How do you treat a patient with a gram-negative infection with resistance to imipenem but sensitivity to meropenem and negative for Carbapenem resistant organism by xpert Carba-R-assay?  

The finding of meropenem susceptible, imipenem resistant GNR can be explained in Pseudomonas aeruginosa by efflux pump overexpression and porin (particularly OprD) loss. The opposite pattern in P. aeruginosa - imipenem susceptible, meropenem resistant – has often been attributed to overexpress...