The impact of residential villages in a karstic watershed on numbers and diversity of nontuberculous mycobacteria

Abstract

Abstract The impact of residential villages on the nontuberculous mycobacteria (NTM) in streams flowing through them has not been studied in detail. Water and sediments of streams are highly susceptible to anthropogenic inputs such as surface water flows. This study investigated the impact of 7 residential villages in a karst watershed on the prevalence and species spectrum of NTM in water and sediments. Higher NTM species diversity (i.e., 19 out of 28 detected) was recorded downstream of the villages and wastewater treatment plants (WWTPs) compared to sampling sites upstream (i.e., 5). Significantly higher pH and Zn concentration were detected in sediments inside the village and downstream of the WWTP’s effluents. P and Cu sediment concentrations were higher only downstream of WWTPs compared to sediments inside the settlement. The effluent from the WWTPs had a substantial impact on water quality parameters with significant increases in total N, P, anions (HCO3–, Cl–, N-NO3–, and N-NH3–), and cations (Na+ and K+). The results provide insights into NTM numbers and species diversity distribution in a karst watershed and the impact of urban areas. Although in this report the focus is on the NTM, it is likely that other water and sediment microbes will be influenced as well.