title: Nosocomial outbreak by imipenem-resistant metallo-beta-lactamase-producing Pseudomonas aeruginosa in an adult intensive care unit in a Brazilian teaching hospital.
abstract: OBJECTIVE
  To describe an outbreak of imipenem-resistant metallo-beta-lactamase-producing Pseudomonas aeruginosa, enzyme type bla, by horizontal transmission in patients admitted to a mixed adult ICU.
  
  
  METHODS
  A case-control study was carried out, including 47 patients (cases) and 122 patients (control) admitted to the mixed ICU of a university hospital in Minas Gerais, Brazil from November 2003 to July 2005. The infection site, risk factors, mortality, antibiotic susceptibility, metallo-beta-lactamase (MBL) production, enzyme type, and clonal diversity were analyzed.
  
  
  RESULTS
  A temporal/spatial relationship was detected in most patients (94%), overall mortality was 55.3%, and pneumonia was the predominant infection (85%). The majority of isolates (95%) were resistant to imipenem and other antibiotics, except for polymyxin, and showed MBL production (76.7%). Only bla SPM-1 (33%) was identified in the 15 specimens analyzed. In addition, 4 clones were identified, with a predominance of clone A (61.5%) and B (23.1%). On multivariate analysis, advanced age, mechanical ventilation, tracheostomy, and previous imipenem use were significant risk factors for imipenem-resistant P. aeruginosa infection.
  
  
  CONCLUSIONS
  Clonal dissemination of MBL-producing P. aeruginosa strains with a spatial/temporal relationship disclosed problems in the practice of hospital infection control, low adherence to hand hygiene, and empirical antibiotic use.
authors.affiliation: Area Immunology, Parasitology and Microbiology at Universidade Federal de Uberlândia, Uberlândia-Minas Gerais, Brazil. cezariorenata@yahoo.com
authors.forename: Renata Cristina
authors.initials: RC
authors.lastname: Cezário
authors.forename: Lea
authors.initials: L
authors.lastname: Duarte De Morais
authors.forename: Joseane Cristina
authors.initials: JC
authors.lastname: Ferreira
authors.forename: Rogério M
authors.initials: RM
authors.lastname: Costa-Pinto
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: da Costa Darini
authors.forename: Paulo P
authors.initials: PP
authors.lastname: Gontijo-Filho
mesh_terms: D001938:Brazil; D016022:Case-Control Studies; D003428:Cross Infection / Q000453:epidemiology*; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology*; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D015378:Imipenem; D001618:beta-Lactamases