A prospective study of ceftriaxone treatment in acute pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria.

BACKGROUND Much controversy exists as to whether cephalosporin treatment is appropriate for infections caused by ESBL-producing organisms because no randomized controlled studies have been performed. OBJECTIVE Evaluate the therapeutic outcomes of ceftriaxone treatment in acute pyelonephritis caused by ESBL-producing Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis. MATERIAL AND METHOD The authors performed a prospective study in female patients hospitalized with acute pyelonephritis caused by ESBL-producing or ESBL-nonproducing E. coli, K. pneumoniae, or P. mirabilis in four hospitals in Thailand from 2004 to 2006. The clinical and microbiological outcomes were evaluated at 72 hours after empirical ceftriaxone treatment. RESULTS One hundred eleven patients with the mean age of 65.29 years participated in this study. There were no differences in demographic and clinical characteristics and laboratory data between the ESBL-producing and ESBL-nonproducing groups except the higher rates of previous antibiotic use and urinary tract infection; and the lower frequency of costovertebral angle tenderness in the ESBL-producing group. Both clinical (65% and 93%) and microbiological (67.5% and 100%) responses at 72 hours after ceftriaxone treatment were poorer in the ESBL-producing group than in the ESBL-nonproducing group (p < 0.0002). CONCLUSION To the authors' knowledge, this is the first prospective study to evaluate the outcomes of ceftriaxone treatment in acute pyelonephritis caused by ESBL-producing Enterobacteriaceae. The present study confirms that acute pyelonephritis in the female patients caused by ESBL-producing strains could not be treated with ceftriaxone.