Pandrug-resistant Pseudomonas aeruginosa among hospitalised patients: clinical features, risk-factors and outcomes

ABSTRACTBetween 1 January 2003 and 31 December 2003, 37 patients had positive cultures of pandrug-resistant Pseudomonas aeruginosa (PDRPA) resistant to all commercially available anti-pseudomonal antimicrobial agents in Taiwan, including anti-pseudomonal penicillins, ceftazidime, fourth-generation cephalosporins, aztreonam, carbapenems, aminoglycosides and ciprofloxacin. Nineteen (51.4%) patients had PDRPA infections, including pneumonia (17 patients), catheter-related bacteraemia (one patient) and anal abscess (one patient). Eighteen patients were classified as having PDRPA colonisation, based on absence of clinical signs or symptoms of infection. In total, 92 isolates were recovered from various specimens, with the majority (85.9%) recovered from respiratory tract secretions (sputa, bronchial washings and pleural effusions), followed by urine (4.3%) and catheter tips (3.3%). Twenty-eight (75.7%) patients yielded cultures of non-PDR P. aeruginosa isolates before isolation of PDRPA, with a mean period between the first isolation of non-PDR P. aeruginosa and the isolation of PDRPA of 128.3 days. Most patients had received β-lactam antibiotics, fluoroquinolones or carbapenems for prolonged periods. Univariate analysis showed that PDRPA infection, male gender and the presence of fever at the time of PDRPA isolation were associated with increased mortality.