Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics (original) (raw)
Fig 4
Resistance (A-C) and cross-resistance (D-F) levels of resistance genes isolated from ancient permafrost and its overlaying active layer.
Each unique gene is depicted by a shape and color combination based on sampling site and antibiotic on which it was isolated (shown on top of panels): A) & D) β-lactams, penicillin (PEN) & carbenicillin (CAR); B) & E) tetracyclines, tetracycline (TET) & doxycycline (DOX); and C) & F) aminoglycosides, sisomicin (SIS) & amikacin (AMK). In panels A) to C), each point shows resistance to antibiotics indicated at left (measured as minimum inhibitory concentration, MIC). Grey panels indicate resistance levels to the drug in which genes were isolated, and white panels show cross-resistance to the other drug in the same class. Dashed line indicates MIC of control libraries. Panels D) to F) show slopegraphs of cross-resistance between antibiotics of a same family. The left axis represents relative resistance (MIC of the isolated genes / MIC of the control E. coli library) in the antibiotics where the gene was isolated. The right axis represents the relative fitness of the genes in the other antibiotic of the same class. Any slope that doesn’t go down to one on the right axis indicates some degree of cross-resistance.