Cefmetazole for ESBL-producing Enterobacteriaceae in Pediatric Pyelonephritis.

BACKGROUND: Pyelonephritis caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are an urgent problem in pediatrics. Although carbapenem is the standard therapy for infections caused by ESBL-producing Enterobacteriaceaes, some cephamycins, including cefmetazole, are stable against hydrolysis by ESBL. However, there are few reports of the use of cefmetazole in children. The aim of our study was to evaluate the therapeutic effect of cefmetazole in pediatric pyelonephritis caused by ESBL-producing Enterobacteriaceae.

METHODS: Children with pyelonephritis caused by ESBL-producing Enterobacteriaceae were enrolled between April 2010 and November 2016 at Tokyo Metropolitan Children's Medical Center. ESBL was tested for using the disk diffusion method. Medical records were reviewed for a past history of bacterial infection. The outcomes were the clinical cure rate at 4 weeks and the duration of therapy in the cefmetazole and non-cefmetazole groups.

RESULTS: Fifty-five cases met the criteria for pyelonephritis caused by ESBL-producing Enterobacteriaceae. The most common causative organisms were Escherichia coli (51, 92.7%), Klebsiella pneumoniae (3, 5.5%), and Klebsiella oxytoca (1, 1.8%). Thirty-six and 19 cases were treated with cefmetazole and other antibiotics as definitive therapy, respectively. There was no difference in the clinical cure rate (86.1% vs 89.5%; p=0.72) or duration of therapy (median, 7.0 vs 7.0 days; p=0.73) between the cefmetazole and non-cefmetazole groups.

CONCLUSIONS: Cefmetazole was not inferior to the other antibiotics in the treatment of pyelonephritis caused by ESBL-producing Enterobacteriaceae in children. Cefmetazole is a valuable therapeutic alternative to carbapenems for treating pyelonephritis caused by ESBL-producing Enterobacteriaceaes. This article is protected by copyright. All rights reserved.