in southern Brazil

metallo-b-lactamase (MBL) in southern Brazil. Patients and methods: From January to October 2004, carbapenem-resistant P. aeruginosa (CRPA) were recovered from hospitalized patients. Mortality, site of infection/colonization, patient location and sus-ceptibility profiles were analysed. A sample of CRPA was screened for MBL production, evaluated for the presence of blaSPM-1, blaIMP-1 and blaVIM-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 CRPAwere screened forMBLproduction (10 isolates fromApril, June and July, and25 fromSeptemberandOctober) and27 (77.1%)proved tobepositive forMBLproduction.Twenty-one of the 24 CRPA tested carried the blaSPM-1 gene. Themortality of patients with CRPAwas 48.1 % and no variable was associated with death. Molecular typing revealed the presence of a clone with four related subtypes among the blaSPM-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