Incidence, management and outcomes of the first cfr-mediated linezolid-resistant Staphylococcus epidermidis outbreak in a tertiary referral centre in the Republic of Ireland

Abstract

This is the first documented outbreak of cfr-mediated linezolid-resistant S. epidermidis in the Republic of Ireland. Despite this, and due to existing outbreak management protocols, the responsible micro-organism and source were identified efficiently. However, it became apparent that staff knowledge of antimicrobial susceptibilities and appropriate hygiene practices were suboptimal at the time of the outbreak, and that educational interventions (and re-inforcement) are necessary to avoid occurrence of antimicrobial resistance and outbreaks such as reported here.

Five-Year Summary of In Vitro Activity and Resistance Mechanisms of Linezolid against Clinically Important Gram-Positive Cocci in the United States from the LEADER Surveillance Program (2011 to 2015)

“…The low number of isolates nonsusceptible to linezolid relates to target site modifications, which remain the main resistance mechanism, developing slowly due to the redundancy of rRNA in bacteria (14). Isolates carrying target site mutations and/or cfr have been associated with prolonged drug exposure in at-risk patient populations, and these isolates can also disseminate due to breaks in infection prevention practices that lead to local outbreaks or endemic occurrences (25,(29)(30)(31). In addition, occasional outbreaks of cfr-carrying isolates have been reported; those outbreaks were usually contained after infection control measures were implemented (30,32,33).…”

“…Isolates carrying target site mutations and/or cfr have been associated with prolonged drug exposure in at-risk patient populations, and these isolates can also disseminate due to breaks in infection prevention practices that lead to local outbreaks or endemic occurrences (25,(29)(30)(31). In addition, occasional outbreaks of cfr-carrying isolates have been reported; those outbreaks were usually contained after infection control measures were implemented (30,32,33). However, others reported unsuccessful results with respect to suppressing cfr isolates despite implementing control measures (34), which can be observed here by the presence of eventual clonal isolates recovered over time in the same institution (Table 4).…”

Molecular Epidemiology of a Vancomycin-Intermediate Heteroresistant Staphylococcus epidermidis Outbreak in a Neonatal Intensive Care Unit

“…An outbreak of linezolid-resistant S. epidermidis has recently been reported in a tertiary care referral university hospital in Ireland. The outbreak was quickly contained through infection control practices and cessation of linezolid use (46). Although linezolid is an alternative to vancomycin, the potential for rapid acquisition of linezolid resistance in CoNS following treatment and trends toward increasing rates of resistance are of concern (45,47,48).…”

Characterisation of clinical meticillin-resistant Staphylococcus epidermidis demonstrating high levels of linezolid resistance (>256 μg/ml) resulting from transmissible and mutational mechanisms

“…This point mutation arises from the substitution of thymine for guanine at position 2576 (Escherichia coli numbering) in the central loop of the domain V region of the 23S rRNA. It has been noted that in addition to mutations in the rRNA, alterations in the rplC, rplD and rplV genes encoding the ribosomal proteins L3, L4 and L22 respectively have been observed in some LZD resistant Grampositive isolates [5,6,9,10]. We identified a mutation at R172C of the L3 ribosomal protein in isolate A only (the first isolate recovered), given that none of the other isolates contained this mutation it is therefore unlikely to be associated with LZD resistance.…”