Infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBLEC) in nonhospitalized patients seem to be emerging in different countries. Their incidence, epidemiology, and clinical impact in the community have not been studied. We describe the epidemiology and clinical features of infections caused by ESBLEC in nonhospitalized patients in Spain and the results of a case-control study performed to investigate the risk factors associated with the acquisition of these organisms. The clonal relatedness of the organisms was assessed by repetitive extragenic palindromic sequence PCR. The ESBLs and the genes encoding the ESBLs were initially characterized by isoelectric focusing and PCR, respectively. Forty-nine patients (76% with urinary tract infections, 22% with asymptomatic bacteriuria, and 2% with acute cholangitis) were included. Six patients were bacteremic. Diabetes mellitus (odds ratio, 5.5; 95% confidence interval, 1.6 to 18.7), previous fluoroquinolone use (odds ratio, 7.6; 95% confidence interval, 1.9 to 30.1), recurrent urinary tract infections (odds ratio, 4.5; 95% confidence interval, 1.3 to 15.1), a previous hospital admission (odds ratio, 18.2; 95% confidence interval, 5.3 to 61.1), and older age in male patients (odds ratio per year, 1.03; 95% confidence interval, 1.03 to 1.05) were identified as risk factors by multivariate analysis. The ESBLEC isolates were not clonally related. The ESBLs were characterized as members of the CTX-M-9 group, the SHV group, and the TEM group in 64, 18, and 18% of the isolates, respectively. ESBLEC is an emergent cause of urinary tract infections in nonhospitalized patients. There was no evidence of horizontal transmission of ESBLEC strains. Avoidance of fluoroquinolone use in high-risk patients should be considered whenever possible in order to avoid the selection of these organisms.Extended-spectrum beta-lactamase (ESBL)-producing members of the family Enterobacteriaceae are resistant to penicillins, narrow-and extended-spectrum cephalosporins, and aztreonam (4). ESBL-producing organisms are also frequently resistant to aminoglycosides, trimethoprim-sulfamethoxazole, and quinolones.Until recently, most infections caused by ESBL-producing Escherichia coli (ESBLEC) or Klebsiella pneumoniae had mostly been described as nosocomially acquired (4) or nursing home related (32). However, some recent data suggest that infections due to ESBL-producing organisms might be an emergent problem in outpatients in different countries (1,8,9,11,14,15), but detailed epidemiological data were not collected in most of those studies. Moreover, the clinical relevance and the epidemiology of these infections outside nursing homes have not been studied.In a recent nationwide study of ESBL-producing organisms in Spain, 93% of ESBL-producing K. pneumoniae strains were isolated from inpatients, while 51% of ESBL-producing E. coli (ESBLEC) strains were isolated from outpatients (13) Consequently, we conducted the study described in this report, in which we describe an...

These results suggest that AMC and PTZ are suitable alternatives to carbapenems for treating patients with bloodstream infections due to ESBL-EC if active in vitro and would be particularly useful as definitive therapy.

Antimicrobial resistance poses a growing threat to public health and the provision of health care. Its surveillance should provide up-to-date and relevant information to monitor the appropriateness of therapy guidelines, antibiotic formulary, antibiotic stewardship programmes, public health interventions, infection control policies, and antimicrobial development. In Europe, although the European Antimicrobial Resistance Surveillance Network provides annual reports on monitored resistant bacteria, national surveillance efforts are still fragmented and heterogeneous, and have substantial structural problems and issues with laboratory data. Most incidence and prevalence data cannot be linked with relevant epidemiological, clinical, or outcome data. Genetic typing, to establish whether trends of antimicrobial resistance are caused by spread of resistant strains or by transfer of resistance determinants among different strains and species, is not routinely done. Furthermore, laboratory-based surveillance using only clinical samples is not likely to be useful as an early warning system for emerging pathogens and resistance mechanisms. Insufficient coordination of surveillance systems of human antimicrobial resistance with animal surveillance systems is even more concerning. Because results from food surveillance are considered commercially sensitive, they are rarely released publicly by regulators. Inaccurate or incomplete surveillance data delay a translational approach to the threat of antimicrobial resistance and inhibit the identification of relevant target microorganisms and populations for research and the revitalisation of dormant drug-discovery programmes. High-quality, comprehensive, and real-time surveillance data are essential to reduce the burden of antimicrobial resistance. Improvement of national antimicrobial resistance surveillance systems and better alignment between human and veterinary surveillance systems in Europe must become a scientific and political priority, coordinated with international stakeholders within a global approach to reduce the burden of antimicrobial resistance.

ESBL-producing E. coli is a significant cause of bloodstream infection in hospitalized and nonhospitalized patients in the context of the emergence of CTX-M enzymes. Empirical treatment of sepsis potentially caused by E. coli may need to be reconsidered in areas where such ESBL-producing isolates are present.

Our results suggest that both acquisition from a common source and person-to-person transmission might contribute to ESBL dissemination.