title: Clonality and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus at the University Hospital Zurich, Switzerland between 2012 and 2014.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) is a global epidemic threat. The aim of this study was to determine which globally known MRSA lineages are currently present at our tertiary care hospital in Switzerland, a hospital with low MRSA prevalence. In light of the increasing prevalence of multi drug resistance including vancomycin resistance we also assessed antibiotic susceptibilities.
  
  
  METHODS
  The 146 MRSA strains collected over two years (March 2012 until February 2014) at the University Hospital Zurich, Switzerland, were analyzed by PFGE analysis of SmaI digests in combination with spa-typing. In addition, representative isolates were analyzed by multi locus sequence typing (MLST). Susceptibilities to eight antibiotics were assessed using the Kirby-Bauer disc diffusion method.
  
  
  RESULTS
  Isolates showed resistance to erythromycin (48%), ciprofloxacin (43%), clindamycin (31%), tetracycline (22%), and gentamicin (16%). All isolates were susceptible to vancomycin, 95% were susceptible to sulfamethoxazole/trimethoprim and rifampicin, respectively. PFGE analysis revealed 22 different patterns, with four major patterns that accounted for 53.4% of all MRSA isolates, and seven sporadic patterns. Spa typing revealed 50 different spa types with the predominant types being t008 (14%), t002 (10%), and t127 (9%). 82% of the MRSA isolates could be assigned to six clonal complexes (CCs) namely CC1 (10%), CC5 (23%), CC8 (18%), CC22 (17%), CC30 (11%), and CC45 (3%) based on spa-types, PFGE patterns, and MLST. Two isolates could not be typed by either PFGE analysis or spa-typing and three isolates had spa-types that have not yet been described.
  
  
  CONCLUSIONS
  The combination of the two typing methods was more discriminatory as compared to the use of a single method. Several of the lineages that are predominant in Europe are present in our hospital. Resistances to antibiotics have decreased in comparison to a study conducted between 2004 and 2006.
authors: Kati
authors: K
authors: Seidl
authors: Nadja
authors: N
authors: Leimer
authors: Miguel
authors: M
authors: Palheiros Marques
authors: Alexandra
authors: A
authors: Furrer
authors: Anne
authors: A
authors: Holzmann-Bürgel
authors: Gabriela
authors: G
authors: Senn
authors: Reinhard
authors: R
authors: Zbinden
authors: Annelies S
authors: AS
authors: Zinkernagel
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D024881:Drug Resistance, Bacterial; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D008712:Methicillin / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013557:Switzerland / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D008712:Methicillin