ANTIBIOTIC RESISTANCE PROFILE OF METALLURGY IMPACTED SOILS IN EAST KAZAKHSTAN

Abstract

IIndustrial soils that are persistently polluted with heavy metals are considered as sources of antibiotic resistance genes (ARGs). However, the mechanisms and magnitude of this effect, especially with regard to long-read metagenomics, have not been well studied. As a part of this study, whole-metagenome sequencing was performed with the Oxford Nanopore PromethION 2 Solo and the data analyzed using the DeepARG tool. A total of 33 soil samples were taken from technogenic areas in six industrial districts of East Kazakhstan (Ust-Kamenogorsk, Ridder and others). The levels of Zn, Cu, Cd and Pb were found to be widely distributed with some locations exceeding the maximum allowable concentration by many times. The Spearman correlation analysis revealed a statistically significant positive correlation between the ompR and bacA genes with the concentration of these metals (p<0.05), suggesting the possibility of cross-resistance due to decreased permeability of the membrane and co-regulation. The heavy metals explained 15.9% of the variation in ARG profiles (R²=0.1588; F=1.32; p=0.033) and non-metric multidimensional scaling (NMDS) analysis indicated that the resistome was significantly changing across the contamination gradient. The results presented suggest that long-term metallogenic contamination is an ecological factor independent of the other factors that is responsible for the preservation and restructuring of the soil ARG resistome. This should therefore be considered when evaluating the risk of the spread of antibiotic resistance in industrial areas.