title: Chlorhexidine and Mupirocin Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolates in the REDUCE-MRSA Trial.
abstract: Whether targeted or universal decolonization strategies for the control of methicillin-resistant Staphylococcus aureus (MRSA) select for resistance to decolonizing agents is unresolved. The REDUCE-MRSA trial (ClinicalTrials registration no. NCT00980980) provided an opportunity to investigate this question. REDUCE-MRSA was a 3-arm, cluster-randomized trial of either screening and isolation without decolonization, targeted decolonization with chlorhexidine and mupirocin, or universal decolonization without screening to prevent MRSA infection in intensive-care unit (ICU) patients. Isolates from the baseline and intervention periods were collected and tested for susceptibility to chlorhexidine gluconate (CHG) by microtiter dilution; mupirocin susceptibility was tested by Etest. The presence of the qacA or qacB gene was determined by PCR and DNA sequence analysis. A total of 3,173 isolates were analyzed; 2 were nonsusceptible to CHG (MICs, 8 μg/ml), and 5/814 (0.6%) carried qacA or qacB At baseline, 7.1% of MRSA isolates expressed low-level mupirocin resistance, and 7.5% expressed high-level mupirocin resistance. In a mixed-effects generalized logistic regression model, the odds of mupirocin resistance among clinical MRSA isolates or MRSA isolates acquired in an ICU in intervention versus baseline periods did not differ across arms, although estimates were imprecise due to small numbers. Reduced susceptibility to chlorhexidine and carriage of qacA or qacB were rare among MRSA isolates in the REDUCE-MRSA trial. The odds of mupirocin resistance were no different in the intervention versus baseline periods across arms, but the confidence limits were broad, and the results should be interpreted with caution.
authors: Department of Medicine (Infectious Diseases), Rush University Medical Center, Chicago, Illinois, USA mhayden@rush.edu.|Department of Pathology, Rush University Medical Center, Chicago, Illinois, USA.
authors: Mary K
authors: MK
authors: Hayden
authors: Department of Pathology, Rush University Medical Center, Chicago, Illinois, USA.
authors: Karen
authors: K
authors: Lolans
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Katherine
authors: K
authors: Haffenreffer
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Taliser R
authors: TR
authors: Avery
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Ken
authors: K
authors: Kleinman
authors: Department of Pathology, Rush University Medical Center, Chicago, Illinois, USA.
authors: Haiying
authors: H
authors: Li
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Rebecca E
authors: RE
authors: Kaganov
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Julie
authors: J
authors: Lankiewicz
authors: Hospital Corporation of America, Nashville, Tennessee, USA.
authors: Julia
authors: J
authors: Moody
authors: Division of Internal Medicine, Texas A&M Health Science Center College of Medicine, Houston, Texas, USA.
authors: Edward
authors: E
authors: Septimus
authors: Department of Medicine (Infectious Diseases), Rush University Medical Center, Chicago, Illinois, USA.|Cook County Health and Hospitals System, Chicago, Illinois, USA.
authors: Robert A
authors: RA
authors: Weinstein
authors: Hospital Corporation of America, Nashville, Tennessee, USA.
authors: Jason
authors: J
authors: Hickok
authors: Office of HAI Prevention Research and Evaluation, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors: John
authors: J
authors: Jernigan
authors: Hospital Corporation of America, Nashville, Tennessee, USA.
authors: Jonathan B
authors: JB
authors: Perlin
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors: Richard
authors: R
authors: Platt
authors: Division of Infectious Diseases, University of California-Irvine School of Medicine, Orange, California, USA.
authors: Susan S
authors: SS
authors: Huang
mesh_terms: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D002353:Carrier State / Q000188:drug therapy / Q000382:microbiology; D002710:Chlorhexidine / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D016712:Mupirocin / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D016712:Mupirocin; D002710:Chlorhexidine