Low Prevalence of Cfr-Mediated Linezolid Resistance among Methicillin-Resistant Staphylococcus aureus in a Spanish Hospital: Case Report on Linezolid Resistance Acquired during Linezolid Therapy

Josep M Sierra,Mariana Camoez,M Angeles Domínguez,Miquel Pujol,Oriol Gasch,Rogelio Martin,Fe Tubau

doi:10.1371/journal.pone.0059215

Josep M Sierra, Mariana Camoez + Show 5 more

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https://doi.org/10.1371/journal.pone.0059215

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Abstract

Linezolid is an effective antimicrobial agent to treat methicillin-resistant Staphylococcus aureus (MRSA). Resistance to linezolid due to the cfr gene is described worldwide. The present study aimed to analyze the prevalence of the cfr–mediated linezolid resistance among MRSA clinical isolates in our area. A very low prevalence of cfr mediated linezolid resistance was found: only one bacteremic isolate out of 2 215 screened isolates. The only linezolid resistant isolate arose in a patient, previously colonized by MRSA, following linezolid therapy. Despite the low rate of resistance in our area, ongoing surveillance is advisable to avoid the spread of linezolid resistance.

Highlights

Linezolid has been introduced into the medical practice to treat Gram-positive infections, especially those related with staphylococcal infections including methicillin resistance Staphylococcus aureus (MRSA)
Linezolid was introduced in the clinical practice in Hospital Universitari de Bellvitge (HUB) during 2003
The patient had been admitted to the intensive care unit (ICU) in February 2009 because of complications derived from a laryngeal cancer surgery performed on December 2008

Summary

Introduction

Linezolid has been introduced into the medical practice to treat Gram-positive infections, especially those related with staphylococcal infections including methicillin resistance Staphylococcus aureus (MRSA).Since the introduction of linezolid in the clinical practice several mechanisms of linezolid-resistance have been described. Due to the presence of multiple copies of the 23SrRNA gene, a relationship between the number of mutated genes and the level of resistance is well established, and known as ‘‘gene dosage’’ [3]. Another mechanism involved in linezolid resistance is the modification of ribosomal proteins L3 and L4 encoded by rplC and rplD genes, respectively. Some outbreaks of crf-mediated linezolid-resistant strains have been reported in the literature, such as the recent outbreak described in Spain by Morales et al [7] In this case, the epidemic strain was involved in surgical site infections; ventilatorassisted pneumonia; and primary bacteremia in an intensive care unit, affecting a total of 12 patients

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