Pandrug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii infections: characteristics and outcome in a series of 28 patients.

We describe the characteristics and outcome of pandrug-resistant (PDR) Gram-negative bacterial infections (23 Klebsiella pneumoniae isolates, 3 Pseudomonas aeruginosa and 3 Acinetobacter baumannii) of hospitalised patients at a tertiary-care centre (1 January 2006-31 May 2007). The site of infection was central venous catheter-related in 5 of 24 patients with clinical infection, bacteraemia in 5, the respiratory system in 5, surgical site in 5, the urinary system in 2, the ascitic fluid in 1 and the central nervous system in one. Twenty of 24 patients with infection received an antibiotic regimen containing colistin (in combination with meropenem in 8 patients). The overall in-hospital mortality was 41.7% (10/24); 8 patients died because of the PDR infection (infection-related mortality 33.3%). Significant co-morbidity was present not only in the patients who died but also in survivors. PDR Gram-negative bacterial infections are associated with considerable mortality, although not as high as expected given the fact that the isolates were resistant to all tested antibiotics, including polymyxins. Antibiotics that are ineffective in vitro may prove life-saving for some of these patients, especially combination regimens containing colistin.