[Presence of metallo beta-lactamases in imipenem-resistant Pseudomonas aeruginosa].
BACKGROUND
Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes.


OBJECTIVE
To detect the presence of MBL in imipenem resistant Psae strains.


METHODS
Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains were studied by pulse field gel electrophoresis.


RESULTS
The presence of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. All the strains were also multiresistant.


CONCLUSIONS
The presence of MBL was detected in 19% of imipenem resistant Psae strains.
Pérez I
Alfonso
A
Departamento de Laboratorios Clínicos, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
García C
Patricia
P
Poggi M
Helena
H
Braun J
Stephanie
S
Castillo V
Claudia
C
Román
Juan Carlos
JC
Lagos
Marcela
M
Romeo O
Eliana
E
Porte T
Lorena
L
Labarca L
Jaime
J
González R
Gerardo
G