Differences in the proportions of fluoroquinolone-resistant Gram-negative bacteria isolated from bacteraemic children with cancer in two Italian centres.

The proportion of ciprofloxacin-resistant Gram-negative bacteria isolated from the blood of children with cancer (not receiving prophylaxis) was 10% in a paediatric hospital (Genoa) where the use of quinolones was highly restricted, compared with 41% in a department of haematology (Rome) where leukaemic adults, who received fluoroquinolone prophylaxis, were also treated (p < 0.0001). Moreover, simultaneous resistance to ciprofloxacin and ceftazidime, amikacin or imipenem-cilastatin was 11% in Genoa compared with 37% in Rome (p < 0.001). Ciprofloxacin resistance was more frequent in children who shared an environment with adults who were receiving ciprofloxacin prophylaxis.