Bacteremia due to multiresistant gram-negative bacilli in neutropenic cancer patients: a case controlled study

The aim of this study was to see if multiresistant Gram-negative bacteremias (MRGNB) are associated with specific risk factors and/or higher mortality in comparison to sensitive GNB (SGNB). Both groups, 51 patients and 102 controls, were matched for sex, age, underlying disease and neutropenia. In addition there were no significant differences in the incidence of cytotoxic chemotherapy administered, vascular catheter insertion and catheter as source of bacteremia and etiology of bacteremia. The proportion of Klebsiella-Enterobacter, Pseudomonas aeruginosa, Acinetobacter spp. and Stenotrophomonas maltophilia was similar in both groups. Prior surgery (21.6% vs 7.6%, p<0.02) was significantly associated with SGNB. Previous prophylaxis with quinolones (45.1% vs 24.5%, p<0.045), and prior therapy with broad spectrum antibiotics (41.2% vs 27.5%, p<0.05) were significantly more frequently observed among patients than controls. Patients with bacteremia due to MRGNB were also significantly more frequently infected with resistant bacteria. Attributable mortality was similar (15.7% vs 13.75%, NS) in both groups, however cure rates were lower among MRGNB patients. Crude mortality was higher among patients (35.3% vs 13.75%, p<0.01) in comparison to controls. In conclusion, prior antimicrobial prophylaxis and therapy with several classes of antimicrobials represents a significant risk for development of resistance. Mortality due to multiresistant Gram-negative bacteremias was higher in comparison to bacteremias due to susceptible organisms.