 Relative abundance of resistant genes The blaTEM primer used will be as described by Kim et al 22. Primers to analyze the presence of erm G, erm B and erm F resistance genes will be as described by Jansonn et al 23. Primers for Tet M and Tet W genes will as described by Diaz-Torez et al 24. 16S universal primers will be used for the relative quantification as a standard. 