FIG 3.

Correlation of tobramycin MIC values with mexY gene expression. Expression of mexY in 412 clinical P. aeruginosa isolates relative to the tobramycin MIC as reported previously (28, 29). Clinical isolates exhibiting mexY expression levels above the orange line were defined to exhibit intermediate, and above the red line exhibit high mexY expression levels. The black line delineates the CLSI breakpoint for clinical resistance. The blue color code indicates that the respective clinical isolate does not harbor an aminoglycoside modifying enzyme (AME⁻ isolates), while the red color code indicates that the isolates are AME positive (AME⁺).