title: Outbreak of carbapenem-resistant Pseudomonas aeruginosa producing SPM-1 metallo-{beta}-lactamase in a teaching hospital in southern Brazil.
abstract: OBJECTIVE
  To describe the first nosocomial outbreak of Pseudomonas aeruginosa producing SPM-1 metallo-beta-lactamase (MBL) in southern Brazil.
  
  
  METHODS
  From January to October 2004, carbapenem-resistant P. aeruginosa (CRPA) were recovered from hospitalized patients. Mortality, site of infection/colonization, patient location and susceptibility profiles were analysed. A sample of CRPA was screened for MBL production, evaluated for the presence of bla(SPM-1), bla(IMP-1) and bla(VIM-2) genes by PCR and submitted for molecular typing by DNA macrorestriction.
  
  
  RESULTS
  A total of 135 CRPA (one isolate per patient) were recovered. Two major antibiotic susceptibility profiles comprised 63.7% of the isolates (susceptibility to polymyxin B and aztreonam, and susceptibility only to polymyxin B). Thirty-five CRPA were screened for MBL production (10 isolates from April, June and July, and 25 from September and October) and 27 (77.1%) proved to be positive for MBL production. Twenty-one of the 24 CRPA tested carried the bla(SPM-1) gene. The mortality of patients with CRPA was 48.1% and no variable was associated with death. Molecular typing revealed the presence of a clone with four related subtypes among the bla(SPM-1)-positive CRPA.
  
  
  CONCLUSIONS
  The prevalence of MBL production by CRPA is high and horizontal transmission is a major determinant for the spread of SPM-1 CRPA among patients in this institution. As infection control measures failed to control the spread of CRPA, continuous surveillance for MBL production is warranted.
authors.affiliation: Infectious Diseases Service, Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil. apzavascki@terra.com.br
authors.forename: Alexandre Prehn
authors.initials: AP
authors.lastname: Zavascki
authors.forename: Patrick Barcelos
authors.initials: PB
authors.lastname: Gaspareto
authors.forename: Andreza Francisco
authors.initials: AF
authors.lastname: Martins
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Gonçalves
authors.forename: Afonso Luís
authors.initials: AL
authors.lastname: Barth
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D015780:Carbapenems / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006784:Hospitals, Teaching; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D012150:Polymorphism, Restriction Fragment Length; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality / Q000635:transmission; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004269:DNA, Bacterial; C476155:beta-lactamase SPM-1, Pseudomonas aeruginosa; D001618:beta-Lactamases