Epidemiology of ciprofloxacin resistance and its relationship to extended-spectrum β-lactamase production in Proteus mirabilis bacteremia

Korean J Intern Med. 2011 Mar;26(1):89-93. doi: 10.3904/kjim.2011.26.1.89. Epub 2011 Mar 3.

Abstract

Background/aims: We evaluated the clinical features of ciprofloxacin-resistant Proteus mirabilis bacteremia and risk factors for ciprofloxacin resistance.

Methods: From October 2000 to July 2009, 37 patients with clinically significant P. mirabilis bacteremia were identified and data from patients with ciprofloxacin-resistant and ciprofloxacin-susceptible P. mirabilis bacteremia were compared.

Results: The most common underlying diseases were neurologic disease (37.8%) and solid tumors (29.7%). The most common site of infection was the urinary tract (35.1%). Ten of the 37 patients (27.0%) were infected with ciprofloxacin-resistant isolates, and univariate analysis revealed a significant relationship between ciprofloxacin-resistant P. mirabilis bacteremia and neurologic disease, recent operation, L-tube insertion, percutaneous tube use, and extended-spectrum β-lactamase (ESBL) production (all p < 0.05). ESBL was detected in six of 10 (60%) ciprofloxacin-resistant isolates, while only three of 27 (11%) ciprofloxacin-susceptible isolates produced ESBL (p = 0.005). In a logistic regression analysis, ESBL production remained a significant factor associated with ciprofloxacin resistance, after adjusting for other variables.

Conclusions: These data indicate a close association between ciprofloxacin resistance and ESBL-production in P. mirabilis bacteremia. This association is particularly troublesome because the therapeutic options for serious infections caused by ESBL-producing P. mirabilis are severely restricted.

Keywords: Bacterial; Cephalosporin resistance; Ciprofloxacin; Drug resistance; Proteus mirabilis; Risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Infective Agents / pharmacology*
  • Bacteremia / drug therapy*
  • Ciprofloxacin / pharmacology*
  • Drug Resistance, Bacterial
  • Female
  • Humans
  • Male
  • Middle Aged
  • Proteus Infections / drug therapy*
  • Proteus mirabilis / drug effects*
  • Proteus mirabilis / enzymology
  • Risk Factors
  • beta-Lactamases / biosynthesis*

Substances

  • Anti-Infective Agents
  • Ciprofloxacin
  • beta-Lactamases