title: Staphylococcus aureus isolates colonizing and infecting cirrhotic and liver-transplantation patients: comparison of molecular typing and virulence factors.
abstract: BACKGROUND
  S. aureus is an important agent of colonization and infection in liver transplant patients. It harbors several virulence factors that can increase its pathogenicity. However, studies of virulence and molecular typing of MRSA in cirrhotic and liver transplantation patients are scarce.
  
  
  RESULTS
  Here we use SCCmec, PFGE, spa typing, MLST and virulence factors to characterize MRSA isolates in pre and post liver transplantation patients. Sixteen (13%) of 126 cirrhotic and 15 of the 64 liver-transplanted patients (23%) were colonized by MRSA (p=0.091). SCCmec types I, II and III that are generally associated with nosocomial infections were identified in 91% of the isolates. None of the isolates carried PVL, adhesion factors and fib gene. Only three MRSA colonized isolates carried tst gene and were characterized as SCCmec type I and t149. Ten spa types and five STs were identified; t002 and ST105 were the most frequent profiles. Spa types and ST1510 never described in Brazil and a new spa type t14789 were identified. Nineteen PFGE subtypes were found and grouped into nine types. There was a predominant cluster, which was related to the New York/Japanese epidemic clone and harboured SCCmec type II identified in both cirrhotic and post-transplantation patients. Based on SCCmec and virulence factors the MRSA isolates belonged to NY/Jpn clone seen be more similar to the USA100 MRSA isolates.
  
  
  CONCLUSIONS
  Although without significance, liver-transplantation was more frequently colonized by MRSA than cirrhotic patients. The most frequent SCCmec was type II, and the predominant cluster was related to the New York/Japanese clone. A new spa t14789, and ST1510 never reported in Brazil were identified.
authors.affiliation: Department of Infection Control, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil. issa_bg@hotmail.com.|Laboratory of Medical Investigation 54 (LIM-54), Hospital Das Clínicas FMUSP, São Paulo, Brazil. issa_bg@hotmail.com.
authors.forename: Larissa Marques
authors.initials: LM
authors.lastname: de Oliveira
authors.affiliation: Department of Infection Control, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil. innekemicro@yahoo.com.br.|Laboratory of Medical Investigation 54 (LIM-54), Hospital Das Clínicas FMUSP, São Paulo, Brazil. innekemicro@yahoo.com.br.
authors.forename: Inneke Marie
authors.initials: IM
authors.lastname: van der Heijden
authors.affiliation: National Microbiology Laboratory, Winnipeg, Manitoba, Canada. george.golding@phac-aspc.gc.ca.
authors.forename: George R
authors.initials: GR
authors.lastname: Golding
authors.affiliation: Liver Transplantation Unit, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil. eabdala@uol.com.br.
authors.forename: Edson
authors.initials: E
authors.lastname: Abdala
authors.affiliation: Liver Transplantation Unit, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.
authors.forename: Maristela P
authors.initials: MP
authors.lastname: Freire
authors.affiliation: Laboratory of Microbiology, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil. f.rossi@hc.fm.usp.br.
authors.forename: Flavia
authors.initials: F
authors.lastname: Rossi
authors.affiliation: Liver Transplantation Unit, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil. profluizcarneiro@gmail.com.
authors.forename: Luiz C
authors.initials: LC
authors.lastname: D' alburquerque
authors.affiliation: Department of Infection Control, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil. anna@usp.br.|Laboratory of Medical Investigation 54 (LIM-54), Hospital Das Clínicas FMUSP, São Paulo, Brazil. anna@usp.br.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Levin
authors.affiliation: Laboratory of Medical Investigation 54 (LIM-54), Hospital Das Clínicas FMUSP, São Paulo, Brazil. costasilviaf@ig.com.br.|Department of Infectious Diseases, LIM-54, Faculdade de Medicina, University of São Paulo, Avenida Doutor Enéas de Carvalho Aguiar, 470, São Paulo, SP, 05403-000, Brazil. costasilviaf@ig.com.br.
authors.forename: Silvia F
authors.initials: SF
authors.lastname: Costa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D005260:Female; D005838:Genotype; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications*; D016031:Liver Transplantation; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008875:Middle Aged; D058889:Molecular Typing; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics*; D055815:Young Adult
chemical_list: D037521:Virulence Factors