 2024-10-09

The aim: study of the antimicrobial activity of a new compound of 1,2,4-triazole derivatives against pathogens of poultry bacteriosis.

Materials and methods. Research was conducted on the bactericidal activity of a new compound of 1,2,4-triazole derivatives against pathogens of poultry bacteriosis. Dimethylsulfoxide was used to dissolve the ASP compound. In order to study the bactericidal activity of the compounds, reference and field strains of S. typhimurium, E. coli, St. aureus, P. aeruginosa, P. vulgaris, K. pneumoniae, L. monocytogenes, E. faecalis were used. The study of the minimum inhibitory concentration (MIC) was carried out by the method of serial dilution in Muller-Hinton broth, the minimum bactericidal concentration (MBC) - by seeding from transparent tubes on Petri dishes with differential nutrient media.

The results. The inhibitory effect of the ASP compound at a concentration of 62.5 μg/ml against E. coli, L. Monocytogenes, E. faecalis, and at a concentration of 125 μg/ml against S. typhimurium, E. coli, St. aureus, P. aeruginosa, P. vulgaris, K. pneumoniae, L. monocytogenes, E. faecalis was established. The bactericidal effect of the ASP compound was detected at a concentration of 62.5 μg/ml against L. monocytogenes, at a concentration of 125 μg/ml - against E. coli, St. aureus, L. monocytogenes and E. faecalis. The ASP compound at a concentration of 250 μg/ml has the inhibitory and bactericidal effect on all tested reference and field strains of poultry bacteriosis pathogens.

Conclusions. A new synthesized compound of 1,2,4 triazole derivatives of ASP exhibits the inhibitory effect at a concentration of 125 μg/ml - in relation to E. coli, St. aureus, L. monocytogenes and E. faecalis and the bactericidal effect against bacteriosis pathogens S. typhimurium, E. coli, St. aureus, P. aeruginosa, P. vulgaris, K. pneumoniae, L. monocytogenes, E. faecalis at a concentration of 250 μg/ml