title: Methicillin-resistant Staphylococcus aureus (MRSA) carriage in a dermatology unit.
abstract: OBJECTIVE
  The aim of this study was to characterize Staphylococcus aureus (MRSA) carriage in a dermatology unit.
  
  
  METHODS
  This was a prospective and descriptive study. Over the course of 26 weeks, surveillance cultures were collected weekly from the anterior nares and skin of all patients hospitalized in a 20-bed dermatology unit of a tertiary-care hospital. Samples from healthcare workers (HCWS) were cultured at the beginning and end of the study. Colonized patients were put under contact precautions, and basic infection control measures were enforced. Staphylococcus aureus colonization pressure was determined monthly. Colonized and non-colonized patients were compared, and isolates were evaluated for antimicrobial susceptibility, SCCmec type, virulence factors, and type.
  
  
  RESULTS
  Of the 142 patients evaluated, 64 (45%) were colonized by MRSA (39% hospital acquired; 25% community acquired; 36% indeterminate). Despite isolation precautions, hospital-acquired Staphylococcus aureus occurred in addition to the continuous entry of Staphylococcus aureus from the community. Colonization pressure increased from 13% to 59%, and pemphigus and other bullous diseases were associated with MRSA colonization. Eleven out of 71 HCWs (15%) were Staphylococcus aureus carriers, although only one worker carried a persistent clone. Of the hospital-acquired MRSA cases, 14/28 (50%) were SCCmec type IV (3 PFGE types), 13 were SCCmec type III (46%), and one had an indeterminate type. These types were also present among the community-acquired Staphylococcus aureus isolates. SSCmec type IV isolates were shown to be more susceptible than type III isolates. There were two cases of bloodstream infection, and the pvl and tst virulence genes were absent from all isolates.
  
  
  CONCLUSIONS
  Dermatology patients were colonized by community- and hospital-acquired Staphylococcus aureus. Half of the nosocomial Staphylococcus aureus isolates were SCCmec type IV. Despite the identification of colonized patients and the subsequent contact precautions and room placement, Staphylococcus aureus colonization continued to occur, and colonization pressure increased. Pemphigus and other bullous diseases were associated with Staphylococcus aureus.
authors.affiliation: Hospital das Clínicas da Universidade de São Paulo, Department of Infectious Diseases and LIM-54, São Paulo/SP, Brazil.
authors.forename: Renata L
authors.initials: RL
authors.lastname: Pacheco
authors.forename: Renata D
authors.initials: RD
authors.lastname: Lobo
authors.forename: Maura S
authors.initials: MS
authors.lastname: Oliveira
authors.forename: Elthon F
authors.initials: EF
authors.lastname: Farina
authors.forename: Cleide R
authors.initials: CR
authors.lastname: Santos
authors.forename: Silvia F
authors.initials: SF
authors.lastname: Costa
authors.forename: Maria Clara
authors.initials: MC
authors.lastname: Padoveze
authors.forename: Cilmara P
authors.initials: CP
authors.lastname: Garcia
authors.forename: Priscila A
authors.initials: PA
authors.lastname: Trindade
authors.forename: Ligia M
authors.initials: LM
authors.lastname: Quitério
authors.forename: Evandro A
authors.initials: EA
authors.lastname: Rivitti
authors.forename: Elsa M
authors.initials: EM
authors.lastname: Mamizuka
authors.forename: Anna S
authors.initials: AS
authors.lastname: Levin
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002353:Carrier State / Q000382:microbiology*; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology*; D003880:Dermatology; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents