Spread of Antibiotic-Resistant Actinobacteria in Soils Exposed to Various Types of Anthropogenic Impact

The spectra of resistance to a certain set of antibiotics and the frequency of occurrence of resistant strains among typical soil bacteria—actinomycetes—are considered. This study used equal samples of isolates from sod-podzolic soil selected at sites typifying various types of economic activity, namely, the production areas of a plywood factory and a chemical plant, the territory of a medical institution, and a solid waste collection and storage site. A total of 58 isolates with features characteristic of actinomycetes of the genus Streptomyces of the division Cinereus, Helvolo-Flavus, and Albus were obtained. It has been established that various types of economic activity lead to specific changes in the antibiotic resistance, which characterizes the soil of a natural grass–herb meadow (background). Isolates with resistance to nalidixic acid, amoxicillin, and ceftriaxone were found in the sample taken on the territory of the chemical plant more often than in the soil of the background site. The proportion of strains resistant to nalidixic acid, lincomycin, and azithromycin was significantly (P < 0.05) higher in the soil samples taken at the MSW collection site and the territory of the medical institution, while those resistant to nalidixic acid and amoxicillin were in the sample from the plywood factory. Groups of antibiotics (quinolones like nalidixic acid and β-lactams like amoxicillin and ceftriaxone) were identified, the resistance to which in streptomyces isolates from soils involved in economic activity was significantly higher than in soil isolates from the background territory. The data obtained in this work indicate the need to monitor the spread of antibiotic resistance in soils that are not only at risk of accumulation of residual concentrations of antibiotics, but also other consequences of anthropogenic influences.