title: Rifaximin intake leads to emergence of rifampin-resistant staphylococci.
abstract: OBJECTIVE
  Rifaximin is a poorly absorbed non-systemic antimicrobial agent used in various gastrointestinal disorders. Rifampin is pivotal for the treatment of staphylococcal foreign body infections and resistance develops rapidly during monotherapy. The close structural relation of rifaximin to rifampin may lead to cross-resistance. The aim of our study was to determine whether rifampin-resistance emerges in human skin staphylococci during or after oral intake of rifaximin.
  
  
  METHODS
  Rifampin resistance of skin staphylococci in healthy volunteers during and after intake of rifaximin was determined by E-Test.
  
  
  RESULTS
  Seven out of eleven volunteers developed rifampin-resistant staphylococci after intake of rifaximin. A total of eleven rifampin-resistant and three rifampin-intermediate staphylococcal isolates were found. Before or during intake no resistant isolate was detected. Shortly after discontinuation the rifampin-resistant strains were primarily isolated from the perianal skin, a few weeks later they were found more frequently on the skin of the hands and lower arms.
  
  
  CONCLUSIONS
  Our data show that rifampin-resistant staphylococci emerge after intake of rifaximin. Since rifampin resistance is associated with treatment failure in staphylococcal foreign body infections, we conclude that rifaximin should be avoided in patients at risk for these infections.
authors.affiliation: Section of Infectious Diseases, Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 20, Graz, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Valentin
authors.forename: Eva
authors.initials: E
authors.lastname: Leitner
authors.forename: Angelika
authors.initials: A
authors.lastname: Rohn
authors.forename: Ines
authors.initials: I
authors.lastname: Zollner-Schwetz
authors.forename: Martin
authors.initials: M
authors.lastname: Hoenigl
authors.forename: Helmut J F
authors.initials: HJ
authors.lastname: Salzer
authors.forename: Robert
authors.initials: R
authors.lastname: Krause
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012293:Rifampin / Q000494:pharmacology* / Q000627:therapeutic use; D012294:Rifamycins / Q000008:administration & dosage / Q000494:pharmacology*; D000078262:Rifaximin; D012867:Skin / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy; D013210:Staphylococcus / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D005765:Gastrointestinal Agents; D012294:Rifamycins; D000078262:Rifaximin; D012293:Rifampin