Decreasing antibiotic resistance of Enterobacteriaceae by introducing a new antibiotic combination therapy for neutropenic fever patients.

Prompt empiric antibiotic therapy is of critical importance for patients with neutropenic fever. However, a major concern with important clinical consequences is the emergence of bacterial resistance to antibiotics. After using ceftazidime with a glycopeptide as initial empiric therapy for neutropenic fever, we were confronted with a 75% reduced susceptibility rate to ceftazidime of inducible Enterobacteriaceae collected in 1994. The initial empiric therapy was therefore replaced in May 1995 by a combination of cefepime with amikacin, with addition of a glycopeptide after 48 h if necessary. After this change, we observed a significant decrease in reduced susceptibility of inducible Enterobacteriaceae, not only to ceftazidime, but also to amikacin, cotrimoxazole and ciprofloxacin. There was also a decrease in reduced susceptibility of non-inducible Enterobacteriaceae, such as Klebsiella spp, to ceftazidime. The reduction of resistance may be related at least in part to the combined use of cefepime together with an aminoglycoside. This study shows that it is possible to reverse bacterial resistance by modifying the antibiotic regimen used.