FIG 1.

Antibiotic susceptibility profiles and resistance phenotypes of selected soil metagenomic fosmid clones and distributions of their associated antibiotic resistance genes (ARGs). (A) The MICs of antibiotics (except sulfonamides) for 31 nonredundant metagenomic fosmid clones were determined using the broth microdilution method and are presented as fold change relative to those for a control strain. Light gray indicates that the MIC not determined (n.d.). For detecting sulfonamide resistance, serial dilutions of culture were spotted onto agar plates supplemented with the appropriate sulfonamide antibiotic. (B) Resistance phenotypes of the soil metagenomic clones. Each number represents the number of unique clones that displayed resistance against antibiotics belonging to the labeled drug classes. (C) Distribution of putative ARGs based on their predicted resistance mechanism and sequence homology against best matches found by blastX.