| The goal of this study was to characterize the soil and the presence of antibiotic resistance genes (ARG) erm(B) in soils from 26 parks across California to investigate the correlation between the human population density and land use with levels of the antibiotic resistance gene erm(B) . Los Angeles, San Diego, Bakersfield and Fresno were selected and sampled at six publicly accessible park sites in each city. Two pristine sites, Yosemite National Park and Mount Baldy were selected and sampled as well. DNA was extracted from soil samples, normalized and quantified for the presence of 16S rDNA erm(B) using quantitative polymerase chain reaction (qPCR). Erm(B) levels were quantified via two analysis approaches, on a per gram of soil basis and normalized to relative 16S gene abundance. Among 26 parks, the highest levels of erm(B) occurred in one park located in Yosemite. However, levels of erm(B) decreased as population density increased for the 4 urban cities, which thus erm(B) abundance seems not clearly related to population density. In addition, agricultural areas showed high detection of gene erm (B) , which it might be influential to the erm(B) detection. |
