Association of antibiotic utilization measures and control of multiple-drug resistance in Klebsiella pneumoniae

OBJECTIVE: To study the association of antibiotic-utilization measures and control of multidrug-resistant (MDR) Klebsiella pneumoniae after emergence in two hospitals in our medical center. DESIGN AND SETTING: Rates of MDR K pneumoniae at two hospitals were compare d before and after acute interventions, including emphasis on Contact Preca utions and education in antibiotic utilization. Antipseudomonal beta-lactam antibiotic use was measured before and after the interventions at both hos pitals. Pulsed-field gel electrophoresis of whole cell DNA was used as a ma rker of strain identity. RESULTS: Clonal strain dissemination was the major mechanism of emergence a t hospital A ; emergence was polyclonal at hospital B. Antibiotic-utilizati on interventions at both institutions included physician education regardin g the association of ceftazidime use and MDR K pneumoniae. At hospital a ce ftazidime use decreased from 4,301g in the preintervention period, to 1,248 g in the postintervention period. Piperacillin-tazobactam increased from 1 2,455 g to 17,464 g. Ceftazidime resistance in K pneumoniae decreased from 110 (22%) of 503 isolates to 61 (15%) of 407 isolates (P<.05); piperacillin -tazobactam resistance decreased from 181 (36%) of 503 to 77 (19%) of 407 i solates (P<.05). At hospital B, ceftazidime use decreased from 6,533 g in t he preintervention period to 4,792 g in the postintervention period. Pipera cillin-tazobactam use increased from 58,691 g to 67,027 g. Ceftazidime resi stance in K pneumoniae decreased from 42 (10%) of 415 isolates to 19 (5%) o f 383 isolates (P<.05). Piperacillin-tazobactam resistance decreased from 9 1 (22%) of 415 isolates to 54 (14%) of 383 isolates (P<.05). Follow-up data showed continued decrease in piperacillin-tazobactam resistance despite in creased use at both hospitals. CONCLUSIONS: Antibiotic-use measures may be particularly important for cont rol of MDR K pneumoniae, whether emergence is clonal or polyclonal.