Decolonization of intestinal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae with oral colistin and neomycin: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are an increasingly frequent cause of infections in the community and the healthcare setting. In this study, we aimed to investigate whether intestinal carriage of ESBL-E can be eradicated. METHODS We conducted a double-blind, randomized, placebo-controlled, single-centre trial to assess the efficacy of an oral decolonization regimen on intestinal ESBL-E carriage in adult patients with an ESBL-E-positive rectal swab. Fifty-eight patients were allocated 1 : 1 to either placebo or colistin sulphate (50 mg 4×/day) and neomycin sulphate (250 mg 4×/day) for 10 days plus nitrofurantoin (100 mg 3×/day) for 5 days in the presence of ESBL-E bacteriuria. The primary outcome was detection of ESBL-E by rectal swab 28 ± 7 days after the end of treatment. Missing primary outcome data were imputed based on the last available observation. Additional cultures (rectal, inguinal and urine) were taken on day 6 of treatment and on days 1 and 7 post-treatment. The study protocol has been registered with ClinicalTrials.gov (NCT00826670). RESULTS Among 54 patients (27 in each group) included in the primary analysis, there was no statistically significant difference between the groups with regard to the primary outcome [14/27 (52%) versus 10/27 (37%), P = 0.27]. During treatment and shortly afterwards, there was significantly lower rectal ESBL-E carriage in the treatment group: 9/26 versus 19/22 on day 6 of treatment (P < 0.001) and 8/25 versus 20/26 on day 1 post-treatment (P = 0.001). This effect had disappeared by day 7 post-treatment (18/27 versus 17/25, P = 0.92). Liquid stools were more common in the treatment group (7/27 versus 2/29, P = 0.05). CONCLUSIONS The regimen used in this study temporarily suppressed ESBL-E carriage, but had no long-term effect.