Cfr-mediated linezolid resistance in methicillin-resistant Staphylococcus aureus and Staphylococcus haemolyticus associated with clinical infections in humans: two case reports.

Sir, Linezolid is a last-resort antimicrobial agent in human medicine approved for the control of serious infections caused by Grampositive pathogens. Transferable linezolid resistance is based on the multiresistance gene cfr. Although originally found in staphylococci, this gene has meanwhile been reported in various Grampositive and even Gram-negative bacteria. The emergence of the multiresistance gene cfr in staphylococci is of global concern. Here we report the detection of the cfr gene in a methicillin-resistant Staphylococcus aureus and a methicillin-resistant Staphylococcus haemolyticus strain from two clinical cases of septic shock identified in the same hospital in Spain.