Phenotypic and genotypic diversity of multidrug-resistant Pseudomonas aeruginosa Isolates from bloodstream infections recovered in the Hospitals of Belo Horizonte, Brazil.

BACKGROUND

Pseudomonas aeruginosa commonly causes nosocomial bloodstream infections and the emergence of a variety of β-lactamases (BLs) is worrying. In 5 hospitals in Belo Horizonte, Brazil, the presence of phenotypes encoding BL genes was established and the genetic diversity of the P. aeruginosa strains recovered from bloodstream infections was analyzed.

MATERIALS AND

METHODS

The isolates were investigated using a disk diffusion (DD) method and the Etest, for encoding metallo-β-lactamases (MBLs), oxacillinases and cephalosporinases. Genes and genetic diversity were evaluated by random amplified polymorphic DNA (RAPD) genotyping and enterobacterial repetitive intergenic consensus (ERIC)-PCR.

RESULTS

Twelve strains (30%) were positive for MBLs by Etest and DD, 15 were cephalosporinase-positive and 87.5% were positive for blaSPM-1 and blaVIM-1. Twenty-three strains (57.5%) were grouped into profile A, 32.5% into profile B and 10% into profile C by RAPD genotyping. ERIC-PCR revealed a varying degree of similarity between strains, ranging from 45 to 100%.

CONCLUSIONS

The results suggest distinct clonal populations in the 5 hospitals studied, indicating a potentially problematic epidemiological situation in Belo Horizonte, Brazil.