Emergence of linezolid resistance of S. epidermidis in a critical care unit

Abstract number: 1733_1579

Martínez L., Treviño M., Cortizo S., Peñalver M., García-Zabarte M., Pardo F., Regueiro B.

Objectives: Linezolid is the first member of the oxazolidinone class of antimicrobials, approved for clinical use in 2000, particularly appropriate for treating multiresistant staphylococci. In the present work, we report four cases of linezolid-resistant coagulase-negative staphylococci (CoNS).

Methods: CoNS strains were isolated from blood and/or wound cultures from patients belonging to the same clinical unit (postsurgical care unit) from July to October, 2006. Identification and susceptibility testing of the strains were performed by the VITEK 2 System (bioMérieux®, France) and E-test (ABBiodisk®, Sweden).

Results: All strains showed slower growth than linezolid-sensitive CoNS strains, were identified as Staphylococcus epidermidis and were sensitive to glycopeptides, quinupristin-dalfopristin, fosfomycin, tetracycline, erythromycin, clindamycin and moxifloxacin, and resistant to oxacillin, rifampicin, fusidic acid, trimethoprim-sulfamethoxazole, ciprofloxacin, gentamicin and tobramycin. CMI range for linezolid was 8–16 mg/L. Only one of these patients had been previously treated with linezolid.

Conclusions: Linezolid resistance in CoNS has emerged at our institution. We think that, probably, person-to-person spread of linezolid-resistant CoNS has led to establishment of skin colonisation with the strain, however, genotypical characterisation methods must be applied to comfirm this approach. In any case, in vitro susceptibility testing of linezolid is advisable for accurate therapy of CoNS in medical units where linezolid is habitually used.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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