Metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from a large tertiary centre in Kenya

This study was designed to characterize the beta-lactamase content of carbapenem-resistant Pseudomonas aeruginosa isolates recovered during 2006 and 2007 in a large tertiary-care centre in Nairobi, Kenya. Molecular characterization was done using PCR and sequencing, and typing was performed using pulsed-field gel electrophoresis (PFGE). In total, 416 P. aeruginosa isolates were obtained during that period, of which 57 (13.7%) were resistant to carbapenems. All carbapenem-resistant isolates tested positive for metallo-beta-lactamase (MBL) production. All MBL isolates produced VIM-2 with two types of integron structures. PFGE identified three clonally related groups of VIM-2-producing P. aeruginosa, including a pan-resistant clone that was responsible for nosocomial outbreaks during 2006 and 2007 in the intensive-care unit. These findings suggest that continuous molecular surveillance needs to be performed to monitor the spread within the hospital of this pan-resistant strain. This study is the first report of VIM-2-producing P. aeruginosa from the African continent.