Decontamination of Cephalosporin-resistant Enterobacteriaceae During Selective Digestive Tract Decontamination in Intensive Care Units

Objectives: Prevalences of cephalosporin-resistant Enterobacteriaceae are increasing globally, especially in intensive care units (ICUs). The effect of selective digestive tract decontamination (SDD) on the eradication of cephalosporin-resistant Enterobacteriaceae from the intestinal tract is unknown. We quantified eradication rates of cephalosporin-resistant and cephalosporin-susceptible Enterobacteriaceae during SDD in patients participating in a 13 centre cluster-randomized study and from a single-centre cohort.

Methods: All SDD patients colonized with Enterobacteriaceae in the intestinal tract at ICU admission were included. Cephalosporin resistance was defined as resistance to ceftazidime, cefotaxime or ceftriaxone and aminoglycoside resistance as resistance to tobramycin or gentamicin. Duration of rectal colonization was determined by screening twice weekly during ICU stay. Swabs were inoculated on selective medium supplemented with tobramycin or cefotaxime.

Results: Five hundred and seven (17%) of 2959 SDD patients with at least one rectal sample were colonized with Enterobacteriaceae at ICU admission: 77 (15%) with cephalosporin-resistant Enterobacteriaceae and 50 (10%) with aminoglycoside-resistant Enterobacteriaceae. Fifty-six (73%) patients colonized with cephalosporin-resistant Enterobacteriaceae were successfully decontaminated before ICU discharge, as were 343 (80%) patients colonized with cephalosporin-susceptible Enterobacteriaceae (P = 0.17). For aminoglycoside resistance, 31 (62%) patients were decontaminated, as were 368 patients (81%) colonized with aminoglycoside-susceptible Enterobacteriaceae (P < 0.01). On average, decolonization was demonstrated after 4 days if colonized with cephalosporin-susceptible Enterobacteriaceae and aminoglycoside-susceptible Enterobacteriaceae, and after 5 and 5.5 days if colonized with cephalosporin-resistant Enterobacteriaceae and aminoglycoside-resistant Enterobacteriaceae, respectively (log-rank test P = 0.053 for cephalosporin resistance and P = 0.03 for aminoglycoside resistance). If eradication failed, no associations were found with increased resistance in time (P > 0.05 for all comparisons).

Conclusions: SDD can successfully eradicate cephalosporin-resistant Enterobacteriaceae from the intestinal tract.