title: Factors associated with rifampin resistance in staphylococcal periprosthetic joint infections (PJI): a matched case-control study.
abstract: OBJECTIVE
  Rifampin combination therapy plays an important role in the management of staphylococcal periprosthetic joint infection (PJI). However, the emergence of rifampin resistance is a feared complication. We retrospectively analysed predetermined potential risk factors in patients with rifampin-resistant staphylococcal PJI in a multicentre case-control study.
  
  
  METHODS
  Cases (n = 48) were defined as PJI caused by rifampin-resistant staphylococci. Rifampin-susceptible controls (n = 48) were matched for microorganism and type of prosthetic joint. Uni- and multivariable conditional logistic regression analyses were performed to estimate odds ratios (OR) with 95 % confidence intervals (95 % CI).
  
  
  RESULTS
  Forty-eight cases (31 men; median age 67 years; age range 39-88 years) with hip- (n = 29), knee- (n = 13), elbow- (n = 4), shoulder- (n = 1) or ankle-PJI (n = 1) were enrolled in the study. Staphylococcus aureus and coagulase-negative staphylococci were isolated in ten and 38 episodes, respectively. Most of the cases (n = 44, 92 %) had a previous PJI, and 93 % (n = 41) of these had been treated with rifampin. There was an independent association of emergence of rifampin resistance with male sex (OR 3.6, 95 % CI 1.2-11), ≥ 3 previous surgical revisions (OR 4.7, 95 % CI 1.6-14.2), PJI treatment with high initial bacterial load (inadequate surgical debridement, <2 weeks of intravenous treatment of the combination medication; OR 4.9, 95 % CI 1.6-15) and inadequate rifampin therapy (OR 5.4, 95 % CI 1.2-25).
  
  
  CONCLUSIONS
  Based on our results, extensive surgical debridement and adequate antibiotic therapy are needed to prevent the emergence of rifampin resistance.
authors.affiliation: University and University Hospital Zurich, Zurich, Switzerland.
authors.forename: Y
authors.initials: Y
authors.lastname: Achermann
authors.forename: K
authors.initials: K
authors.lastname: Eigenmann
authors.forename: B
authors.initials: B
authors.lastname: Ledergerber
authors.forename: L
authors.initials: L
authors.lastname: Derksen
authors.forename: P
authors.initials: P
authors.lastname: Rafeiner
authors.forename: M
authors.initials: M
authors.lastname: Clauss
authors.forename: R
authors.initials: R
authors.lastname: Nüesch
authors.forename: C
authors.initials: C
authors.lastname: Zellweger
authors.forename: M
authors.initials: M
authors.lastname: Vogt
authors.forename: W
authors.initials: W
authors.lastname: Zimmerli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D016022:Case-Control Studies; D016001:Confidence Intervals; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000601:surgery; D007595:Joint Prosthesis / Q000382:microbiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016459:Prosthesis-Related Infections / Q000188:drug therapy* / Q000382:microbiology; D012189:Retrospective Studies; D012293:Rifampin / Q000627:therapeutic use*; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D012293:Rifampin