Characterization of the onset and consequences of pneumonia due to fluoroquinolone-susceptible or-resistant Pseudomonas aeruginosa

Objectives: This study was conducted to identify and compare the microbiological and clinical outcomes among hospitalized adults with pneumonia caused by fluoroquinolone-susceptible or-resistant strains of Pseudomonas aeruginosa. Antibiotic regimens used prior to, as well as those used to treat, the infections were characterized. Patients and methods: This non-randomized multicentre study included 100 consecutively identified patients with pneumonia caused by fluoroquinolone-susceptible (n = 50) or fluoroquinolone-resistant (n = 50) strains of P. aeruginosa. Medical records were examined for demographic, clinical and treatment variables including antibiotics received in the 30 days before the index respiratory or blood culture; AUICs were calculated for each patient using reported or derived MICs. Multivariate logistic and linear regressions were used to identify factors associated with successful clinical and microbiological outcomes. Results: The study population was primarily elderly, frequently in a critical care unit, with low serum albumin and with a high probability of failure and mortality. Patients with pneumonia caused by fluoroquinolone-resistant P. aeruginosa were more likely to have received antibiotics within 7 days before the infectio