A nosocomial outbreak of Pseudomonas aeruginosa isolates expressing the extended-spectrum beta-lactamase GES-2 in South Africa.

Eight Pseudomonas aeruginosa clinical strains that produce the clavulanic-acid-inhibited beta-lactamase GES-2 were isolated from patients of a South African hospital from March to July 2000. They were clonally related and each harboured a 150 kb conjugative plasmid carrying a class 1 integron containing a gene cassette encoding GES-2, followed by those for beta-lactamase OXA-5 and an aminoglycoside modifying AAC(3)I-like enzyme. Hence, incidences of infection, several fatal, due to bacteria displaying clavulanate-inhibited resistance to extended-spectrum cephalosporins and reduced susceptibility to imipenem in Pretoria Academic Hospital, South Africa, can be explained, at least in part, by the spread of P. aeruginosa expressing the GES-2 beta-lactamase.