UCLA

Dissemination of antibiotic resistance genes (ARGs) in the environment has prompted concerns over the use of fertilizers to supply nutrients to plants. In this study, two sulfonamide resistance genes, sul1 and sul2, and one class 1 integron-integrase gene, intI1, were quantified in 34 garden products, 3 community soils, and 5 natural soils. sul1, sul2, and intI1 were present in 33, 34, and 31 garden products, respectively. sul1 absolute gene abundances ranged from 4.8 x 102 - 9.4 x 107 gene copies per gram and relative gene abundances ranged from 9.0 x 10-6 - 4.9 x 10-2 gene copies per 16s rRNA. Similarly, sul2 quantities ranged from 2.9 x 102 - 1.3 x 107 gene copies per gram and 6.1 x 10-6 - 5.9 x 10-1 gene copies per 16s rRNA. intI1 values were observed to range from 3.8 x 103 - 8.8 x 106 gene copies per gram and 3.4 x 10-5 - 5.1 x 10-2 gene copies per 16s rRNA. Although detected natural soils were approximately 2-4 orders of magnitude lower than garden products, community soils had comparable values to garden products. These results point to the importance of fertilizers in the proliferation of ARGs at the nexus of human-environment interaction.