Gram-negative bacteremia: which empirical antibiotic therapy?

PURPOSE: Given the increasing frequency of cefotaxime-resistant strains, third-generation cephalosporins (3GC e.g. cefotaxime, ceftriaxone) might not be recommended any longer as empirical antibiotic therapy for community-acquired Gram-negative bacteremia (CA-GNB).

PATIENTS AND METHODS: We conducted a multicenter prospective descriptive study including patients with CA-GNB.

RESULTS: Two hundred and nineteen patients were included. Escherichia coli and Pseudomonas aeruginosa were the most frequently isolated species in 63% (n=138) and 11% (n=24) of the cases, respectively. The prevalence of cefotaxime-resistance reached 18% (n=39) mostly due to intrinsic resistance (27 cases, 12%). The presence of invasive material (P<0.001), the origin of the patient (Paris region or West of France) (P=0.006), and home health care (P<0.001) were variables predicting resistant GNB. The negative predictive value for resistance in patients with invasive material coming from the West of France, or without invasive material and with home health care was 94%. The positive predictive value for patients with invasive material living in Paris, or without invasive material and with home health care only reached 58 and 54%, respectively.

CONCLUSIONS: Using 3GC for CA-GNB due to cefotaxime-resistant strains was relatively frequent, ESBL-producing Enterobacteriaceae being rarely involved. Our study highlights the role of local epidemiology; before any changes to first-line antibiotic therapy, local epidemiological data should be taken into account.