Clonal dissemination of linezolid-resistant Staphylococcus haemolyticus harbouring a G2576T mutation and the cfr gene in an Indian hospital

Linezolid, an oxazolidinone drug available in both parenteral and oral formulations, has emerged as a novel alternative to vancomycin and other second-generation drugs for treatment of infections from Gram-positive cocci (Gu et al., 2013). Mutation at domain V of 23S rRNA can result in modification of the ribososmal peptidyl transferase centre region and resistance in isolates. A naturally occurring resistance gene cfr, encoding a cfr methyltransferase, has also been reported in clinical isolates. Moreover, resistance has also been associated with mutations in the genes for the ribosomal proteins L3 and L4, which interact closely with the linezolid binding site in the peptidyl transferase centre region (Long & Vester, 2012). Linezolid resistance in clinical staphylococcus isolates is increasingly being reported worldwide (Jones et al., 2009). Here, we describe four linezolidresistant clinical isolates of Staphylococcus haemolyticus with a dual mechanism of resistance.