title: [Nosocomial spread of linezolid-resistant Staphylococcus hominis in two hospitals in Majorca].
abstract: OBJECTIVE
  Since March 2008, several linezolid and teicoplanin-resistant Staphylococcus hominis (S. hominis) isolates have been recovered from patients admitted to the two major hospitals on the island of Majorca, Spain. For this reason, a study was conducted to determine the molecular epidemiology of these isolates and the mechanism of linezolid resistance.
  
  
  METHODS
  The molecular epidemiology study was performed by pulsed-field gel electrophoresis (PFGE) analysis, after digestion with ApaI. Linezolid resistance mechanisms were evaluated by PCR amplification of a fragment of the domain V of the 23S rRNA gene (followed by sequencing) and cfr gene.
  
  
  RESULTS
  From March 2008 to February 2009, 15 linezolid and teicoplanin-resistant S. hominis isolates were recovered from 14 patients. All of them, except one, were hospitalised in the intensive care units of either of the two institutions. Isolates were obtained mainly from blood cultures (9). The majority of infected patients (12 of 15 infectious episodes, 80.0%) had received courses of linezolid prior to detection of the resistant isolate. PFGE analysis revealed the presence of a unique clone among linezolid resistant S. hominis isolates. The G2576T mutation was detected in all the linezolid resistant strains. None of the resistant isolates showed a positive PCR for the cfr gene. All of the isolates were also resistant to penicillin, oxacillin, trimethoprim-sulfamethoxazole, ciprofloxacin, levofloxacin, and tobramicin; whereas all of them were susceptible to erythromycin, tetracycline, gentamicin, and daptomycin. The MIC of vancomycin was 4μg/ml for all the strains.
  
  
  CONCLUSIONS
  The detection of linezolid resistant Staphylococci highlights the need to rationalise the use of linezolid, and maintain an active surveillance of its resistance to preserve the clinical usefulness of this antimicrobial.
authors: Servicio de Microbiología, Hospital Universitari Son Espases, Palma de Mallorca, España. enrique.ruiz@ssib.es
authors: Enrique
authors: E
authors: Ruiz de Gopegui
authors: Carmen
authors: C
authors: Iuliana Marinescu
authors: Paz
authors: P
authors: Díaz
authors: Antònia
authors: A
authors: Socías
authors: Margarita
authors: M
authors: Garau
authors: José Ignacio
authors: JI
authors: Ayestarán
authors: Antonio
authors: A
authors: Pareja
authors: M Carmen
authors: MC
authors: Gallegos
authors: José L
authors: JL
authors: Pérez
authors: Antonio
authors: A
authors: Oliver
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology* / Q000635:transmission; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D000069349:Linezolid; D008297:Male; D023303:Oxazolidinones / Q000494:pharmacology*; D013030:Spain; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000635:transmission; D041181:Staphylococcus hominis / Q000187:drug effects*
chemical_list: D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D000069349:Linezolid