title: Dissemination of Pseudomonas aeruginosa producing SPM-1-like and IMP-1-like metallo-beta-lactamases in hospitals from southern Brazil.
abstract: BACKGROUND
  Metallo-beta-lactamase (MBL) is an emerging resistance mechanism among Pseudomonas aeruginosa. The prevalence of this mechanism is particularly high in Latin America. We aimed to describe the prevalence and molecular characteristics of SPM-1-like, IMP-1-like and VIM type MBLs among ceftazidime and/or imipenem-resistant nosocomial P. aeruginosa isolates.
  
  
  METHODS
  Pseudomonas aeruginosa isolates resistant to ceftazidime and/or imipenem recovered from hospitalized patients from two teaching hospitals from Porto Alegre, Brazil, were prospectively selected. Isolates were tested for MBL production using two phenotypic screening tests. Those isolates with positive results were further tested for the presence of MBL genes (SPM-1-like, IMP-1-like and VIM type) and submitted to molecular typing.
  
  
  RESULTS
  A total of 92 isolates were analyzed and 33 (35.9%) were presumptively MBL producers by phenotypic tests. The SPM-1-like gene was found in 18 isolates and IMP-1-like in 5 isolates. In ten isolates the MBL type could not be identified. Three IMP-1-like isolates were susceptible to imipenem. SPM-1-like isolates comprised a single clone, and IMP-1-like isolates another single clone.
  
  
  CONCLUSIONS
  The prevalence of MBL production among ceftazidime-resistant P. aeruginosa isolates is relatively high in both hospitals. Infection control measures have been challenged and further improvements in such measures are required to prevent dissemination of these isolates among hospitals. This is the first report of IMP-1-like MBLs in P. aeruginosa in southern Brazil.
authors.affiliation: Pharmaceutical Sciences Post-graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: A F
authors.initials: AF
authors.lastname: Martins
authors.forename: A P
authors.initials: AP
authors.lastname: Zavascki
authors.forename: P B
authors.initials: PB
authors.lastname: Gaspareto
authors.forename: A L
authors.initials: AL
authors.lastname: Barth
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D002442:Ceftazidime / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006784:Hospitals, Teaching; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015378:Imipenem; D002442:Ceftazidime; D001618:beta-Lactamases