Spread of antibiotic-resistant actinobacteria in soils exposed to various types of anthropogenic impact

Abstract

The work investigated the spectra of resistance to a certain set of antibiotics and the frequency of occurrence of resistant strains among typical soil bacteria – actinomycetes. Equal samples of isolates from sod-podzolic soil were used,  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 sections 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-grass meadow (back-ground). 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 – nalidixic acid, and  β-lactams – 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  the 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.