title: Antibiotic susceptibility of Clostridium difficile is similar worldwide over two decades despite widespread use of broad-spectrum antibiotics: an analysis done at the University Hospital of Zurich.
abstract: BACKGROUND
  Clostridium difficile infection (CDI) remains a major health problem worldwide. Antibiotic use, in general, and clindamycin and ciprofloxacin, in particular, have been implicated in the pathogenesis of CDI. Here, we hypothesized that antibiotics that are highly active in vitro against C. difficile are less frequently associated with CDI than others. The primary goals of our study were to determine if antibiotic susceptibility and CDI are associated and whether the antimicrobial susceptibility of C. difficile changed over the years.
  
  
  RESULTS
  We examined a large panel of C. difficile strains collected in 2006-2008 at the University Hospital of Zurich. We found that the antimicrobial susceptibilities to amoxicillin/clavulanate, piperacillin/tazobactam, meropenem, clindamycin, ciprofloxacin, ceftriaxone, metronidazole and vancomycin were similar to those reported in the literature and that they are similar to those reported in other populations over the last two decades. Antibiotic activity did not prevent CDI. For example, thre use of meropenem, which is highly active against all strains tested, was a clear risk factor for CDI. Most of the antibiotics tested also showed a higher minimum inhibitory concentration distribution than that of EUCAST. All strains were susceptible to metronidazole. One strain was resistant to vancomycin.
  
  
  CONCLUSIONS
  Antibiotic susceptibilities of the collection of C. difficile from the University Hospital of Zurich are similar to those reported by others since the 1980. Patients treated with carbapenems and cephalosporins had the highest risk of developing CDI irrespective of the antimicrobial activity of carbapenems.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. andrea.buechler@gmx.ch.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Büchler
authors.affiliation: Division of Internal Medicine, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. Silvana.rampini@usz.ch.
authors.forename: Silvana K
authors.initials: SK
authors.lastname: Rampini
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. simon.stelling@ergon.ch.|Current address: Ergon Informatik AG, Kleinstrasse 15, 8008, Zürich, Switzerland. simon.stelling@ergon.ch.
authors.forename: Simon
authors.initials: S
authors.lastname: Stelling
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. infled@usz.uzh.ch.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ledergerber
authors.affiliation: Institute of Medical Microbiology, University of Zurich, Gloriastrasse 30/32, 8006, Zurich, Switzerland. silke.peter@med.uni-tuebingen.d.|Current address: Institute of Medical Microbiology and Hygiene, University of Tübingen, Elfriede-Aulhorn Str. 6, Tübingen, Germany. silke.peter@med.uni-tuebingen.d.
authors.forename: Silke
authors.initials: S
authors.lastname: Peter
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. Alexander.Schweiger@spital-schwyz.ch.|Current address: Internal Medicine, Hospital Schwyz, Waldeggstrasse 10, 6430, Schwyz, Switzerland. Alexander.Schweiger@spital-schwyz.ch.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schweiger
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. Christian.ruef@hirslanden.ch.|Current address: Hirslanden Klinik, Witellikerstrasse 40, 8032, Zürich, Switzerland. Christian.ruef@hirslanden.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Ruef
authors.affiliation: Institute of Medical Microbiology, University of Zurich, Gloriastrasse 30/32, 8006, Zurich, Switzerland. rzbinden@imm.uzh.ch.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Zbinden
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland. Roberto.speck@usz.ch.
authors.forename: Roberto F
authors.initials: RF
authors.lastname: Speck
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000494:pharmacology / Q000627:therapeutic use; D002981:Clindamycin / Q000494:pharmacology / Q000627:therapeutic use; D016360:Clostridioides difficile / Q000187:drug effects*; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D013557:Switzerland / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D002981:Clindamycin; D002939:Ciprofloxacin