221. The efficacy of cefmetazole for pyelonephritis caused by Extended-Spectrum-β-Lactamase (ESBL) producing enterobacteriaceae. A case-series
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
  • ESBL.IDSA2011.png (397.2 kB)
  • Background: ESBL producing enterobactericeae can cause infections such as urinary tract infections (UTIs). UTIs associated with ESBLs are now seen even in community settings. Until now, only one study evaluated the clinical efficacy of cephamycin (flomoxef) but the result was not conclusive. Although cefmetazole has in vitro susceptibility against ESBLs, no clinical study has ever evaluated the role of cefmetazole for infections associated with ESBLs. We therefore evaluated cases to see the efficacy of cefmetazole against pyelonephritis caused by ESBL producing enterobacteriaceae comparing to carbapenems, which are considered as the standard therapeutic agents for these organisms.

    Methods: A retrospective chart review was conducted at a tertiary care teaching hospital with about 400 beds from August 2008 to July 2010. During the study period, the proportion of ESBL producing Escherichia coli and Klebsiella pneumoniae at this hospital was 15.6% and 3.4% respectively. Chart reviews were done for positive ESBL producing organisms in urine based on the microbiology database. Pyelonephritis based on the diagnosis of treating physicians were evaluated. Patients who were treated with cefmetazole were compared with those who were treated with carbapenems and those treated with both antimicrobials together were excluded from the analysis. Clinical and bacteriological cure at 4 weeeks were evaluated.

    Results: Two hundreds and fifty-five urine cultures with positive ESBLs were identified during the study period. Ten patients treated with cefmetazole and 12 patients treated with carbapenems were evaluated. There was no difference in patient characteristics except for the presence of diabetes mellitus (5/10 vs 0/12, p=0.01) and concurrent bacteremia (0/7 vs 8/12, p=0.01). There was no difference in clinical cure at 4 weeks (9/10 vs 12/12, p=0.46) and bacteriological cure (5/7 vs 6/7, p=1.00). There was no difference in the incidence of adverse effects (2/10 vs 2/12, p=1.00).

    Conclusion: Although bacteremia was seen only in carbapenem group, cefmetazole may be useful in treating UTI caused by ESBL producing organisms, particularly when there is no concurrent bacteremia. Prospective studies with larger size will be needed to confirm our findings.

    Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

    Asako Doi, MD, Dept. of Infectious Diseases, Rakuwakai Otowa Hospital, Kyoto city, Japan; Dept. of Infectious Diseases, Rakuwakai Otowa Hospital, Kyoto , Japan, Toshihiko Shimada, Dept.of General Internal Medicine, Rakuwakai Otowa Hospital, Kyoto, Japan, Kentaro Iwata, MD, Division of Infectious Diseases Therapeutics, Department of Microbiology and Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan and Toru Kamiya, Dept. of Infectious Disease and General Internal Medicine, Rakuwakai Otowa Hospital, Kyoto, Japan


    A. Doi, None

    T. Shimada, None

    K. Iwata, Rhoto Pharmaceutical Co Ltd: Investigator, Research grant

    T. Kamiya, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.