Bacteremia due to ciprofloxacin-resistant Pseudomonas aeruginosa in cancerpatients: Risk factors for resistance and outcome of 25 episodes. A case-control study

The aim of this study was to investigate whether quinolone resistance in Ps eudomonas aeruginosa has clinical significance, e.g., whether ciprofloxacin (CIP)resistant P, aeruginosa bacteremia (CR PAB) causes more infection-ass ociated death than do sensitive strains. another study objective was to obs erve specific risk factors related to CR PAB in a group of bacteremias that were identified in a cancer patient population from a single cancer center that had had a consistent antibiotic policy for the previous 7 years. Ther e were several risk factors associated with CIP-resistant bacteremia (cases ) compared with controls: resistance to ceftazidime and amikacin was signif icantly higher (P <.01 and P <.02, respectively) among cases that were CIP- resistant (72% of CR Pas were also resistant to ceftazidime, and 64% were a lso resistant to amikacin). Previous prophylaxis with quinolones was not a significant risk factor for CR PAB, but prior therapy with aminoglycosides was (36% vs. 16%, respectively; P<.05), Bacteremia with a documented site o f infection was less frequently observed among cases (P <.01) compared with the controls. Outcome was similar in both groups: cases infected with CR P as had attributable (12%) or crude mortality (24% vs. 20%; P = not signific ant) similar to that of controls infected with CIP-sensitive organisms.