The genes and genetic backgrounds that are important for antibiotic resistance are a growing concern. In this study we are doing a genome wide association study with E. coli data on growth in different low level antibiotic conditions. We have data on 30 conditions and 2000 sequenced natural strains and are looking for new genes that are associated with better growth on low level antibiotics. These represent genes that could be targeted in the future to limit the spread and evolution of resistance. This project is part of the Transpred project funded by JPIAMR: Predicting cell-cell horizontal transmission of antibiotics resistance from genome and phenome.